diff --git a/2.0/src/query/inc/qExecutor.h b/2.0/src/query/inc/qExecutor.h
index 9c738dad98..970b826303 100644
--- a/2.0/src/query/inc/qExecutor.h
+++ b/2.0/src/query/inc/qExecutor.h
@@ -589,7 +589,7 @@ SOperatorInfo* createTableSeqScanOperatorInfo(void* pTsdbQueryHandle, SQueryRunt
 SOperatorInfo* createAggregateOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
 SOperatorInfo* createProjectOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
 SOperatorInfo* createLimitOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream);
-SOperatorInfo* createTimeIntervalOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
+SOperatorInfo* createIntervalOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
 SOperatorInfo* createAllTimeIntervalOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
 SOperatorInfo* createSWindowOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput);
 SOperatorInfo* createFillOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput, bool multigroupResult);
diff --git a/2.0/src/query/src/qExecutor.c b/2.0/src/query/src/qExecutor.c
index ca656b81ff..490584c75a 100644
--- a/2.0/src/query/src/qExecutor.c
+++ b/2.0/src/query/src/qExecutor.c
@@ -2166,7 +2166,7 @@ static int32_t setupQueryRuntimeEnv(SQueryRuntimeEnv *pRuntimeEnv, int32_t numOf
       }
       case OP_TimeWindow: {
         pRuntimeEnv->proot =
-            createTimeIntervalOperatorInfo(pRuntimeEnv, pRuntimeEnv->proot, pQueryAttr->pExpr1, pQueryAttr->numOfOutput);
+            createIntervalOperatorInfo(pRuntimeEnv, pRuntimeEnv->proot, pQueryAttr->pExpr1, pQueryAttr->numOfOutput);
         int32_t opType = pRuntimeEnv->proot->upstream[0]->operatorType;
         if (opType != OP_DummyInput && opType != OP_Join) {
           setTableScanFilterOperatorInfo(pRuntimeEnv->proot->upstream[0]->info, pRuntimeEnv->proot);
@@ -6756,7 +6756,7 @@ SOperatorInfo* createLimitOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorI
   return pOperator;
 }
 
-SOperatorInfo* createTimeIntervalOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput) {
+SOperatorInfo* createIntervalOperatorInfo(SQueryRuntimeEnv* pRuntimeEnv, SOperatorInfo* upstream, SExprInfo* pExpr, int32_t numOfOutput) {
   STableIntervalOperatorInfo* pInfo = calloc(1, sizeof(STableIntervalOperatorInfo));
 
   pInfo->pCtx = createSQLFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pInfo->rowCellInfoOffset);
diff --git a/include/common/tep.h b/include/common/tep.h
index 956cf6ec36..2be86aa095 100644
--- a/include/common/tep.h
+++ b/include/common/tep.h
@@ -18,9 +18,6 @@ typedef struct SBlockOrderInfo {
   int32_t          order;
   int32_t          colIndex;
   SColumnInfoData *pColData;
-//  int32_t          type;
-//  int32_t          bytes;
-//  bool             hasNull;
 } SBlockOrderInfo;
 
 int  taosGetFqdnPortFromEp(const char *ep, SEp *pEp);
@@ -67,16 +64,16 @@ static FORCE_INLINE bool colDataIsNull(const SColumnInfoData* pColumnInfoData, u
   }
 }
 
-#define colDataGet(p1_, r_)                                                          \
-  ((IS_VAR_DATA_TYPE((p1_)->info.type)) ? ((p1_)->pData + (p1_)->varmeta.offset[(r_)]) \
-                                        : ((p1_)->pData + ((r_) * (p1_)->info.bytes)))
+#define colDataGetData(p1_, r_)                                                          \
+  ((IS_VAR_DATA_TYPE((p1_)->info.type)) ? (p1_)->pData + (p1_)->varmeta.offset[(r_)] \
+                                        : (p1_)->pData + ((r_) * (p1_)->info.bytes))
 
 int32_t colDataAppend(SColumnInfoData* pColumnInfoData, uint32_t currentRow, const char* pData, bool isNull);
 int32_t colDataMergeCol(SColumnInfoData* pColumnInfoData, uint32_t numOfRow1, const SColumnInfoData* pSource, uint32_t numOfRow2);
 int32_t blockDataUpdateTsWindow(SSDataBlock* pDataBlock);
 
-int32_t colDataGetSize(const SColumnInfoData* pColumnInfoData, int32_t numOfRows);
-void colDataTrim(SColumnInfoData* pColumnInfoData);
+int32_t colDataGetLength(const SColumnInfoData* pColumnInfoData, int32_t numOfRows);
+void    colDataTrim(SColumnInfoData* pColumnInfoData);
 
 size_t colDataGetNumOfCols(const SSDataBlock* pBlock);
 size_t colDataGetNumOfRows(const SSDataBlock* pBlock);
@@ -93,13 +90,15 @@ size_t blockDataGetRowSize(const SSDataBlock* pBlock);
 double blockDataGetSerialRowSize(const SSDataBlock* pBlock);
 size_t blockDataGetSerialMetaSize(const SSDataBlock* pBlock);
 
-size_t blockDataNumOfRowsForSerialize(const SSDataBlock* pBlock, int32_t blockSize);
+SSchema* blockDataExtractSchema(const SSDataBlock* pBlock, int32_t* numOfCols);
 
 int32_t blockDataSort(SSDataBlock* pDataBlock, SArray* pOrderInfo, bool nullFirst);
 int32_t blockDataSort_rv(SSDataBlock* pDataBlock, SArray* pOrderInfo, bool nullFirst);
 
 int32_t blockDataEnsureCapacity(SSDataBlock* pDataBlock, uint32_t numOfRows);
 void    blockDataClearup(SSDataBlock* pDataBlock, bool hasVarCol);
+SSDataBlock* createOneDataBlock(const SSDataBlock* pDataBlock);
+size_t blockDataGetCapacityInRow(const SSDataBlock* pBlock, size_t pageSize);
 void   *blockDataDestroy(SSDataBlock *pBlock);
 
 #ifdef __cplusplus
diff --git a/include/libs/executor/executor.h b/include/libs/executor/executor.h
index d9e1957e5d..4d53f40176 100644
--- a/include/libs/executor/executor.h
+++ b/include/libs/executor/executor.h
@@ -31,6 +31,7 @@ typedef struct SReadHandle {
   void* reader;
   void* meta;
 } SReadHandle;
+
  /**
   * Create the exec task for streaming mode
   * @param pMsg
@@ -40,12 +41,22 @@ typedef struct SReadHandle {
 qTaskInfo_t qCreateStreamExecTaskInfo(void *msg, void* streamReadHandle);
 
 /**
- *
+ * Set the input data block for the stream scan.
  * @param tinfo
  * @param input
  * @return
  */
-int32_t     qSetStreamInput(qTaskInfo_t tinfo, const void* input);
+int32_t qSetStreamInput(qTaskInfo_t tinfo, const void* input);
+
+/**
+ * Update the table id list, add or remove.
+ *
+ * @param tinfo
+ * @param id
+ * @param isAdd
+ * @return
+ */
+int32_t qUpdateQualifiedTableId(qTaskInfo_t tinfo, SArray* tableIdList, bool isAdd);
 
  /**
   * Create the exec task object according to task json
diff --git a/include/libs/function/function.h b/include/libs/function/function.h
index e970a0d693..ffd861ff3b 100644
--- a/include/libs/function/function.h
+++ b/include/libs/function/function.h
@@ -138,8 +138,10 @@ extern SFunctionFpSet fpSet[1];
 
 // sql function runtime context
 typedef struct SqlFunctionCtx {
+  int32_t      startRow;
   int32_t      size;      // number of rows
-  void *       pInput;    // input data buffer
+  SColumnInfoData* pInput;
+
   uint32_t     order;     // asc|desc
   int16_t      inputType;
   int16_t      inputBytes;
diff --git a/include/libs/planner/plannerOp.h b/include/libs/planner/plannerOp.h
index 9030ffc946..af8a7dccd4 100644
--- a/include/libs/planner/plannerOp.h
+++ b/include/libs/planner/plannerOp.h
@@ -47,5 +47,6 @@ OP_ENUM_MACRO(AllTimeWindow)
 OP_ENUM_MACRO(AllMultiTableTimeInterval)
 OP_ENUM_MACRO(Order)
 OP_ENUM_MACRO(Exchange)
+OP_ENUM_MACRO(SortedMerge)
 
 //OP_ENUM_MACRO(TableScan)
diff --git a/include/util/tarray.h b/include/util/tarray.h
index 6d6120a49b..117e60dede 100644
--- a/include/util/tarray.h
+++ b/include/util/tarray.h
@@ -43,8 +43,8 @@ extern "C" {
 
 typedef struct SArray {
   size_t size;
-  size_t capacity;
-  size_t elemSize;
+  uint32_t capacity;
+  uint32_t elemSize;
   void*  pData;
 } SArray;
 
diff --git a/include/util/tpagedbuf.h b/include/util/tpagedbuf.h
index e989c31cd6..76501b51ad 100644
--- a/include/util/tpagedbuf.h
+++ b/include/util/tpagedbuf.h
@@ -30,10 +30,9 @@ typedef struct SPageInfo SPageInfo;
 typedef struct SDiskbasedBuf SDiskbasedBuf;
 
 #define DEFAULT_INTERN_BUF_PAGE_SIZE  (1024L)                          // in bytes
-#define DEFAULT_PAGE_SIZE             (16384L)
 
 typedef struct SFilePage {
-  int64_t num;
+  int32_t num;
   char    data[];
 } SFilePage;
 
@@ -55,7 +54,7 @@ typedef struct SDiskbasedBufStatis {
  * @param handle
  * @return
  */
-int32_t createDiskbasedBuffer(SDiskbasedBuf** pBuf, int32_t pagesize, int32_t inMemBufSize, uint64_t qId, const char* dir);
+int32_t createDiskbasedBuf(SDiskbasedBuf** pBuf, int32_t pagesize, int32_t inMemBufSize, uint64_t qId, const char* dir);
 
 /**
  *
@@ -64,7 +63,7 @@ int32_t createDiskbasedBuffer(SDiskbasedBuf** pBuf, int32_t pagesize, int32_t in
  * @param pageId
  * @return
  */
-SFilePage* getNewDataBuf(SDiskbasedBuf* pBuf, int32_t groupId, int32_t* pageId);
+void* getNewBufPage(SDiskbasedBuf* pBuf, int32_t groupId, int32_t* pageId);
 
 /**
  *
@@ -80,7 +79,7 @@ SIDList getDataBufPagesIdList(SDiskbasedBuf* pBuf, int32_t groupId);
  * @param id
  * @return
  */
-SFilePage* getBufPage(SDiskbasedBuf* pBuf, int32_t id);
+void* getBufPage(SDiskbasedBuf* pBuf, int32_t id);
 
 /**
  * release the referenced buf pages
@@ -108,13 +107,13 @@ size_t getTotalBufSize(const SDiskbasedBuf* pBuf);
  * @param pBuf
  * @return
  */
-size_t getNumOfResultBufGroupId(const SDiskbasedBuf* pBuf);
+size_t getNumOfBufGroupId(const SDiskbasedBuf* pBuf);
 
 /**
  * destroy result buffer
  * @param pBuf
  */
-void destroyResultBuf(SDiskbasedBuf* pBuf);
+void destroyDiskbasedBuf(SDiskbasedBuf* pBuf);
 
 /**
  *
@@ -137,6 +136,11 @@ int32_t getPageId(const SPageInfo* pPgInfo);
  */
 int32_t getBufPageSize(const SDiskbasedBuf* pBuf);
 
+/**
+ *
+ * @param pBuf
+ * @return
+ */
 int32_t getNumOfInMemBufPages(const SDiskbasedBuf* pBuf);
 
 /**
@@ -148,22 +152,43 @@ bool isAllDataInMemBuf(const SDiskbasedBuf* pBuf);
 
 /**
  * Set the buffer page is dirty, and needs to be flushed to disk when swap out.
- * @param pPageInfo
+ * @param pPage
  * @param dirty
  */
-void setBufPageDirty(SFilePage* pPageInfo, bool dirty);
+void setBufPageDirty(void* pPage, bool dirty);
+
+/**
+ * Set the compress/ no-compress flag for paged buffer, when flushing data in disk.
+ * @param pBuf
+ */
+void setBufPageCompressOnDisk(SDiskbasedBuf* pBuf, bool comp);
+
+/**
+ * Set the pageId page buffer is not need
+ * @param pBuf
+ * @param pageId
+ */
+void dBufSetBufPageRecycled(SDiskbasedBuf *pBuf, void* pPage);
 
 /**
  * Print the statistics when closing this buffer
  * @param pBuf
  */
-void printStatisBeforeClose(SDiskbasedBuf* pBuf);
+void dBufSetPrintInfo(SDiskbasedBuf* pBuf);
 
 /**
- * return buf statistics.
+ * Return buf statistics.
+ * @param pBuf
+ * @return
  */
 SDiskbasedBufStatis getDBufStatis(const SDiskbasedBuf* pBuf);
 
+/**
+ * Print the buffer statistics information
+ * @param pBuf
+ */
+void dBufPrintStatis(const SDiskbasedBuf* pBuf);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/client/test/clientTests.cpp b/source/client/test/clientTests.cpp
index ac36179a26..276c19538c 100644
--- a/source/client/test/clientTests.cpp
+++ b/source/client/test/clientTests.cpp
@@ -53,8 +53,10 @@ TEST(testCase, driverInit_Test) {
 //  taos_init();
 }
 
-#if 0
+#if 1
 TEST(testCase, connect_Test) {
+//  taos_options(TSDB_OPTION_CONFIGDIR, "/home/ubuntu/first/cfg");
+
   TAOS* pConn = taos_connect("localhost", "root", "taosdata", NULL, 0);
   if (pConn == NULL) {
     printf("failed to connect to server, reason:%s\n", taos_errstr(NULL));
diff --git a/source/common/src/tep.c b/source/common/src/tep.c
index 970b6d954f..d325f57c91 100644
--- a/source/common/src/tep.c
+++ b/source/common/src/tep.c
@@ -63,7 +63,7 @@ SEpSet getEpSet_s(SCorEpSet *pEpSet) {
 
 #define BitmapLen(_n)     (((_n) + ((1<<NBIT)-1)) >> NBIT)
 
-int32_t colDataGetSize(const SColumnInfoData* pColumnInfoData, int32_t numOfRows) {
+int32_t colDataGetLength(const SColumnInfoData* pColumnInfoData, int32_t numOfRows) {
   ASSERT(pColumnInfoData != NULL);
   if (IS_VAR_DATA_TYPE(pColumnInfoData->info.type)) {
     return pColumnInfoData->varmeta.length;
@@ -127,6 +127,7 @@ int32_t colDataAppend(SColumnInfoData* pColumnInfoData, uint32_t currentRow, con
       case TSDB_DATA_TYPE_USMALLINT: {*(int16_t*) p = *(int16_t*) pData;break;}
       case TSDB_DATA_TYPE_INT:
       case TSDB_DATA_TYPE_UINT: {*(int32_t*) p = *(int32_t*) pData;break;}
+      case TSDB_DATA_TYPE_TIMESTAMP:
       case TSDB_DATA_TYPE_BIGINT:
       case TSDB_DATA_TYPE_UBIGINT: {*(int64_t*) p = *(int64_t*) pData;break;}
       default:
@@ -249,8 +250,8 @@ int32_t blockDataUpdateTsWindow(SSDataBlock* pDataBlock) {
   }
 
   ASSERT(pColInfoData->nullbitmap == NULL);
-  pDataBlock->info.window.skey = *(TSKEY*) colDataGet(pColInfoData, 0);
-  pDataBlock->info.window.ekey = *(TSKEY*) colDataGet(pColInfoData, (pDataBlock->info.rows - 1));
+  pDataBlock->info.window.skey = *(TSKEY*) colDataGetData(pColInfoData, 0);
+  pDataBlock->info.window.ekey = *(TSKEY*) colDataGetData(pColInfoData, (pDataBlock->info.rows - 1));
   return 0;
 }
 
@@ -262,8 +263,8 @@ int32_t blockDataMerge(SSDataBlock* pDest, const SSDataBlock* pSrc) {
     SColumnInfoData* pCol2 = taosArrayGet(pDest->pDataBlock, i);
     SColumnInfoData* pCol1 = taosArrayGet(pSrc->pDataBlock, i);
 
-    uint32_t oldLen = colDataGetSize(pCol2, pDest->info.rows);
-    uint32_t newLen = colDataGetSize(pCol1, pSrc->info.rows);
+    uint32_t oldLen = colDataGetLength(pCol2, pDest->info.rows);
+    uint32_t newLen = colDataGetLength(pCol1, pSrc->info.rows);
 
     int32_t newSize = oldLen + newLen;
     char* tmp = realloc(pCol2->pData, newSize);
@@ -287,7 +288,7 @@ size_t blockDataGetSize(const SSDataBlock* pBlock) {
 
   for(int32_t i = 0; i < numOfCols; ++i) {
     SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
-    total += colDataGetSize(pColInfoData, pBlock->info.rows);
+    total += colDataGetLength(pColInfoData, pBlock->info.rows);
 
     if (IS_VAR_DATA_TYPE(pColInfoData->info.type)) {
       total += sizeof(int32_t) * pBlock->info.rows;
@@ -336,7 +337,7 @@ int32_t blockDataSplitRows(SSDataBlock* pBlock, bool hasVarCol, int32_t startInd
           if (isNull) {
             // do nothing
           } else {
-            char* p = colDataGet(pColInfoData, j);
+            char* p = colDataGetData(pColInfoData, j);
             size += varDataTLen(p);
           }
 
@@ -401,7 +402,7 @@ SSDataBlock* blockDataExtractBlock(SSDataBlock* pBlock, int32_t startIndex, int3
 
     for (int32_t j = startIndex; j < (startIndex + rowCount); ++j) {
       bool isNull = colDataIsNull(pColData, pBlock->info.rows, j, pBlock->pBlockAgg);
-      char* p = colDataGet(pColData, j);
+      char* p = colDataGetData(pColData, j);
 
       colDataAppend(pDstCol, j - startIndex, p, isNull);
     }
@@ -411,7 +412,6 @@ SSDataBlock* blockDataExtractBlock(SSDataBlock* pBlock, int32_t startIndex, int3
   return pDst;
 }
 
-
 /**
  *
  * +------------------+---------------+--------------------+
@@ -444,7 +444,7 @@ int32_t blockDataToBuf(char* buf, const SSDataBlock* pBlock) {
       pStart += BitmapLen(pBlock->info.rows);
     }
 
-    uint32_t dataSize = colDataGetSize(pCol, numOfRows);
+    uint32_t dataSize = colDataGetLength(pCol, numOfRows);
 
     *(int32_t*) pStart = dataSize;
     pStart += sizeof(int32_t);
@@ -522,6 +522,22 @@ size_t blockDataGetSerialMetaSize(const SSDataBlock* pBlock) {
   return sizeof(int32_t) + pBlock->info.numOfCols * sizeof(int32_t);
 }
 
+SSchema* blockDataExtractSchema(const SSDataBlock* pBlock, int32_t* numOfCols) {
+  SSchema* pSchema = calloc(pBlock->info.numOfCols, sizeof(SSchema));
+  for(int32_t i = 0; i < pBlock->info.numOfCols; ++i) {
+    SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
+    pSchema[i].bytes = pColInfoData->info.bytes;
+    pSchema[i].type  = pColInfoData->info.type;
+    pSchema[i].colId = pColInfoData->info.colId;
+  }
+
+  if (numOfCols != NULL) {
+    *numOfCols = pBlock->info.numOfCols;
+  }
+
+  return pSchema;
+}
+
 double blockDataGetSerialRowSize(const SSDataBlock* pBlock) {
   ASSERT(pBlock != NULL);
   double rowSize = 0;
@@ -577,8 +593,8 @@ int32_t dataBlockCompar(const void* p1, const void* p2, const void* param) {
       }
     }
 
-    void* left1  = colDataGet(pColInfoData, left);
-    void* right1 = colDataGet(pColInfoData, right);
+    void* left1  = colDataGetData(pColInfoData, left);
+    void* right1 = colDataGetData(pColInfoData, right);
 
     switch(pColInfoData->info.type) {
       case TSDB_DATA_TYPE_INT: {
@@ -617,7 +633,7 @@ static int32_t doAssignOneTuple(SColumnInfoData* pDstCols, int32_t numOfRows, co
         return code;
       }
     } else {
-      char* p = colDataGet(pSrc, tupleIndex);
+      char* p = colDataGetData(pSrc, tupleIndex);
       code = colDataAppend(pDst, numOfRows, p, false);
       if (code != TSDB_CODE_SUCCESS) {
         return code;
@@ -956,8 +972,8 @@ int32_t dataBlockCompar_rv(const void* p1, const void* p2, const void* param) {
 //      }
 //    }
 
-//    void* left1  = colDataGet(pColInfoData, left);
-//    void* right1 = colDataGet(pColInfoData, right);
+//    void* left1  = colDataGetData(pColInfoData, left);
+//    void* right1 = colDataGetData(pColInfoData, right);
 
 //    switch(pColInfoData->info.type) {
 //      case TSDB_DATA_TYPE_INT: {
@@ -1098,4 +1114,25 @@ void* blockDataDestroy(SSDataBlock* pBlock) {
   tfree(pBlock->pBlockAgg);
   tfree(pBlock);
   return NULL;
+}
+
+SSDataBlock* createOneDataBlock(const SSDataBlock* pDataBlock) {
+  int32_t numOfCols = pDataBlock->info.numOfCols;
+
+  SSDataBlock* pBlock = calloc(1, sizeof(SSDataBlock));
+  pBlock->pDataBlock = taosArrayInit(numOfCols, sizeof(SColumnInfoData));
+  pBlock->info.numOfCols = numOfCols;
+
+  for(int32_t i = 0; i < numOfCols; ++i) {
+    SColumnInfoData  colInfo = {0};
+    SColumnInfoData* p = taosArrayGet(pDataBlock->pDataBlock, i);
+    colInfo.info = p->info;
+    taosArrayPush(pBlock->pDataBlock, &colInfo);
+  }
+
+  return pBlock;
+}
+
+size_t blockDataGetCapacityInRow(const SSDataBlock* pBlock, size_t pageSize) {
+  return pageSize / (blockDataGetSerialRowSize(pBlock) + blockDataGetSerialMetaSize(pBlock));
 }
\ No newline at end of file
diff --git a/source/common/test/commonTests.cpp b/source/common/test/commonTests.cpp
index e9e8d086b3..9b05b5a780 100644
--- a/source/common/test/commonTests.cpp
+++ b/source/common/test/commonTests.cpp
@@ -162,7 +162,7 @@ TEST(testCase, Datablock_test) {
   ASSERT_EQ(colDataGetNumOfCols(b), 2);
   ASSERT_EQ(colDataGetNumOfRows(b), 40);
 
-  char* pData = colDataGet(p1, 3);
+  char* pData = colDataGetData(p1, 3);
   printf("the second row of binary:%s, length:%d\n", (char*)varDataVal(pData), varDataLen(pData));
 
   SArray* pOrderInfo = taosArrayInit(3, sizeof(SBlockOrderInfo));
diff --git a/source/dnode/vnode/inc/vnode.h b/source/dnode/vnode/inc/vnode.h
index 3a06674e3c..31f04e840a 100644
--- a/source/dnode/vnode/inc/vnode.h
+++ b/source/dnode/vnode/inc/vnode.h
@@ -216,13 +216,15 @@ static FORCE_INLINE void tqReadHandleSetColIdList(STqReadHandle *pReadHandle, SA
 static FORCE_INLINE int tqReadHandleSetTbUidList(STqReadHandle *pHandle, const SArray *tbUidList) {
   pHandle->tbIdHash = taosHashInit(64, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), true, HASH_NO_LOCK);
   if (pHandle->tbIdHash == NULL) {
+    terrno = TSDB_CODE_OUT_OF_MEMORY;
     return -1;
   }
+
   for (int i = 0; i < taosArrayGetSize(tbUidList); i++) {
     int64_t *pKey = (int64_t *)taosArrayGet(tbUidList, i);
     taosHashPut(pHandle->tbIdHash, pKey, sizeof(int64_t), NULL, 0);
-    // pHandle->tbUid = tbUid;
   }
+
   return 0;
 }
 
diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index bed2c0cd41..653e1b6380 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -88,7 +88,7 @@ typedef struct STableCheckInfo {
   int32_t       compSize;
   int32_t       numOfBlocks:29; // number of qualified data blocks not the original blocks
   uint8_t       chosen:2;       // indicate which iterator should move forward
-  bool          initBuf;        // whether to initialize the in-memory skip list iterator or not
+  bool          initBuf:1;        // whether to initialize the in-memory skip list iterator or not
   SSkipListIterator* iter;      // mem buffer skip list iterator
   SSkipListIterator* iiter;     // imem buffer skip list iterator
 } STableCheckInfo;
diff --git a/source/libs/executor/inc/executil.h b/source/libs/executor/inc/executil.h
index 10d884cb3f..e729c868a7 100644
--- a/source/libs/executor/inc/executil.h
+++ b/source/libs/executor/inc/executil.h
@@ -68,9 +68,10 @@ typedef struct SResultRow {
 } SResultRow;
 
 typedef struct SResultRowInfo {
+  SResultRow  *pCurResult; // current active result row info
   SResultRow** pResult;    // result list
-  int16_t      type:8;     // data type for hash key
-  int32_t      size:24;    // number of result set
+//  int16_t      type:8;     // data type for hash key
+  int32_t      size;       // number of result set
   int32_t      capacity;   // max capacity
   int32_t      curPos;     // current active result row index of pResult list
 } SResultRowInfo;
@@ -95,7 +96,7 @@ struct SUdfInfo;
 int32_t getOutputInterResultBufSize(struct STaskAttr* pQueryAttr);
 
 size_t  getResultRowSize(SArray* pExprInfo);
-int32_t initResultRowInfo(SResultRowInfo* pResultRowInfo, int32_t size, int16_t type);
+int32_t initResultRowInfo(SResultRowInfo* pResultRowInfo, int32_t size);
 void    cleanupResultRowInfo(SResultRowInfo* pResultRowInfo);
 
 void    resetResultRowInfo(struct STaskRuntimeEnv* pRuntimeEnv, SResultRowInfo* pResultRowInfo);
@@ -105,7 +106,7 @@ void    closeAllResultRows(SResultRowInfo* pResultRowInfo);
 int32_t initResultRow(SResultRow *pResultRow);
 void    closeResultRow(SResultRowInfo* pResultRowInfo, int32_t slot);
 bool    isResultRowClosed(SResultRowInfo *pResultRowInfo, int32_t slot);
-void    clearResultRow(struct STaskRuntimeEnv* pRuntimeEnv, SResultRow* pResultRow, int16_t type);
+void    clearResultRow(struct STaskRuntimeEnv* pRuntimeEnv, SResultRow* pResultRow);
 
 struct SResultRowEntryInfo* getResultCell(const SResultRow* pRow, int32_t index, int32_t* offset);
 
diff --git a/source/libs/executor/inc/executorimpl.h b/source/libs/executor/inc/executorimpl.h
index 23acdf1c33..4e7076530b 100644
--- a/source/libs/executor/inc/executorimpl.h
+++ b/source/libs/executor/inc/executorimpl.h
@@ -15,6 +15,7 @@
 #ifndef TDENGINE_EXECUTORIMPL_H
 #define TDENGINE_EXECUTORIMPL_H
 
+#include "tsort.h"
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -444,16 +445,32 @@ typedef struct SOptrBasicInfo {
   int32_t         capacity;
 } SOptrBasicInfo;
 
-typedef struct SOptrBasicInfo STableIntervalOperatorInfo;
-
-typedef struct SAggOperatorInfo {
-  SOptrBasicInfo       binfo;
-  SDiskbasedBuf       *pResultBuf;           // query result buffer based on blocked-wised disk file
+typedef struct SAggSupporter {
   SHashObj*            pResultRowHashTable;  // quick locate the window object for each result
   SHashObj*            pResultRowListSet;    // used to check if current ResultRowInfo has ResultRow object or not
   SArray*              pResultRowArrayList;  // The array list that contains the Result rows
   char*                keyBuf;               // window key buffer
   SResultRowPool      *pool;  // The window result objects pool, all the resultRow Objects are allocated and managed by this object.
+} SAggSupporter;
+
+typedef struct STableIntervalOperatorInfo {
+  SOptrBasicInfo       binfo;
+  SDiskbasedBuf       *pResultBuf;           // query result buffer based on blocked-wised disk file
+  SGroupResInfo        groupResInfo;
+  SInterval            interval;
+  STimeWindow          win;
+  int32_t              precision;
+  bool                 timeWindowInterpo;
+  char               **pRow;
+  SAggSupporter        aggSup;
+  STableQueryInfo     *pCurrent;
+  int32_t              order;
+} STableIntervalOperatorInfo;
+
+typedef struct SAggOperatorInfo {
+  SOptrBasicInfo       binfo;
+  SDiskbasedBuf       *pResultBuf;           // query result buffer based on blocked-wised disk file
+  SAggSupporter        aggSup;
   STableQueryInfo     *current;
   uint32_t             groupId;
   SGroupResInfo        groupResInfo;
@@ -549,49 +566,42 @@ typedef struct SDistinctOperatorInfo {
   SArray*      pDistinctDataInfo;
 } SDistinctOperatorInfo;
 
-struct SGlobalMerger;
+typedef struct SSortedMergeOperatorInfo {
+  SOptrBasicInfo     binfo;
+  bool               hasVarCol;
+  
+  SArray            *orderInfo;   // SArray<SBlockOrderInfo>
+  bool               nullFirst;
+  int32_t            numOfSources;
 
-typedef struct SMultiwayMergeInfo {
-  struct SGlobalMerger* pMerge;
-  SOptrBasicInfo        binfo;
-  int32_t               bufCapacity;
-  int64_t               seed;
-  char**                prevRow;
-  SArray*               orderColumnList;
-  int32_t               resultRowFactor;
+  SSortHandle       *pSortHandle;
 
-  bool         hasGroupColData;
-  char**       currentGroupColData;
-  SArray*      groupColumnList;
-  bool         hasDataBlockForNewGroup;
-  SSDataBlock* pExistBlock;
+  int32_t            bufPageSize;
+  uint32_t           sortBufSize;  // max buffer size for in-memory sort
 
-  SArray* udfInfo;
-  bool    hasPrev;
-  bool    multiGroupResults;
-} SMultiwayMergeInfo;
+  int32_t            resultRowFactor;
+  bool               hasGroupVal;
 
-typedef struct SMsortComparParam {
-  struct SExternalMemSource **pSources;
-  int32_t       numOfSources;
-  SArray       *orderInfo;   // SArray<SBlockOrderInfo>
-  bool          nullFirst;
-} SMsortComparParam;
+  SDiskbasedBuf     *pTupleStore;  // keep the final results
+  int32_t            numOfResPerPage;
+
+  char**             groupVal;
+  SArray            *groupInfo;
+  SAggSupporter      aggSup;
+} SSortedMergeOperatorInfo;
 
 typedef struct SOrderOperatorInfo {
-  int32_t                 sourceId;
   uint32_t                sortBufSize;  // max buffer size for in-memory sort
   SSDataBlock            *pDataBlock;
   bool                    hasVarCol;    // has variable length column, such as binary/varchar/nchar
-  int32_t                 numOfCompleted;
-  SDiskbasedBuf          *pSortInternalBuf;
-  SMultiwayMergeTreeInfo *pMergeTree;
-  SArray                 *pSources;     // SArray<SExternalMemSource*>
+  SArray                 *orderInfo;
+  bool                    nullFirst;
+  SSortHandle            *pSortHandle;
+
   int32_t                 bufPageSize;
   int32_t                 numOfRowsInRes;
 
-  SMsortComparParam       cmpParam;
-
+  // TODO extact struct
   int64_t                 startTs;       // sort start time
   uint64_t                sortElapsed;   // sort elapsed time, time to flush to disk not included.
   uint64_t                totalSize;     // total load bytes from remote
@@ -608,8 +618,8 @@ SOperatorInfo* createMultiTableAggOperatorInfo(SOperatorInfo* downstream, SArray
 SOperatorInfo* createProjectOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream, SExprInfo* pExpr,
                                          int32_t numOfOutput);
 SOperatorInfo* createLimitOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream);
-SOperatorInfo* createTimeIntervalOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream, SExprInfo* pExpr,
-                                              int32_t numOfOutput);
+SOperatorInfo* createIntervalOperatorInfo(SOperatorInfo* downstream, SArray* pExprInfo, SExecTaskInfo* pTaskInfo);
+
 SOperatorInfo* createAllTimeIntervalOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream,
                                                  SExprInfo* pExpr, int32_t numOfOutput);
 SOperatorInfo* createSWindowOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream, SExprInfo* pExpr,
@@ -641,9 +651,8 @@ SOperatorInfo* createFilterOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorI
 
 SOperatorInfo* createJoinOperatorInfo(SOperatorInfo** pdownstream, int32_t numOfDownstream, SSchema* pSchema,
                                       int32_t numOfOutput);
-SOperatorInfo* createOrderOperatorInfo(SOperatorInfo* downstream, SArray* pExprInfo, SArray* pOrderVal);
-SOperatorInfo* createMergeSortOperatorInfo(SOperatorInfo* downstream, SExprInfo* pExpr, int32_t numOfOutput,
-                                           SOrder* pOrderVal);
+SOperatorInfo* createOrderOperatorInfo(SOperatorInfo* downstream, SArray* pExprInfo, SArray* pOrderVal, SExecTaskInfo* pTaskInfo);
+SOperatorInfo* createSortedMergeOperatorInfo(SOperatorInfo** downstream, int32_t numOfDownstream, SArray* pExprInfo, SArray* pOrderVal, SArray* pGroupInfo, SExecTaskInfo* pTaskInfo);
 
 // SSDataBlock* doGlobalAggregate(void* param, bool* newgroup);
 // SSDataBlock* doMultiwayMergeSort(void* param, bool* newgroup);
@@ -691,9 +700,6 @@ int32_t checkForQueryBuf(size_t numOfTables);
 bool    checkNeedToCompressQueryCol(SQInfo* pQInfo);
 void    setQueryStatus(STaskRuntimeEnv* pRuntimeEnv, int8_t status);
 
-bool onlyQueryTags(STaskAttr* pQueryAttr);
-// void destroyUdfInfo(struct SUdfInfo* pUdfInfo);
-
 int32_t doDumpQueryResult(SQInfo* pQInfo, char* data, int8_t compressed, int32_t* compLen);
 
 size_t getResultSize(SQInfo* pQInfo, int64_t* numOfRows);
diff --git a/source/libs/executor/inc/tlinearhash.h b/source/libs/executor/inc/tlinearhash.h
new file mode 100644
index 0000000000..a419058216
--- /dev/null
+++ b/source/libs/executor/inc/tlinearhash.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TDENGINE_TLINEARHASH_H
+#define TDENGINE_TLINEARHASH_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "thash.h"
+
+enum {
+  LINEAR_HASH_STATIS = 0x1,
+  LINEAR_HASH_DATA   = 0x2,
+};
+
+typedef struct SLHashObj SLHashObj;
+
+SLHashObj* tHashInit(int32_t inMemPages, int32_t pageSize, _hash_fn_t fn, int32_t numOfTuplePerPage);
+void*      tHashCleanup(SLHashObj* pHashObj);
+
+int32_t    tHashPut(SLHashObj* pHashObj, const void *key, size_t keyLen, void *data, size_t size);
+char*      tHashGet(SLHashObj* pHashObj, const void *key, size_t keyLen);
+int32_t    tHashRemove(SLHashObj* pHashObj, const void *key, size_t keyLen);
+
+void       tHashPrint(const SLHashObj* pHashObj, int32_t type);
+
+#ifdef __cplusplus
+}
+#endif
+#endif  // TDENGINE_TLINEARHASH_H
diff --git a/source/libs/executor/inc/tsort.h b/source/libs/executor/inc/tsort.h
new file mode 100644
index 0000000000..9c9368bb1a
--- /dev/null
+++ b/source/libs/executor/inc/tsort.h
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef TDENGINE_TSORT_H
+#define TDENGINE_TSORT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "common.h"
+#include "os.h"
+
+enum {
+  SORT_MULTISOURCE_MERGE = 0x1,
+  SORT_SINGLESOURCE_SORT = 0x2,
+};
+
+typedef struct SMultiMergeSource {
+  int32_t      type;
+  int32_t      rowIndex;
+  SSDataBlock *pBlock;
+} SMultiMergeSource;
+
+typedef struct SExternalMemSource {
+  SMultiMergeSource src;
+  SArray*           pageIdList;
+  int32_t           pageIndex;
+} SExternalMemSource;
+
+typedef struct SGenericSource {
+  SMultiMergeSource src;
+  void             *param;
+} SGenericSource;
+
+typedef struct SMsortComparParam {
+  void        **pSources;
+  int32_t       numOfSources;
+  SArray       *orderInfo;   // SArray<SBlockOrderInfo>
+  bool          nullFirst;
+} SMsortComparParam;
+
+typedef struct SSortHandle SSortHandle;
+typedef struct STupleHandle STupleHandle;
+
+typedef SSDataBlock* (*_sort_fetch_block_fn_t)(void* param);
+typedef int32_t (*_sort_merge_compar_fn_t)(const void* p1, const void* p2, void* param);
+
+/**
+ *
+ * @param type
+ * @return
+ */
+SSortHandle* tsortCreateSortHandle(SArray* pOrderInfo, bool nullFirst, int32_t type, int32_t pageSize, int32_t numOfPages, SSchema* pSchema, int32_t numOfCols, const char* idstr);
+
+/**
+ *
+ * @param pSortHandle
+ */
+void tsortDestroySortHandle(SSortHandle* pSortHandle);
+
+/**
+ *
+ * @param pHandle
+ * @return
+ */
+int32_t tsortOpen(SSortHandle* pHandle);
+
+/**
+ *
+ * @param pHandle
+ * @return
+ */
+int32_t tsortClose(SSortHandle* pHandle);
+
+/**
+ *
+ * @return
+ */
+int32_t tsortSetFetchRawDataFp(SSortHandle* pHandle, _sort_fetch_block_fn_t fp);
+
+/**
+ *
+ * @param pHandle
+ * @param fp
+ * @return
+ */
+int32_t tsortSetComparFp(SSortHandle* pHandle, _sort_merge_compar_fn_t fp);
+
+/**
+ *
+ * @param pHandle
+ * @param pSource
+ * @return success or failed
+ */
+int32_t tsortAddSource(SSortHandle* pSortHandle, void* pSource);
+
+/**
+ *
+ * @param pHandle
+ * @return
+ */
+STupleHandle* tsortNextTuple(SSortHandle* pHandle);
+
+/**
+ *
+ * @param pHandle
+ * @param colIndex
+ * @return
+ */
+bool tsortIsNullVal(STupleHandle* pVHandle, int32_t colIndex);
+
+/**
+ *
+ * @param pHandle
+ * @param colIndex
+ * @return
+ */
+void* tsortGetValue(STupleHandle* pVHandle, int32_t colIndex);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // TDENGINE_TSORT_H
diff --git a/source/libs/executor/src/executil.c b/source/libs/executor/src/executil.c
index 52ab8493f1..1b901ee9f6 100644
--- a/source/libs/executor/src/executil.c
+++ b/source/libs/executor/src/executil.c
@@ -53,8 +53,7 @@ int32_t getOutputInterResultBufSize(STaskAttr* pQueryAttr) {
   return size;
 }
 
-int32_t initResultRowInfo(SResultRowInfo *pResultRowInfo, int32_t size, int16_t type) {
-  pResultRowInfo->type     = type;
+int32_t initResultRowInfo(SResultRowInfo *pResultRowInfo, int32_t size) {
   pResultRowInfo->size     = 0;
   pResultRowInfo->curPos  = -1;
   pResultRowInfo->capacity = size;
@@ -93,7 +92,7 @@ void resetResultRowInfo(STaskRuntimeEnv *pRuntimeEnv, SResultRowInfo *pResultRow
 
   for (int32_t i = 0; i < pResultRowInfo->size; ++i) {
     SResultRow *pWindowRes = pResultRowInfo->pResult[i];
-    clearResultRow(pRuntimeEnv, pWindowRes, pResultRowInfo->type);
+    clearResultRow(pRuntimeEnv, pWindowRes);
 
     int32_t groupIndex = 0;
     int64_t uid = 0;
@@ -136,7 +135,7 @@ void closeResultRow(SResultRowInfo *pResultRowInfo, int32_t slot) {
   getResultRow(pResultRowInfo, slot)->closed = true;
 }
 
-void clearResultRow(STaskRuntimeEnv *pRuntimeEnv, SResultRow *pResultRow, int16_t type) {
+void clearResultRow(STaskRuntimeEnv *pRuntimeEnv, SResultRow *pResultRow) {
   if (pResultRow == NULL) {
     return;
   }
diff --git a/source/libs/executor/src/executor.c b/source/libs/executor/src/executor.c
index 4078ee9291..b90ce275d2 100644
--- a/source/libs/executor/src/executor.c
+++ b/source/libs/executor/src/executor.c
@@ -93,3 +93,25 @@ qTaskInfo_t qCreateStreamExecTaskInfo(void* msg, void* streamReadHandle) {
 
   return pTaskInfo;
 }
+
+int32_t qUpdateQualifiedTableId(qTaskInfo_t tinfo, SArray* tableIdList, bool isAdd) {
+  SExecTaskInfo* pTaskInfo = (SExecTaskInfo* )tinfo;
+
+  // traverse to the streamscan node to add this table id
+  SOperatorInfo* pInfo = pTaskInfo->pRoot;
+  while(pInfo->operatorType != OP_StreamScan) {
+    pInfo = pInfo->pDownstream[0];
+  }
+
+  SStreamBlockScanInfo* pScanInfo = pInfo->info;
+  if (isAdd) {
+    int32_t code = tqReadHandleSetTbUidList(pScanInfo->readerHandle, tableIdList);
+    if (code != TSDB_CODE_SUCCESS) {
+      return code;
+    }
+  } else {
+    assert(0);
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
\ No newline at end of file
diff --git a/source/libs/executor/src/executorimpl.c b/source/libs/executor/src/executorimpl.c
index 5508b5ecd7..a4a09c91fe 100644
--- a/source/libs/executor/src/executorimpl.c
+++ b/source/libs/executor/src/executorimpl.c
@@ -12,13 +12,14 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
-#include <tep.h>
-#include "exception.h"
 #include "os.h"
+
+#include "tep.h"
+#include "tsort.h"
+#include "exception.h"
 #include "parser.h"
 #include "tglobal.h"
 #include "tmsg.h"
-#include "tq.h"
 #include "ttime.h"
 
 #include "executorimpl.h"
@@ -140,19 +141,19 @@ static int32_t getExprFunctionId(SExprInfo *pExprInfo) {
   return 0;
 }
 
-static void getNextTimeWindow(STaskAttr* pQueryAttr, STimeWindow* tw) {
-  int32_t factor = GET_FORWARD_DIRECTION_FACTOR(pQueryAttr->order.order);
-  if (pQueryAttr->interval.intervalUnit != 'n' && pQueryAttr->interval.intervalUnit != 'y') {
-    tw->skey += pQueryAttr->interval.sliding * factor;
-    tw->ekey = tw->skey + pQueryAttr->interval.interval - 1;
+static void getNextTimeWindow(SInterval* pInterval, int32_t precision, int32_t order, STimeWindow* tw) {
+  int32_t factor = GET_FORWARD_DIRECTION_FACTOR(order);
+  if (pInterval->intervalUnit != 'n' && pInterval->intervalUnit != 'y') {
+    tw->skey += pInterval->sliding * factor;
+    tw->ekey = tw->skey + pInterval->interval - 1;
     return;
   }
 
-  int64_t key = tw->skey, interval = pQueryAttr->interval.interval;
+  int64_t key = tw->skey, interval = pInterval->interval;
   //convert key to second
-  key = convertTimePrecision(key, pQueryAttr->precision, TSDB_TIME_PRECISION_MILLI) / 1000;
+  key = convertTimePrecision(key, precision, TSDB_TIME_PRECISION_MILLI) / 1000;
 
-  if (pQueryAttr->interval.intervalUnit == 'y') {
+  if (pInterval->intervalUnit == 'y') {
     interval *= 12;
   }
 
@@ -163,12 +164,12 @@ static void getNextTimeWindow(STaskAttr* pQueryAttr, STimeWindow* tw) {
   int mon = (int)(tm.tm_year * 12 + tm.tm_mon + interval * factor);
   tm.tm_year = mon / 12;
   tm.tm_mon = mon % 12;
-  tw->skey = convertTimePrecision((int64_t)mktime(&tm) * 1000L, TSDB_TIME_PRECISION_MILLI, pQueryAttr->precision);
+  tw->skey = convertTimePrecision((int64_t)mktime(&tm) * 1000L, TSDB_TIME_PRECISION_MILLI, precision);
 
   mon = (int)(mon + interval);
   tm.tm_year = mon / 12;
   tm.tm_mon = mon % 12;
-  tw->ekey = convertTimePrecision((int64_t)mktime(&tm) * 1000L, TSDB_TIME_PRECISION_MILLI, pQueryAttr->precision);
+  tw->ekey = convertTimePrecision((int64_t)mktime(&tm) * 1000L, TSDB_TIME_PRECISION_MILLI, precision);
 
   tw->ekey -= 1;
 }
@@ -178,7 +179,7 @@ static void setResultOutputBuf(STaskRuntimeEnv* pRuntimeEnv, SResultRow* pResult
                                int32_t numOfCols, int32_t* rowCellInfoOffset);
 
 void setResultRowOutputBufInitCtx(STaskRuntimeEnv *pRuntimeEnv, SResultRow *pResult, SqlFunctionCtx* pCtx, int32_t numOfOutput, int32_t* rowCellInfoOffset);
-static bool functionNeedToExecute(STaskRuntimeEnv *pRuntimeEnv, SqlFunctionCtx *pCtx);
+static bool functionNeedToExecute(SqlFunctionCtx *pCtx);
 
 static void setBlockStatisInfo(SqlFunctionCtx *pCtx, SSDataBlock* pSDataBlock, SColumn* pColumn);
 
@@ -221,7 +222,8 @@ static int32_t getGroupbyColumnIndex(SGroupbyExpr *pGroupbyExpr, SSDataBlock* pD
 static int32_t setGroupResultOutputBuf(STaskRuntimeEnv *pRuntimeEnv, SOptrBasicInfo *binf, int32_t numOfCols, char *pData, int16_t type, int16_t bytes, int32_t groupIndex);
 
 static void initCtxOutputBuffer(SqlFunctionCtx* pCtx, int32_t size);
-static void getAlignQueryTimeWindow(STaskAttr *pQueryAttr, int64_t key, int64_t keyFirst, int64_t keyLast, STimeWindow *win);
+static void getAlignQueryTimeWindow(SInterval* pInterval, int32_t precision, int64_t key, int64_t keyFirst, int64_t keyLast, STimeWindow *win);
+
 static void setResultBufSize(STaskAttr* pQueryAttr, SRspResultInfo* pResultInfo);
 static void setCtxTagForJoin(STaskRuntimeEnv* pRuntimeEnv, SqlFunctionCtx* pCtx, SExprInfo* pExprInfo, void* pTable);
 static void setParamForStableStddev(STaskRuntimeEnv* pRuntimeEnv, SqlFunctionCtx* pCtx, int32_t numOfOutput, SExprInfo* pExpr);
@@ -380,18 +382,23 @@ static bool hasNull(SColumn* pColumn, SColumnDataAgg *pStatis) {
 }
 
 static void prepareResultListBuffer(SResultRowInfo* pResultRowInfo, jmp_buf env) {
+  int64_t newCapacity = 0;
+
   // more than the capacity, reallocate the resources
   if (pResultRowInfo->size < pResultRowInfo->capacity) {
     return;
   }
 
-  int64_t newCapacity = 0;
   if (pResultRowInfo->capacity > 10000) {
     newCapacity = (int64_t)(pResultRowInfo->capacity * 1.25);
   } else {
     newCapacity = (int64_t)(pResultRowInfo->capacity * 1.5);
   }
 
+  if (newCapacity == pResultRowInfo->capacity) {
+    newCapacity += 4;
+  }
+
   char *t = realloc(pResultRowInfo->pResult, (size_t)(newCapacity * POINTER_BYTES));
   if (t == NULL) {
     longjmp(env, TSDB_CODE_QRY_OUT_OF_MEMORY);
@@ -518,12 +525,12 @@ static SResultRow* doSetResultOutBufByKey(STaskRuntimeEnv* pRuntimeEnv, SResultR
 }
 
 static SResultRow* doSetResultOutBufByKey_rv(SResultRowInfo* pResultRowInfo, int64_t tid, char* pData, int16_t bytes,
-    bool masterscan, uint64_t tableGroupId, SExecTaskInfo* pTaskInfo, bool isIntervalQuery, SAggOperatorInfo* pAggInfo) {
+    bool masterscan, uint64_t tableGroupId, SExecTaskInfo* pTaskInfo, bool isIntervalQuery, SAggSupporter* pSup) {
   bool existed = false;
-  SET_RES_WINDOW_KEY(pAggInfo->keyBuf, pData, bytes, tableGroupId);
+  SET_RES_WINDOW_KEY(pSup->keyBuf, pData, bytes, tableGroupId);
 
   SResultRow **p1 =
-      (SResultRow **)taosHashGet(pAggInfo->pResultRowHashTable, pAggInfo->keyBuf, GET_RES_WINDOW_KEY_LEN(bytes));
+      (SResultRow **)taosHashGet(pSup->pResultRowHashTable, pSup->keyBuf, GET_RES_WINDOW_KEY_LEN(bytes));
 
   // in case of repeat scan/reverse scan, no new time window added.
   if (isIntervalQuery) {
@@ -539,8 +546,8 @@ static SResultRow* doSetResultOutBufByKey_rv(SResultRowInfo* pResultRowInfo, int
         existed = (pResultRowInfo->pResult[0] == (*p1));
         pResultRowInfo->curPos = 0;
       } else {  // check if current pResultRowInfo contains the existed pResultRow
-        SET_RES_EXT_WINDOW_KEY(pAggInfo->keyBuf, pData, bytes, tid, pResultRowInfo);
-        int64_t* index = taosHashGet(pAggInfo->pResultRowListSet, pAggInfo->keyBuf, GET_RES_EXT_WINDOW_KEY_LEN(bytes));
+        SET_RES_EXT_WINDOW_KEY(pSup->keyBuf, pData, bytes, tid, pResultRowInfo);
+        int64_t* index = taosHashGet(pSup->pResultRowListSet, pSup->keyBuf, GET_RES_EXT_WINDOW_KEY_LEN(bytes));
         if (index != NULL) {
           pResultRowInfo->curPos = (int32_t) *index;
           existed = true;
@@ -561,16 +568,16 @@ static SResultRow* doSetResultOutBufByKey_rv(SResultRowInfo* pResultRowInfo, int
 
     SResultRow *pResult = NULL;
     if (p1 == NULL) {
-      pResult = getNewResultRow(pAggInfo->pool);
+      pResult = getNewResultRow(pSup->pool);
       int32_t ret = initResultRow(pResult);
       if (ret != TSDB_CODE_SUCCESS) {
         longjmp(pTaskInfo->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
       }
 
       // add a new result set for a new group
-      taosHashPut(pAggInfo->pResultRowHashTable, pAggInfo->keyBuf, GET_RES_WINDOW_KEY_LEN(bytes), &pResult, POINTER_BYTES);
+      taosHashPut(pSup->pResultRowHashTable, pSup->keyBuf, GET_RES_WINDOW_KEY_LEN(bytes), &pResult, POINTER_BYTES);
       SResultRowCell cell = {.groupId = tableGroupId, .pRow = pResult};
-      taosArrayPush(pAggInfo->pResultRowArrayList, &cell);
+      taosArrayPush(pSup->pResultRowArrayList, &cell);
     } else {
       pResult = *p1;
     }
@@ -579,8 +586,8 @@ static SResultRow* doSetResultOutBufByKey_rv(SResultRowInfo* pResultRowInfo, int
     pResultRowInfo->pResult[pResultRowInfo->size++] = pResult;
 
     int64_t index = pResultRowInfo->curPos;
-    SET_RES_EXT_WINDOW_KEY(pAggInfo->keyBuf, pData, bytes, tid, pResultRowInfo);
-    taosHashPut(pAggInfo->pResultRowListSet, pAggInfo->keyBuf, GET_RES_EXT_WINDOW_KEY_LEN(bytes), &index, POINTER_BYTES);
+    SET_RES_EXT_WINDOW_KEY(pSup->keyBuf, pData, bytes, tid, pResultRowInfo);
+    taosHashPut(pSup->pResultRowListSet, pSup->keyBuf, GET_RES_EXT_WINDOW_KEY_LEN(bytes), &index, POINTER_BYTES);
   }
 
   // too many time window in query
@@ -591,19 +598,19 @@ static SResultRow* doSetResultOutBufByKey_rv(SResultRowInfo* pResultRowInfo, int
   return pResultRowInfo->pResult[pResultRowInfo->curPos];
 }
 
-static void getInitialStartTimeWindow(STaskAttr* pQueryAttr, TSKEY ts, STimeWindow* w) {
-  if (QUERY_IS_ASC_QUERY(pQueryAttr)) {
-    getAlignQueryTimeWindow(pQueryAttr, ts, ts, pQueryAttr->window.ekey, w);
+static void getInitialStartTimeWindow(SInterval* pInterval, int32_t precision, TSKEY ts, STimeWindow* w, TSKEY ekey, bool ascQuery) {
+  if (ascQuery) {
+    getAlignQueryTimeWindow(pInterval, precision, ts, ts, ekey, w);
   } else {
     // the start position of the first time window in the endpoint that spreads beyond the queried last timestamp
-    getAlignQueryTimeWindow(pQueryAttr, ts, pQueryAttr->window.ekey, ts, w);
+    getAlignQueryTimeWindow(pInterval, precision, ts, ekey, ts, w);
 
     int64_t key = w->skey;
     while(key < ts) { // moving towards end
-      if (pQueryAttr->interval.intervalUnit == 'n' || pQueryAttr->interval.intervalUnit == 'y') {
-        key = taosTimeAdd(key, pQueryAttr->interval.sliding, pQueryAttr->interval.slidingUnit, pQueryAttr->precision);
+      if (pInterval->intervalUnit == 'n' || pInterval->intervalUnit == 'y') {
+        key = taosTimeAdd(key, pInterval->sliding, pInterval->slidingUnit, precision);
       } else {
-        key += pQueryAttr->interval.sliding;
+        key += pInterval->sliding;
       }
 
       if (key >= ts) {
@@ -616,39 +623,39 @@ static void getInitialStartTimeWindow(STaskAttr* pQueryAttr, TSKEY ts, STimeWind
 }
 
 // get the correct time window according to the handled timestamp
-static STimeWindow getActiveTimeWindow(SResultRowInfo * pResultRowInfo, int64_t ts, STaskAttr *pQueryAttr) {
+static STimeWindow getActiveTimeWindow(SResultRowInfo * pResultRowInfo, int64_t ts, SInterval* pInterval, int32_t precision, STimeWindow* win) {
   STimeWindow w = {0};
 
  if (pResultRowInfo->curPos == -1) {  // the first window, from the previous stored value
-    getInitialStartTimeWindow(pQueryAttr, ts, &w);
+    getInitialStartTimeWindow(pInterval, precision, ts, &w, win->ekey, true);
 
-    if (pQueryAttr->interval.intervalUnit == 'n' || pQueryAttr->interval.intervalUnit == 'y') {
-      w.ekey = taosTimeAdd(w.skey, pQueryAttr->interval.interval, pQueryAttr->interval.intervalUnit, pQueryAttr->precision) - 1;
+    if (pInterval->intervalUnit == 'n' || pInterval->intervalUnit == 'y') {
+      w.ekey = taosTimeAdd(w.skey, pInterval->interval, pInterval->intervalUnit, precision) - 1;
     } else {
-      w.ekey = w.skey + pQueryAttr->interval.interval - 1;
+      w.ekey = w.skey + pInterval->interval - 1;
     }
   } else {
     w = getResultRow(pResultRowInfo, pResultRowInfo->curPos)->win;
   }
 
   if (w.skey > ts || w.ekey < ts) {
-    if (pQueryAttr->interval.intervalUnit == 'n' || pQueryAttr->interval.intervalUnit == 'y') {
-      w.skey = taosTimeTruncate(ts, &pQueryAttr->interval, pQueryAttr->precision);
-      w.ekey = taosTimeAdd(w.skey, pQueryAttr->interval.interval, pQueryAttr->interval.intervalUnit, pQueryAttr->precision) - 1;
+    if (pInterval->intervalUnit == 'n' || pInterval->intervalUnit == 'y') {
+      w.skey = taosTimeTruncate(ts, pInterval, precision);
+      w.ekey = taosTimeAdd(w.skey, pInterval->interval, pInterval->intervalUnit, precision) - 1;
     } else {
       int64_t st = w.skey;
 
       if (st > ts) {
-        st -= ((st - ts + pQueryAttr->interval.sliding - 1) / pQueryAttr->interval.sliding) * pQueryAttr->interval.sliding;
+        st -= ((st - ts + pInterval->sliding - 1) / pInterval->sliding) * pInterval->sliding;
       }
 
-      int64_t et = st + pQueryAttr->interval.interval - 1;
+      int64_t et = st + pInterval->interval - 1;
       if (et < ts) {
-        st += ((ts - et + pQueryAttr->interval.sliding - 1) / pQueryAttr->interval.sliding) * pQueryAttr->interval.sliding;
+        st += ((ts - et + pInterval->sliding - 1) / pInterval->sliding) * pInterval->sliding;
       }
 
       w.skey = st;
-      w.ekey = w.skey + pQueryAttr->interval.interval - 1;
+      w.ekey = w.skey + pInterval->interval - 1;
     }
   }
 
@@ -656,10 +663,7 @@ static STimeWindow getActiveTimeWindow(SResultRowInfo * pResultRowInfo, int64_t
    * query border check, skey should not be bounded by the query time range, since the value skey will
    * be used as the time window index value. So we only change ekey of time window accordingly.
    */
-  if (w.ekey > pQueryAttr->window.ekey && QUERY_IS_ASC_QUERY(pQueryAttr)) {
-    w.ekey = pQueryAttr->window.ekey;
-  }
-
+//  ASSERT(win->skey <= win->ekey); // todo no need this
   return w;
 }
 
@@ -668,7 +672,7 @@ static STimeWindow getCurrentActiveTimeWindow(SResultRowInfo * pResultRowInfo, i
   STimeWindow w = {0};
 
  if (pResultRowInfo->curPos == -1) {  // the first window, from the previous stored value
-    getInitialStartTimeWindow(pQueryAttr, ts, &w);
+//    getInitialStartTimeWindow(pQueryAttr, ts, &w);
 
     if (pQueryAttr->interval.intervalUnit == 'n' || pQueryAttr->interval.intervalUnit == 'y') {
       w.ekey = taosTimeAdd(w.skey, pQueryAttr->interval.interval, pQueryAttr->interval.intervalUnit, pQueryAttr->precision) - 1;
@@ -703,7 +707,7 @@ static int32_t addNewWindowResultBuf(SResultRow *pWindowRes, SDiskbasedBuf *pRes
   SIDList list = getDataBufPagesIdList(pResultBuf, tid);
 
   if (taosArrayGetSize(list) == 0) {
-    pData = getNewDataBuf(pResultBuf, tid, &pageId);
+    pData = getNewBufPage(pResultBuf, tid, &pageId);
   } else {
     SPageInfo* pi = getLastPageInfo(list);
     pData = getBufPage(pResultBuf, getPageId(pi));
@@ -712,7 +716,7 @@ static int32_t addNewWindowResultBuf(SResultRow *pWindowRes, SDiskbasedBuf *pRes
     if (pData->num + size > getBufPageSize(pResultBuf)) {
       // release current page first, and prepare the next one
       releaseBufPageInfo(pResultBuf, pi);
-      pData = getNewDataBuf(pResultBuf, tid, &pageId);
+      pData = getNewBufPage(pResultBuf, tid, &pageId);
       if (pData != NULL) {
         assert(pData->num == 0);  // number of elements must be 0 for new allocated buffer
       }
@@ -770,6 +774,37 @@ static int32_t setResultOutputBufByKey(STaskRuntimeEnv *pRuntimeEnv, SResultRowI
   return TSDB_CODE_SUCCESS;
 }
 
+static void setResultRowOutputBufInitCtx_rv(SDiskbasedBuf * pBuf, SResultRow *pResult, SqlFunctionCtx* pCtx, int32_t numOfOutput, int32_t* rowCellInfoOffset);
+
+static int32_t setResultOutputBufByKey_rv(SResultRowInfo *pResultRowInfo, int64_t id, STimeWindow *win,
+                                       bool masterscan, SResultRow **pResult, int64_t tableGroupId, SqlFunctionCtx* pCtx,
+                                       int32_t numOfOutput, int32_t* rowCellInfoOffset, SDiskbasedBuf *pBuf, SAggSupporter *pAggSup, SExecTaskInfo* pTaskInfo) {
+  assert(win->skey <= win->ekey);
+  SResultRow *pResultRow = doSetResultOutBufByKey_rv(pResultRowInfo, id, (char *)&win->skey, TSDB_KEYSIZE, masterscan, tableGroupId,
+       pTaskInfo, true, pAggSup);
+
+  if (pResultRow == NULL) {
+    *pResult = NULL;
+    return TSDB_CODE_SUCCESS;
+  }
+
+  // not assign result buffer yet, add new result buffer
+  if (pResultRow->pageId == -1) { // todo intermediate result size
+    int32_t ret = addNewWindowResultBuf(pResultRow, pBuf, (int32_t) tableGroupId, 0);
+    if (ret != TSDB_CODE_SUCCESS) {
+      return -1;
+    }
+  }
+
+  // set time window for current result
+  pResultRow->win = (*win);
+  *pResult = pResultRow;
+  setResultRowOutputBufInitCtx_rv(pBuf, pResultRow, pCtx, numOfOutput, rowCellInfoOffset);
+
+  return TSDB_CODE_SUCCESS;
+}
+
+
 static void setResultRowInterpo(SResultRow* pResult, SResultTsInterpType type) {
   assert(pResult != NULL && (type == RESULT_ROW_START_INTERP || type == RESULT_ROW_END_INTERP));
   if (type == RESULT_ROW_START_INTERP) {
@@ -871,48 +906,44 @@ static void doUpdateResultRowIndex(SResultRowInfo*pResultRowInfo, TSKEY lastKey,
   }
 }
 
-static void updateResultRowInfoActiveIndex(SResultRowInfo* pResultRowInfo, STaskAttr* pQueryAttr, TSKEY lastKey) {
-  bool ascQuery = QUERY_IS_ASC_QUERY(pQueryAttr);
-  if ((lastKey > pQueryAttr->window.ekey && ascQuery) || (lastKey < pQueryAttr->window.ekey && (!ascQuery))) {
+static void updateResultRowInfoActiveIndex(SResultRowInfo* pResultRowInfo, const STimeWindow* pWin, TSKEY lastKey, bool ascQuery, bool interp) {
+  if ((lastKey > pWin->ekey && ascQuery) || (lastKey < pWin->ekey && (!ascQuery))) {
     closeAllResultRows(pResultRowInfo);
     pResultRowInfo->curPos = pResultRowInfo->size - 1;
   } else {
     int32_t step = ascQuery ? 1 : -1;
-    doUpdateResultRowIndex(pResultRowInfo, lastKey - step, ascQuery, pQueryAttr->timeWindowInterpo);
+    doUpdateResultRowIndex(pResultRowInfo, lastKey - step, ascQuery, interp);
   }
 }
 
-static int32_t getNumOfRowsInTimeWindow(STaskRuntimeEnv* pRuntimeEnv, SDataBlockInfo *pDataBlockInfo, TSKEY *pPrimaryColumn,
-                                        int32_t startPos, TSKEY ekey, __block_search_fn_t searchFn, bool updateLastKey) {
+static int32_t getNumOfRowsInTimeWindow(SDataBlockInfo *pDataBlockInfo, TSKEY *pPrimaryColumn,
+                                        int32_t startPos, TSKEY ekey, __block_search_fn_t searchFn, STableQueryInfo* item, int32_t order) {
   assert(startPos >= 0 && startPos < pDataBlockInfo->rows);
-  STaskAttr* pQueryAttr = pRuntimeEnv->pQueryAttr;
-  STableQueryInfo* item = pRuntimeEnv->current;
 
   int32_t num   = -1;
-  int32_t order = pQueryAttr->order.order;
   int32_t step  = GET_FORWARD_DIRECTION_FACTOR(order);
 
-  if (QUERY_IS_ASC_QUERY(pQueryAttr)) {
+  if (order == TSDB_ORDER_ASC) {
     if (ekey < pDataBlockInfo->window.ekey && pPrimaryColumn) {
       num = getForwardStepsInBlock(pDataBlockInfo->rows, searchFn, ekey, startPos, order, pPrimaryColumn);
-      if (updateLastKey) { // update the last key
+      if (item != NULL) {
         item->lastKey = pPrimaryColumn[startPos + (num - 1)] + step;
       }
     } else {
       num = pDataBlockInfo->rows - startPos;
-      if (updateLastKey) {
+      if (item != NULL) {
         item->lastKey = pDataBlockInfo->window.ekey + step;
       }
     }
   } else {  // desc
     if (ekey > pDataBlockInfo->window.skey && pPrimaryColumn) {
       num = getForwardStepsInBlock(pDataBlockInfo->rows, searchFn, ekey, startPos, order, pPrimaryColumn);
-      if (updateLastKey) {  // update the last key
+      if (item != NULL) {
         item->lastKey = pPrimaryColumn[startPos - (num - 1)] + step;
       }
     } else {
       num = startPos + 1;
-      if (updateLastKey) {
+      if (item != NULL) {
         item->lastKey = pDataBlockInfo->window.skey + step;
       }
     }
@@ -922,22 +953,18 @@ static int32_t getNumOfRowsInTimeWindow(STaskRuntimeEnv* pRuntimeEnv, SDataBlock
   return num;
 }
 
-static void doApplyFunctions(STaskRuntimeEnv* pRuntimeEnv, SqlFunctionCtx* pCtx, STimeWindow* pWin, int32_t offset,
-                             int32_t forwardStep, TSKEY* tsCol, int32_t numOfTotal, int32_t numOfOutput) {
-  STaskAttr *pQueryAttr = pRuntimeEnv->pQueryAttr;
-  bool hasAggregates = pCtx[0].isAggSet;
-
+static void doApplyFunctions(SqlFunctionCtx* pCtx, STimeWindow* pWin, int32_t offset, int32_t forwardStep, TSKEY* tsCol,
+    int32_t numOfTotal, int32_t numOfOutput, int32_t order) {
   for (int32_t k = 0; k < numOfOutput; ++k) {
     pCtx[k].size    = forwardStep;
     pCtx[k].startTs = pWin->skey;
 
     // keep it temporarialy
-    char* start = pCtx[k].pInput;
+    int32_t startOffset = pCtx[k].startRow;
+    bool    hasAgg      = pCtx[k].isAggSet;
 
-    int32_t pos = (QUERY_IS_ASC_QUERY(pQueryAttr)) ? offset : offset - (forwardStep - 1);
-    if (pCtx[k].pInput != NULL) {
-      pCtx[k].pInput = (char *)pCtx[k].pInput + pos * pCtx[k].inputBytes;
-    }
+    int32_t pos = (order == TSDB_ORDER_ASC) ? offset : offset - (forwardStep - 1);
+    pCtx[k].startRow = pos;
 
     if (tsCol != NULL) {
       pCtx[k].ptsList = &tsCol[pos];
@@ -949,88 +976,80 @@ static void doApplyFunctions(STaskRuntimeEnv* pRuntimeEnv, SqlFunctionCtx* pCtx,
       pCtx[k].isAggSet = false;
     }
 
-    if (functionNeedToExecute(pRuntimeEnv, &pCtx[k])) {
+    if (functionNeedToExecute(&pCtx[k])) {
       pCtx[k].fpSet->addInput(&pCtx[k]);
     }
 
     // restore it
-    pCtx[k].isAggSet = hasAggregates;
-    pCtx[k].pInput = start;
+    pCtx[k].isAggSet = hasAgg;
+    pCtx[k].startRow = startOffset;
   }
 }
 
-static int32_t getNextQualifiedWindow(STaskAttr* pQueryAttr, STimeWindow* pNext, SDataBlockInfo* pDataBlockInfo,
-                                      TSKEY* primaryKeys, __block_search_fn_t searchFn, int32_t prevPosition) {
-  getNextTimeWindow(pQueryAttr, pNext);
+static int32_t getNextQualifiedWindow(SInterval* pInterval, STimeWindow* pNext, SDataBlockInfo* pDataBlockInfo,
+                                      TSKEY* primaryKeys, int32_t prevPosition, STableIntervalOperatorInfo* pInfo) {
+  int32_t order = pInfo->order;
+  bool    ascQuery  = (order == TSDB_ORDER_ASC);
+
+  int32_t precision = pInfo->precision;
+  getNextTimeWindow(pInterval, precision, order, pNext);
 
   // next time window is not in current block
-  if ((pNext->skey > pDataBlockInfo->window.ekey && QUERY_IS_ASC_QUERY(pQueryAttr)) ||
-      (pNext->ekey < pDataBlockInfo->window.skey && !QUERY_IS_ASC_QUERY(pQueryAttr))) {
+  if ((pNext->skey > pDataBlockInfo->window.ekey && order == TSDB_ORDER_ASC) ||
+      (pNext->ekey < pDataBlockInfo->window.skey && order == TSDB_ORDER_DESC)) {
     return -1;
   }
 
-  TSKEY startKey = -1;
-  if (QUERY_IS_ASC_QUERY(pQueryAttr)) {
-    startKey = pNext->skey;
-    if (startKey < pQueryAttr->window.skey) {
-      startKey = pQueryAttr->window.skey;
-    }
-  } else {
-    startKey = pNext->ekey;
-    if (startKey > pQueryAttr->window.skey) {
-      startKey = pQueryAttr->window.skey;
-    }
-  }
-
+  TSKEY startKey = ascQuery? pNext->skey:pNext->ekey;
   int32_t startPos = 0;
 
   // tumbling time window query, a special case of sliding time window query
-  if (pQueryAttr->interval.sliding == pQueryAttr->interval.interval && prevPosition != -1) {
-    int32_t factor = GET_FORWARD_DIRECTION_FACTOR(pQueryAttr->order.order);
+  if (pInterval->sliding == pInterval->interval && prevPosition != -1) {
+    int32_t factor = GET_FORWARD_DIRECTION_FACTOR(order);
     startPos = prevPosition + factor;
   } else {
-    if (startKey <= pDataBlockInfo->window.skey && QUERY_IS_ASC_QUERY(pQueryAttr)) {
+    if (startKey <= pDataBlockInfo->window.skey && ascQuery) {
       startPos = 0;
-    } else if (startKey >= pDataBlockInfo->window.ekey && !QUERY_IS_ASC_QUERY(pQueryAttr)) {
+    } else if (startKey >= pDataBlockInfo->window.ekey && !ascQuery) {
       startPos = pDataBlockInfo->rows - 1;
     } else {
-      startPos = searchFn((char *)primaryKeys, pDataBlockInfo->rows, startKey, pQueryAttr->order.order);
+      startPos = binarySearchForKey((char *)primaryKeys, pDataBlockInfo->rows, startKey, order);
     }
   }
 
   /* interp query with fill should not skip time window */
-  if (pQueryAttr->pointInterpQuery && pQueryAttr->fillType != TSDB_FILL_NONE) {
-    return startPos;
-  }
+//  if (pQueryAttr->pointInterpQuery && pQueryAttr->fillType != TSDB_FILL_NONE) {
+//    return startPos;
+//  }
 
   /*
    * This time window does not cover any data, try next time window,
    * this case may happen when the time window is too small
    */
   if (primaryKeys == NULL) {
-    if (QUERY_IS_ASC_QUERY(pQueryAttr)) {
+    if (ascQuery) {
       assert(pDataBlockInfo->window.skey <= pNext->ekey);
     } else {
       assert(pDataBlockInfo->window.ekey >= pNext->skey);
     }
   } else {
-    if (QUERY_IS_ASC_QUERY(pQueryAttr) && primaryKeys[startPos] > pNext->ekey) {
+    if (ascQuery && primaryKeys[startPos] > pNext->ekey) {
       TSKEY next = primaryKeys[startPos];
-      if (pQueryAttr->interval.intervalUnit == 'n' || pQueryAttr->interval.intervalUnit == 'y') {
-        pNext->skey = taosTimeTruncate(next, &pQueryAttr->interval, pQueryAttr->precision);
-        pNext->ekey = taosTimeAdd(pNext->skey, pQueryAttr->interval.interval, pQueryAttr->interval.intervalUnit, pQueryAttr->precision) - 1;
+      if (pInterval->intervalUnit == 'n' || pInterval->intervalUnit == 'y') {
+        pNext->skey = taosTimeTruncate(next, pInterval, precision);
+        pNext->ekey = taosTimeAdd(pNext->skey, pInterval->interval, pInterval->intervalUnit, precision) - 1;
       } else {
-        pNext->ekey += ((next - pNext->ekey + pQueryAttr->interval.sliding - 1)/pQueryAttr->interval.sliding) * pQueryAttr->interval.sliding;
-        pNext->skey = pNext->ekey - pQueryAttr->interval.interval + 1;
+        pNext->ekey += ((next - pNext->ekey + pInterval->sliding - 1)/pInterval->sliding) * pInterval->sliding;
+        pNext->skey = pNext->ekey - pInterval->interval + 1;
       }
-    } else if ((!QUERY_IS_ASC_QUERY(pQueryAttr)) && primaryKeys[startPos] < pNext->skey) {
+    } else if ((!ascQuery) && primaryKeys[startPos] < pNext->skey) {
       TSKEY next = primaryKeys[startPos];
-      if (pQueryAttr->interval.intervalUnit == 'n' || pQueryAttr->interval.intervalUnit == 'y') {
-        pNext->skey = taosTimeTruncate(next, &pQueryAttr->interval, pQueryAttr->precision);
-        pNext->ekey = taosTimeAdd(pNext->skey, pQueryAttr->interval.interval, pQueryAttr->interval.intervalUnit, pQueryAttr->precision) - 1;
+      if (pInterval->intervalUnit == 'n' || pInterval->intervalUnit == 'y') {
+        pNext->skey = taosTimeTruncate(next, pInterval, precision);
+        pNext->ekey = taosTimeAdd(pNext->skey, pInterval->interval, pInterval->intervalUnit, precision) - 1;
       } else {
-        pNext->skey -= ((pNext->skey - next + pQueryAttr->interval.sliding - 1) / pQueryAttr->interval.sliding) * pQueryAttr->interval.sliding;
-        pNext->ekey = pNext->skey + pQueryAttr->interval.interval - 1;
+        pNext->skey -= ((pNext->skey - next + pInterval->sliding - 1) / pInterval->sliding) * pInterval->sliding;
+        pNext->ekey = pNext->skey + pInterval->interval - 1;
       }
     }
   }
@@ -1067,23 +1086,19 @@ static void setNotInterpoWindowKey(SqlFunctionCtx* pCtx, int32_t numOfOutput, in
   }
 }
 
-static void saveDataBlockLastRow(STaskRuntimeEnv* pRuntimeEnv, SDataBlockInfo* pDataBlockInfo, SArray* pDataBlock,
-    int32_t rowIndex) {
+static void saveDataBlockLastRow(char** pRow, SArray* pDataBlock, int32_t rowIndex, int32_t numOfCols) {
   if (pDataBlock == NULL) {
     return;
   }
 
-  STaskAttr* pQueryAttr = pRuntimeEnv->pQueryAttr;
-  for (int32_t k = 0; k < pQueryAttr->numOfCols; ++k) {
+  for (int32_t k = 0; k < numOfCols; ++k) {
     SColumnInfoData *pColInfo = taosArrayGet(pDataBlock, k);
-    memcpy(pRuntimeEnv->prevRow[k], ((char*)pColInfo->pData) + (pColInfo->info.bytes * rowIndex), pColInfo->info.bytes);
+    memcpy(pRow[k], ((char*)pColInfo->pData) + (pColInfo->info.bytes * rowIndex), pColInfo->info.bytes);
   }
 }
 
-static TSKEY getStartTsKey(STaskAttr* pQueryAttr, STimeWindow* win, const TSKEY* tsCols, int32_t rows) {
+static TSKEY getStartTsKey(STimeWindow* win, const TSKEY* tsCols, int32_t rows, bool ascQuery) {
   TSKEY ts = TSKEY_INITIAL_VAL;
-
-  bool ascQuery = QUERY_IS_ASC_QUERY(pQueryAttr);
   if (tsCols == NULL) {
     ts = ascQuery? win->skey : win->ekey;
   } else {
@@ -1151,7 +1166,7 @@ static void doSetInputDataBlock(SOperatorInfo* pOperator, SqlFunctionCtx* pCtx,
 
         SColumnInfoData* p = taosArrayGet(pBlock->pDataBlock, pCtx[i].columnIndex);
         // in case of the block distribution query, the inputBytes is not a constant value.
-        pCtx[i].pInput = p->pData;
+        pCtx[i].pInput = p;
         assert(p->info.colId == pCol->info.colId);
 
         if (pCtx[i].functionId < 0) {
@@ -1163,14 +1178,14 @@ static void doSetInputDataBlock(SOperatorInfo* pOperator, SqlFunctionCtx* pCtx,
 
 //        uint32_t status = aAggs[pCtx[i].functionId].status;
 //        if ((status & (FUNCSTATE_SELECTIVITY | FUNCSTATE_NEED_TS)) != 0) {
-          SColumnInfoData* tsInfo = taosArrayGet(pBlock->pDataBlock, 0);
+//          SColumnInfoData* tsInfo = taosArrayGet(pBlock->pDataBlock, 0);
           // In case of the top/bottom query again the nest query result, which has no timestamp column
           // don't set the ptsList attribute.
-          if (tsInfo->info.type == TSDB_DATA_TYPE_TIMESTAMP) {
-            pCtx[i].ptsList = (int64_t*) tsInfo->pData;
-          } else {
-            pCtx[i].ptsList = NULL;
-          }
+//          if (tsInfo->info.type == TSDB_DATA_TYPE_TIMESTAMP) {
+//            pCtx[i].ptsList = (int64_t*) tsInfo->pData;
+//          } else {
+//            pCtx[i].ptsList = NULL;
+//          }
 //        }
 //      } else if (TSDB_COL_IS_UD_COL(pCol->flag) && (pOperator->pRuntimeEnv->scanFlag == MERGE_STAGE)) {
 //        SColIndex*       pColIndex = &pOperator->pExpr[i].base.colInfo;
@@ -1189,7 +1204,7 @@ static void doSetInputDataBlock(SOperatorInfo* pOperator, SqlFunctionCtx* pCtx,
 
 static void doAggregateImpl(SOperatorInfo* pOperator, TSKEY startTs, SqlFunctionCtx* pCtx, SSDataBlock* pSDataBlock) {
   for (int32_t k = 0; k < pOperator->numOfOutput; ++k) {
-    if (functionNeedToExecute(NULL, &pCtx[k])) {
+    if (functionNeedToExecute(&pCtx[k])) {
       pCtx[k].startTs = startTs;// this can be set during create the struct
       pCtx[k].fpSet->addInput(&pCtx[k]);
     }
@@ -1348,20 +1363,19 @@ static bool setTimeWindowInterpolationEndTs(SOperatorInfo* pOperatorInfo, SqlFun
 }
 
 static void doWindowBorderInterpolation(SOperatorInfo* pOperatorInfo, SSDataBlock* pBlock, SqlFunctionCtx* pCtx,
-    SResultRow* pResult, STimeWindow* win, int32_t startPos, int32_t forwardStep) {
-  STaskRuntimeEnv* pRuntimeEnv = pOperatorInfo->pRuntimeEnv;
-  STaskAttr* pQueryAttr = pRuntimeEnv->pQueryAttr;
-  if (!pQueryAttr->timeWindowInterpo) {
+    SResultRow* pResult, STimeWindow* win, int32_t startPos, int32_t forwardStep, int32_t order, bool timeWindowInterpo) {
+  if (!timeWindowInterpo) {
     return;
   }
 
   assert(pBlock != NULL);
-  int32_t step = GET_FORWARD_DIRECTION_FACTOR(pQueryAttr->order.order);
+  int32_t step = GET_FORWARD_DIRECTION_FACTOR(order);
 
   if (pBlock->pDataBlock == NULL){
 //    tscError("pBlock->pDataBlock == NULL");
     return;
   }
+
   SColumnInfoData *pColInfo = taosArrayGet(pBlock->pDataBlock, 0);
 
   TSKEY  *tsCols = (TSKEY *)(pColInfo->pData);
@@ -1374,38 +1388,37 @@ static void doWindowBorderInterpolation(SOperatorInfo* pOperatorInfo, SSDataBloc
       setResultRowInterpo(pResult, RESULT_ROW_START_INTERP);
     }
   } else {
-    setNotInterpoWindowKey(pCtx, pQueryAttr->numOfOutput, RESULT_ROW_START_INTERP);
+    setNotInterpoWindowKey(pCtx, pOperatorInfo->numOfOutput, RESULT_ROW_START_INTERP);
   }
 
   // point interpolation does not require the end key time window interpolation.
-  if (pQueryAttr->pointInterpQuery) {
-    return;
-  }
+//  if (pointInterpQuery) {
+//    return;
+//  }
 
   // interpolation query does not generate the time window end interpolation
   done = resultRowInterpolated(pResult, RESULT_ROW_END_INTERP);
   if (!done) {
     int32_t endRowIndex = startPos + (forwardStep - 1) * step;
 
-    TSKEY endKey = QUERY_IS_ASC_QUERY(pQueryAttr)? pBlock->info.window.ekey:pBlock->info.window.skey;
+    TSKEY endKey = (order == TSDB_ORDER_ASC)? pBlock->info.window.ekey:pBlock->info.window.skey;
     bool  interp = setTimeWindowInterpolationEndTs(pOperatorInfo, pCtx, endRowIndex, pBlock->pDataBlock, tsCols, endKey, win);
     if (interp) {
       setResultRowInterpo(pResult, RESULT_ROW_END_INTERP);
     }
   } else {
-    setNotInterpoWindowKey(pCtx, pQueryAttr->numOfOutput, RESULT_ROW_END_INTERP);
+    setNotInterpoWindowKey(pCtx, pOperatorInfo->numOfOutput, RESULT_ROW_END_INTERP);
   }
 }
 
 static void hashIntervalAgg(SOperatorInfo* pOperatorInfo, SResultRowInfo* pResultRowInfo, SSDataBlock* pSDataBlock, int32_t tableGroupId) {
   STableIntervalOperatorInfo* pInfo = (STableIntervalOperatorInfo*) pOperatorInfo->info;
 
-  STaskRuntimeEnv* pRuntimeEnv = pOperatorInfo->pRuntimeEnv;
-  int32_t           numOfOutput = pOperatorInfo->numOfOutput;
-  STaskAttr*       pQueryAttr = pRuntimeEnv->pQueryAttr;
+  SExecTaskInfo* pTaskInfo = pOperatorInfo->pTaskInfo;
+  int32_t numOfOutput = pOperatorInfo->numOfOutput;
 
-  int32_t step = GET_FORWARD_DIRECTION_FACTOR(pQueryAttr->order.order);
-  bool ascQuery = QUERY_IS_ASC_QUERY(pQueryAttr);
+  int32_t step = 1;
+  bool ascQuery = true;
 
   int32_t prevIndex = pResultRowInfo->curPos;
 
@@ -1418,26 +1431,26 @@ static void hashIntervalAgg(SOperatorInfo* pOperatorInfo, SResultRowInfo* pResul
   }
 
   int32_t startPos = ascQuery? 0 : (pSDataBlock->info.rows - 1);
-  TSKEY ts = getStartTsKey(pQueryAttr, &pSDataBlock->info.window, tsCols, pSDataBlock->info.rows);
+  TSKEY ts = getStartTsKey(&pSDataBlock->info.window, tsCols, pSDataBlock->info.rows, ascQuery);
 
-  STimeWindow win = getActiveTimeWindow(pResultRowInfo, ts, pQueryAttr);
-  bool masterScan = IS_MAIN_SCAN(pRuntimeEnv);
+  STimeWindow win = getActiveTimeWindow(pResultRowInfo, ts, &pInfo->interval, pInfo->precision, &pInfo->win);
+  bool masterScan = true;
 
   SResultRow* pResult = NULL;
-  int32_t ret = setResultOutputBufByKey(pRuntimeEnv, pResultRowInfo, pSDataBlock->info.uid, &win, masterScan, &pResult, tableGroupId, pInfo->pCtx,
-                                        numOfOutput, pInfo->rowCellInfoOffset);
+  int32_t ret = setResultOutputBufByKey_rv(pResultRowInfo, pSDataBlock->info.uid, &win, masterScan, &pResult, tableGroupId, pInfo->binfo.pCtx,
+                                        numOfOutput, pInfo->binfo.rowCellInfoOffset, pInfo->pResultBuf, &pInfo->aggSup, pTaskInfo);
   if (ret != TSDB_CODE_SUCCESS || pResult == NULL) {
-    longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
+    longjmp(pTaskInfo->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
   }
 
   int32_t forwardStep = 0;
-  TSKEY   ekey = reviseWindowEkey(pQueryAttr, &win);
+  TSKEY   ekey = win.ekey;
   forwardStep =
-      getNumOfRowsInTimeWindow(pRuntimeEnv, &pSDataBlock->info, tsCols, startPos, ekey, binarySearchForKey, true);
+      getNumOfRowsInTimeWindow(&pSDataBlock->info, tsCols, startPos, ekey, binarySearchForKey, NULL, TSDB_ORDER_ASC);
 
   // prev time window not interpolation yet.
   int32_t curIndex = pResultRowInfo->curPos;
-  if (prevIndex != -1 && prevIndex < curIndex && pQueryAttr->timeWindowInterpo) {
+  if (prevIndex != -1 && prevIndex < curIndex && pInfo->timeWindowInterpo) {
     for (int32_t j = prevIndex; j < curIndex; ++j) {  // previous time window may be all closed already.
       SResultRow* pRes = getResultRow(pResultRowInfo, j);
       if (pRes->closed) {
@@ -1446,64 +1459,64 @@ static void hashIntervalAgg(SOperatorInfo* pOperatorInfo, SResultRowInfo* pResul
       }
 
         STimeWindow w = pRes->win;
-        ret = setResultOutputBufByKey(pRuntimeEnv, pResultRowInfo, pSDataBlock->info.uid, &w, masterScan, &pResult,
-                                      tableGroupId, pInfo->pCtx, numOfOutput, pInfo->rowCellInfoOffset);
+        ret = setResultOutputBufByKey_rv(pResultRowInfo, pSDataBlock->info.uid, &w, masterScan, &pResult,
+                                      tableGroupId, pInfo->binfo.pCtx, numOfOutput, pInfo->binfo.rowCellInfoOffset, pInfo->pResultBuf, &pInfo->aggSup, pTaskInfo);
         if (ret != TSDB_CODE_SUCCESS) {
-          longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
+          longjmp(pTaskInfo->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
         }
 
         assert(!resultRowInterpolated(pResult, RESULT_ROW_END_INTERP));
 
-        doTimeWindowInterpolation(pOperatorInfo, pInfo, pSDataBlock->pDataBlock, *(TSKEY*)pRuntimeEnv->prevRow[0], -1,
+        doTimeWindowInterpolation(pOperatorInfo, &pInfo->binfo, pSDataBlock->pDataBlock, *(TSKEY*)pInfo->pRow[0], -1,
                                   tsCols[startPos], startPos, w.ekey, RESULT_ROW_END_INTERP);
 
         setResultRowInterpo(pResult, RESULT_ROW_END_INTERP);
-        setNotInterpoWindowKey(pInfo->pCtx, pQueryAttr->numOfOutput, RESULT_ROW_START_INTERP);
+        setNotInterpoWindowKey(pInfo->binfo.pCtx, pOperatorInfo->numOfOutput, RESULT_ROW_START_INTERP);
 
-        doApplyFunctions(pRuntimeEnv, pInfo->pCtx, &w, startPos, 0, tsCols, pSDataBlock->info.rows, numOfOutput);
+        doApplyFunctions(pInfo->binfo.pCtx, &w, startPos, 0, tsCols, pSDataBlock->info.rows, numOfOutput, TSDB_ORDER_ASC);
       }
 
     // restore current time window
-    ret = setResultOutputBufByKey(pRuntimeEnv, pResultRowInfo, pSDataBlock->info.uid, &win, masterScan, &pResult, tableGroupId, pInfo->pCtx,
-                                  numOfOutput, pInfo->rowCellInfoOffset);
+    ret = setResultOutputBufByKey_rv(pResultRowInfo, pSDataBlock->info.uid, &win, masterScan, &pResult, tableGroupId, pInfo->binfo.pCtx,
+                                  numOfOutput, pInfo->binfo.rowCellInfoOffset, pInfo->pResultBuf, &pInfo->aggSup, pTaskInfo);
     if (ret != TSDB_CODE_SUCCESS) {
-      longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
+      longjmp(pTaskInfo->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
     }
   }
 
   // window start key interpolation
-  doWindowBorderInterpolation(pOperatorInfo, pSDataBlock, pInfo->pCtx, pResult, &win, startPos, forwardStep);
-  doApplyFunctions(pRuntimeEnv, pInfo->pCtx, &win, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput);
+  doWindowBorderInterpolation(pOperatorInfo, pSDataBlock, pInfo->binfo.pCtx, pResult, &win, startPos, forwardStep, pInfo->order, false);
+  doApplyFunctions(pInfo->binfo.pCtx, &win, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput, TSDB_ORDER_ASC);
 
   STimeWindow nextWin = win;
   while (1) {
     int32_t prevEndPos = (forwardStep - 1) * step + startPos;
-    startPos = getNextQualifiedWindow(pQueryAttr, &nextWin, &pSDataBlock->info, tsCols, binarySearchForKey, prevEndPos);
+    startPos = getNextQualifiedWindow(&pInfo->interval, &nextWin, &pSDataBlock->info, tsCols, prevEndPos, pInfo);
     if (startPos < 0) {
       break;
     }
 
     // null data, failed to allocate more memory buffer
-    int32_t code = setResultOutputBufByKey(pRuntimeEnv, pResultRowInfo, pSDataBlock->info.uid, &nextWin, masterScan, &pResult, tableGroupId,
-                                           pInfo->pCtx, numOfOutput, pInfo->rowCellInfoOffset);
+    int32_t code = setResultOutputBufByKey_rv(pResultRowInfo, pSDataBlock->info.uid, &nextWin, masterScan, &pResult, tableGroupId,
+                                           pInfo->binfo.pCtx, numOfOutput, pInfo->binfo.rowCellInfoOffset, pInfo->pResultBuf, &pInfo->aggSup, pTaskInfo);
     if (code != TSDB_CODE_SUCCESS || pResult == NULL) {
-      longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
+      longjmp(pTaskInfo->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
     }
 
-    ekey = reviseWindowEkey(pQueryAttr, &nextWin);
-    forwardStep = getNumOfRowsInTimeWindow(pRuntimeEnv, &pSDataBlock->info, tsCols, startPos, ekey, binarySearchForKey, true);
+    ekey = nextWin.ekey;//reviseWindowEkey(pQueryAttr, &nextWin);
+    forwardStep = getNumOfRowsInTimeWindow(&pSDataBlock->info, tsCols, startPos, ekey, binarySearchForKey, NULL, TSDB_ORDER_ASC);
 
     // window start(end) key interpolation
-    doWindowBorderInterpolation(pOperatorInfo, pSDataBlock, pInfo->pCtx, pResult, &nextWin, startPos, forwardStep);
-    doApplyFunctions(pRuntimeEnv, pInfo->pCtx, &nextWin, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput);
+    doWindowBorderInterpolation(pOperatorInfo, pSDataBlock, pInfo->binfo.pCtx, pResult, &nextWin, startPos, forwardStep, pInfo->order, false);
+    doApplyFunctions(pInfo->binfo.pCtx, &nextWin, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput, TSDB_ORDER_ASC);
   }
 
-  if (pQueryAttr->timeWindowInterpo) {
+  if (pInfo->timeWindowInterpo) {
     int32_t rowIndex = ascQuery? (pSDataBlock->info.rows-1):0;
-    saveDataBlockLastRow(pRuntimeEnv, &pSDataBlock->info, pSDataBlock->pDataBlock, rowIndex);
+    saveDataBlockLastRow(pInfo->pRow, pSDataBlock->pDataBlock, rowIndex, pSDataBlock->info.numOfCols);
   }
 
-  updateResultRowInfoActiveIndex(pResultRowInfo, pQueryAttr, pRuntimeEnv->current->lastKey);
+//  updateResultRowInfoActiveIndex(pResultRowInfo, &pInfo->win, pRuntimeEnv->current->lastKey, true, false);
 }
 
 
@@ -1526,7 +1539,7 @@ static void hashAllIntervalAgg(SOperatorInfo* pOperatorInfo, SResultRowInfo* pRe
   }
 
   int32_t startPos = ascQuery? 0 : (pSDataBlock->info.rows - 1);
-  TSKEY ts = getStartTsKey(pQueryAttr, &pSDataBlock->info.window, tsCols, pSDataBlock->info.rows);
+  TSKEY ts = getStartTsKey(&pSDataBlock->info.window, tsCols, pSDataBlock->info.rows, ascQuery);
 
   STimeWindow win = getCurrentActiveTimeWindow(pResultRowInfo, ts, pQueryAttr);
   bool masterScan = IS_MAIN_SCAN(pRuntimeEnv);
@@ -1539,25 +1552,25 @@ static void hashAllIntervalAgg(SOperatorInfo* pOperatorInfo, SResultRowInfo* pRe
   while (1) {
     // null data, failed to allocate more memory buffer
     ret = setResultOutputBufByKey(pRuntimeEnv, pResultRowInfo, pSDataBlock->info.uid, &win, masterScan, &pResult,
-                                  tableGroupId, pInfo->pCtx, numOfOutput, pInfo->rowCellInfoOffset);
+                                  tableGroupId, pInfo->binfo.pCtx, numOfOutput, pInfo->binfo.rowCellInfoOffset);
     if (ret != TSDB_CODE_SUCCESS) {
       longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
     }
 
     TSKEY   ekey = reviseWindowEkey(pQueryAttr, &win);
-    forwardStep = getNumOfRowsInTimeWindow(pRuntimeEnv, &pSDataBlock->info, tsCols, startPos, ekey, binarySearchForKey, true);
+//    forwardStep = getNumOfRowsInTimeWindow(pRuntimeEnv, &pSDataBlock->info, tsCols, startPos, ekey, binarySearchForKey, true);
 
     // window start(end) key interpolation
-    doWindowBorderInterpolation(pOperatorInfo, pSDataBlock, pInfo->pCtx, pResult, &win, startPos, forwardStep);
-    doApplyFunctions(pRuntimeEnv, pInfo->pCtx, ascQuery ? &win : &preWin, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput);
+//    doWindowBorderInterpolation(pOperatorInfo, pSDataBlock, pInfo->binfo.pCtx, pResult, &win, startPos, forwardStep);
+//    doApplyFunctions(pRuntimeEnv, pInfo->binfo.pCtx, ascQuery ? &win : &preWin, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput);
     preWin = win;
 
     int32_t prevEndPos = (forwardStep - 1) * step + startPos;
-    startPos = getNextQualifiedWindow(pQueryAttr, &win, &pSDataBlock->info, tsCols, binarySearchForKey, prevEndPos);
+//    startPos = getNextQualifiedWindow(pQueryAttr, &win, &pSDataBlock->info, tsCols, binarySearchForKey, prevEndPos);
     if (startPos < 0) {
       if ((ascQuery && win.skey <= pQueryAttr->window.ekey) || ((!ascQuery) && win.ekey >= pQueryAttr->window.ekey)) {
         int32_t code = setResultOutputBufByKey(pRuntimeEnv, pResultRowInfo, pSDataBlock->info.uid, &win, masterScan, &pResult, tableGroupId,
-                                               pInfo->pCtx, numOfOutput, pInfo->rowCellInfoOffset);
+                                               pInfo->binfo.pCtx, numOfOutput, pInfo->binfo.rowCellInfoOffset);
         if (code != TSDB_CODE_SUCCESS || pResult == NULL) {
           longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
         }
@@ -1565,8 +1578,8 @@ static void hashAllIntervalAgg(SOperatorInfo* pOperatorInfo, SResultRowInfo* pRe
         startPos = pSDataBlock->info.rows - 1;
 
         // window start(end) key interpolation
-        doWindowBorderInterpolation(pOperatorInfo, pSDataBlock, pInfo->pCtx, pResult, &win, startPos, forwardStep);
-        doApplyFunctions(pRuntimeEnv, pInfo->pCtx, ascQuery ? &win : &preWin, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput);
+//        doWindowBorderInterpolation(pOperatorInfo, pSDataBlock, pInfo->binfo.pCtx, pResult, &win, startPos, forwardStep);
+//        doApplyFunctions(pRuntimeEnv, pInfo->binfo.pCtx, ascQuery ? &win : &preWin, startPos, forwardStep, tsCols, pSDataBlock->info.rows, numOfOutput);
       }
 
       break;
@@ -1576,10 +1589,10 @@ static void hashAllIntervalAgg(SOperatorInfo* pOperatorInfo, SResultRowInfo* pRe
 
   if (pQueryAttr->timeWindowInterpo) {
     int32_t rowIndex = ascQuery? (pSDataBlock->info.rows-1):0;
-    saveDataBlockLastRow(pRuntimeEnv, &pSDataBlock->info, pSDataBlock->pDataBlock, rowIndex);
+//    saveDataBlockLastRow(pRuntimeEnv, &pSDataBlock->info, pSDataBlock->pDataBlock, rowIndex);
   }
 
-  updateResultRowInfoActiveIndex(pResultRowInfo, pQueryAttr, pRuntimeEnv->current->lastKey);
+//  updateResultRowInfoActiveIndex(pResultRowInfo, pQueryAttr, pRuntimeEnv->current->lastKey);
 }
 
 
@@ -1641,7 +1654,7 @@ static void doHashGroupbyAgg(SOperatorInfo* pOperator, SGroupbyOperatorInfo *pIn
       longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_APP_ERROR);
     }
 
-    doApplyFunctions(pRuntimeEnv, pInfo->binfo.pCtx, &w, j - num, num, tsList, pSDataBlock->info.rows, pOperator->numOfOutput);
+//    doApplyFunctions(pRuntimeEnv, pInfo->binfo.pCtx, &w, j - num, num, tsList, pSDataBlock->info.rows, pOperator->numOfOutput);
 
     num = 1;
     memcpy(pInfo->prevData, val, bytes);
@@ -1660,7 +1673,7 @@ static void doHashGroupbyAgg(SOperatorInfo* pOperator, SGroupbyOperatorInfo *pIn
       longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_APP_ERROR);
     }
 
-    doApplyFunctions(pRuntimeEnv, pInfo->binfo.pCtx, &w, pSDataBlock->info.rows - num, num, tsList, pSDataBlock->info.rows, pOperator->numOfOutput);
+//    doApplyFunctions(pRuntimeEnv, pInfo->binfo.pCtx, &w, pSDataBlock->info.rows - num, num, tsList, pSDataBlock->info.rows, pOperator->numOfOutput);
   }
 
   tfree(pInfo->prevData);
@@ -1710,8 +1723,8 @@ static void doSessionWindowAggImpl(SOperatorInfo* pOperator, SSWindowOperatorInf
         longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_APP_ERROR);
       }
 
-      doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, pInfo->start, pInfo->numOfRows, tsList,
-                       pSDataBlock->info.rows, pOperator->numOfOutput);
+//      doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, pInfo->start, pInfo->numOfRows, tsList,
+//                       pSDataBlock->info.rows, pOperator->numOfOutput);
 
       pInfo->curWindow.skey = tsList[j];
       pInfo->curWindow.ekey = tsList[j];
@@ -1731,8 +1744,8 @@ static void doSessionWindowAggImpl(SOperatorInfo* pOperator, SSWindowOperatorInf
     longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_APP_ERROR);
   }
 
-  doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, pInfo->start, pInfo->numOfRows, tsList,
-                   pSDataBlock->info.rows, pOperator->numOfOutput);
+//  doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, pInfo->start, pInfo->numOfRows, tsList,
+//                   pSDataBlock->info.rows, pOperator->numOfOutput);
 }
 
 static void setResultRowKey(SResultRow* pResultRow, char* pData, int16_t type) {
@@ -1806,7 +1819,7 @@ static int32_t getGroupbyColumnIndex(SGroupbyExpr *pGroupbyExpr, SSDataBlock* pD
   return -1;
 }
 
-static bool functionNeedToExecute(STaskRuntimeEnv *pRuntimeEnv, SqlFunctionCtx *pCtx) {
+static bool functionNeedToExecute(SqlFunctionCtx *pCtx) {
   struct SResultRowEntryInfo *pResInfo = GET_RES_INFO(pCtx);
 
   // in case of timestamp column, always generated results.
@@ -2046,6 +2059,10 @@ static SqlFunctionCtx* createSqlFunctionCtx_rv(SArray* pExprInfo, int32_t** rowC
     pCtx->resDataInfo.type   = pSqlExpr->resSchema.type;
 
     pCtx->order        = TSDB_ORDER_ASC;
+    if (i == 0) {
+      pCtx->functionId = FUNCTION_TS;
+    }
+
 //    pCtx->functionId   = pSqlExpr->functionId;
 //    pCtx->stableQuery  = pQueryAttr->stableQuery;
     pCtx->resDataInfo.intermediateBytes = pSqlExpr->interBytes;
@@ -2214,7 +2231,7 @@ static void teardownQueryRuntimeEnv(STaskRuntimeEnv *pRuntimeEnv) {
 
   //destroyScalarFuncSupport(pRuntimeEnv->scalarSup, pQueryAttr->numOfOutput);
 //  destroyUdfInfo(pRuntimeEnv->pUdfInfo);
-  destroyResultBuf(pRuntimeEnv->pResultBuf);
+  destroyDiskbasedBuf(pRuntimeEnv->pResultBuf);
   doFreeQueryHandle(pRuntimeEnv);
 
   destroyTsComp(pRuntimeEnv, pQueryAttr);
@@ -2340,46 +2357,23 @@ static bool isCachedLastQuery(STaskAttr *pQueryAttr) {
   return true;
 }
 
-
-
-/**
- * The following 4 kinds of query are treated as the tags query
- * tagprj, tid_tag query, count(tbname), 'abc' (user defined constant value column) query
- */
-bool onlyQueryTags(STaskAttr* pQueryAttr) {
-  for(int32_t i = 0; i < pQueryAttr->numOfOutput; ++i) {
-    SExprInfo* pExprInfo = &pQueryAttr->pExpr1[i];
-
-    int32_t functionId = getExprFunctionId(pExprInfo);
-
-    if (functionId != FUNCTION_TAGPRJ &&
-        functionId != FUNCTION_TID_TAG &&
-        (!(functionId == FUNCTION_COUNT && pExprInfo->base.pColumns->info.colId == TSDB_TBNAME_COLUMN_INDEX)) &&
-        (!(functionId == FUNCTION_PRJ && TSDB_COL_IS_UD_COL(pExprInfo->base.pColumns->flag)))) {
-      return false;
-    }
-  }
-
-  return true;
-}
-
 /////////////////////////////////////////////////////////////////////////////////////////////
-
-void getAlignQueryTimeWindow(STaskAttr *pQueryAttr, int64_t key, int64_t keyFirst, int64_t keyLast, STimeWindow *win) {
-  assert(key >= keyFirst && key <= keyLast && pQueryAttr->interval.sliding <= pQueryAttr->interval.interval);
-  win->skey = taosTimeTruncate(key, &pQueryAttr->interval, pQueryAttr->precision);
+//todo refactor : return window
+void getAlignQueryTimeWindow(SInterval* pInterval, int32_t precision, int64_t key, int64_t keyFirst, int64_t keyLast, STimeWindow *win) {
+  assert(key >= keyFirst && key <= keyLast && pInterval->sliding <= pInterval->interval);
+  win->skey = taosTimeTruncate(key, pInterval, precision);
 
   /*
-   * if the realSkey > INT64_MAX - pQueryAttr->interval.interval, the query duration between
+   * if the realSkey > INT64_MAX - pInterval->interval, the query duration between
    * realSkey and realEkey must be less than one interval.Therefore, no need to adjust the query ranges.
    */
-  if (keyFirst > (INT64_MAX - pQueryAttr->interval.interval)) {
-    assert(keyLast - keyFirst < pQueryAttr->interval.interval);
+  if (keyFirst > (INT64_MAX - pInterval->interval)) {
+    assert(keyLast - keyFirst < pInterval->interval);
     win->ekey = INT64_MAX;
-  } else if (pQueryAttr->interval.intervalUnit == 'n' || pQueryAttr->interval.intervalUnit == 'y') {
-    win->ekey = taosTimeAdd(win->skey, pQueryAttr->interval.interval, pQueryAttr->interval.intervalUnit, pQueryAttr->precision) - 1;
+  } else if (pInterval->intervalUnit == 'n' || pInterval->intervalUnit == 'y') {
+    win->ekey = taosTimeAdd(win->skey, pInterval->interval, pInterval->intervalUnit, precision) - 1;
   } else {
-    win->ekey = win->skey + pQueryAttr->interval.interval - 1;
+    win->ekey = win->skey + pInterval->interval - 1;
   }
 }
 
@@ -2605,7 +2599,7 @@ static bool overlapWithTimeWindow(STaskAttr* pQueryAttr, SDataBlockInfo* pBlockI
   TSKEY ek = TMAX(pQueryAttr->window.skey, pQueryAttr->window.ekey);
 
   if (QUERY_IS_ASC_QUERY(pQueryAttr)) {
-    getAlignQueryTimeWindow(pQueryAttr, pBlockInfo->window.skey, sk, ek, &w);
+//    getAlignQueryTimeWindow(pQueryAttr, pBlockInfo->window.skey, sk, ek, &w);
     assert(w.ekey >= pBlockInfo->window.skey);
 
     if (w.ekey < pBlockInfo->window.ekey) {
@@ -2613,7 +2607,7 @@ static bool overlapWithTimeWindow(STaskAttr* pQueryAttr, SDataBlockInfo* pBlockI
     }
 
     while(1) {
-      getNextTimeWindow(pQueryAttr, &w);
+//      getNextTimeWindow(pQueryAttr, &w);
       if (w.skey > pBlockInfo->window.ekey) {
         break;
       }
@@ -2624,7 +2618,7 @@ static bool overlapWithTimeWindow(STaskAttr* pQueryAttr, SDataBlockInfo* pBlockI
       }
     }
   } else {
-    getAlignQueryTimeWindow(pQueryAttr, pBlockInfo->window.ekey, sk, ek, &w);
+//    getAlignQueryTimeWindow(pQueryAttr, pBlockInfo->window.ekey, sk, ek, &w);
     assert(w.skey <= pBlockInfo->window.ekey);
 
     if (w.skey > pBlockInfo->window.skey) {
@@ -2632,7 +2626,7 @@ static bool overlapWithTimeWindow(STaskAttr* pQueryAttr, SDataBlockInfo* pBlockI
     }
 
     while(1) {
-      getNextTimeWindow(pQueryAttr, &w);
+//      getNextTimeWindow(pQueryAttr, &w);
       if (w.ekey < pBlockInfo->window.skey) {
         break;
       }
@@ -2863,8 +2857,6 @@ void filterColRowsInDataBlock(STaskRuntimeEnv* pRuntimeEnv, SSDataBlock* pBlock,
  tfree(p);
 }
 
-                           
-
 static SColumnInfo* doGetTagColumnInfoById(SColumnInfo* pTagColList, int32_t numOfTags, int16_t colId);
 static void doSetTagValueInParam(void* pTable, int32_t tagColId, SVariant *tag, int16_t type, int16_t bytes);
 
@@ -3379,10 +3371,8 @@ void setDefaultOutputBuf(STaskRuntimeEnv *pRuntimeEnv, SOptrBasicInfo *pInfo, in
 
   initCtxOutputBuffer(pCtx, pDataBlock->info.numOfCols);
 }
-
-void setDefaultOutputBuf_rv(SAggOperatorInfo* pAggInfo, int32_t stage, SExecTaskInfo* pTaskInfo) {
-  SOptrBasicInfo *pInfo = &pAggInfo->binfo;
-
+// TODO refactor: some function move away
+void setDefaultOutputBuf_rv(SOptrBasicInfo* pInfo, SAggSupporter* pSup, int32_t stage, SExecTaskInfo* pTaskInfo) {
   SqlFunctionCtx* pCtx           = pInfo->pCtx;
   SSDataBlock* pDataBlock        = pInfo->pRes;
   int32_t* rowCellInfoOffset     = pInfo->rowCellInfoOffset;
@@ -3390,9 +3380,7 @@ void setDefaultOutputBuf_rv(SAggOperatorInfo* pAggInfo, int32_t stage, SExecTask
 
   int64_t tid = 0;
   int64_t groupId = 0;
-
-  pAggInfo->keyBuf = realloc(pAggInfo->keyBuf, sizeof(tid) + sizeof(int64_t) + POINTER_BYTES);
-  SResultRow* pRow = doSetResultOutBufByKey_rv(pResultRowInfo, tid, (char *)&tid, sizeof(tid), true, groupId, pTaskInfo, false, pAggInfo);
+  SResultRow* pRow = doSetResultOutBufByKey_rv(pResultRowInfo, tid, (char *)&tid, sizeof(tid), true, groupId, pTaskInfo, false, pSup);
 
   for (int32_t i = 0; i < pDataBlock->info.numOfCols; ++i) {
     SColumnInfoData* pData = taosArrayGet(pDataBlock->pDataBlock, i);
@@ -3540,9 +3528,6 @@ static void setupEnvForReverseScan(STableScanInfo *pTableScanInfo, SqlFunctionCt
 }
 
 void finalizeQueryResult(SOperatorInfo* pOperator, SqlFunctionCtx* pCtx, SResultRowInfo* pResultRowInfo, int32_t* rowCellInfoOffset) {
-  STaskRuntimeEnv *pRuntimeEnv = pOperator->pRuntimeEnv;
-//  STaskAttr *pQueryAttr = pRuntimeEnv->pQueryAttr;
-
   int32_t numOfOutput = pOperator->numOfOutput;
 //  if (pQueryAttr->groupbyColumn || QUERY_IS_INTERVAL_QUERY(pQueryAttr) || pQueryAttr->sw.gap > 0 || pQueryAttr->stateWindow) {
 //    // for each group result, call the finalize function for each column
@@ -3605,7 +3590,7 @@ STableQueryInfo *createTableQueryInfo(void* buf, bool groupbyColumn, STimeWindow
   // set more initial size of interval/groupby query
 //  if (/*QUERY_IS_INTERVAL_QUERY(pQueryAttr) || */groupbyColumn) {
     int32_t initialSize = 128;
-    int32_t code = initResultRowInfo(&pTableQueryInfo->resInfo, initialSize, TSDB_DATA_TYPE_INT);
+    int32_t code = initResultRowInfo(&pTableQueryInfo->resInfo, initialSize);
     if (code != TSDB_CODE_SUCCESS) {
       return NULL;
     }
@@ -3623,7 +3608,7 @@ STableQueryInfo* createTmpTableQueryInfo(STimeWindow win) {
 
   // set more initial size of interval/groupby query
   int32_t initialSize = 16;
-  int32_t code = initResultRowInfo(&pTableQueryInfo->resInfo, initialSize, TSDB_DATA_TYPE_INT);
+  int32_t code = initResultRowInfo(&pTableQueryInfo->resInfo, initialSize);
   if (code != TSDB_CODE_SUCCESS) {
     tfree(pTableQueryInfo);
     return NULL;
@@ -3716,7 +3701,7 @@ void doSetTableGroupOutputBuf(SAggOperatorInfo* pAggInfo, int32_t numOfOutput, i
   int32_t* rowCellInfoOffset = pAggInfo->binfo.rowCellInfoOffset;
 
   SResultRow* pResultRow =
-      doSetResultOutBufByKey_rv(pResultRowInfo, tid, (char*)&tableGroupId, sizeof(tableGroupId), true, uid, pTaskInfo, false, pAggInfo);
+      doSetResultOutBufByKey_rv(pResultRowInfo, tid, (char*)&tableGroupId, sizeof(tableGroupId), true, uid, pTaskInfo, false, &pAggInfo->aggSup);
   assert (pResultRow != NULL);
 
   /*
@@ -3935,7 +3920,7 @@ void setIntervalQueryRange(STaskRuntimeEnv *pRuntimeEnv, TSKEY key) {
 
   TSKEY sk = TMIN(win.skey, win.ekey);
   TSKEY ek = TMAX(win.skey, win.ekey);
-  getAlignQueryTimeWindow(pQueryAttr, win.skey, sk, ek, &w);
+//  getAlignQueryTimeWindow(pQueryAttr, win.skey, sk, ek, &w);
 
 //  if (pResultRowInfo->prevSKey == TSKEY_INITIAL_VAL) {
 //    if (!QUERY_IS_ASC_QUERY(pQueryAttr)) {
@@ -4520,18 +4505,23 @@ void queryCostStatis(SExecTaskInfo *pTaskInfo) {
 //  return true;
 //}
 
-void appendDownstream(SOperatorInfo* p, SOperatorInfo* pUpstream) {
+int32_t appendDownstream(SOperatorInfo* p, SOperatorInfo** pDownstream, int32_t num) {
   if (p->pDownstream == NULL) {
     assert(p->numOfDownstream == 0);
   }
 
-  p->pDownstream = realloc(p->pDownstream, POINTER_BYTES * (p->numOfDownstream + 1));
-  p->pDownstream[p->numOfDownstream++] = pUpstream;
+  p->pDownstream = calloc(1, num * POINTER_BYTES);
+  if (p->pDownstream == NULL) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  memcpy(p->pDownstream, pDownstream, num * POINTER_BYTES);
+  p->numOfDownstream = num;
+  return TSDB_CODE_SUCCESS;
 }
 
 static void doDestroyTableQueryInfo(STableGroupInfo* pTableqinfoGroupInfo);
 
-void createResultBlock(const SArray* pExprInfo, SExchangeInfo* pInfo, const SOperatorInfo* pOperator, size_t size);
 static int32_t setupQueryHandle(void* tsdb, STaskRuntimeEnv* pRuntimeEnv, int64_t qId, bool isSTableQuery) {
   STaskAttr *pQueryAttr = pRuntimeEnv->pQueryAttr;
 #if 0
@@ -4624,11 +4614,11 @@ int32_t doInitQInfo(SQInfo* pQInfo, STSBuf* pTsBuf, void* tsdb, void* sourceOptr
     tsBufSetTraverseOrder(pRuntimeEnv->pTsBuf, order);
   }
 
-  int32_t ps = DEFAULT_PAGE_SIZE;
+  int32_t ps = 4096;
   getIntermediateBufInfo(pRuntimeEnv, &ps, &pQueryAttr->intermediateResultRowSize);
 
   int32_t TENMB = 1024*1024*10;
-  int32_t code = createDiskbasedBuffer(&pRuntimeEnv->pResultBuf, ps, TENMB, pQInfo->qId, tsTempDir);
+  int32_t code = createDiskbasedBuf(&pRuntimeEnv->pResultBuf, ps, TENMB, pQInfo->qId, "/tmp");
   if (code != TSDB_CODE_SUCCESS) {
     return code;
   }
@@ -5441,13 +5431,17 @@ SOperatorInfo* createStreamScanOperatorInfo(void *streamReadHandle, SArray* pExp
   SArray* pColList = taosArrayInit(numOfOutput, sizeof(int32_t));
   for(int32_t i = 0; i < numOfOutput; ++i) {
     SExprInfo* pExpr = taosArrayGetP(pExprInfo, i);
-
     taosArrayPush(pColList, &pExpr->pExpr->pSchema[0].colId);
   }
   
   // set the extract column id to streamHandle
   tqReadHandleSetColIdList((STqReadHandle* )streamReadHandle, pColList);
-  tqReadHandleSetTbUidList(streamReadHandle, pTableIdList);
+  int32_t code = tqReadHandleSetTbUidList(streamReadHandle, pTableIdList);
+  if (code != 0) {
+    tfree(pInfo);
+    tfree(pOperator);
+    return NULL;
+  }
 
   pInfo->readerHandle = streamReadHandle;
 
@@ -5462,7 +5456,6 @@ SOperatorInfo* createStreamScanOperatorInfo(void *streamReadHandle, SArray* pExp
   return pOperator;
 }
 
-
 void setTableScanFilterOperatorInfo(STableScanInfo* pTableScanInfo, SOperatorInfo* pDownstream) {
   assert(pTableScanInfo != NULL && pDownstream != NULL);
 
@@ -5595,14 +5588,20 @@ SArray* getResultGroupCheckColumns(STaskAttr* pQuery) {
   return pOrderColumns;
 }
 
-static void destroyGlobalAggOperatorInfo(void* param, int32_t numOfOutput) {
-  SMultiwayMergeInfo *pInfo = (SMultiwayMergeInfo*) param;
-  destroyBasicOperatorInfo(&pInfo->binfo, numOfOutput);
+static int32_t initAggSup(SAggSupporter* pAggSup, SArray* pExprInfo);
+static void clearupAggSup(SAggSupporter* pAggSup);
 
-  taosArrayDestroy(pInfo->orderColumnList);
-  taosArrayDestroy(pInfo->groupColumnList);
-  tfree(pInfo->prevRow);
-  tfree(pInfo->currentGroupColData);
+static void destroySortedMergeOperatorInfo(void* param, int32_t numOfOutput) {
+  SSortedMergeOperatorInfo* pInfo = (SSortedMergeOperatorInfo*) param;
+  taosArrayDestroy(pInfo->orderInfo);
+  taosArrayDestroy(pInfo->groupInfo);
+
+  if (pInfo->pSortHandle != NULL) {
+    tsortDestroySortHandle(pInfo->pSortHandle);
+  }
+  blockDataDestroy(pInfo->binfo.pRes);
+
+  clearupAggSup(&pInfo->aggSup);
 }
 
 static void destroySlimitOperatorInfo(void* param, int32_t numOfOutput) {
@@ -5612,568 +5611,260 @@ static void destroySlimitOperatorInfo(void* param, int32_t numOfOutput) {
   tfree(pInfo->prevRow);
 }
 
-SOperatorInfo* createGlobalAggregateOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream,
-                                                 SExprInfo* pExpr, int32_t numOfOutput, void* param, SArray* pUdfInfo, bool groupResultMixedUp) {
-  SMultiwayMergeInfo* pInfo = calloc(1, sizeof(SMultiwayMergeInfo));
+static SExprInfo* exprArrayDup(SArray* pExprList) {
+  size_t numOfOutput = taosArrayGetSize(pExprList);
 
-  pInfo->resultRowFactor =
-      (int32_t)(getRowNumForMultioutput(pRuntimeEnv->pQueryAttr, pRuntimeEnv->pQueryAttr->topBotQuery, false));
-
-  pRuntimeEnv->scanFlag = MERGE_STAGE;  // TODO init when creating pCtx
-
-  pInfo->multiGroupResults = groupResultMixedUp;
-  pInfo->pMerge            = param;
-  pInfo->bufCapacity       = 4096;
-  pInfo->udfInfo           = pUdfInfo;
-  pInfo->binfo.pRes        = createOutputBuf(pExpr, numOfOutput, pInfo->bufCapacity * pInfo->resultRowFactor);
-  pInfo->binfo.pCtx        = createSqlFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pInfo->binfo.rowCellInfoOffset);
-  pInfo->orderColumnList   = getOrderCheckColumns(pRuntimeEnv->pQueryAttr);
-  pInfo->groupColumnList   = getResultGroupCheckColumns(pRuntimeEnv->pQueryAttr);
-
-  // TODO refactor
-  int32_t len = 0;
-  for(int32_t i = 0; i < numOfOutput; ++i) {
-//    len += pExpr[i].base.;
+  SExprInfo* p = calloc(numOfOutput, sizeof(SExprInfo));
+  for (int32_t i = 0; i < numOfOutput; ++i) {
+    SExprInfo* pExpr = taosArrayGetP(pExprList, i);
+    assignExprInfo(&p[i], pExpr);
   }
 
-  int32_t numOfCols = (pInfo->orderColumnList != NULL)? (int32_t) taosArrayGetSize(pInfo->orderColumnList):0;
-  pInfo->prevRow = calloc(1, (POINTER_BYTES * numOfCols + len));
-  int32_t offset = POINTER_BYTES * numOfCols;
-
-  for(int32_t i = 0; i < numOfCols; ++i) {
-    pInfo->prevRow[i] = (char*)pInfo->prevRow + offset;
-
-    SColIndex* index = taosArrayGet(pInfo->orderColumnList, i);
-    offset += pExpr[index->colIndex].base.resSchema.bytes;
-  }
-
-  numOfCols = (pInfo->groupColumnList != NULL)? (int32_t)taosArrayGetSize(pInfo->groupColumnList):0;
-  pInfo->currentGroupColData = calloc(1, (POINTER_BYTES * numOfCols + len));
-  offset = POINTER_BYTES * numOfCols;
-
-  for(int32_t i = 0; i < numOfCols; ++i) {
-    pInfo->currentGroupColData[i] = (char*)pInfo->currentGroupColData + offset;
-
-    SColIndex* index = taosArrayGet(pInfo->groupColumnList, i);
-    offset += pExpr[index->colIndex].base.resSchema.bytes;
-  }
-
-  initResultRowInfo(&pInfo->binfo.resultRowInfo, 8, TSDB_DATA_TYPE_INT);
-
-  pInfo->seed = rand();
-  setDefaultOutputBuf(pRuntimeEnv, &pInfo->binfo, pInfo->seed, MERGE_STAGE);
-
-  SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
-  pOperator->name         = "GlobalAggregate";
-//  pOperator->operatorType = OP_GlobalAggregate;
-  pOperator->blockingOptr = true;
-  pOperator->status       = OP_IN_EXECUTING;
-  pOperator->info         = pInfo;
-  pOperator->pExpr        = pExpr;
-  pOperator->numOfOutput  = numOfOutput;
-  pOperator->pRuntimeEnv  = pRuntimeEnv;
-//  pOperator->exec         = doGlobalAggregate;
-  pOperator->cleanupFn    = destroyGlobalAggOperatorInfo;
-  appendDownstream(pOperator, downstream);
-
-  return pOperator;
+  return p;
 }
 
-SOperatorInfo *createMultiwaySortOperatorInfo(STaskRuntimeEnv *pRuntimeEnv, SExprInfo *pExpr, int32_t numOfOutput,
-                                              int32_t numOfRows, void *merger) {
-  SMultiwayMergeInfo* pInfo = calloc(1, sizeof(SMultiwayMergeInfo));
-
-  pInfo->pMerge          = merger;
-  pInfo->bufCapacity     = numOfRows;
-  pInfo->orderColumnList = getResultGroupCheckColumns(pRuntimeEnv->pQueryAttr);
-  pInfo->binfo.pRes      = createOutputBuf(pExpr, numOfOutput, numOfRows);
-
-  {  // todo extract method to create prev compare buffer
-    int32_t len = 0;
-    for(int32_t i = 0; i < numOfOutput; ++i) {
-//      len += pExpr[i].base.colBytes;
-    }
-
-    int32_t numOfCols = (pInfo->orderColumnList != NULL)? (int32_t) taosArrayGetSize(pInfo->orderColumnList):0;
-    pInfo->prevRow = calloc(1, (POINTER_BYTES * numOfCols + len));
-
-    int32_t offset = POINTER_BYTES * numOfCols;
-    for(int32_t i = 0; i < numOfCols; ++i) {
-      pInfo->prevRow[i] = (char*)pInfo->prevRow + offset;
-
-      SColIndex* index = taosArrayGet(pInfo->orderColumnList, i);
-//      offset += pExpr[index->colIndex].base.colBytes;
-    }
-  }
-
-  SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
-  pOperator->name         = "MultiwaySortOperator";
-//  pOperator->operatorType = OP_MultiwayMergeSort;
-  pOperator->blockingOptr = false;
-  pOperator->status       = OP_IN_EXECUTING;
-  pOperator->info         = pInfo;
-  pOperator->pRuntimeEnv  = pRuntimeEnv;
-  pOperator->numOfOutput  = numOfOutput;
-  pOperator->pExpr        = pExpr;
-//  pOperator->exec         = doMultiwayMergeSort;
-  pOperator->cleanupFn    = destroyGlobalAggOperatorInfo;
-  return pOperator;
-}
-
-typedef struct SExternalMemSource {
-  SArray*        pageIdList;
-  int32_t        pageIndex;
-  int32_t        sourceId;
-  int32_t        rowIndex;
-  SSDataBlock   *pBlock;
-} SExternalMemSource;
-
-int32_t msortComparFn(const void *pLeft, const void *pRight, void *param) {
-  int32_t pLeftIdx  = *(int32_t *)pLeft;
-  int32_t pRightIdx = *(int32_t *)pRight;
-
-  SMsortComparParam   *pParam = (SMsortComparParam *)param;
-
-  SArray *pInfo = pParam->orderInfo;
-
-  SExternalMemSource* pLeftSource  = pParam->pSources[pLeftIdx];
-  SExternalMemSource* pRightSource = pParam->pSources[pRightIdx];
-
-  // this input is exhausted, set the special value to denote this
-  if (pLeftSource->rowIndex == -1) {
-    return 1;
-  }
-
-  if (pRightSource->rowIndex == -1) {
-    return -1;
-  }
-
-  SSDataBlock* pLeftBlock = pLeftSource->pBlock;
-  SSDataBlock* pRightBlock = pRightSource->pBlock;
-
-  for(int32_t i = 0; i < pInfo->size; ++i) {
-    SBlockOrderInfo* pOrder = TARRAY_GET_ELEM(pInfo, i);
-
-    SColumnInfoData* pLeftColInfoData = TARRAY_GET_ELEM(pLeftBlock->pDataBlock, pOrder->colIndex);
-
-    bool leftNull  = false;
-    if (pLeftColInfoData->hasNull) {
-      leftNull = colDataIsNull(pLeftColInfoData, pLeftBlock->info.rows, pLeftSource->rowIndex, pLeftBlock->pBlockAgg);
-    }
-
-    SColumnInfoData* pRightColInfoData = TARRAY_GET_ELEM(pRightBlock->pDataBlock, pOrder->colIndex);
-    bool rightNull = false;
-    if (pRightColInfoData->hasNull) {
-      rightNull = colDataIsNull(pRightColInfoData, pRightBlock->info.rows, pRightSource->rowIndex, pRightBlock->pBlockAgg);
-    }
-
-    if (leftNull && rightNull) {
-      continue; // continue to next slot
-    }
-
-    if (rightNull) {
-      return pParam->nullFirst? 1:-1;
-    }
-
-    if (leftNull) {
-      return pParam->nullFirst? -1:1;
-    }
-
-    void* left1  = colDataGet(pLeftColInfoData, pLeftSource->rowIndex);
-    void* right1 = colDataGet(pRightColInfoData, pRightSource->rowIndex);
-
-    switch(pLeftColInfoData->info.type) {
-      case TSDB_DATA_TYPE_INT: {
-        int32_t leftv = *(int32_t*)left1;
-        int32_t rightv = *(int32_t*)right1;
-
-        if (leftv == rightv) {
-          break;
-        } else {
-          if (pOrder->order == TSDB_ORDER_ASC) {
-            return leftv < rightv? -1 : 1;
-          } else {
-            return leftv < rightv? 1 : -1;
-          }
-        }
-      }
-      default:
-        assert(0);
-    }
-  }
-}
-
-static int32_t adjustMergeTreeForNextTuple(SExternalMemSource *pSource, SMultiwayMergeTreeInfo *pTree, SOrderOperatorInfo* pInfo) {
-  /*
-   * load a new SDataBlock into memory of a given intermediate data-set source,
-   * since it's last record in buffer has been chosen to be processed, as the winner of loser-tree
-   */
-  if (pSource->rowIndex >= pSource->pBlock->info.rows) {
-    pSource->rowIndex = 0;
-    pSource->pageIndex += 1;
-
-    if (pSource->pageIndex >= taosArrayGetSize(pSource->pageIdList)) {
-      pInfo->numOfCompleted += 1;
-      pSource->rowIndex = -1;
-      pSource->pageIndex = -1;
-      pSource->pBlock = blockDataDestroy(pSource->pBlock);
-    } else {
-      SPageInfo* pPgInfo = *(SPageInfo**)taosArrayGet(pSource->pageIdList, pSource->pageIndex);
-
-      SFilePage* pPage = getBufPage(pInfo->pSortInternalBuf, getPageId(pPgInfo));
-      int32_t code = blockDataFromBuf(pSource->pBlock, pPage->data);
-      if (code != TSDB_CODE_SUCCESS) {
-        return code;
-      }
-
-      releaseBufPage(pInfo->pSortInternalBuf, pPage);
-    }
-  }
-
-  /*
-   * Adjust loser tree otherwise, according to new candidate data
-   * if the loser tree is rebuild completed, we do not need to adjust
-   */
-  int32_t leafNodeIndex = tMergeTreeGetAdjustIndex(pTree);
-
-#ifdef _DEBUG_VIEW
-  printf("before adjust:\t");
-  tMergeTreePrint(pTree);
-#endif
-
-  tMergeTreeAdjust(pTree, leafNodeIndex);
-
-#ifdef _DEBUG_VIEW
-  printf("\nafter adjust:\t");
-  tMergeTreePrint(pTree);
-#endif
-}
-
-static void appendOneRowToDataBlock(SSDataBlock *pBlock, const SSDataBlock* pSource, int32_t* rowIndex) {
+// TODO merge aggregate super table
+static void appendOneRowToDataBlock(SSDataBlock *pBlock, STupleHandle* pTupleHandle) {
   for (int32_t i = 0; i < pBlock->info.numOfCols; ++i) {
     SColumnInfoData* pColInfo = taosArrayGet(pBlock->pDataBlock, i);
 
-    SColumnInfoData* pSrcColInfo = taosArrayGet(pSource->pDataBlock, i);
-    bool isNull = colDataIsNull(pSrcColInfo, pSource->info.rows, *rowIndex, NULL);
-
+    bool isNull = tsortIsNullVal(pTupleHandle, i);
     if (isNull) {
       colDataAppend(pColInfo, pBlock->info.rows, NULL, true);
     } else {
-      char* pData = colDataGet(pSrcColInfo, *rowIndex);
+      char* pData = tsortGetValue(pTupleHandle, i);
       colDataAppend(pColInfo, pBlock->info.rows, pData, false);
     }
   }
 
   pBlock->info.rows += 1;
-  *rowIndex += 1;
 }
 
-static int32_t doAddNewSource(SOrderOperatorInfo* pInfo, SArray* pAllSources, int32_t numOfCols) {
-  SExternalMemSource* pSource = calloc(1, sizeof(SExternalMemSource));
-  if (pSource == NULL) {
-    return TSDB_CODE_QRY_OUT_OF_MEMORY;
-  }
-
-  pSource->pageIdList = getDataBufPagesIdList(pInfo->pSortInternalBuf, pInfo->sourceId);
-  pSource->sourceId   = pInfo->sourceId;
-
-  pSource->pBlock     = calloc(1, sizeof(SSDataBlock));
-  pSource->pBlock->pDataBlock = taosArrayInit(numOfCols, sizeof(SColumnInfoData));
-  pSource->pBlock->info.numOfCols = numOfCols;
-
-  for(int32_t i = 0; i < numOfCols; ++i) {
-    SColumnInfoData  colInfo = {0};
-    SColumnInfoData* p = taosArrayGet(pInfo->pDataBlock->pDataBlock, i);
-    colInfo.info = p->info;
-    taosArrayPush(pSource->pBlock->pDataBlock, &colInfo);
-  }
-
-  taosArrayPush(pAllSources, &pSource);
-
-  pInfo->sourceId += 1;
-
-  int32_t rowSize = blockDataGetSerialRowSize(pSource->pBlock);
-  int32_t numOfRows = (getBufPageSize(pInfo->pSortInternalBuf) - blockDataGetSerialMetaSize(pInfo->pDataBlock))/rowSize;
-
-  return blockDataEnsureCapacity(pSource->pBlock, numOfRows);
-}
-
-void addToDiskbasedBuf(SOrderOperatorInfo* pInfo, SArray* pSources, jmp_buf env) {
-  int32_t start = 0;
-
-  while(start < pInfo->pDataBlock->info.rows) {
-    int32_t stop = 0;
-    blockDataSplitRows(pInfo->pDataBlock, pInfo->hasVarCol, start, &stop, getBufPageSize(pInfo->pSortInternalBuf));
-    SSDataBlock* p = blockDataExtractBlock(pInfo->pDataBlock, start, stop - start + 1);
-    if (p == NULL) {
-      longjmp(env, TSDB_CODE_QRY_OUT_OF_MEMORY);
-    }
-
-    int32_t pageId = -1;
-    SFilePage* pPage = getNewDataBuf(pInfo->pSortInternalBuf, pInfo->sourceId, &pageId);
-    if (pPage == NULL) {
-      assert(0);
-      longjmp(env, terrno);
-    }
-
-    int32_t size = blockDataGetSize(p) + sizeof(int32_t)  + p->info.numOfCols * sizeof(int32_t);
-    assert(size <= getBufPageSize(pInfo->pSortInternalBuf));
-
-    blockDataToBuf(pPage->data, p);
-
-    setBufPageDirty(pPage, true);
-    releaseBufPage(pInfo->pSortInternalBuf, pPage);
-
-    blockDataDestroy(p);
-    start = stop + 1;
-  }
-
-  int32_t numOfCols = pInfo->pDataBlock->info.numOfCols;
-  blockDataClearup(pInfo->pDataBlock, pInfo->hasVarCol);
-
-  int32_t code = doAddNewSource(pInfo, pSources, numOfCols);
-  if (code != TSDB_CODE_SUCCESS) {
-    longjmp(env, code);
-  }
-}
-
-static int32_t sortComparInit(SMsortComparParam* cmpParam, SArray* pSources, int32_t startIndex, int32_t endIndex, SDiskbasedBuf* pBuf) {
-  cmpParam->pSources  = taosArrayGet(pSources, startIndex);
-  cmpParam->numOfSources = (endIndex - startIndex + 1);
-
-  for(int32_t i = 0; i < cmpParam->numOfSources; ++i) {
-    SExternalMemSource* pSource = cmpParam->pSources[i];
-    SPageInfo* pPgInfo = *(SPageInfo**) taosArrayGet(pSource->pageIdList, pSource->pageIndex);
-
-    SFilePage* pPage = getBufPage(pBuf, getPageId(pPgInfo));
-    int32_t code = blockDataFromBuf(cmpParam->pSources[i]->pBlock, pPage->data);
-    if (code != TSDB_CODE_SUCCESS) {
-      return code;
-    }
-
-    releaseBufPage(pBuf, pPage);
-  }
-
-  return TSDB_CODE_SUCCESS;
-}
-
-static int32_t sortComparClearup(SMsortComparParam* cmpParam) {
-  for(int32_t i = 0; i < cmpParam->numOfSources; ++i) {
-    SExternalMemSource* pSource = cmpParam->pSources[i];
-    blockDataDestroy(pSource->pBlock);
-    tfree(pSource);
-  }
-
-  cmpParam->numOfSources = 0;
-}
-
-static SSDataBlock* getSortedBlockData(SExecTaskInfo* pTaskInfo, SOrderOperatorInfo* pInfo, SMsortComparParam* cmpParam, int32_t capacity) {
-  blockDataClearup(pInfo->pDataBlock, pInfo->hasVarCol);
+static SSDataBlock* getSortedBlockData(SSortHandle* pHandle, SSDataBlock* pDataBlock, bool hasVarCol, int32_t capacity) {
+  blockDataClearup(pDataBlock, hasVarCol);
 
   while(1) {
-    if (cmpParam->numOfSources == pInfo->numOfCompleted) {
+    STupleHandle* pTupleHandle = tsortNextTuple(pHandle);
+    if (pTupleHandle == NULL) {
       break;
     }
 
-    int32_t index = tMergeTreeGetChosenIndex(pInfo->pMergeTree);
-
-    SExternalMemSource *pSource = (*cmpParam).pSources[index];
-    appendOneRowToDataBlock(pInfo->pDataBlock, pSource->pBlock, &pSource->rowIndex);
-
-    int32_t code = adjustMergeTreeForNextTuple(pSource, pInfo->pMergeTree, pInfo);
-    if (code != TSDB_CODE_SUCCESS) {
-      longjmp(pTaskInfo->env, code);
-    }
-
-    if (pInfo->pDataBlock->info.rows >= capacity) {
-      return pInfo->pDataBlock;
+    appendOneRowToDataBlock(pDataBlock, pTupleHandle);
+    if (pDataBlock->info.rows >= capacity) {
+      return pDataBlock;
     }
   }
 
-  return (pInfo->pDataBlock->info.rows > 0)? pInfo->pDataBlock:NULL;
+  return (pDataBlock->info.rows > 0)? pDataBlock:NULL;
 }
 
-static int32_t doInternalSort(SExecTaskInfo* pTaskInfo, SOrderOperatorInfo* pInfo) {
-  size_t numOfSources = taosArrayGetSize(pInfo->pSources);
+SSDataBlock* loadNextDataBlock(void* param) {
+  SOperatorInfo* pOperator = (SOperatorInfo*) param;
+  bool newgroup = false;
 
-  // Calculate the I/O counts to complete the data sort.
-  double sortCount = floorl(log2(numOfSources) / log2(getNumOfInMemBufPages(pInfo->pSortInternalBuf)));
+  return pOperator->exec(pOperator, &newgroup);
+}
 
-  pInfo->totalElapsed = taosGetTimestampUs() - pInfo->startTs;
-  qDebug("%s %d rounds mergesort required to complete the sort, first-round sorted data size:%"PRIzu", sort:%"PRId64", total elapsed:%"PRId64,
-      GET_TASKID(pTaskInfo), (int32_t) (sortCount + 1), getTotalBufSize(pInfo->pSortInternalBuf), pInfo->sortElapsed,
-      pInfo->totalElapsed);
-
-  size_t pgSize = getBufPageSize(pInfo->pSortInternalBuf);
-  int32_t numOfRows = (pgSize - blockDataGetSerialMetaSize(pInfo->pDataBlock))/ blockDataGetSerialRowSize(pInfo->pDataBlock);
-
-  blockDataEnsureCapacity(pInfo->pDataBlock, numOfRows);
-
-  size_t numOfSorted = taosArrayGetSize(pInfo->pSources);
-  for(int32_t t = 0; t < sortCount; ++t) {
-    int64_t st = taosGetTimestampUs();
-
-    SArray* pResList = taosArrayInit(4, POINTER_BYTES);
-    SMsortComparParam resultParam = {.orderInfo = pInfo->cmpParam.orderInfo};
-
-    int32_t numOfInputSources = getNumOfInMemBufPages(pInfo->pSortInternalBuf);
-    int32_t sortGroup = (numOfSorted + numOfInputSources - 1) / numOfInputSources;
-
-    // Only *numOfInputSources* can be loaded into buffer to perform the external sort.
-    for(int32_t i = 0; i < sortGroup; ++i) {
-      pInfo->sourceId += 1;
-
-      int32_t end = (i + 1) * numOfInputSources - 1;
-      if (end > numOfSorted - 1) {
-        end = numOfSorted - 1;
-      }
-
-      pInfo->cmpParam.numOfSources = end - i * numOfInputSources + 1;
-
-      int32_t code = sortComparInit(&pInfo->cmpParam, pInfo->pSources, i * numOfInputSources, end, pInfo->pSortInternalBuf);
-      if (code != TSDB_CODE_SUCCESS) {
-        longjmp(pTaskInfo->env, code);
-      }
-
-      code = tMergeTreeCreate(&pInfo->pMergeTree, pInfo->cmpParam.numOfSources, &pInfo->cmpParam, msortComparFn);
-      if (code != TSDB_CODE_SUCCESS) {
-        longjmp(pTaskInfo->env, code);
-      }
-
-      while (1) {
-        SSDataBlock* pDataBlock = getSortedBlockData(pTaskInfo, pInfo, &pInfo->cmpParam, numOfRows);
-        if (pDataBlock == NULL) {
-          break;
-        }
-
-        int32_t pageId = -1;
-        SFilePage* pPage = getNewDataBuf(pInfo->pSortInternalBuf, pInfo->sourceId, &pageId);
-        if (pPage == NULL) {
-          assert(0);
-          longjmp(pTaskInfo->env, terrno);
-        }
-
-        int32_t size = blockDataGetSize(pDataBlock) + sizeof(int32_t) + pDataBlock->info.numOfCols * sizeof(int32_t);
-        assert(size <= getBufPageSize(pInfo->pSortInternalBuf));
-
-        blockDataToBuf(pPage->data, pDataBlock);
-
-        setBufPageDirty(pPage, true);
-        releaseBufPage(pInfo->pSortInternalBuf, pPage);
-
-        blockDataClearup(pDataBlock, pInfo->hasVarCol);
-      }
-
-      tMergeTreeDestroy(pInfo->pMergeTree);
-      pInfo->numOfCompleted = 0;
-
-      code = doAddNewSource(pInfo, pResList, pInfo->pDataBlock->info.numOfCols);
-      if (code != 0) {
-        longjmp(pTaskInfo->env, code);
-      }
-    }
-
-    sortComparClearup(&pInfo->cmpParam);
-
-    taosArrayClear(pInfo->pSources);
-    taosArrayAddAll(pInfo->pSources, pResList);
-    taosArrayDestroy(pResList);
-
-    pInfo->cmpParam = resultParam;
-    numOfSorted = taosArrayGetSize(pInfo->pSources);
-
-    int64_t el = taosGetTimestampUs() - st;
-    pInfo->totalElapsed += el;
-
-    SDiskbasedBufStatis statis = getDBufStatis(pInfo->pSortInternalBuf);
-
-    qDebug("%s %d round mergesort, elapsed:%"PRId64" readDisk:%.2f Kb, flushDisk:%.2f Kb", GET_TASKID(pTaskInfo), t + 1, el, statis.loadBytes/1024.0,
-        statis.flushBytes/1024.0);
+static bool needToMerge(SSDataBlock* pBlock, SArray* groupInfo, char **buf, int32_t rowIndex) {
+  size_t size = taosArrayGetSize(groupInfo);
+  if (size == 0) {
+    return true;
+  }
+
+  for (int32_t i = 0; i < size; ++i) {
+    int32_t* index = taosArrayGet(groupInfo, i);
+
+    SColumnInfoData* pColInfo = taosArrayGet(pBlock->pDataBlock, *index);
+    bool isNull = colDataIsNull(pColInfo, rowIndex, pBlock->info.rows, NULL);
+
+    if ((isNull && buf[i] != NULL) || (!isNull && buf[i] == NULL)) {
+      return false;
+    }
+
+    char* pCell = colDataGetData(pColInfo, rowIndex);
+    if (IS_VAR_DATA_TYPE(pColInfo->info.type)) {
+      if (varDataLen(pCell) != varDataLen(buf[i])) {
+        return false;
+      } else {
+        if (memcmp(varDataVal(pCell), varDataVal(buf[i]), varDataLen(pCell)) != 0) {
+          return false;
+        }
+      }
+    } else {
+      if (memcmp(pCell, buf[i], pColInfo->info.bytes) != 0) {
+        return false;
+      }
+    }
   }
 
-  pInfo->cmpParam.numOfSources = taosArrayGetSize(pInfo->pSources);
   return 0;
 }
 
-static SSDataBlock* doSort(void* param, bool* newgroup) {
+static void doMergeResultImpl(SSortedMergeOperatorInfo* pInfo, SqlFunctionCtx *pCtx, int32_t numOfExpr, int32_t rowIndex) {
+  for (int32_t j = 0; j < numOfExpr; ++j) { // TODO set row index
+    pCtx[j].startRow = rowIndex;
+  }
+
+  for (int32_t j = 0; j < numOfExpr; ++j) {
+    int32_t functionId = pCtx[j].functionId;
+    pCtx[j].fpSet->addInput(&pCtx[j]);
+
+//    if (functionId < 0) {
+//      SUdfInfo* pUdfInfo = taosArrayGet(pInfo->udfInfo, -1 * functionId - 1);
+//      doInvokeUdf(pUdfInfo, &pCtx[j], 0, TSDB_UDF_FUNC_MERGE);
+//    } else {
+//      assert(!TSDB_FUNC_IS_SCALAR(functionId));
+//      aAggs[functionId].mergeFunc(&pCtx[j]);
+//    }
+  }
+}
+
+static void doFinalizeResultImpl(SqlFunctionCtx *pCtx, int32_t numOfExpr) {
+  for(int32_t j = 0; j < numOfExpr; ++j) {
+    int32_t functionId = pCtx[j].functionId;
+    //    if (functionId == FUNC_TAG_DUMMY || functionId == FUNC_TS_DUMMY) {
+    //      continue;
+    //    }
+
+    //    if (functionId < 0) {
+    //      SUdfInfo* pUdfInfo = taosArrayGet(pInfo->udfInfo, -1 * functionId - 1);
+    //      doInvokeUdf(pUdfInfo, &pCtx[j], 0, TSDB_UDF_FUNC_FINALIZE);
+    //    } else {
+    pCtx[j].fpSet->addInput(&pCtx[j]);
+  }
+}
+
+static bool saveCurrentTuple(char** rowColData, SArray* pColumnList, SSDataBlock* pBlock, int32_t rowIndex) {
+  int32_t size = (int32_t) taosArrayGetSize(pColumnList);
+
+  for(int32_t i = 0; i < size; ++i) {
+    int32_t* index = taosArrayGet(pColumnList, i);
+    SColumnInfoData* pColInfo = taosArrayGet(pBlock->pDataBlock, *index);
+
+    char* data = colDataGetData(pColInfo, rowIndex);
+    memcpy(rowColData[i], data, colDataGetLength(pColInfo, rowIndex));
+  }
+
+  return true;
+}
+
+static void doMergeImpl(SOperatorInfo* pOperator, int32_t numOfExpr, SSDataBlock* pBlock) {
+  SSortedMergeOperatorInfo* pInfo = pOperator->info;
+
+  SqlFunctionCtx* pCtx = pInfo->binfo.pCtx;
+  for(int32_t i = 0; i < pBlock->info.numOfCols; ++i) {
+    pCtx[i].size = 1;
+  }
+
+  for(int32_t i = 0; i < pBlock->info.rows; ++i) {
+    if (!pInfo->hasGroupVal) {
+      ASSERT(i == 0);
+      doMergeResultImpl(pInfo, pCtx, numOfExpr, i);
+      pInfo->hasGroupVal = saveCurrentTuple(pInfo->groupVal, pInfo->groupInfo, pBlock, i);
+    } else {
+      if (needToMerge(pBlock, pInfo->groupInfo, pInfo->groupVal, i)) {
+        doMergeResultImpl(pInfo, pCtx, numOfExpr, i);
+      } else {
+        doFinalizeResultImpl(pCtx, numOfExpr);
+        int32_t numOfRows = getNumOfResult(pInfo->binfo.pCtx, pOperator->numOfOutput);
+        //        setTagValueForMultipleRows(pCtx, pOperator->numOfOutput, numOfRows);
+
+        // TODO check for available buffer;
+
+        // next group info data
+        pInfo->binfo.pRes->info.rows += numOfRows;
+        for (int32_t j = 0; j < numOfExpr; ++j) {
+          if (pCtx[j].functionId < 0) {
+            continue;
+          }
+
+          pCtx[j].fpSet->addInput(&pCtx[j]);
+        }
+
+        doMergeResultImpl(pInfo, pCtx, numOfExpr, i);
+        pInfo->hasGroupVal = saveCurrentTuple(pInfo->groupVal, pInfo->groupInfo, pBlock, i);
+      }
+    }
+  }
+}
+
+static SSDataBlock* doMerge(SOperatorInfo* pOperator) {
+  SSortedMergeOperatorInfo* pInfo = pOperator->info;
+  SSortHandle* pHandle = pInfo->pSortHandle;
+
+  SSDataBlock* pDataBlock = createOneDataBlock(pInfo->binfo.pRes);
+  blockDataEnsureCapacity(pDataBlock, pInfo->binfo.capacity);
+
+  while(1) {
+
+    blockDataClearup(pDataBlock, pInfo->hasVarCol);
+    while (1) {
+      STupleHandle* pTupleHandle = tsortNextTuple(pHandle);
+      if (pTupleHandle == NULL) {
+        break;
+      }
+
+      // build datablock for merge for one group
+      appendOneRowToDataBlock(pDataBlock, pTupleHandle);
+      if (pDataBlock->info.rows >= pInfo->binfo.capacity) {
+        break;
+      }
+    }
+
+    if (pDataBlock->info.rows == 0) {
+      break;
+    }
+
+    setInputDataBlock(pOperator, pInfo->binfo.pCtx, pDataBlock, TSDB_ORDER_ASC);
+    //  updateOutputBuf(&pInfo->binfo, &pAggInfo->bufCapacity, pBlock->info.rows * pAggInfo->resultRowFactor, pOperator->pRuntimeEnv, true);
+    doMergeImpl(pOperator, pOperator->numOfOutput, pDataBlock);
+    // flush to tuple store, and after all data have been handled, return to upstream node or sink node
+  }
+
+  doFinalizeResultImpl(pInfo->binfo.pCtx, pOperator->numOfOutput);
+  int32_t numOfRows = getNumOfResult(pInfo->binfo.pCtx, pOperator->numOfOutput);
+  //        setTagValueForMultipleRows(pCtx, pOperator->numOfOutput, numOfRows);
+
+  // TODO check for available buffer;
+
+  // next group info data
+  pInfo->binfo.pRes->info.rows += numOfRows;
+  return (pInfo->binfo.pRes->info.rows > 0)? pInfo->binfo.pRes:NULL;
+}
+
+static SSDataBlock* doSortedMerge(void* param, bool* newgroup) {
   SOperatorInfo* pOperator = (SOperatorInfo*) param;
   if (pOperator->status == OP_EXEC_DONE) {
     return NULL;
   }
 
   SExecTaskInfo* pTaskInfo = pOperator->pTaskInfo;
-  SOrderOperatorInfo* pInfo = pOperator->info;
-  SSDataBlock* pBlock = NULL;
-
+  SSortedMergeOperatorInfo* pInfo = pOperator->info;
   if (pOperator->status == OP_RES_TO_RETURN) {
-    return getSortedBlockData(pTaskInfo, pInfo, &pInfo->cmpParam, pInfo->numOfRowsInRes);
+    return getSortedBlockData(pInfo->pSortHandle, pInfo->binfo.pRes, pInfo->hasVarCol, pInfo->binfo.capacity);
   }
 
-  int64_t st = taosGetTimestampUs();
+  SSchema* p = blockDataExtractSchema(pInfo->binfo.pRes, NULL);
+  int32_t numOfBufPage = pInfo->sortBufSize / pInfo->bufPageSize;
+  pInfo->pSortHandle = tsortCreateSortHandle(pInfo->orderInfo, pInfo->nullFirst, SORT_MULTISOURCE_MERGE, pInfo->bufPageSize,
+                                        numOfBufPage, p, pInfo->binfo.pRes->info.numOfCols, "GET_TASKID(pTaskInfo)");
 
-  while(1) {
-    publishOperatorProfEvent(pOperator->pDownstream[0], QUERY_PROF_BEFORE_OPERATOR_EXEC);
-    pBlock = pOperator->pDownstream[0]->exec(pOperator->pDownstream[0], newgroup);
-    publishOperatorProfEvent(pOperator->pDownstream[0], QUERY_PROF_AFTER_OPERATOR_EXEC);
+  tfree(p);
+  tsortSetFetchRawDataFp(pInfo->pSortHandle, loadNextDataBlock);
 
-    // start to flush data into disk and try do multiway merge sort
-    if (pBlock == NULL) {
-      break;
-    }
-
-    int32_t code = blockDataMerge(pInfo->pDataBlock, pBlock);
-    if (code != TSDB_CODE_SUCCESS) {
-      longjmp(pOperator->pTaskInfo->env, code);
-    }
-
-    size_t size = blockDataGetSize(pInfo->pDataBlock);
-    if (size > pInfo->sortBufSize) {
-      // Perform the in-memory sort and then flush data in the buffer into disk.
-      int64_t p = taosGetTimestampUs();
-      blockDataSort(pInfo->pDataBlock, pInfo->cmpParam.orderInfo, pInfo->cmpParam.nullFirst);
-
-      int64_t el = taosGetTimestampUs() - p;
-      pInfo->sortElapsed += el;
-
-      addToDiskbasedBuf(pInfo, pInfo->pSources, pTaskInfo->env);
-    }
+  for(int32_t i = 0; i < pOperator->numOfDownstream; ++i) {
+    SGenericSource* ps = calloc(1, sizeof(SGenericSource));
+    ps->param = pOperator->pDownstream[i];
+    tsortAddSource(pInfo->pSortHandle, ps);
   }
 
-  if (pInfo->pDataBlock->info.rows > 0) {
-    // Perform the in-memory sort and then flush data in the buffer into disk.
-    blockDataSort(pInfo->pDataBlock, pInfo->cmpParam.orderInfo, pInfo->cmpParam.nullFirst);
-
-    // All sorted data are resident in memory, external memory sort is not needed.
-    // Return to the upstream operator directly
-    if (isAllDataInMemBuf(pInfo->pSortInternalBuf)) {
-      pOperator->status = OP_EXEC_DONE;
-      return (pInfo->pDataBlock->info.rows == 0)? NULL:pInfo->pDataBlock;
-    }
-
-    addToDiskbasedBuf(pInfo, pInfo->pSources, pTaskInfo->env);
-  }
-
-  doInternalSort(pTaskInfo, pInfo);
-
-  int32_t code = blockDataEnsureCapacity(pInfo->pDataBlock, pInfo->numOfRowsInRes);
+  int32_t code = tsortOpen(pInfo->pSortHandle);
   if (code != TSDB_CODE_SUCCESS) {
-    longjmp(pTaskInfo->env, code);
-  }
-
-  int32_t numOfSources = taosArrayGetSize(pInfo->pSources);
-  ASSERT(numOfSources <= getNumOfInMemBufPages(pInfo->pSortInternalBuf));
-  code = sortComparInit(&pInfo->cmpParam, pInfo->pSources, 0, numOfSources - 1, pInfo->pSortInternalBuf);
-  if (code != TSDB_CODE_SUCCESS) {
-    longjmp(pTaskInfo->env, code);
-  }
-
-  code = tMergeTreeCreate(&pInfo->pMergeTree, pInfo->cmpParam.numOfSources, &pInfo->cmpParam, msortComparFn);
-  if (code != TSDB_CODE_SUCCESS) {
-    longjmp(pTaskInfo->env, code);
+    longjmp(pTaskInfo->env, terrno);
   }
 
   pOperator->status = OP_RES_TO_RETURN;
-  return getSortedBlockData(pTaskInfo, pInfo, &pInfo->cmpParam, pInfo->numOfRowsInRes);
+  return doMerge(pOperator);
 }
 
 static SArray* createBlockOrder(SArray* pExprInfo, SArray* pOrderVal) {
@@ -6199,7 +5890,154 @@ static SArray* createBlockOrder(SArray* pExprInfo, SArray* pOrderVal) {
   return pOrderInfo;
 }
 
-SOperatorInfo *createOrderOperatorInfo(SOperatorInfo* downstream, SArray* pExprInfo, SArray* pOrderVal) {
+static int32_t initGroupCol(SArray* pExprInfo, SArray* pGroupInfo, SSortedMergeOperatorInfo* pInfo) {
+  if (pGroupInfo == NULL || taosArrayGetSize(pGroupInfo) == 0) {
+    return 0;
+  }
+
+  int32_t len = 0;
+  SArray* plist = taosArrayInit(3, sizeof(SColumn));
+  pInfo->groupInfo = taosArrayInit(3, sizeof(int32_t));
+
+  if (plist == NULL || pInfo->groupInfo == NULL) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  size_t  numOfGroupCol = taosArrayGetSize(pInfo->groupInfo);
+  for(int32_t i = 0; i < numOfGroupCol; ++i) {
+    SColumn* pCol = taosArrayGet(pGroupInfo, i);
+    for(int32_t j = 0; j < taosArrayGetSize(pExprInfo); ++j) {
+      SExprInfo* pe = taosArrayGet(pExprInfo, j);
+      if (pe->base.resSchema.colId == pCol->info.colId) {
+        taosArrayPush(plist, pCol);
+        taosArrayPush(pInfo->groupInfo, &j);
+        len += pCol->info.bytes;
+        break;
+      }
+    }
+  }
+
+  ASSERT(taosArrayGetSize(pGroupInfo) == taosArrayGetSize(plist));
+
+  pInfo->groupVal = calloc(1, (POINTER_BYTES * numOfGroupCol + len));
+  if (pInfo->groupVal == NULL) {
+    taosArrayDestroy(plist);
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  int32_t offset = 0;
+  char   *start = (char*)(pInfo->groupVal + (POINTER_BYTES * numOfGroupCol));
+  for(int32_t i = 0; i < numOfGroupCol; ++i) {
+    pInfo->groupVal[i] = start + offset;
+    SColumn* pCol = taosArrayGet(plist, i);
+    offset += pCol->info.bytes;
+  }
+
+  taosArrayDestroy(plist);
+
+  return TSDB_CODE_SUCCESS;
+}
+
+SOperatorInfo* createSortedMergeOperatorInfo(SOperatorInfo** downstream, int32_t numOfDownstream, SArray* pExprInfo, SArray* pOrderVal, SArray* pGroupInfo, SExecTaskInfo* pTaskInfo) {
+  SSortedMergeOperatorInfo* pInfo = calloc(1, sizeof(SSortedMergeOperatorInfo));
+  SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
+  if (pInfo == NULL || pOperator == NULL) {
+    goto _error;
+  }
+
+  int32_t numOfOutput = taosArrayGetSize(pExprInfo);
+  pInfo->binfo.pCtx   = createSqlFunctionCtx_rv(pExprInfo, &pInfo->binfo.rowCellInfoOffset, &pInfo->binfo.resRowSize);
+  pInfo->binfo.pRes   = createOutputBuf_rv(pExprInfo, pInfo->binfo.capacity);
+  initResultRowInfo(&pInfo->binfo.resultRowInfo, (int32_t)1);
+
+  if (pInfo->binfo.pCtx == NULL || pInfo->binfo.pRes == NULL) {
+    goto _error;
+  }
+
+  int32_t code = initAggSup(&pInfo->aggSup, pExprInfo);
+  if (code != TSDB_CODE_SUCCESS) {
+    goto _error;
+  }
+
+  setDefaultOutputBuf_rv(&pInfo->binfo, &pInfo->aggSup, MAIN_SCAN, pTaskInfo);
+  code = initGroupCol(pExprInfo, pGroupInfo, pInfo);
+  if (code != TSDB_CODE_SUCCESS) {
+    goto _error;
+  }
+
+//  pInfo->resultRowFactor = (int32_t)(getRowNumForMultioutput(pRuntimeEnv->pQueryAttr,
+//      pRuntimeEnv->pQueryAttr->topBotQuery, false));
+  pInfo->sortBufSize    = 1024 * 16; // 1MB
+  pInfo->bufPageSize    = 1024;
+  pInfo->orderInfo      = createBlockOrder(pExprInfo, pOrderVal);
+
+  pInfo->binfo.capacity = blockDataGetCapacityInRow(pInfo->binfo.pRes, pInfo->bufPageSize);
+
+  pOperator->name         = "SortedMerge";
+  pOperator->operatorType = OP_SortedMerge;
+  pOperator->blockingOptr = true;
+  pOperator->status       = OP_IN_EXECUTING;
+  pOperator->info         = pInfo;
+  pOperator->numOfOutput  = numOfOutput;
+  pOperator->pExpr        = exprArrayDup(pExprInfo);
+
+  pOperator->pTaskInfo    = pTaskInfo;
+  pOperator->exec         = doSortedMerge;
+  pOperator->cleanupFn    = destroySortedMergeOperatorInfo;
+
+  code = appendDownstream(pOperator, downstream, numOfDownstream);
+  if (code != TSDB_CODE_SUCCESS) {
+    goto _error;
+  }
+
+  return pOperator;
+
+  _error:
+  if (pInfo != NULL) {
+    destroySortedMergeOperatorInfo(pInfo, numOfOutput);
+  }
+
+  tfree(pInfo);
+  tfree(pOperator);
+  terrno = TSDB_CODE_QRY_OUT_OF_MEMORY;
+  return NULL;
+}
+
+static SSDataBlock* doSort(void* param, bool* newgroup) {
+  SOperatorInfo* pOperator = (SOperatorInfo*) param;
+  if (pOperator->status == OP_EXEC_DONE) {
+    return NULL;
+  }
+
+  SExecTaskInfo* pTaskInfo = pOperator->pTaskInfo;
+  SOrderOperatorInfo* pInfo = pOperator->info;
+  if (pOperator->status == OP_RES_TO_RETURN) {
+    return getSortedBlockData(pInfo->pSortHandle, pInfo->pDataBlock, pInfo->hasVarCol, pInfo->numOfRowsInRes);
+  }
+
+  SSchema* p = blockDataExtractSchema(pInfo->pDataBlock, NULL);
+  int32_t numOfBufPage = pInfo->sortBufSize / pInfo->bufPageSize;
+  pInfo->pSortHandle = tsortCreateSortHandle(pInfo->orderInfo, pInfo->nullFirst, SORT_SINGLESOURCE_SORT, pInfo->bufPageSize,
+                                        numOfBufPage, p, pInfo->pDataBlock->info.numOfCols, "GET_TASKID(pTaskInfo)");
+
+  tfree(p);
+  tsortSetFetchRawDataFp(pInfo->pSortHandle, loadNextDataBlock);
+
+  SGenericSource* ps = calloc(1, sizeof(SGenericSource));
+  ps->param = pOperator;
+  tsortAddSource(pInfo->pSortHandle, ps);
+
+  // TODO set error code;
+  int32_t code = tsortOpen(pInfo->pSortHandle);
+  if (code != TSDB_CODE_SUCCESS) {
+    longjmp(pTaskInfo->env, terrno);
+  }
+
+  pOperator->status = OP_RES_TO_RETURN;
+  return getSortedBlockData(pInfo->pSortHandle, pInfo->pDataBlock, pInfo->hasVarCol, pInfo->numOfRowsInRes);
+}
+
+SOperatorInfo *createOrderOperatorInfo(SOperatorInfo* downstream, SArray* pExprInfo, SArray* pOrderVal, SExecTaskInfo* pTaskInfo) {
   SOrderOperatorInfo* pInfo = calloc(1, sizeof(SOrderOperatorInfo));
   SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
   if (pInfo == NULL || pOperator == NULL) {
@@ -6214,8 +6052,7 @@ SOperatorInfo *createOrderOperatorInfo(SOperatorInfo* downstream, SArray* pExprI
   pInfo->numOfRowsInRes = 1024;
 
   pInfo->pDataBlock  = createOutputBuf_rv(pExprInfo, pInfo->numOfRowsInRes);
-  pInfo->pSources    = taosArrayInit(4, POINTER_BYTES);
-  pInfo->cmpParam.orderInfo  = createBlockOrder(pExprInfo, pOrderVal);
+  pInfo->orderInfo  = createBlockOrder(pExprInfo, pOrderVal);
 
   for(int32_t i = 0; i < taosArrayGetSize(pExprInfo); ++i) {
     SExprInfo* pExpr = taosArrayGetP(pExprInfo, i);
@@ -6225,8 +6062,7 @@ SOperatorInfo *createOrderOperatorInfo(SOperatorInfo* downstream, SArray* pExprI
     }
   }
 
-  int32_t code = createDiskbasedBuffer(&pInfo->pSortInternalBuf, pInfo->bufPageSize, pInfo->sortBufSize, 1, "/tmp/");
-  if (pInfo->pSources == NULL || code != 0 || pInfo->cmpParam.orderInfo == NULL || pInfo->pDataBlock == NULL) {
+  if (pInfo->orderInfo == NULL || pInfo->pDataBlock == NULL) {
     tfree(pOperator);
     destroyOrderOperatorInfo(pInfo, taosArrayGetSize(pExprInfo));
     tfree(pInfo);
@@ -6240,10 +6076,12 @@ SOperatorInfo *createOrderOperatorInfo(SOperatorInfo* downstream, SArray* pExprI
   pOperator->blockingOptr  = true;
   pOperator->status        = OP_IN_EXECUTING;
   pOperator->info          = pInfo;
+
+  pOperator->pTaskInfo     = pTaskInfo;
   pOperator->exec          = doSort;
   pOperator->cleanupFn     = destroyOrderOperatorInfo;
 
-  appendDownstream(pOperator, downstream);
+  int32_t code = appendDownstream(pOperator, &downstream, 1);
   return pOperator;
 }
 
@@ -6537,22 +6375,19 @@ static SSDataBlock* doIntervalAgg(void* param, bool* newgroup) {
     return NULL;
   }
 
-  STableIntervalOperatorInfo* pIntervalInfo = pOperator->info;
+  STableIntervalOperatorInfo* pInfo = pOperator->info;
 
-  STaskRuntimeEnv* pRuntimeEnv = pOperator->pRuntimeEnv;
   if (pOperator->status == OP_RES_TO_RETURN) {
 //    toSDatablock(pAggInfo->pGroupResInfo, pAggInfo->pResultBuf, pInfo->pRes, pAggInfo->binfo.capacity);
-    if (pIntervalInfo->pRes->info.rows == 0 || !hasRemainDataInCurrentGroup(&pRuntimeEnv->groupResInfo)) {
+    if (pInfo->binfo.pRes->info.rows == 0 || !hasRemainDataInCurrentGroup(&pInfo->groupResInfo)) {
       doSetOperatorCompleted(pOperator);
     }
 
-    return pIntervalInfo->pRes;
+    return pInfo->binfo.pRes;
   }
 
-  STaskAttr* pQueryAttr = pRuntimeEnv->pQueryAttr;
-  int32_t order = pQueryAttr->order.order;
-  STimeWindow win = pQueryAttr->window;
-
+//  int32_t order = pQueryAttr->order.order;
+//  STimeWindow win = pQueryAttr->window;
   SOperatorInfo* downstream = pOperator->pDownstream[0];
 
   while(1) {
@@ -6564,30 +6399,30 @@ static SSDataBlock* doIntervalAgg(void* param, bool* newgroup) {
       break;
     }
 
-//    setTagValue(pOperator, pRuntimeEnv->current->pTable, pIntervalInfo->pCtx, pOperator->numOfOutput);
+//    setTagValue(pOperator, pRuntimeEnv->current->pTable, pInfo->pCtx, pOperator->numOfOutput);
 
     // the pDataBlock are always the same one, no need to call this again
-    setInputDataBlock(pOperator, pIntervalInfo->pCtx, pBlock, pQueryAttr->order.order);
-    hashIntervalAgg(pOperator, &pIntervalInfo->resultRowInfo, pBlock, 0);
+    setInputDataBlock(pOperator, pInfo->binfo.pCtx, pBlock, TSDB_ORDER_ASC);
+    hashIntervalAgg(pOperator, &pInfo->binfo.resultRowInfo, pBlock, 0);
   }
 
   // restore the value
-  pQueryAttr->order.order = order;
-  pQueryAttr->window = win;
+//  pQueryAttr->order.order = order;
+//  pQueryAttr->window = win;
 
   pOperator->status = OP_RES_TO_RETURN;
-  closeAllResultRows(&pIntervalInfo->resultRowInfo);
+  closeAllResultRows(&pInfo->binfo.resultRowInfo);
   setTaskStatus(pOperator->pTaskInfo, TASK_COMPLETED);
-  finalizeQueryResult(pOperator, pIntervalInfo->pCtx, &pIntervalInfo->resultRowInfo, pIntervalInfo->rowCellInfoOffset);
+  finalizeQueryResult(pOperator, pInfo->binfo.pCtx, &pInfo->binfo.resultRowInfo, pInfo->binfo.rowCellInfoOffset);
 
-  initGroupResInfo(&pRuntimeEnv->groupResInfo, &pIntervalInfo->resultRowInfo);
-//  toSDatablock(&pRuntimeEnv->groupResInfo, pRuntimeEnv, pIntervalInfo->pRes);
+  initGroupResInfo(&pInfo->groupResInfo, &pInfo->binfo.resultRowInfo);
+  toSDatablock(&pInfo->groupResInfo, pInfo->pResultBuf, pInfo->binfo.pRes, pInfo->binfo.capacity);
 
-  if (pIntervalInfo->pRes->info.rows == 0 || !hasRemainDataInCurrentGroup(&pRuntimeEnv->groupResInfo)) {
+  if (pInfo->binfo.pRes->info.rows == 0 || !hasRemainDataInCurrentGroup(&pInfo->groupResInfo)) {
     doSetOperatorCompleted(pOperator);
   }
 
-  return pIntervalInfo->pRes->info.rows == 0? NULL:pIntervalInfo->pRes;
+  return pInfo->binfo.pRes->info.rows == 0? NULL:pInfo->binfo.pRes;
 }
 
 static SSDataBlock* doAllIntervalAgg(void* param, bool* newgroup) {
@@ -6602,11 +6437,11 @@ static SSDataBlock* doAllIntervalAgg(void* param, bool* newgroup) {
   if (pOperator->status == OP_RES_TO_RETURN) {
 //    toSDatablock(&pRuntimeEnv->groupResInfo, pRuntimeEnv, pIntervalInfo->pRes);
 
-    if (pIntervalInfo->pRes->info.rows == 0 || !hasRemainDataInCurrentGroup(&pRuntimeEnv->groupResInfo)) {
+    if (pIntervalInfo->binfo.pRes->info.rows == 0 || !hasRemainDataInCurrentGroup(&pRuntimeEnv->groupResInfo)) {
       doSetOperatorCompleted(pOperator);
     }
 
-    return pIntervalInfo->pRes;
+    return pIntervalInfo->binfo.pRes;
   }
 
   STaskAttr* pQueryAttr = pRuntimeEnv->pQueryAttr;
@@ -6627,8 +6462,8 @@ static SSDataBlock* doAllIntervalAgg(void* param, bool* newgroup) {
 //    setTagValue(pOperator, pRuntimeEnv->current->pTable, pIntervalInfo->pCtx, pOperator->numOfOutput);
 
     // the pDataBlock are always the same one, no need to call this again
-    setInputDataBlock(pOperator, pIntervalInfo->pCtx, pBlock, pQueryAttr->order.order);
-    hashAllIntervalAgg(pOperator, &pIntervalInfo->resultRowInfo, pBlock, 0);
+    setInputDataBlock(pOperator, pIntervalInfo->binfo.pCtx, pBlock, pQueryAttr->order.order);
+    hashAllIntervalAgg(pOperator, &pIntervalInfo->binfo.resultRowInfo, pBlock, 0);
   }
 
   // restore the value
@@ -6636,18 +6471,18 @@ static SSDataBlock* doAllIntervalAgg(void* param, bool* newgroup) {
   pQueryAttr->window = win;
 
   pOperator->status = OP_RES_TO_RETURN;
-  closeAllResultRows(&pIntervalInfo->resultRowInfo);
+  closeAllResultRows(&pIntervalInfo->binfo.resultRowInfo);
   setTaskStatus(pOperator->pTaskInfo, TASK_COMPLETED);
-  finalizeQueryResult(pOperator, pIntervalInfo->pCtx, &pIntervalInfo->resultRowInfo, pIntervalInfo->rowCellInfoOffset);
+  finalizeQueryResult(pOperator, pIntervalInfo->binfo.pCtx, &pIntervalInfo->binfo.resultRowInfo, pIntervalInfo->binfo.rowCellInfoOffset);
 
-  initGroupResInfo(&pRuntimeEnv->groupResInfo, &pIntervalInfo->resultRowInfo);
+  initGroupResInfo(&pRuntimeEnv->groupResInfo, &pIntervalInfo->binfo.resultRowInfo);
 //  toSDatablock(&pRuntimeEnv->groupResInfo, pRuntimeEnv, pIntervalInfo->pRes);
 
-  if (pIntervalInfo->pRes->info.rows == 0 || !hasRemainDataInCurrentGroup(&pRuntimeEnv->groupResInfo)) {
+  if (pIntervalInfo->binfo.pRes->info.rows == 0 || !hasRemainDataInCurrentGroup(&pRuntimeEnv->groupResInfo)) {
     pOperator->status = OP_EXEC_DONE;
   }
 
-  return pIntervalInfo->pRes->info.rows == 0? NULL:pIntervalInfo->pRes;
+  return pIntervalInfo->binfo.pRes->info.rows == 0? NULL:pIntervalInfo->binfo.pRes;
 }
 
 static SSDataBlock* doSTableIntervalAgg(void* param, bool* newgroup) {
@@ -6663,14 +6498,14 @@ static SSDataBlock* doSTableIntervalAgg(void* param, bool* newgroup) {
     int64_t st = taosGetTimestampUs();
 
 //    copyToSDataBlock(NULL, 3000, pIntervalInfo->pRes, pIntervalInfo->rowCellInfoOffset);
-    if (pIntervalInfo->pRes->info.rows == 0 || !hasRemainData(&pRuntimeEnv->groupResInfo)) {
+    if (pIntervalInfo->binfo.pRes->info.rows == 0 || !hasRemainData(&pRuntimeEnv->groupResInfo)) {
       doSetOperatorCompleted(pOperator);
     }
 
     SQInfo* pQInfo = pRuntimeEnv->qinfo;
     pQInfo->summary.firstStageMergeTime += (taosGetTimestampUs() - st);
 
-    return pIntervalInfo->pRes;
+    return pIntervalInfo->binfo.pRes;
   }
 
   STaskAttr* pQueryAttr = pRuntimeEnv->pQueryAttr;
@@ -6691,7 +6526,7 @@ static SSDataBlock* doSTableIntervalAgg(void* param, bool* newgroup) {
     STableQueryInfo* pTableQueryInfo = pRuntimeEnv->current;
 
 //    setTagValue(pOperator, pTableQueryInfo->pTable, pIntervalInfo->pCtx, pOperator->numOfOutput);
-    setInputDataBlock(pOperator, pIntervalInfo->pCtx, pBlock, pQueryAttr->order.order);
+    setInputDataBlock(pOperator, pIntervalInfo->binfo.pCtx, pBlock, pQueryAttr->order.order);
     setIntervalQueryRange(pRuntimeEnv, pBlock->info.window.skey);
 
     hashIntervalAgg(pOperator, &pTableQueryInfo->resInfo, pBlock, pTableQueryInfo->groupIndex);
@@ -6703,11 +6538,11 @@ static SSDataBlock* doSTableIntervalAgg(void* param, bool* newgroup) {
   setTaskStatus(pOperator->pTaskInfo, TASK_COMPLETED);
 
 //  copyToSDataBlock(pRuntimeEnv, 3000, pIntervalInfo->pRes, pIntervalInfo->rowCellInfoOffset);
-  if (pIntervalInfo->pRes->info.rows == 0 || !hasRemainData(&pRuntimeEnv->groupResInfo)) {
+  if (pIntervalInfo->binfo.pRes->info.rows == 0 || !hasRemainData(&pRuntimeEnv->groupResInfo)) {
     pOperator->status = OP_EXEC_DONE;
   }
 
-  return pIntervalInfo->pRes;
+  return pIntervalInfo->binfo.pRes;
 }
 
 static SSDataBlock* doAllSTableIntervalAgg(void* param, bool* newgroup) {
@@ -6721,11 +6556,11 @@ static SSDataBlock* doAllSTableIntervalAgg(void* param, bool* newgroup) {
 
   if (pOperator->status == OP_RES_TO_RETURN) {
 //    copyToSDataBlock(pRuntimeEnv, 3000, pIntervalInfo->pRes, pIntervalInfo->rowCellInfoOffset);
-    if (pIntervalInfo->pRes->info.rows == 0 || !hasRemainData(&pRuntimeEnv->groupResInfo)) {
+    if (pIntervalInfo->binfo.pRes->info.rows == 0 || !hasRemainData(&pRuntimeEnv->groupResInfo)) {
       pOperator->status = OP_EXEC_DONE;
     }
 
-    return pIntervalInfo->pRes;
+    return pIntervalInfo->binfo.pRes;
   }
 
   STaskAttr* pQueryAttr = pRuntimeEnv->pQueryAttr;
@@ -6746,7 +6581,7 @@ static SSDataBlock* doAllSTableIntervalAgg(void* param, bool* newgroup) {
     STableQueryInfo* pTableQueryInfo = pRuntimeEnv->current;
 
 //    setTagValue(pOperator, pTableQueryInfo->pTable, pIntervalInfo->pCtx, pOperator->numOfOutput);
-    setInputDataBlock(pOperator, pIntervalInfo->pCtx, pBlock, pQueryAttr->order.order);
+    setInputDataBlock(pOperator, pIntervalInfo->binfo.pCtx, pBlock, pQueryAttr->order.order);
     setIntervalQueryRange(pRuntimeEnv, pBlock->info.window.skey);
 
     hashAllIntervalAgg(pOperator, &pTableQueryInfo->resInfo, pBlock, pTableQueryInfo->groupIndex);
@@ -6759,14 +6594,14 @@ static SSDataBlock* doAllSTableIntervalAgg(void* param, bool* newgroup) {
 
   int64_t st = taosGetTimestampUs();
 //  copyToSDataBlock(pRuntimeEnv, 3000, pIntervalInfo->pRes, pIntervalInfo->rowCellInfoOffset);
-  if (pIntervalInfo->pRes->info.rows == 0 || !hasRemainData(&pRuntimeEnv->groupResInfo)) {
+  if (pIntervalInfo->binfo.pRes->info.rows == 0 || !hasRemainData(&pRuntimeEnv->groupResInfo)) {
     pOperator->status = OP_EXEC_DONE;
   }
 
   SQInfo* pQInfo = pRuntimeEnv->qinfo;
   pQInfo->summary.firstStageMergeTime += (taosGetTimestampUs() - st);
 
-  return pIntervalInfo->pRes;
+  return pIntervalInfo->binfo.pRes;
 }
 
 static void doStateWindowAggImpl(SOperatorInfo* pOperator, SStateWindowOperatorInfo *pInfo, SSDataBlock *pSDataBlock) {
@@ -6818,8 +6653,8 @@ static void doStateWindowAggImpl(SOperatorInfo* pOperator, SStateWindowOperatorI
       if (ret != TSDB_CODE_SUCCESS) {  // null data, too many state code
         longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_APP_ERROR);
       }
-      doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, pInfo->start, pInfo->numOfRows, tsList,
-                       pSDataBlock->info.rows, pOperator->numOfOutput);
+//      doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, pInfo->start, pInfo->numOfRows, tsList,
+//                       pSDataBlock->info.rows, pOperator->numOfOutput);
 
       pInfo->curWindow.skey = tsList[j];
       pInfo->curWindow.ekey = tsList[j];
@@ -6840,8 +6675,8 @@ static void doStateWindowAggImpl(SOperatorInfo* pOperator, SStateWindowOperatorI
     longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_APP_ERROR);
   }
 
-  doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, pInfo->start, pInfo->numOfRows, tsList,
-                   pSDataBlock->info.rows, pOperator->numOfOutput);
+//  doApplyFunctions(pRuntimeEnv, pBInfo->pCtx, &pInfo->curWindow, pInfo->start, pInfo->numOfRows, tsList,
+//                   pSDataBlock->info.rows, pOperator->numOfOutput);
 }
 
 static SSDataBlock* doStateWindowAgg(void *param, bool* newgroup) {
@@ -7160,18 +6995,37 @@ static void destroyOperatorInfo(SOperatorInfo* pOperator) {
   tfree(pOperator);
 }
 
+static int32_t initAggSup(SAggSupporter* pAggSup, SArray* pExprInfo) {
+  _hash_fn_t hashFn = taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY);
+
+  pAggSup->keyBuf              = calloc(1, sizeof(int64_t) + sizeof(int64_t) + POINTER_BYTES);
+  pAggSup->pResultRowHashTable = taosHashInit(10, hashFn, true, HASH_NO_LOCK);
+  pAggSup->pResultRowListSet   = taosHashInit(100, hashFn, false, HASH_NO_LOCK);
+  pAggSup->pool                = initResultRowPool(getResultRowSize(pExprInfo));
+  pAggSup->pResultRowArrayList = taosArrayInit(10, sizeof(SResultRowCell));
+
+  if (pAggSup->keyBuf == NULL || pAggSup->pResultRowArrayList == NULL || pAggSup->pResultRowListSet == NULL ||
+      pAggSup->pResultRowHashTable == NULL || pAggSup->pool == NULL) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static void clearupAggSup(SAggSupporter* pAggSup) {
+  tfree(pAggSup->keyBuf);
+  taosHashCleanup(pAggSup->pResultRowHashTable);
+  taosHashCleanup(pAggSup->pResultRowListSet);
+  taosArrayDestroy(pAggSup->pResultRowArrayList);
+  destroyResultRowPool(pAggSup->pool);
+}
+
 static int32_t initAggInfo(SAggOperatorInfo* pInfo, SArray* pExprInfo, int32_t numOfRows, const STableGroupInfo* pTableGroupInfo) {
   pInfo->binfo.pRes = createOutputBuf_rv(pExprInfo, numOfRows);
   pInfo->binfo.pCtx = createSqlFunctionCtx_rv(pExprInfo, &pInfo->binfo.rowCellInfoOffset, &pInfo->binfo.resRowSize);
   pInfo->binfo.capacity = 4096;
 
-  _hash_fn_t hashFn = taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY);
-
-  pInfo->pResultRowHashTable = taosHashInit(10, hashFn, true, HASH_NO_LOCK);
-  pInfo->pResultRowListSet   = taosHashInit(100, hashFn, false, HASH_NO_LOCK);
-  pInfo->pool                = initResultRowPool(getResultRowSize(pExprInfo));
-  pInfo->pResultRowArrayList = taosArrayInit(10, sizeof(SResultRowCell));
-
+  initAggSup(&pInfo->aggSup, pExprInfo);
   pInfo->pTableQueryInfo = calloc(pTableGroupInfo->numOfTables, sizeof(STableQueryInfo));
 
   int32_t index = 0;
@@ -7193,17 +7047,6 @@ static int32_t initAggInfo(SAggOperatorInfo* pInfo, SArray* pExprInfo, int32_t n
   return TSDB_CODE_SUCCESS;
 }
 
-static SExprInfo* exprArrayDup(SArray* pExprInfo) {
-  size_t     numOfOutput = taosArrayGetSize(pExprInfo);
-  SExprInfo* p = calloc(numOfOutput, sizeof(SExprInfo));
-  for (int32_t i = 0; i < taosArrayGetSize(pExprInfo); ++i) {
-    SExprInfo* pExpr = taosArrayGetP(pExprInfo, i);
-    assignExprInfo(&p[i], pExpr);
-  }
-
-  return p;
-}
-
 SOperatorInfo* createAggregateOperatorInfo(SOperatorInfo* downstream, SArray* pExprInfo, SExecTaskInfo* pTaskInfo, const STableGroupInfo* pTableGroupInfo) {
   SAggOperatorInfo* pInfo = calloc(1, sizeof(SAggOperatorInfo));
 
@@ -7211,7 +7054,7 @@ SOperatorInfo* createAggregateOperatorInfo(SOperatorInfo* downstream, SArray* pE
   //(int32_t)(getRowNumForMultioutput(pQueryAttr, pQueryAttr->topBotQuery, pQueryAttr->stableQuery));
 
   initAggInfo(pInfo, pExprInfo, numOfRows, pTableGroupInfo);
-  setDefaultOutputBuf_rv(pInfo, MAIN_SCAN, pTaskInfo);
+  setDefaultOutputBuf_rv(&pInfo->binfo, &pInfo->aggSup, MAIN_SCAN, pTaskInfo);
 
   SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
   pOperator->name         = "TableAggregate";
@@ -7225,7 +7068,7 @@ SOperatorInfo* createAggregateOperatorInfo(SOperatorInfo* downstream, SArray* pE
   pOperator->pTaskInfo    = pTaskInfo;
   pOperator->exec         = doAggregate;
   pOperator->cleanupFn    = destroyAggOperatorInfo;
-  appendDownstream(pOperator, downstream);
+  int32_t code = appendDownstream(pOperator, &downstream, 1);
 
   return pOperator;
 }
@@ -7285,10 +7128,7 @@ static void destroyOrderOperatorInfo(void* param, int32_t numOfOutput) {
   SOrderOperatorInfo* pInfo = (SOrderOperatorInfo*) param;
   pInfo->pDataBlock = blockDataDestroy(pInfo->pDataBlock);
 
-  taosArrayDestroy(pInfo->cmpParam.orderInfo);
-  destroyResultBuf(pInfo->pSortInternalBuf);
-
-  tMergeTreeDestroy(pInfo->pMergeTree);
+  taosArrayDestroy(pInfo->orderInfo);
 }
 
 static void destroyConditionOperatorInfo(void* param, int32_t numOfOutput) {
@@ -7312,7 +7152,7 @@ SOperatorInfo* createMultiTableAggOperatorInfo(SOperatorInfo* downstream, SArray
   initAggInfo(pInfo, pExprInfo, numOfRows, pTableGroupInfo);
 
   size_t  tableGroup = taosArrayGetSize(pTableGroupInfo->pGroupList);
-  initResultRowInfo(&pInfo->binfo.resultRowInfo, (int32_t)tableGroup, TSDB_DATA_TYPE_INT);
+  initResultRowInfo(&pInfo->binfo.resultRowInfo, (int32_t)tableGroup);
 
   SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
   pOperator->name         = "MultiTableAggregate";
@@ -7325,7 +7165,7 @@ SOperatorInfo* createMultiTableAggOperatorInfo(SOperatorInfo* downstream, SArray
 
   pOperator->exec         = doMultiTableAggregate;
   pOperator->cleanupFn    = destroyAggOperatorInfo;
-  appendDownstream(pOperator, downstream);
+  int32_t code = appendDownstream(pOperator, &downstream, 1);
 
   return pOperator;
 }
@@ -7340,7 +7180,7 @@ SOperatorInfo* createProjectOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperator
   pBInfo->pRes  = createOutputBuf(pExpr, numOfOutput, pInfo->bufCapacity);
   pBInfo->pCtx  = createSqlFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pBInfo->rowCellInfoOffset);
 
-  initResultRowInfo(&pBInfo->resultRowInfo, 8, TSDB_DATA_TYPE_INT);
+  initResultRowInfo(&pBInfo->resultRowInfo, 8);
   setDefaultOutputBuf(pRuntimeEnv, pBInfo, pInfo->seed, MAIN_SCAN);
 
   SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
@@ -7355,7 +7195,7 @@ SOperatorInfo* createProjectOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperator
 
   pOperator->exec         = doProjectOperation;
   pOperator->cleanupFn    = destroyProjectOperatorInfo;
-  appendDownstream(pOperator, downstream);
+  int32_t code = appendDownstream(pOperator, &downstream, 1);
 
   return pOperator;
 }
@@ -7413,7 +7253,7 @@ SOperatorInfo* createFilterOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorI
   pOperator->info         = pInfo;
   pOperator->pRuntimeEnv  = pRuntimeEnv;
   pOperator->cleanupFn    = destroyConditionOperatorInfo;
-  appendDownstream(pOperator, downstream);
+  int32_t code = appendDownstream(pOperator, &downstream, 1);
 
   return pOperator;
 }
@@ -7431,32 +7271,49 @@ SOperatorInfo* createLimitOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorIn
   pOperator->exec         = doLimit;
   pOperator->info         = pInfo;
   pOperator->pRuntimeEnv  = pRuntimeEnv;
-  appendDownstream(pOperator, downstream);
+    int32_t code = appendDownstream(pOperator, &downstream, 1);
 
   return pOperator;
 }
 
-SOperatorInfo* createTimeIntervalOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream, SExprInfo* pExpr, int32_t numOfOutput) {
+SOperatorInfo* createIntervalOperatorInfo(SOperatorInfo* downstream, SArray* pExprInfo, SExecTaskInfo* pTaskInfo) {
   STableIntervalOperatorInfo* pInfo = calloc(1, sizeof(STableIntervalOperatorInfo));
 
-  pInfo->pCtx = createSqlFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pInfo->rowCellInfoOffset);
-  pInfo->pRes = createOutputBuf(pExpr, numOfOutput, pRuntimeEnv->resultInfo.capacity);
-  initResultRowInfo(&pInfo->resultRowInfo, 8, TSDB_DATA_TYPE_INT);
+  initAggSup(&pInfo->aggSup, pExprInfo);
+
+  // todo:
+  pInfo->order = TSDB_ORDER_ASC;
+  pInfo->precision = TSDB_TIME_PRECISION_MICRO;
+  pInfo->win.skey = INT64_MIN;
+  pInfo->win.ekey = INT64_MAX;
+  pInfo->interval.intervalUnit = 's';
+  pInfo->interval.slidingUnit  = 's';
+  pInfo->interval.interval = 1000;
+  pInfo->interval.sliding  = 1000;
+
+  int32_t code = createDiskbasedBuf(&pInfo->pResultBuf, 4096, 4096 * 256, 0, "/tmp/");
+
+  int32_t numOfOutput = taosArrayGetSize(pExprInfo);
+  pInfo->binfo.pCtx = createSqlFunctionCtx_rv(pExprInfo, &pInfo->binfo.rowCellInfoOffset, &pInfo->binfo.resRowSize);
+  pInfo->binfo.pRes = createOutputBuf_rv(pExprInfo, pInfo->binfo.capacity);
+
+  initResultRowInfo(&pInfo->binfo.resultRowInfo, (int32_t)1);
 
   SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
 
   pOperator->name         = "TimeIntervalAggOperator";
-//  pOperator->operatorType = OP_TimeWindow;
+  pOperator->operatorType = OP_TimeWindow;
   pOperator->blockingOptr = true;
   pOperator->status       = OP_IN_EXECUTING;
-  pOperator->pExpr        = pExpr;
+  pOperator->pExpr        = exprArrayDup(pExprInfo);
+
+  pOperator->pTaskInfo    = pTaskInfo;
   pOperator->numOfOutput  = numOfOutput;
   pOperator->info         = pInfo;
-  pOperator->pRuntimeEnv  = pRuntimeEnv;
   pOperator->exec         = doIntervalAgg;
   pOperator->cleanupFn    = destroyBasicOperatorInfo;
 
-  appendDownstream(pOperator, downstream);
+  code = appendDownstream(pOperator, &downstream, 1);
   return pOperator;
 }
 
@@ -7464,9 +7321,9 @@ SOperatorInfo* createTimeIntervalOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOpe
 SOperatorInfo* createAllTimeIntervalOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream, SExprInfo* pExpr, int32_t numOfOutput) {
   STableIntervalOperatorInfo* pInfo = calloc(1, sizeof(STableIntervalOperatorInfo));
 
-  pInfo->pCtx = createSqlFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pInfo->rowCellInfoOffset);
-  pInfo->pRes = createOutputBuf(pExpr, numOfOutput, pRuntimeEnv->resultInfo.capacity);
-  initResultRowInfo(&pInfo->resultRowInfo, 8, TSDB_DATA_TYPE_INT);
+  pInfo->binfo.pCtx = createSqlFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pInfo->binfo.rowCellInfoOffset);
+  pInfo->binfo.pRes = createOutputBuf(pExpr, numOfOutput, pRuntimeEnv->resultInfo.capacity);
+  initResultRowInfo(&pInfo->binfo.resultRowInfo, 8);
 
   SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
 
@@ -7481,7 +7338,7 @@ SOperatorInfo* createAllTimeIntervalOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, S
   pOperator->exec         = doAllIntervalAgg;
   pOperator->cleanupFn    = destroyBasicOperatorInfo;
 
-  appendDownstream(pOperator, downstream);
+    int32_t code = appendDownstream(pOperator, &downstream, 1);
   return pOperator;
 }
 
@@ -7491,7 +7348,7 @@ SOperatorInfo* createStatewindowOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOper
   pInfo->reptScan   = false;
   pInfo->binfo.pCtx = createSqlFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pInfo->binfo.rowCellInfoOffset);
   pInfo->binfo.pRes = createOutputBuf(pExpr, numOfOutput, pRuntimeEnv->resultInfo.capacity);
-  initResultRowInfo(&pInfo->binfo.resultRowInfo, 8, TSDB_DATA_TYPE_INT);
+  initResultRowInfo(&pInfo->binfo.resultRowInfo, 8);
 
   SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
   pOperator->name         = "StateWindowOperator";
@@ -7505,7 +7362,7 @@ SOperatorInfo* createStatewindowOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOper
   pOperator->exec         = doStateWindowAgg;
   pOperator->cleanupFn    = destroyStateWindowOperatorInfo;
 
-  appendDownstream(pOperator, downstream);
+    int32_t code = appendDownstream(pOperator, &downstream, 1);
   return pOperator;
 }
 SOperatorInfo* createSWindowOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream, SExprInfo* pExpr, int32_t numOfOutput) {
@@ -7513,7 +7370,7 @@ SOperatorInfo* createSWindowOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperator
 
   pInfo->binfo.pCtx = createSqlFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pInfo->binfo.rowCellInfoOffset);
   pInfo->binfo.pRes = createOutputBuf(pExpr, numOfOutput, pRuntimeEnv->resultInfo.capacity);
-  initResultRowInfo(&pInfo->binfo.resultRowInfo, 8, TSDB_DATA_TYPE_INT);
+  initResultRowInfo(&pInfo->binfo.resultRowInfo, 8);
 
   pInfo->prevTs   = INT64_MIN;
   pInfo->reptScan = false;
@@ -7530,16 +7387,16 @@ SOperatorInfo* createSWindowOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperator
   pOperator->exec         = doSessionWindowAgg;
   pOperator->cleanupFn    = destroySWindowOperatorInfo;
 
-  appendDownstream(pOperator, downstream);
+    int32_t code = appendDownstream(pOperator, &downstream, 1);
   return pOperator;
 }
 
 SOperatorInfo* createMultiTableTimeIntervalOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream, SExprInfo* pExpr, int32_t numOfOutput) {
   STableIntervalOperatorInfo* pInfo = calloc(1, sizeof(STableIntervalOperatorInfo));
 
-  pInfo->pCtx = createSqlFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pInfo->rowCellInfoOffset);
-  pInfo->pRes = createOutputBuf(pExpr, numOfOutput, pRuntimeEnv->resultInfo.capacity);
-  initResultRowInfo(&pInfo->resultRowInfo, 8, TSDB_DATA_TYPE_INT);
+  pInfo->binfo.pCtx = createSqlFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pInfo->binfo.rowCellInfoOffset);
+  pInfo->binfo.pRes = createOutputBuf(pExpr, numOfOutput, pRuntimeEnv->resultInfo.capacity);
+  initResultRowInfo(&pInfo->binfo.resultRowInfo, 8);
 
   SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
   pOperator->name         = "MultiTableTimeIntervalOperator";
@@ -7554,16 +7411,16 @@ SOperatorInfo* createMultiTableTimeIntervalOperatorInfo(STaskRuntimeEnv* pRuntim
   pOperator->exec         = doSTableIntervalAgg;
   pOperator->cleanupFn    = destroyBasicOperatorInfo;
 
-  appendDownstream(pOperator, downstream);
+    int32_t code = appendDownstream(pOperator, &downstream, 1);
   return pOperator;
 }
 
 SOperatorInfo* createAllMultiTableTimeIntervalOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream, SExprInfo* pExpr, int32_t numOfOutput) {
   STableIntervalOperatorInfo* pInfo = calloc(1, sizeof(STableIntervalOperatorInfo));
 
-  pInfo->pCtx = createSqlFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pInfo->rowCellInfoOffset);
-  pInfo->pRes = createOutputBuf(pExpr, numOfOutput, pRuntimeEnv->resultInfo.capacity);
-  initResultRowInfo(&pInfo->resultRowInfo, 8, TSDB_DATA_TYPE_INT);
+  pInfo->binfo.pCtx = createSqlFunctionCtx(pRuntimeEnv, pExpr, numOfOutput, &pInfo->binfo.rowCellInfoOffset);
+  pInfo->binfo.pRes = createOutputBuf(pExpr, numOfOutput, pRuntimeEnv->resultInfo.capacity);
+  initResultRowInfo(&pInfo->binfo.resultRowInfo, 8);
 
   SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
   pOperator->name         = "AllMultiTableTimeIntervalOperator";
@@ -7578,12 +7435,11 @@ SOperatorInfo* createAllMultiTableTimeIntervalOperatorInfo(STaskRuntimeEnv* pRun
   pOperator->exec         = doAllSTableIntervalAgg;
   pOperator->cleanupFn    = destroyBasicOperatorInfo;
 
-  appendDownstream(pOperator, downstream);
+    int32_t code = appendDownstream(pOperator, &downstream, 1);
 
   return pOperator;
 }
 
-
 SOperatorInfo* createGroupbyOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInfo* downstream, SExprInfo* pExpr, int32_t numOfOutput) {
   SGroupbyOperatorInfo* pInfo = calloc(1, sizeof(SGroupbyOperatorInfo));
   pInfo->colIndex = -1;  // group by column index
@@ -7597,7 +7453,7 @@ SOperatorInfo* createGroupbyOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperator
       (int32_t)(getRowNumForMultioutput(pQueryAttr, pQueryAttr->topBotQuery, pQueryAttr->stableQuery)));
 
   pInfo->binfo.pRes = createOutputBuf(pExpr, numOfOutput, pRuntimeEnv->resultInfo.capacity);
-  initResultRowInfo(&pInfo->binfo.resultRowInfo, 8, TSDB_DATA_TYPE_INT);
+  initResultRowInfo(&pInfo->binfo.resultRowInfo, 8);
 
   SOperatorInfo* pOperator = calloc(1, sizeof(SOperatorInfo));
   pOperator->name         = "GroupbyAggOperator";
@@ -7611,7 +7467,7 @@ SOperatorInfo* createGroupbyOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperator
   pOperator->exec         = hashGroupbyAggregate;
   pOperator->cleanupFn    = destroyGroupbyOperatorInfo;
 
-  appendDownstream(pOperator, downstream);
+    int32_t code = appendDownstream(pOperator, &downstream, 1);
   return pOperator;
 }
 
@@ -7627,7 +7483,7 @@ SOperatorInfo* createFillOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInf
 
     TSKEY sk = TMIN(pQueryAttr->window.skey, pQueryAttr->window.ekey);
     TSKEY ek = TMAX(pQueryAttr->window.skey, pQueryAttr->window.ekey);
-    getAlignQueryTimeWindow(pQueryAttr, pQueryAttr->window.skey, sk, ek, &w);
+//    getAlignQueryTimeWindow(pQueryAttr, pQueryAttr->window.skey, sk, ek, &w);
 
     pInfo->pFillInfo =
         taosCreateFillInfo(pQueryAttr->order.order, w.skey, 0, (int32_t)pRuntimeEnv->resultInfo.capacity, numOfOutput,
@@ -7650,7 +7506,7 @@ SOperatorInfo* createFillOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorInf
   pOperator->exec         = doFill;
   pOperator->cleanupFn    = destroySFillOperatorInfo;
 
-  appendDownstream(pOperator, downstream);
+    int32_t code = appendDownstream(pOperator, &downstream, 1);
   return pOperator;
 }
 
@@ -7698,7 +7554,7 @@ SOperatorInfo* createSLimitOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperatorI
   pOperator->pRuntimeEnv  = pRuntimeEnv;
   pOperator->cleanupFn    = destroySlimitOperatorInfo;
 
-  appendDownstream(pOperator, downstream);
+    int32_t code = appendDownstream(pOperator, &downstream, 1);
   return pOperator;
 }
 
@@ -7996,7 +7852,7 @@ SOperatorInfo* createDistinctOperatorInfo(STaskRuntimeEnv* pRuntimeEnv, SOperato
   pOperator->pExpr        = pExpr; 
   pOperator->cleanupFn    = destroyDistinctOperatorInfo;
 
-  appendDownstream(pOperator, downstream);
+    int32_t code = appendDownstream(pOperator, &downstream, 1);
   return pOperator;
 }
 
@@ -8186,16 +8042,22 @@ SOperatorInfo* doCreateOperatorTreeNode(SPhyNode* pPhyNode, SExecTaskInfo* pTask
       STableGroupInfo groupInfo = {0};
 
       int32_t code = doCreateTableGroup(pHandle->meta, pScanPhyNode->tableType, pScanPhyNode->uid, &groupInfo, queryId, taskId);
+      SArray* idList = NULL;
 
-      SArray* pa = taosArrayGetP(groupInfo.pGroupList, 0);
-      ASSERT(taosArrayGetSize(groupInfo.pGroupList) == 1);
+      if (groupInfo.numOfTables > 0) {
+        SArray* pa = taosArrayGetP(groupInfo.pGroupList, 0);
+        ASSERT(taosArrayGetSize(groupInfo.pGroupList) == 1);
 
-      // Transfer the Array of STableKeyInfo into uid list.
-      size_t numOfTables = taosArrayGetSize(pa);
-      SArray* idList = taosArrayInit(numOfTables, sizeof(uint64_t));
-      for(int32_t i = 0; i < numOfTables; ++i) {
-        STableKeyInfo* pkeyInfo = taosArrayGet(pa, i);
-        taosArrayPush(idList, &pkeyInfo->uid);
+        // Transfer the Array of STableKeyInfo into uid list.
+        size_t  numOfTables = taosArrayGetSize(pa);
+        idList = taosArrayInit(numOfTables, sizeof(uint64_t));
+
+        for (int32_t i = 0; i < numOfTables; ++i) {
+          STableKeyInfo* pkeyInfo = taosArrayGet(pa, i);
+          taosArrayPush(idList, &pkeyInfo->uid);
+        }
+      } else {
+        idList = taosArrayInit(4, sizeof(uint64_t));
       }
 
       SOperatorInfo* pOperator = createStreamScanOperatorInfo(pHandle->reader, pPhyNode->pTargets, idList, pTaskInfo);
@@ -8370,7 +8232,6 @@ int32_t buildArithmeticExprFromMsg(SExprInfo *pExprInfo, void *pQueryMsg) {
   return TSDB_CODE_SUCCESS;
 }
 
-
 static int32_t updateOutputBufForTopBotQuery(SQueriedTableInfo* pTableInfo, SColumnInfo* pTagCols, SExprInfo* pExprs, int32_t numOfOutput, int32_t tagLen, bool superTable) {
   for (int32_t i = 0; i < numOfOutput; ++i) {
     int16_t functId = getExprFunctionId(&pExprs[i]);
@@ -8534,66 +8395,6 @@ int32_t createQueryFilter(char *data, uint16_t len, SFilterInfo** pFilters) {
 //  return ret;
 }
 
-
-// todo refactor
-int32_t createIndirectQueryFuncExprFromMsg(SQueryTableReq* pQueryMsg, int32_t numOfOutput, SExprInfo** pExprInfo,
-                                           SSqlExpr** pExpr, SExprInfo* prevExpr, struct SUdfInfo *pUdfInfo) {
-//  *pExprInfo = NULL;
-//  int32_t code = TSDB_CODE_SUCCESS;
-//
-//  SExprInfo *pExprs = (SExprInfo *)calloc(numOfOutput, sizeof(SExprInfo));
-//  if (pExprs == NULL) {
-//    return TSDB_CODE_QRY_OUT_OF_MEMORY;
-//  }
-//
-//  bool isSuperTable = QUERY_IS_STABLE_QUERY(pQueryMsg->queryType);
-//
-//  for (int32_t i = 0; i < numOfOutput; ++i) {
-//    pExprs[i].base = *pExpr[i];
-//    memset(pExprs[i].base.param, 0, sizeof(SVariant) * tListLen(pExprs[i].base.param));
-//
-//    for (int32_t j = 0; j < pExpr[i]->numOfParams; ++j) {
-//      taosVariantAssign(&pExprs[i].base.param[j], &pExpr[i]->param[j]);
-//    }
-//
-//    pExprs[i].base.resSchema.type = 0;
-//
-//    int16_t type = 0;
-//    int16_t bytes = 0;
-//
-//    // parse the arithmetic expression
-//    if (pExprs[i].base.functionId == FUNCTION_ARITHM) {
-//      code = buildArithmeticExprFromMsg(&pExprs[i], pQueryMsg);
-//
-//      if (code != TSDB_CODE_SUCCESS) {
-//        tfree(pExprs);
-//        return code;
-//      }
-//
-//      type  = TSDB_DATA_TYPE_DOUBLE;
-//      bytes = tDataTypes[type].bytes;
-//    } else {
-//      int32_t index = pExprs[i].base.colInfo.colIndex;
-//      assert(prevExpr[index].base.resSchema.colId == pExprs[i].base.pColumns->info.colId);
-//
-//      type  = prevExpr[index].base.resSchema.type;
-//      bytes = prevExpr[index].base.resSchema.bytes;
-//    }
-//
-//    int32_t param = (int32_t)pExprs[i].base.param[0].i;
-//    if (getResultDataInfo(type, bytes, functionId, param, &pExprs[i].base.resSchema.type, &pExprs[i].base.resSchema.bytes,
-//                          &pExprs[i].base.interBytes, 0, isSuperTable, pUdfInfo) != TSDB_CODE_SUCCESS) {
-//      tfree(pExprs);
-//      return TSDB_CODE_QRY_INVALID_MSG;
-//    }
-//
-//    assert(isValidDataType(pExprs[i].base.resSchema.type));
-//  }
-//
-//  *pExprInfo = pExprs;
-  return TSDB_CODE_SUCCESS;
-}
-
 SGroupbyExpr *createGroupbyExprFromMsg(SQueryTableReq *pQueryMsg, SColIndex *pColIndex, int32_t *code) {
   if (pQueryMsg->numOfGroupCols == 0) {
     return NULL;
@@ -9002,30 +8803,3 @@ void releaseQueryBuf(size_t numOfTables) {
   // restore value is not enough buffer available
   atomic_add_fetch_64(&tsQueryBufferSizeBytes, t);
 }
-
-void freeQueryAttr(STaskAttr* pQueryAttr) {
-  if (pQueryAttr != NULL) {
-    if (pQueryAttr->fillVal != NULL) {
-      tfree(pQueryAttr->fillVal);
-    }
-
-    pQueryAttr->pFilterInfo = doDestroyFilterInfo(pQueryAttr->pFilterInfo, pQueryAttr->numOfFilterCols);
-
-    pQueryAttr->pExpr1 = destroyQueryFuncExpr(pQueryAttr->pExpr1, pQueryAttr->numOfOutput);
-    pQueryAttr->pExpr2 = destroyQueryFuncExpr(pQueryAttr->pExpr2, pQueryAttr->numOfExpr2);
-    pQueryAttr->pExpr3 = destroyQueryFuncExpr(pQueryAttr->pExpr3, pQueryAttr->numOfExpr3);
-
-    tfree(pQueryAttr->tagColList);
-    tfree(pQueryAttr->pFilterInfo);
-
-    pQueryAttr->tableCols = freeColumnInfo(pQueryAttr->tableCols, pQueryAttr->numOfCols);
-
-    if (pQueryAttr->pGroupbyExpr != NULL) {
-      taosArrayDestroy(pQueryAttr->pGroupbyExpr->columnInfo);
-      tfree(pQueryAttr->pGroupbyExpr);
-    }
-
-//    filterFreeInfo(pQueryAttr->pFilters);
-  }
-}
-
diff --git a/source/libs/executor/src/tlinearhash.c b/source/libs/executor/src/tlinearhash.c
new file mode 100644
index 0000000000..3a58253d81
--- /dev/null
+++ b/source/libs/executor/src/tlinearhash.c
@@ -0,0 +1,427 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "tlinearhash.h"
+#include "tcfg.h"
+#include "taoserror.h"
+#include "tpagedbuf.h"
+
+#define LHASH_CAP_RATIO 0.85
+
+// Always located in memory
+typedef struct SLHashBucket {
+  SArray        *pPageIdList;
+  int32_t        size;            // the number of element in this entry
+} SLHashBucket;
+
+typedef struct SLHashObj {
+  SDiskbasedBuf *pBuf;
+  _hash_fn_t     hashFn;
+  int32_t        tuplesPerPage;
+  SLHashBucket **pBucket;         // entry list
+  int32_t        numOfAlloc;      // number of allocated bucket ptr slot
+  int32_t        bits;            // the number of bits used in hash
+  int32_t        numOfBuckets;    // the number of buckets
+  int64_t        size;            // the number of total items
+} SLHashObj;
+
+/**
+ * the data struct for each hash node
+ * +-----------+-------+--------+
+ * | SLHashNode|  key  |  data  |
+ * +-----------+-------+--------+
+ */
+typedef struct SLHashNode {
+  uint16_t   keyLen;
+  uint16_t   dataLen;
+} SLHashNode;
+
+#define GET_LHASH_NODE_KEY(_n)      (((char*)(_n)) + sizeof(SLHashNode))
+#define GET_LHASH_NODE_DATA(_n)     ((char*)(_n) + sizeof(SLHashNode) + ((SLHashNode*)(_n))->keyLen)
+#define GET_LHASH_NODE_LEN(_n)      (sizeof(SLHashNode) + ((SLHashNode*)(_n))->keyLen + ((SLHashNode*)(_n))->dataLen)
+
+static int32_t doAddNewBucket(SLHashObj* pHashObj);
+
+static int32_t doGetBucketIdFromHashVal(int32_t hashv, int32_t bits) {
+  return hashv & ((1ul << (bits)) - 1);
+}
+
+static int32_t doGetAlternativeBucketId(int32_t bucketId, int32_t bits, int32_t numOfBuckets) {
+  int32_t v = bucketId - (1ul << (bits - 1));
+  ASSERT(v < numOfBuckets);
+  return v;
+}
+
+static int32_t doGetRelatedSplitBucketId(int32_t bucketId, int32_t bits) {
+  int32_t splitBucketId = (1ul << (bits - 1)) ^ bucketId;
+  return splitBucketId;
+}
+
+static void doCopyObject(char* p, const void* key, int32_t keyLen, const void* data, int32_t size) {
+  *(uint16_t*) p = keyLen;
+  p += sizeof(uint16_t);
+  *(uint16_t*) p = size;
+  p += sizeof(uint16_t);
+
+  memcpy(p, key, keyLen);
+  p += keyLen;
+
+  memcpy(p, data, size);
+}
+
+static int32_t doAddToBucket(SLHashObj* pHashObj, SLHashBucket* pBucket, int32_t index, const void* key, int32_t keyLen,
+                             const void* data, int32_t size) {
+  int32_t pageId = *(int32_t*)taosArrayGetLast(pBucket->pPageIdList);
+
+  SFilePage* pPage = getBufPage(pHashObj->pBuf, pageId);
+  ASSERT (pPage != NULL);
+
+  // put to current buf page
+  size_t nodeSize = sizeof(SLHashNode) + keyLen + size;
+  ASSERT(nodeSize + sizeof(SFilePage) <= getBufPageSize(pHashObj->pBuf));
+
+  if (pPage->num + nodeSize > getBufPageSize(pHashObj->pBuf)) {
+    releaseBufPage(pHashObj->pBuf, pPage);
+
+    // allocate the overflow buffer page to hold this k/v.
+    int32_t newPageId = -1;
+    SFilePage* pNewPage = getNewBufPage(pHashObj->pBuf, 0, &newPageId);
+    if (pNewPage == NULL) {
+      return TSDB_CODE_OUT_OF_MEMORY;
+    }
+
+    taosArrayPush(pBucket->pPageIdList, &newPageId);
+
+    doCopyObject(pNewPage->data, key, keyLen, data, size);
+    pNewPage->num = sizeof(SFilePage) + nodeSize;
+
+    setBufPageDirty(pNewPage, true);
+    releaseBufPage(pHashObj->pBuf, pNewPage);
+  } else {
+    char* p = (char*) pPage + pPage->num;
+    doCopyObject(p, key, keyLen, data, size);
+    pPage->num += nodeSize;
+    setBufPageDirty(pPage, true);
+    releaseBufPage(pHashObj->pBuf, pPage);
+  }
+
+  pBucket->size += 1;
+//  printf("===> add to bucket:0x%x, num:%d, key:%d\n", index, pBucket->size, *(int*) key);
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static void doRemoveFromBucket(SFilePage* pPage, SLHashNode* pNode, SLHashBucket* pBucket) {
+  ASSERT(pPage != NULL && pNode != NULL && pBucket->size >= 1);
+
+  int32_t len = GET_LHASH_NODE_LEN(pNode);
+  char* p = (char*) pNode + len;
+
+  char* pEnd = (char*)pPage + pPage->num;
+  memmove(pNode, p, (pEnd - p));
+
+  pPage->num -= len;
+  if (pPage->num == 0) {
+    // this page is empty, could be recycle in the future.
+  }
+
+  setBufPageDirty(pPage, true);
+
+  pBucket->size -= 1;
+}
+
+static void doCompressBucketPages(SLHashObj *pHashObj, SLHashBucket* pBucket) {
+  size_t numOfPages = taosArrayGetSize(pBucket->pPageIdList);
+  if (numOfPages <= 1) {
+    return;
+  }
+
+  int32_t*   firstPage = taosArrayGet(pBucket->pPageIdList, 0);
+  SFilePage* pFirst = getBufPage(pHashObj->pBuf, *firstPage);
+
+  int32_t*   pageId = taosArrayGetLast(pBucket->pPageIdList);
+  SFilePage* pLast = getBufPage(pHashObj->pBuf, *pageId);
+
+  if (pLast->num <= sizeof(SFilePage)) {
+    // this is empty
+    dBufSetBufPageRecycled(pHashObj->pBuf, pLast);
+    releaseBufPage(pHashObj->pBuf, pFirst);
+    taosArrayRemove(pBucket->pPageIdList, numOfPages - 1);
+    return;
+  }
+
+  char*   pStart = pLast->data;
+  int32_t nodeSize = GET_LHASH_NODE_LEN(pStart);
+  while (1) {
+    if (pFirst->num + nodeSize < getBufPageSize(pHashObj->pBuf)) {
+      char* p = ((char*)pFirst) + pFirst->num;
+
+      SLHashNode* pNode = (SLHashNode*)pStart;
+      doCopyObject(p, GET_LHASH_NODE_KEY(pStart), pNode->keyLen, GET_LHASH_NODE_DATA(pStart), pNode->dataLen);
+
+      setBufPageDirty(pFirst, true);
+      setBufPageDirty(pLast, true);
+
+      ASSERT(pLast->num >= nodeSize + sizeof(SFilePage));
+
+      pFirst->num += nodeSize;
+      pLast->num -= nodeSize;
+
+      pStart += nodeSize;
+      if (pLast->num <= sizeof(SFilePage)) {
+        // this is empty
+        dBufSetBufPageRecycled(pHashObj->pBuf, pLast);
+        releaseBufPage(pHashObj->pBuf, pFirst);
+        taosArrayRemove(pBucket->pPageIdList, numOfPages - 1);
+        break;
+      }
+
+      nodeSize = GET_LHASH_NODE_LEN(pStart);
+    } else { // move to the front of pLast page
+      if (pStart != pLast->data) {
+        memmove(pLast->data, pStart, (((char*)pLast) + pLast->num - pStart));
+        setBufPageDirty(pLast, true);
+      }
+
+      releaseBufPage(pHashObj->pBuf, pLast);
+      releaseBufPage(pHashObj->pBuf, pFirst);
+      break;
+    }
+  }
+}
+
+static int32_t doAddNewBucket(SLHashObj* pHashObj) {
+  if (pHashObj->numOfBuckets + 1 > pHashObj->numOfAlloc) {
+    int32_t newLen = pHashObj->numOfAlloc * 1.25;
+    if (newLen == pHashObj->numOfAlloc) {
+      newLen += 4;
+    }
+
+    char* p = realloc(pHashObj->pBucket, POINTER_BYTES * newLen);
+    if (p == NULL) {
+      return TSDB_CODE_OUT_OF_MEMORY;
+    }
+
+    memset(p + POINTER_BYTES * pHashObj->numOfBuckets, 0, newLen - pHashObj->numOfBuckets);
+    pHashObj->pBucket = (SLHashBucket**) p;
+    pHashObj->numOfAlloc = newLen;
+  }
+
+  SLHashBucket* pBucket = calloc(1, sizeof(SLHashBucket));
+  pHashObj->pBucket[pHashObj->numOfBuckets] = pBucket;
+
+  pBucket->pPageIdList = taosArrayInit(2, sizeof(int32_t));
+  if (pBucket->pPageIdList == NULL || pBucket == NULL) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  int32_t pageId = -1;
+  SFilePage* p = getNewBufPage(pHashObj->pBuf, 0, &pageId);
+  p->num = sizeof(SFilePage);
+  setBufPageDirty(p, true);
+
+  releaseBufPage(pHashObj->pBuf, p);
+  taosArrayPush(pBucket->pPageIdList, &pageId);
+
+  pHashObj->numOfBuckets += 1;
+//  printf("---------------add new bucket, id:0x%x, total:%d\n", pHashObj->numOfBuckets - 1, pHashObj->numOfBuckets);
+  return TSDB_CODE_SUCCESS;
+}
+
+SLHashObj* tHashInit(int32_t inMemPages, int32_t pageSize, _hash_fn_t fn, int32_t numOfTuplePerPage) {
+  SLHashObj* pHashObj = calloc(1, sizeof(SLHashObj));
+  if (pHashObj == NULL) {
+    terrno = TSDB_CODE_OUT_OF_MEMORY;
+    return NULL;
+  }
+
+  int32_t code = createDiskbasedBuf(&pHashObj->pBuf, pageSize, inMemPages * pageSize, 0, "/tmp");
+  if (code != 0) {
+    terrno = code;
+    return NULL;
+  }
+
+  setBufPageCompressOnDisk(pHashObj->pBuf, false);
+
+  /**
+   * The number of bits in the hash value, which is used to decide the exact bucket where the object should be located in.
+   * The initial value is 0.
+   */
+  pHashObj->bits   = 0;
+  pHashObj->hashFn = fn;
+  pHashObj->tuplesPerPage = numOfTuplePerPage;
+
+  pHashObj->numOfAlloc   = 4;  // initial allocated array list
+  pHashObj->pBucket = calloc(pHashObj->numOfAlloc, POINTER_BYTES);
+
+  code = doAddNewBucket(pHashObj);
+  if (code != TSDB_CODE_SUCCESS) {
+    destroyDiskbasedBuf(pHashObj->pBuf);
+    tfree(pHashObj);
+    terrno = code;
+    return NULL;
+  }
+
+  return pHashObj;
+}
+
+void* tHashCleanup(SLHashObj* pHashObj) {
+  destroyDiskbasedBuf(pHashObj->pBuf);
+  for(int32_t i = 0; i < pHashObj->numOfBuckets; ++i) {
+    taosArrayDestroy(pHashObj->pBucket[i]->pPageIdList);
+    tfree(pHashObj->pBucket[i]);
+  }
+
+  tfree(pHashObj->pBucket);
+  tfree(pHashObj);
+  return NULL;
+}
+
+int32_t tHashPut(SLHashObj* pHashObj, const void *key, size_t keyLen, void *data, size_t size) {
+  ASSERT(pHashObj != NULL && key != NULL);
+
+  if (pHashObj->bits == 0) {
+    SLHashBucket* pBucket = pHashObj->pBucket[0];
+    doAddToBucket(pHashObj, pBucket, 0, key, keyLen, data, size);
+  } else {
+    int32_t hashVal = pHashObj->hashFn(key, keyLen);
+    int32_t v = doGetBucketIdFromHashVal(hashVal, pHashObj->bits);
+
+    if (v >= pHashObj->numOfBuckets) {
+      int32_t newBucketId = doGetAlternativeBucketId(v, pHashObj->bits, pHashObj->numOfBuckets);
+//      printf("bucketId: 0x%x not exists, put it into 0x%x instead\n", v, newBucketId);
+      v = newBucketId;
+    }
+
+    SLHashBucket* pBucket = pHashObj->pBucket[v];
+    int32_t code = doAddToBucket(pHashObj, pBucket, v, key, keyLen, data, size);
+    if (code != TSDB_CODE_SUCCESS) {
+      return code;
+    }
+  }
+
+  pHashObj->size += 1;
+
+  // Too many records, needs to bucket split
+  if ((pHashObj->numOfBuckets * LHASH_CAP_RATIO * pHashObj->tuplesPerPage) < pHashObj->size) {
+    int32_t newBucketId = pHashObj->numOfBuckets;
+
+    int32_t code = doAddNewBucket(pHashObj);
+    if (code != TSDB_CODE_SUCCESS) {
+      return code;
+    }
+
+    int32_t numOfBits = ceil(log(pHashObj->numOfBuckets) / log(2));
+    if (numOfBits > pHashObj->bits) {
+//      printf("extend the bits from %d to %d, new bucket:%d\n", pHashObj->bits, numOfBits, newBucketId);
+      ASSERT(numOfBits == pHashObj->bits + 1);
+      pHashObj->bits = numOfBits;
+    }
+
+    int32_t splitBucketId = doGetRelatedSplitBucketId(newBucketId, pHashObj->bits);
+
+    // load all data in this bucket and check if the data needs to relocated into the new bucket
+    SLHashBucket* pBucket = pHashObj->pBucket[splitBucketId];
+//    printf("split %d items' bucket:0x%x to new bucket:0x%x\n", pBucket->size, splitBucketId, newBucketId);
+
+    for (int32_t i = 0; i < taosArrayGetSize(pBucket->pPageIdList); ++i) {
+      int32_t    pageId = *(int32_t*)taosArrayGet(pBucket->pPageIdList, i);
+      SFilePage* p = getBufPage(pHashObj->pBuf, pageId);
+
+      char* pStart = p->data;
+      while (pStart - ((char*) p) < p->num) {
+        SLHashNode* pNode = (SLHashNode*)pStart;
+        ASSERT(pNode->keyLen > 0 && pNode->dataLen >= 0);
+
+        char* k = GET_LHASH_NODE_KEY(pNode);
+        int32_t hashv = pHashObj->hashFn(k, pNode->keyLen);
+        int32_t v1 = doGetBucketIdFromHashVal(hashv, pHashObj->bits);
+
+        if (v1 != splitBucketId) {  // place it into the new bucket
+          ASSERT(v1 == newBucketId);
+//          printf("move key:%d to 0x%x bucket, remain items:%d\n", *(int32_t*)k, v1, pBucket->size - 1);
+
+          SLHashBucket* pNewBucket = pHashObj->pBucket[newBucketId];
+          doAddToBucket(pHashObj, pNewBucket, newBucketId, (void*)GET_LHASH_NODE_KEY(pNode), pNode->keyLen,
+                        GET_LHASH_NODE_KEY(pNode), pNode->dataLen);
+          doRemoveFromBucket(p, pNode, pBucket);
+        } else {
+//          printf("check key:%d, located into: %d, skip it\n", *(int*) k, v1);
+
+          int32_t nodeSize = GET_LHASH_NODE_LEN(pStart);
+          pStart += nodeSize;
+        }
+      }
+      releaseBufPage(pHashObj->pBuf, p);
+    }
+
+    doCompressBucketPages(pHashObj, pBucket);
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+char* tHashGet(SLHashObj* pHashObj, const void *key, size_t keyLen) {
+  ASSERT(pHashObj != NULL && key != NULL && keyLen > 0);
+  int32_t hashv = pHashObj->hashFn(key, keyLen);
+
+  int32_t bucketId = doGetBucketIdFromHashVal(hashv, pHashObj->bits);
+  if (bucketId >= pHashObj->numOfBuckets) {
+    bucketId = doGetAlternativeBucketId(bucketId, pHashObj->bits, pHashObj->numOfBuckets);
+  }
+
+  SLHashBucket* pBucket = pHashObj->pBucket[bucketId];
+  for (int32_t i = 0; i < taosArrayGetSize(pBucket->pPageIdList); ++i) {
+    int32_t    pageId = *(int32_t*)taosArrayGet(pBucket->pPageIdList, i);
+    SFilePage* p = getBufPage(pHashObj->pBuf, pageId);
+
+    char* pStart = p->data;
+    while (pStart - p->data < p->num) {
+      SLHashNode* pNode = (SLHashNode*)pStart;
+
+      char* k = GET_LHASH_NODE_KEY(pNode);
+      if (pNode->keyLen == keyLen && (memcmp(key, k, keyLen) == 0)) {
+        releaseBufPage(pHashObj->pBuf, p);
+        return GET_LHASH_NODE_DATA(pNode);
+      } else {
+        pStart += GET_LHASH_NODE_LEN(pStart);
+      }
+    }
+
+    releaseBufPage(pHashObj->pBuf, p);
+  }
+
+  return NULL;
+}
+
+int32_t tHashRemove(SLHashObj* pHashObj, const void *key, size_t keyLen) {
+  // todo
+}
+
+void tHashPrint(const SLHashObj* pHashObj, int32_t type) {
+  printf("==================== linear hash ====================\n");
+  printf("total bucket:%d, size:%ld, ratio:%.2f\n", pHashObj->numOfBuckets, pHashObj->size, LHASH_CAP_RATIO);
+
+  dBufSetPrintInfo(pHashObj->pBuf);
+
+  if (type == LINEAR_HASH_DATA) {
+    for (int32_t i = 0; i < pHashObj->numOfBuckets; ++i) {
+//      printf("bucket: 0x%x, obj:%d, page:%d\n", i, pHashObj->pBucket[i]->size,
+//             (int)taosArrayGetSize(pHashObj->pBucket[i]->pPageIdList));
+    }
+  } else {
+    dBufPrintStatis(pHashObj->pBuf);
+  }
+}
\ No newline at end of file
diff --git a/source/libs/executor/src/tsort.c b/source/libs/executor/src/tsort.c
new file mode 100644
index 0000000000..6e7b6b4659
--- /dev/null
+++ b/source/libs/executor/src/tsort.c
@@ -0,0 +1,679 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "common.h"
+#include "query.h"
+
+#include "tsort.h"
+#include "tep.h"
+#include "tcfg.h"
+#include "tlosertree.h"
+#include "tpagedbuf.h"
+#include "tutil.h"
+
+typedef struct STupleHandle {
+  SSDataBlock* pBlock;
+  int32_t      rowIndex;
+} STupleHandle;
+
+typedef struct SSortHandle {
+  int32_t           type;
+
+  int32_t           pageSize;
+  int32_t           numOfPages;
+  SDiskbasedBuf    *pBuf;
+
+  SArray           *pOrderInfo;
+  bool              nullFirst;
+  bool              hasVarCol;
+  SArray           *pOrderedSource;
+
+  _sort_fetch_block_fn_t  fetchfp;
+  _sort_merge_compar_fn_t comparFn;
+
+  void             *pParam;
+  SMultiwayMergeTreeInfo *pMergeTree;
+  int32_t           numOfCols;
+
+  int64_t           startTs;
+  uint64_t          sortElapsed;
+  uint64_t          totalElapsed;
+
+  int32_t           sourceId;
+  SSDataBlock      *pDataBlock;
+  SMsortComparParam cmpParam;
+  int32_t           numOfCompletedSources;
+  bool              opened;
+  const char       *idStr;
+
+  bool              inMemSort;
+  bool              needAdjust;
+  STupleHandle      tupleHandle;
+} SSortHandle;
+
+static int32_t msortComparFn(const void *pLeft, const void *pRight, void *param);
+
+static SSDataBlock* createDataBlock_rv(SSchema* pSchema, int32_t numOfCols) {
+  SSDataBlock* pBlock = calloc(1, sizeof(SSDataBlock));
+  pBlock->pDataBlock = taosArrayInit(numOfCols, sizeof(SColumnInfoData));
+  pBlock->info.numOfCols = numOfCols;
+
+  for(int32_t i = 0; i < numOfCols; ++i) {
+    SColumnInfoData  colInfo = {0};
+
+    colInfo.info.type  = pSchema[i].type;
+    colInfo.info.bytes = pSchema[i].bytes;
+    colInfo.info.colId = pSchema[i].colId;
+    taosArrayPush(pBlock->pDataBlock, &colInfo);
+  }
+
+  return pBlock;
+}
+
+/**
+ *
+ * @param type
+ * @return
+ */
+SSortHandle* tsortCreateSortHandle(SArray* pOrderInfo, bool nullFirst, int32_t type, int32_t pageSize, int32_t numOfPages, SSchema* pSchema, int32_t numOfCols, const char* idstr) {
+  SSortHandle* pSortHandle = calloc(1, sizeof(SSortHandle));
+
+  pSortHandle->type       = type;
+  pSortHandle->pageSize   = pageSize;
+  pSortHandle->numOfPages = numOfPages;
+  pSortHandle->pOrderedSource = taosArrayInit(4, POINTER_BYTES);
+  pSortHandle->pOrderInfo = pOrderInfo;
+  pSortHandle->nullFirst  = nullFirst;
+  pSortHandle->cmpParam.orderInfo = pOrderInfo;
+
+  pSortHandle->pDataBlock = createDataBlock_rv(pSchema, numOfCols);
+  tsortSetComparFp(pSortHandle, msortComparFn);
+
+  if (idstr != NULL) {
+    pSortHandle->idStr    = strdup(idstr);
+  }
+
+  return pSortHandle;
+}
+
+void tsortDestroySortHandle(SSortHandle* pSortHandle) {
+  tsortClose(pSortHandle);
+  if (pSortHandle->pMergeTree != NULL) {
+    tMergeTreeDestroy(pSortHandle->pMergeTree);
+  }
+
+  destroyDiskbasedBuf(pSortHandle->pBuf);
+  tfree(pSortHandle->idStr);
+  tfree(pSortHandle);
+}
+
+int32_t tsortAddSource(SSortHandle* pSortHandle, void* pSource) {
+  taosArrayPush(pSortHandle->pOrderedSource, &pSource);
+}
+
+static int32_t doAddNewExternalMemSource(SDiskbasedBuf *pBuf, SArray* pAllSources, SSDataBlock* pBlock, int32_t* sourceId) {
+  SExternalMemSource* pSource = calloc(1, sizeof(SExternalMemSource));
+  if (pSource == NULL) {
+    return TSDB_CODE_QRY_OUT_OF_MEMORY;
+  }
+
+  pSource->pageIdList = getDataBufPagesIdList(pBuf, (*sourceId));
+  pSource->src.pBlock = pBlock;
+
+  taosArrayPush(pAllSources, &pSource);
+
+  (*sourceId) += 1;
+
+  int32_t rowSize = blockDataGetSerialRowSize(pSource->src.pBlock);
+  int32_t numOfRows = (getBufPageSize(pBuf) - blockDataGetSerialMetaSize(pBlock))/rowSize;
+
+  return blockDataEnsureCapacity(pSource->src.pBlock, numOfRows);
+}
+
+static int32_t doAddToBuf(SSDataBlock* pDataBlock, SSortHandle* pHandle) {
+  int32_t start = 0;
+
+  if (pHandle->pBuf == NULL) {
+    int32_t code = createDiskbasedBuf(&pHandle->pBuf, pHandle->pageSize, pHandle->numOfPages * pHandle->pageSize, 0, "/tmp");
+    dBufSetPrintInfo(pHandle->pBuf);
+    if (code != TSDB_CODE_SUCCESS) {
+      return code;
+    }
+  }
+
+  while(start < pDataBlock->info.rows) {
+    int32_t stop = 0;
+    blockDataSplitRows(pDataBlock, pHandle->hasVarCol, start, &stop, pHandle->pageSize);
+    SSDataBlock* p = blockDataExtractBlock(pDataBlock, start, stop - start + 1);
+    if (p == NULL) {
+      return terrno;
+    }
+
+    int32_t pageId = -1;
+    SFilePage* pPage = getNewBufPage(pHandle->pBuf, pHandle->sourceId, &pageId);
+    if (pPage == NULL) {
+      return terrno;
+    }
+
+    int32_t size = blockDataGetSize(p) + sizeof(int32_t)  + p->info.numOfCols * sizeof(int32_t);
+    assert(size <= getBufPageSize(pHandle->pBuf));
+
+    blockDataToBuf(pPage->data, p);
+
+    setBufPageDirty(pPage, true);
+    releaseBufPage(pHandle->pBuf, pPage);
+
+    blockDataDestroy(p);
+    start = stop + 1;
+  }
+
+  blockDataClearup(pDataBlock, pHandle->hasVarCol);
+
+  SSDataBlock* pBlock = createOneDataBlock(pDataBlock);
+  int32_t code = doAddNewExternalMemSource(pHandle->pBuf, pHandle->pOrderedSource, pBlock, &pHandle->sourceId);
+  if (code != TSDB_CODE_SUCCESS) {
+    return code;
+  }
+}
+
+static int32_t sortComparInit(SMsortComparParam* cmpParam, SArray* pSources, int32_t startIndex, int32_t endIndex, SSortHandle* pHandle) {
+  cmpParam->pSources  = taosArrayGet(pSources, startIndex);
+  cmpParam->numOfSources = (endIndex - startIndex + 1);
+
+  int32_t code = 0;
+
+  if (pHandle->type == SORT_SINGLESOURCE_SORT) {
+    for (int32_t i = 0; i < cmpParam->numOfSources; ++i) {
+      SExternalMemSource* pSource = cmpParam->pSources[i];
+      SPageInfo*          pPgInfo = *(SPageInfo**)taosArrayGet(pSource->pageIdList, pSource->pageIndex);
+
+      SFilePage* pPage = getBufPage(pHandle->pBuf, getPageId(pPgInfo));
+      code = blockDataFromBuf(pSource->src.pBlock, pPage->data);
+      if (code != TSDB_CODE_SUCCESS) {
+        return code;
+      }
+
+      releaseBufPage(pHandle->pBuf, pPage);
+    }
+  } else {
+    // multi-pass internal merge sort is required
+    if (pHandle->pBuf == NULL) {
+      code = createDiskbasedBuf(&pHandle->pBuf, pHandle->pageSize, pHandle->numOfPages * pHandle->pageSize, 0, "/tmp");
+      dBufSetPrintInfo(pHandle->pBuf);
+      if (code != TSDB_CODE_SUCCESS) {
+        return code;
+      }
+    }
+
+    for (int32_t i = 0; i < cmpParam->numOfSources; ++i) {
+      SGenericSource* pSource = cmpParam->pSources[i];
+      pSource->src.pBlock = pHandle->fetchfp(pSource->param);
+    }
+  }
+
+  return code;
+}
+
+static int32_t sortComparClearup(SMsortComparParam* cmpParam) {
+  for(int32_t i = 0; i < cmpParam->numOfSources; ++i) {
+    SExternalMemSource* pSource = cmpParam->pSources[i];
+    blockDataDestroy(pSource->src.pBlock);
+    tfree(pSource);
+  }
+
+  cmpParam->numOfSources = 0;
+}
+
+static void appendOneRowToDataBlock(SSDataBlock *pBlock, const SSDataBlock* pSource, int32_t* rowIndex) {
+  for (int32_t i = 0; i < pBlock->info.numOfCols; ++i) {
+    SColumnInfoData* pColInfo = taosArrayGet(pBlock->pDataBlock, i);
+
+    SColumnInfoData* pSrcColInfo = taosArrayGet(pSource->pDataBlock, i);
+    bool isNull = colDataIsNull(pSrcColInfo, pSource->info.rows, *rowIndex, NULL);
+
+    if (isNull) {
+      colDataAppend(pColInfo, pBlock->info.rows, NULL, true);
+    } else {
+      char* pData = colDataGetData(pSrcColInfo, *rowIndex);
+      colDataAppend(pColInfo, pBlock->info.rows, pData, false);
+    }
+  }
+
+  pBlock->info.rows += 1;
+  *rowIndex += 1;
+}
+
+static int32_t adjustMergeTreeForNextTuple(SExternalMemSource *pSource, SMultiwayMergeTreeInfo *pTree, SSortHandle *pHandle, int32_t* numOfCompleted) {
+  /*
+   * load a new SDataBlock into memory of a given intermediate data-set source,
+   * since it's last record in buffer has been chosen to be processed, as the winner of loser-tree
+   */
+  if (pSource->src.rowIndex >= pSource->src.pBlock->info.rows) {
+    pSource->src.rowIndex = 0;
+
+    if (pHandle->type == SORT_SINGLESOURCE_SORT) {
+      if (pSource->pageIndex >= taosArrayGetSize(pSource->pageIdList)) {
+        (*numOfCompleted) += 1;
+        pSource->src.rowIndex = -1;
+        pSource->pageIndex = -1;
+        pSource->src.pBlock = blockDataDestroy(pSource->src.pBlock);
+      } else {
+        SPageInfo* pPgInfo = *(SPageInfo**)taosArrayGet(pSource->pageIdList, pSource->pageIndex);
+
+        SFilePage* pPage = getBufPage(pHandle->pBuf, getPageId(pPgInfo));
+        int32_t    code = blockDataFromBuf(pSource->src.pBlock, pPage->data);
+        if (code != TSDB_CODE_SUCCESS) {
+          return code;
+        }
+
+        releaseBufPage(pHandle->pBuf, pPage);
+      }
+    } else {
+      pSource->src.pBlock = pHandle->fetchfp(((SGenericSource*)pSource)->param);
+      if (pSource->src.pBlock == NULL) {
+        (*numOfCompleted) += 1;
+        pSource->src.rowIndex = -1;
+      }
+    }
+  }
+
+  /*
+   * Adjust loser tree otherwise, according to new candidate data
+   * if the loser tree is rebuild completed, we do not need to adjust
+   */
+  int32_t leafNodeIndex = tMergeTreeGetAdjustIndex(pTree);
+
+#ifdef _DEBUG_VIEW
+  printf("before adjust:\t");
+  tMergeTreePrint(pTree);
+#endif
+
+  tMergeTreeAdjust(pTree, leafNodeIndex);
+
+#ifdef _DEBUG_VIEW
+  printf("\nafter adjust:\t");
+  tMergeTreePrint(pTree);
+#endif
+}
+
+static SSDataBlock* getSortedBlockData(SSortHandle* pHandle, SMsortComparParam* cmpParam, int32_t capacity) {
+  blockDataClearup(pHandle->pDataBlock, pHandle->hasVarCol);
+
+  while(1) {
+    if (cmpParam->numOfSources == pHandle->numOfCompletedSources) {
+      break;
+    }
+
+    int32_t index = tMergeTreeGetChosenIndex(pHandle->pMergeTree);
+
+    SExternalMemSource *pSource = (*cmpParam).pSources[index];
+    appendOneRowToDataBlock(pHandle->pDataBlock, pSource->src.pBlock, &pSource->src.rowIndex);
+
+    int32_t code = adjustMergeTreeForNextTuple(pSource, pHandle->pMergeTree, pHandle, &pHandle->numOfCompletedSources);
+    if (code != TSDB_CODE_SUCCESS) {
+      terrno = code;
+      return NULL;
+    }
+
+    if (pHandle->pDataBlock->info.rows >= capacity) {
+      return pHandle->pDataBlock;
+    }
+  }
+
+  return (pHandle->pDataBlock->info.rows > 0)? pHandle->pDataBlock:NULL;
+}
+
+int32_t msortComparFn(const void *pLeft, const void *pRight, void *param) {
+  int32_t pLeftIdx  = *(int32_t *)pLeft;
+  int32_t pRightIdx = *(int32_t *)pRight;
+
+  SMsortComparParam *pParam = (SMsortComparParam *)param;
+
+  SArray *pInfo = pParam->orderInfo;
+
+  SExternalMemSource* pLeftSource  = pParam->pSources[pLeftIdx];
+  SExternalMemSource* pRightSource = pParam->pSources[pRightIdx];
+
+  // this input is exhausted, set the special value to denote this
+  if (pLeftSource->src.rowIndex == -1) {
+    return 1;
+  }
+
+  if (pRightSource->src.rowIndex == -1) {
+    return -1;
+  }
+
+  SSDataBlock* pLeftBlock = pLeftSource->src.pBlock;
+  SSDataBlock* pRightBlock = pRightSource->src.pBlock;
+
+  for(int32_t i = 0; i < pInfo->size; ++i) {
+    SBlockOrderInfo* pOrder = TARRAY_GET_ELEM(pInfo, i);
+
+    SColumnInfoData* pLeftColInfoData = TARRAY_GET_ELEM(pLeftBlock->pDataBlock, pOrder->colIndex);
+
+    bool leftNull  = false;
+    if (pLeftColInfoData->hasNull) {
+      leftNull = colDataIsNull(pLeftColInfoData, pLeftBlock->info.rows, pLeftSource->src.rowIndex, pLeftBlock->pBlockAgg);
+    }
+
+    SColumnInfoData* pRightColInfoData = TARRAY_GET_ELEM(pRightBlock->pDataBlock, pOrder->colIndex);
+    bool rightNull = false;
+    if (pRightColInfoData->hasNull) {
+      rightNull = colDataIsNull(pRightColInfoData, pRightBlock->info.rows, pRightSource->src.rowIndex, pRightBlock->pBlockAgg);
+    }
+
+    if (leftNull && rightNull) {
+      continue; // continue to next slot
+    }
+
+    if (rightNull) {
+      return pParam->nullFirst? 1:-1;
+    }
+
+    if (leftNull) {
+      return pParam->nullFirst? -1:1;
+    }
+
+    void* left1  = colDataGetData(pLeftColInfoData, pLeftSource->src.rowIndex);
+    void* right1 = colDataGetData(pRightColInfoData, pRightSource->src.rowIndex);
+
+    switch(pLeftColInfoData->info.type) {
+      case TSDB_DATA_TYPE_INT: {
+        int32_t leftv = *(int32_t*)left1;
+        int32_t rightv = *(int32_t*)right1;
+
+        if (leftv == rightv) {
+          break;
+        } else {
+          if (pOrder->order == TSDB_ORDER_ASC) {
+            return leftv < rightv? -1 : 1;
+          } else {
+            return leftv < rightv? 1 : -1;
+          }
+        }
+      }
+      default:
+        assert(0);
+    }
+  }
+}
+
+static int32_t doInternalMergeSort(SSortHandle* pHandle) {
+  size_t numOfSources = taosArrayGetSize(pHandle->pOrderedSource);
+
+  // Calculate the I/O counts to complete the data sort.
+  double sortPass = floorl(log2(numOfSources) / log2(pHandle->numOfPages));
+
+  pHandle->totalElapsed = taosGetTimestampUs() - pHandle->startTs;
+  qDebug("%s %d rounds mergesort required to complete the sort, first-round sorted data size:%"PRIzu", sort:%"PRId64", total elapsed:%"PRId64,
+         pHandle->idStr, (int32_t) (sortPass + 1), getTotalBufSize(pHandle->pBuf), pHandle->sortElapsed, pHandle->totalElapsed);
+
+  size_t pgSize = pHandle->pageSize;
+  int32_t numOfRows = (pgSize - blockDataGetSerialMetaSize(pHandle->pDataBlock))/ blockDataGetSerialRowSize(pHandle->pDataBlock);
+
+  blockDataEnsureCapacity(pHandle->pDataBlock, numOfRows);
+
+  size_t numOfSorted = taosArrayGetSize(pHandle->pOrderedSource);
+  for(int32_t t = 0; t < sortPass; ++t) {
+    int64_t st = taosGetTimestampUs();
+
+    SArray* pResList = taosArrayInit(4, POINTER_BYTES);
+
+    int32_t numOfInputSources = pHandle->numOfPages;
+    int32_t sortGroup = (numOfSorted + numOfInputSources - 1) / numOfInputSources;
+
+    // Only *numOfInputSources* can be loaded into buffer to perform the external sort.
+    for(int32_t i = 0; i < sortGroup; ++i) {
+      pHandle->sourceId += 1;
+
+      int32_t end = (i + 1) * numOfInputSources - 1;
+      if (end > numOfSorted - 1) {
+        end = numOfSorted - 1;
+      }
+
+      pHandle->cmpParam.numOfSources = end - i * numOfInputSources + 1;
+
+      int32_t code = sortComparInit(&pHandle->cmpParam, pHandle->pOrderedSource, i * numOfInputSources, end, pHandle);
+      if (code != TSDB_CODE_SUCCESS) {
+        return code;
+      }
+
+      code = tMergeTreeCreate(&pHandle->pMergeTree, pHandle->cmpParam.numOfSources, &pHandle->cmpParam, pHandle->comparFn);
+      if (code != TSDB_CODE_SUCCESS) {
+        return code;
+      }
+
+      while (1) {
+        SSDataBlock* pDataBlock = getSortedBlockData(pHandle, &pHandle->cmpParam, numOfRows);
+        if (pDataBlock == NULL) {
+          break;
+        }
+
+        int32_t pageId = -1;
+        SFilePage* pPage = getNewBufPage(pHandle->pBuf, pHandle->sourceId, &pageId);
+        if (pPage == NULL) {
+          return terrno;
+        }
+
+        int32_t size = blockDataGetSize(pDataBlock) + sizeof(int32_t) + pDataBlock->info.numOfCols * sizeof(int32_t);
+        assert(size <= getBufPageSize(pHandle->pBuf));
+
+        blockDataToBuf(pPage->data, pDataBlock);
+
+        setBufPageDirty(pPage, true);
+        releaseBufPage(pHandle->pBuf, pPage);
+
+        blockDataClearup(pDataBlock, pHandle->hasVarCol);
+      }
+
+      tMergeTreeDestroy(pHandle->pMergeTree);
+      pHandle->numOfCompletedSources = 0;
+
+      SSDataBlock* pBlock = createOneDataBlock(pHandle->pDataBlock);
+      code = doAddNewExternalMemSource(pHandle->pBuf, pResList, pBlock, &pHandle->sourceId);
+      if (code != 0) {
+        return code;
+      }
+    }
+
+    sortComparClearup(&pHandle->cmpParam);
+
+    taosArrayClear(pHandle->pOrderedSource);
+    taosArrayAddAll(pHandle->pOrderedSource, pResList);
+    taosArrayDestroy(pResList);
+
+    numOfSorted = taosArrayGetSize(pHandle->pOrderedSource);
+
+    int64_t el = taosGetTimestampUs() - st;
+    pHandle->totalElapsed += el;
+
+    SDiskbasedBufStatis statis = getDBufStatis(pHandle->pBuf);
+    qDebug("%s %d round mergesort, elapsed:%"PRId64" readDisk:%.2f Kb, flushDisk:%.2f Kb", pHandle->idStr, t + 1, el, statis.loadBytes/1024.0,
+           statis.flushBytes/1024.0);
+
+    if (pHandle->type == SORT_MULTISOURCE_MERGE) {
+      pHandle->type = SORT_SINGLESOURCE_SORT;
+      pHandle->comparFn = msortComparFn;
+    }
+  }
+
+  pHandle->cmpParam.numOfSources = taosArrayGetSize(pHandle->pOrderedSource);
+  return 0;
+}
+
+static int32_t createInitialSortedMultiSources(SSortHandle* pHandle) {
+  size_t sortBufSize = pHandle->numOfPages * pHandle->pageSize;
+
+  if (pHandle->type == SORT_SINGLESOURCE_SORT) {
+    SGenericSource* source = taosArrayGetP(pHandle->pOrderedSource, 0);
+    taosArrayClear(pHandle->pOrderedSource);
+
+    while (1) {
+      SSDataBlock* pBlock = pHandle->fetchfp(source->param);
+      if (pBlock == NULL) {
+        break;
+      }
+
+      if (pHandle->pDataBlock == NULL) {
+        pHandle->pDataBlock = createOneDataBlock(pBlock);
+      }
+
+      int32_t code = blockDataMerge(pHandle->pDataBlock, pBlock);
+      if (code != 0) {
+        return code;
+      }
+
+      size_t size = blockDataGetSize(pHandle->pDataBlock);
+      if (size > sortBufSize) {
+        // Perform the in-memory sort and then flush data in the buffer into disk.
+        int64_t p = taosGetTimestampUs();
+        blockDataSort(pHandle->pDataBlock, pHandle->pOrderInfo, pHandle->nullFirst);
+
+        int64_t el = taosGetTimestampUs() - p;
+        pHandle->sortElapsed += el;
+
+        doAddToBuf(pHandle->pDataBlock, pHandle);
+      }
+    }
+
+    if (pHandle->pDataBlock->info.rows > 0) {
+      size_t size = blockDataGetSize(pHandle->pDataBlock);
+
+      // Perform the in-memory sort and then flush data in the buffer into disk.
+      blockDataSort(pHandle->pDataBlock, pHandle->pOrderInfo, pHandle->nullFirst);
+
+      // All sorted data can fit in memory, external memory sort is not needed. Return to directly
+      if (size <= sortBufSize) {
+        pHandle->cmpParam.numOfSources = 1;
+        pHandle->inMemSort = true;
+
+        pHandle->tupleHandle.rowIndex  = -1;
+        pHandle->tupleHandle.pBlock = pHandle->pDataBlock;
+        return 0;
+      } else {
+        doAddToBuf(pHandle->pDataBlock, pHandle);
+      }
+    }
+
+    tfree(source);
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+int32_t tsortOpen(SSortHandle* pHandle) {
+  if (pHandle->opened) {
+    return 0;
+  }
+
+  if (pHandle->fetchfp == NULL || pHandle->comparFn == NULL) {
+    return -1;
+  }
+
+  pHandle->opened = true;
+
+  int32_t code = createInitialSortedMultiSources(pHandle);
+  if (code != TSDB_CODE_SUCCESS) {
+    return code;
+  }
+
+  // do internal sort
+  code = doInternalMergeSort(pHandle);
+  if (code != TSDB_CODE_SUCCESS) {
+    return code;
+  }
+
+  int32_t numOfSources = taosArrayGetSize(pHandle->pOrderedSource);
+  if (pHandle->pBuf != NULL) {
+    ASSERT(numOfSources <= getNumOfInMemBufPages(pHandle->pBuf));
+  }
+
+  code = sortComparInit(&pHandle->cmpParam, pHandle->pOrderedSource, 0, numOfSources - 1, pHandle);
+  if (code != TSDB_CODE_SUCCESS) {
+    return code;
+  }
+
+  code = tMergeTreeCreate(&pHandle->pMergeTree, pHandle->cmpParam.numOfSources, &pHandle->cmpParam, pHandle->comparFn);
+  if (code != TSDB_CODE_SUCCESS) {
+    return code;
+  }
+}
+
+int32_t tsortClose(SSortHandle* pHandle) {
+  // do nothing
+}
+
+int32_t tsortSetFetchRawDataFp(SSortHandle* pHandle, _sort_fetch_block_fn_t fp) {
+  pHandle->fetchfp = fp;
+}
+
+int32_t tsortSetComparFp(SSortHandle* pHandle, _sort_merge_compar_fn_t fp) {
+  pHandle->comparFn = fp;
+}
+
+STupleHandle* tsortNextTuple(SSortHandle* pHandle) {
+  if (pHandle->cmpParam.numOfSources == pHandle->numOfCompletedSources) {
+    return NULL;
+  }
+
+  // All the data are hold in the buffer, no external sort is invoked.
+  if (pHandle->inMemSort) {
+    pHandle->tupleHandle.rowIndex += 1;
+    if (pHandle->tupleHandle.rowIndex == pHandle->pDataBlock->info.rows) {
+      pHandle->numOfCompletedSources = 1;
+      return NULL;
+    }
+
+    return &pHandle->tupleHandle;
+  }
+
+  int32_t index = tMergeTreeGetChosenIndex(pHandle->pMergeTree);
+  SExternalMemSource *pSource = pHandle->cmpParam.pSources[index];
+
+  if (pHandle->needAdjust) {
+    int32_t code = adjustMergeTreeForNextTuple(pSource, pHandle->pMergeTree, pHandle, &pHandle->numOfCompletedSources);
+    if (code != TSDB_CODE_SUCCESS) {
+      terrno = code;
+      return NULL;
+    }
+  }
+
+  if (pHandle->cmpParam.numOfSources == pHandle->numOfCompletedSources) {
+    return NULL;
+  }
+
+  // Get the adjusted value after the loser tree is updated.
+  index = tMergeTreeGetChosenIndex(pHandle->pMergeTree);
+  pSource = pHandle->cmpParam.pSources[index];
+
+  assert(pSource->src.pBlock != NULL);
+
+  pHandle->tupleHandle.rowIndex = pSource->src.rowIndex;
+  pHandle->tupleHandle.pBlock = pSource->src.pBlock;
+
+  pHandle->needAdjust = true;
+  pSource->src.rowIndex += 1;
+
+  return &pHandle->tupleHandle;
+}
+
+bool tsortIsNullVal(STupleHandle* pVHandle, int32_t colIndex) {
+  return false;
+}
+
+void* tsortGetValue(STupleHandle* pVHandle, int32_t colIndex) {
+  SColumnInfoData* pColInfo = TARRAY_GET_ELEM(pVHandle->pBlock->pDataBlock, colIndex);
+  return colDataGetData(pColInfo, pVHandle->rowIndex);
+}
diff --git a/source/libs/executor/test/executorTests.cpp b/source/libs/executor/test/executorTests.cpp
index c9657607c2..262232ceb1 100644
--- a/source/libs/executor/test/executorTests.cpp
+++ b/source/libs/executor/test/executorTests.cpp
@@ -14,6 +14,7 @@
  */
 
 #include <executorimpl.h>
+#include <function.h>
 #include <gtest/gtest.h>
 #include <tglobal.h>
 #include <iostream>
@@ -37,22 +38,30 @@
 
 namespace {
 
+enum {
+  data_rand = 0x1,
+  data_asc  = 0x2,
+  data_desc = 0x3,
+};
+
 typedef struct SDummyInputInfo {
-  int32_t max;
-  int32_t current;
-  int32_t startVal;
+  int32_t      totalPages;     // numOfPages
+  int32_t      current;
+  int32_t      startVal;
+  int32_t      type;
+  int32_t      numOfRowsPerPage;
+  int32_t      numOfCols;      // number of columns
+  int64_t      tsStart;
   SSDataBlock* pBlock;
 } SDummyInputInfo;
 
 SSDataBlock* getDummyBlock(void* param, bool* newgroup) {
   SOperatorInfo* pOperator = static_cast<SOperatorInfo*>(param);
   SDummyInputInfo* pInfo = static_cast<SDummyInputInfo*>(pOperator->info);
-  if (pInfo->current >= pInfo->max) {
+  if (pInfo->current >= pInfo->totalPages) {
     return NULL;
   }
 
-  int32_t numOfRows = 1000;
-
   if (pInfo->pBlock == NULL) {
     pInfo->pBlock = static_cast<SSDataBlock*>(calloc(1, sizeof(SSDataBlock)));
 
@@ -62,8 +71,8 @@ SSDataBlock* getDummyBlock(void* param, bool* newgroup) {
     colInfo.info.type = TSDB_DATA_TYPE_INT;
     colInfo.info.bytes = sizeof(int32_t);
     colInfo.info.colId = 1;
-    colInfo.pData = static_cast<char*>(calloc(numOfRows, sizeof(int32_t)));
-    colInfo.nullbitmap = static_cast<char*>(calloc(1, (numOfRows + 7) / 8));
+    colInfo.pData = static_cast<char*>(calloc(pInfo->numOfRowsPerPage, sizeof(int32_t)));
+    colInfo.nullbitmap = static_cast<char*>(calloc(1, (pInfo->numOfRowsPerPage + 7) / 8));
 
     taosArrayPush(pInfo->pBlock->pDataBlock, &colInfo);
 
@@ -85,10 +94,18 @@ SSDataBlock* getDummyBlock(void* param, bool* newgroup) {
 
   char buf[128] = {0};
   char b1[128] = {0};
-  for(int32_t i = 0; i < numOfRows; ++i) {
+  int32_t v = 0;
+  for(int32_t i = 0; i < pInfo->numOfRowsPerPage; ++i) {
     SColumnInfoData* pColInfo = static_cast<SColumnInfoData*>(TARRAY_GET_ELEM(pBlock->pDataBlock, 0));
 
-    int32_t v = (--pInfo->startVal);
+    if (pInfo->type == data_desc) {
+      v = (--pInfo->startVal);
+    } else if (pInfo->type == data_asc) {
+      v = ++pInfo->startVal;
+    } else if (pInfo->type == data_rand) {
+      v = random();
+    }
+
     colDataAppend(pColInfo, i, reinterpret_cast<const char*>(&v), false);
 
 //    sprintf(buf, "this is %d row", i);
@@ -98,21 +115,103 @@ SSDataBlock* getDummyBlock(void* param, bool* newgroup) {
 //    colDataAppend(pColInfo2, i, b1, false);
   }
 
-  pBlock->info.rows = numOfRows;
+  pBlock->info.rows = pInfo->numOfRowsPerPage;
   pBlock->info.numOfCols = 1;
 
   pInfo->current += 1;
   return pBlock;
 }
 
-SOperatorInfo* createDummyOperator(int32_t numOfBlocks) {
+SSDataBlock* get2ColsDummyBlock(void* param, bool* newgroup) {
+  SOperatorInfo* pOperator = static_cast<SOperatorInfo*>(param);
+  SDummyInputInfo* pInfo = static_cast<SDummyInputInfo*>(pOperator->info);
+  if (pInfo->current >= pInfo->totalPages) {
+    return NULL;
+  }
+
+  if (pInfo->pBlock == NULL) {
+    pInfo->pBlock = static_cast<SSDataBlock*>(calloc(1, sizeof(SSDataBlock)));
+
+    pInfo->pBlock->pDataBlock = taosArrayInit(4, sizeof(SColumnInfoData));
+
+    SColumnInfoData colInfo = {0};
+    colInfo.info.type = TSDB_DATA_TYPE_TIMESTAMP;
+    colInfo.info.bytes = sizeof(int64_t);
+    colInfo.info.colId = 1;
+    colInfo.pData = static_cast<char*>(calloc(pInfo->numOfRowsPerPage, sizeof(int64_t)));
+//    colInfo.nullbitmap = static_cast<char*>(calloc(1, (pInfo->numOfRowsPerPage + 7) / 8));
+
+    taosArrayPush(pInfo->pBlock->pDataBlock, &colInfo);
+
+    SColumnInfoData colInfo1 = {0};
+    colInfo1.info.type = TSDB_DATA_TYPE_INT;
+    colInfo1.info.bytes = 4;
+    colInfo1.info.colId = 2;
+
+    colInfo1.pData = static_cast<char*>(calloc(pInfo->numOfRowsPerPage, sizeof(int32_t)));
+    colInfo1.nullbitmap = static_cast<char*>(calloc(1, (pInfo->numOfRowsPerPage + 7) / 8));
+
+    taosArrayPush(pInfo->pBlock->pDataBlock, &colInfo1);
+  } else {
+    blockDataClearup(pInfo->pBlock, false);
+  }
+
+  SSDataBlock* pBlock = pInfo->pBlock;
+
+  char buf[128] = {0};
+  char b1[128] = {0};
+  int64_t ts = 0;
+  int32_t v  = 0;
+  for(int32_t i = 0; i < pInfo->numOfRowsPerPage; ++i) {
+    SColumnInfoData* pColInfo = static_cast<SColumnInfoData*>(TARRAY_GET_ELEM(pBlock->pDataBlock, 0));
+
+    ts = (++pInfo->tsStart);
+    colDataAppend(pColInfo, i, reinterpret_cast<const char*>(&ts), false);
+
+    SColumnInfoData* pColInfo1 = static_cast<SColumnInfoData*>(TARRAY_GET_ELEM(pBlock->pDataBlock, 1));
+    if (pInfo->type == data_desc) {
+      v = (--pInfo->startVal);
+    } else if (pInfo->type == data_asc) {
+      v = ++pInfo->startVal;
+    } else if (pInfo->type == data_rand) {
+      v = random();
+    }
+
+    colDataAppend(pColInfo1, i, reinterpret_cast<const char*>(&v), false);
+
+//    sprintf(buf, "this is %d row", i);
+//    STR_TO_VARSTR(b1, buf);
+//
+//    SColumnInfoData* pColInfo2 = static_cast<SColumnInfoData*>(TARRAY_GET_ELEM(pBlock->pDataBlock, 1));
+//    colDataAppend(pColInfo2, i, b1, false);
+  }
+
+  pBlock->info.rows = pInfo->numOfRowsPerPage;
+  pBlock->info.numOfCols = 1;
+
+  pInfo->current += 1;
+
+  blockDataUpdateTsWindow(pBlock);
+  return pBlock;
+
+}
+
+SOperatorInfo* createDummyOperator(int32_t startVal, int32_t numOfBlocks, int32_t rowsPerPage, int32_t type, int32_t numOfCols) {
   SOperatorInfo* pOperator = static_cast<SOperatorInfo*>(calloc(1, sizeof(SOperatorInfo)));
   pOperator->name = "dummyInputOpertor4Test";
-  pOperator->exec = getDummyBlock;
+
+  if (numOfCols == 1) {
+    pOperator->exec = getDummyBlock;
+  } else {
+    pOperator->exec = get2ColsDummyBlock;
+  }
 
   SDummyInputInfo *pInfo = (SDummyInputInfo*) calloc(1, sizeof(SDummyInputInfo));
-  pInfo->max = numOfBlocks;
-  pInfo->startVal = 1500000;
+  pInfo->totalPages = numOfBlocks;
+  pInfo->startVal   = startVal;
+  pInfo->numOfRowsPerPage = rowsPerPage;
+  pInfo->type       = type;
+  pInfo->tsStart    = 1620000000000;
 
   pOperator->info = pInfo;
   return pOperator;
@@ -123,6 +222,7 @@ int main(int argc, char** argv) {
   return RUN_ALL_TESTS();
 }
 
+#if 0
 TEST(testCase, build_executor_tree_Test) {
   const char* msg = "{\n"
                     "\t\"Id\":\t{\n"
@@ -218,34 +318,34 @@ TEST(testCase, build_executor_tree_Test) {
 //  int32_t code = qCreateExecTask(&handle, 2, 1, NULL, (void**) &pTaskInfo, &sinkHandle);
 }
 
-//TEST(testCase, inMem_sort_Test) {
-//  SArray* pOrderVal = taosArrayInit(4, sizeof(SOrder));
-//  SOrder o = {.order = TSDB_ORDER_ASC};
-//  o.col.info.colId = 1;
-//  o.col.info.type = TSDB_DATA_TYPE_INT;
-//  taosArrayPush(pOrderVal, &o);
-//
-//  SArray* pExprInfo = taosArrayInit(4, sizeof(SExprInfo));
-//  SExprInfo *exp = static_cast<SExprInfo*>(calloc(1, sizeof(SExprInfo)));
-//  exp->base.resSchema = createSchema(TSDB_DATA_TYPE_INT, sizeof(int32_t), 1, "res");
-//  taosArrayPush(pExprInfo, &exp);
-//
-//  SExprInfo *exp1 = static_cast<SExprInfo*>(calloc(1, sizeof(SExprInfo)));
-//  exp1->base.resSchema = createSchema(TSDB_DATA_TYPE_BINARY, 40, 2, "res1");
-//  taosArrayPush(pExprInfo, &exp1);
-//
-//  SOperatorInfo* pOperator = createOrderOperatorInfo(createDummyOperator(5), pExprInfo, pOrderVal);
-//
-//  bool newgroup = false;
-//  SSDataBlock* pRes = pOperator->exec(pOperator, &newgroup);
-//
-//  SColumnInfoData* pCol1 = static_cast<SColumnInfoData*>(taosArrayGet(pRes->pDataBlock, 0));
-//  SColumnInfoData* pCol2 = static_cast<SColumnInfoData*>(taosArrayGet(pRes->pDataBlock, 1));
-//  for(int32_t i = 0; i < pRes->info.rows; ++i) {
-//    char* p = colDataGet(pCol2, i);
-//    printf("%d: %d, %s\n", i, ((int32_t*)pCol1->pData)[i], (char*)varDataVal(p));
-//  }
-//}
+TEST(testCase, inMem_sort_Test) {
+  SArray* pOrderVal = taosArrayInit(4, sizeof(SOrder));
+  SOrder o = {.order = TSDB_ORDER_ASC};
+  o.col.info.colId = 1;
+  o.col.info.type = TSDB_DATA_TYPE_INT;
+  taosArrayPush(pOrderVal, &o);
+
+  SArray* pExprInfo = taosArrayInit(4, sizeof(SExprInfo));
+  SExprInfo *exp = static_cast<SExprInfo*>(calloc(1, sizeof(SExprInfo)));
+  exp->base.resSchema = createSchema(TSDB_DATA_TYPE_INT, sizeof(int32_t), 1, "res");
+  taosArrayPush(pExprInfo, &exp);
+
+  SExprInfo *exp1 = static_cast<SExprInfo*>(calloc(1, sizeof(SExprInfo)));
+  exp1->base.resSchema = createSchema(TSDB_DATA_TYPE_BINARY, 40, 2, "res1");
+  taosArrayPush(pExprInfo, &exp1);
+
+  SOperatorInfo* pOperator = createOrderOperatorInfo(createDummyOperator(5), pExprInfo, pOrderVal, NULL);
+
+  bool newgroup = false;
+  SSDataBlock* pRes = pOperator->exec(pOperator, &newgroup);
+
+  SColumnInfoData* pCol1 = static_cast<SColumnInfoData*>(taosArrayGet(pRes->pDataBlock, 0));
+  SColumnInfoData* pCol2 = static_cast<SColumnInfoData*>(taosArrayGet(pRes->pDataBlock, 1));
+  for(int32_t i = 0; i < pRes->info.rows; ++i) {
+    char* p = colDataGetData(pCol2, i);
+    printf("%d: %d, %s\n", i, ((int32_t*)pCol1->pData)[i], (char*)varDataVal(p));
+  }
+}
 
 typedef struct su {
   int32_t v;
@@ -300,7 +400,7 @@ TEST(testCase, external_sort_Test) {
   exp1->base.resSchema = createSchema(TSDB_DATA_TYPE_BINARY, 40, 2, "res1");
 //  taosArrayPush(pExprInfo, &exp1);
 
-  SOperatorInfo* pOperator = createOrderOperatorInfo(createDummyOperator(1500), pExprInfo, pOrderVal);
+  SOperatorInfo* pOperator = createOrderOperatorInfo(createDummyOperator(1500), pExprInfo, pOrderVal, NULL);
 
   bool newgroup = false;
   SSDataBlock* pRes = NULL;
@@ -326,14 +426,12 @@ TEST(testCase, external_sort_Test) {
     SColumnInfoData* pCol1 = static_cast<SColumnInfoData*>(taosArrayGet(pRes->pDataBlock, 0));
 //    SColumnInfoData* pCol2 = static_cast<SColumnInfoData*>(taosArrayGet(pRes->pDataBlock, 1));
     for (int32_t i = 0; i < pRes->info.rows; ++i) {
-//      char* p = colDataGet(pCol2, i);
+//      char* p = colDataGetData(pCol2, i);
       printf("%d: %d\n", total++, ((int32_t*)pCol1->pData)[i]);
 //      printf("%d: %d, %s\n", total++, ((int32_t*)pCol1->pData)[i], (char*)varDataVal(p));
     }
   }
 
-  printStatisBeforeClose(((SOrderOperatorInfo*) pOperator->info)->pSortInternalBuf);
-
   int64_t s2 = taosGetTimestampUs();
   printf("total:%ld\n", s2 - s1);
 
@@ -343,4 +441,153 @@ TEST(testCase, external_sort_Test) {
   taosArrayDestroy(pExprInfo);
   taosArrayDestroy(pOrderVal);
 }
+
+TEST(testCase, sorted_merge_Test) {
+  srand(time(NULL));
+
+  SArray* pOrderVal = taosArrayInit(4, sizeof(SOrder));
+  SOrder o = {0};
+  o.order = TSDB_ORDER_ASC;
+  o.col.info.colId = 1;
+  o.col.info.type = TSDB_DATA_TYPE_INT;
+  taosArrayPush(pOrderVal, &o);
+
+  SArray* pExprInfo = taosArrayInit(4, sizeof(SExprInfo));
+  SExprInfo *exp = static_cast<SExprInfo*>(calloc(1, sizeof(SExprInfo)));
+  exp->base.resSchema = createSchema(TSDB_DATA_TYPE_BIGINT, sizeof(int64_t), 1, "count_result");
+  exp->base.pColumns = static_cast<SColumn*>(calloc(1, sizeof(SColumn)));
+  exp->base.pColumns->flag = TSDB_COL_NORMAL;
+  exp->base.pColumns->info = (SColumnInfo) {.colId = 1, .type = TSDB_DATA_TYPE_INT, .bytes = 4};
+  exp->base.numOfCols = 1;
+
+  taosArrayPush(pExprInfo, &exp);
+
+  SExprInfo *exp1 = static_cast<SExprInfo*>(calloc(1, sizeof(SExprInfo)));
+  exp1->base.resSchema = createSchema(TSDB_DATA_TYPE_BINARY, 40, 2, "res1");
+//  taosArrayPush(pExprInfo, &exp1);
+
+  int32_t numOfSources = 10;
+  SOperatorInfo** plist = (SOperatorInfo**) calloc(numOfSources, sizeof(void*));
+  for(int32_t i = 0; i < numOfSources; ++i) {
+    plist[i] = createDummyOperator(1, 1, 1, data_asc);
+  }
+
+  SOperatorInfo* pOperator = createSortedMergeOperatorInfo(plist, numOfSources, pExprInfo, pOrderVal, NULL, NULL);
+
+  bool newgroup = false;
+  SSDataBlock* pRes = NULL;
+
+  int32_t total = 1;
+
+  int64_t s1 = taosGetTimestampUs();
+  int32_t t = 1;
+
+  while(1) {
+    int64_t s = taosGetTimestampUs();
+    pRes = pOperator->exec(pOperator, &newgroup);
+
+    int64_t e = taosGetTimestampUs();
+    if (t++ == 1) {
+      printf("---------------elapsed:%ld\n", e - s);
+    }
+
+    if (pRes == NULL) {
+      break;
+    }
+
+    SColumnInfoData* pCol1 = static_cast<SColumnInfoData*>(taosArrayGet(pRes->pDataBlock, 0));
+//    SColumnInfoData* pCol2 = static_cast<SColumnInfoData*>(taosArrayGet(pRes->pDataBlock, 1));
+    for (int32_t i = 0; i < pRes->info.rows; ++i) {
+//      char* p = colDataGetData(pCol2, i);
+      printf("%d: %ld\n", total++, ((int64_t*)pCol1->pData)[i]);
+//      printf("%d: %d, %s\n", total++, ((int32_t*)pCol1->pData)[i], (char*)varDataVal(p));
+    }
+  }
+
+  int64_t s2 = taosGetTimestampUs();
+  printf("total:%ld\n", s2 - s1);
+
+  pOperator->cleanupFn(pOperator->info, 2);
+  tfree(exp);
+  tfree(exp1);
+  taosArrayDestroy(pExprInfo);
+  taosArrayDestroy(pOrderVal);
+}
+
+#endif
+
+TEST(testCase, time_interval_Operator_Test) {
+  srand(time(NULL));
+
+  SArray* pOrderVal = taosArrayInit(4, sizeof(SOrder));
+  SOrder o = {0};
+  o.order = TSDB_ORDER_ASC;
+  o.col.info.colId = 1;
+  o.col.info.type = TSDB_DATA_TYPE_INT;
+  taosArrayPush(pOrderVal, &o);
+
+  SArray* pExprInfo = taosArrayInit(4, sizeof(SExprInfo));
+  SExprInfo *exp = static_cast<SExprInfo*>(calloc(1, sizeof(SExprInfo)));
+  exp->base.resSchema = createSchema(TSDB_DATA_TYPE_TIMESTAMP, sizeof(int64_t), 1, "ts");
+  exp->base.pColumns = static_cast<SColumn*>(calloc(1, sizeof(SColumn)));
+  exp->base.pColumns->flag = TSDB_COL_NORMAL;
+  exp->base.pColumns->info = (SColumnInfo) {.colId = 1, .type = TSDB_DATA_TYPE_TIMESTAMP, .bytes = 8};
+  exp->base.numOfCols = 1;
+
+  taosArrayPush(pExprInfo, &exp);
+
+  SExprInfo *exp1 = static_cast<SExprInfo*>(calloc(1, sizeof(SExprInfo)));
+  exp1->base.resSchema = createSchema(TSDB_DATA_TYPE_BIGINT, 8, 2, "res1");
+  exp1->base.pColumns = static_cast<SColumn*>(calloc(1, sizeof(SColumn)));
+  exp1->base.pColumns->flag = TSDB_COL_NORMAL;
+  exp1->base.pColumns->info = (SColumnInfo) {.colId = 1, .type = TSDB_DATA_TYPE_INT, .bytes = 4};
+  exp1->base.numOfCols = 1;
+
+  taosArrayPush(pExprInfo, &exp1);
+
+  SOperatorInfo* p = createDummyOperator(1, 1, 2000, data_asc, 2);
+
+  SExecTaskInfo ti = {0};
+  SOperatorInfo* pOperator = createIntervalOperatorInfo(p, pExprInfo, &ti);
+
+  bool newgroup = false;
+  SSDataBlock* pRes = NULL;
+
+  int32_t total = 1;
+
+  int64_t s1 = taosGetTimestampUs();
+  int32_t t = 1;
+
+  while(1) {
+    int64_t s = taosGetTimestampUs();
+    pRes = pOperator->exec(pOperator, &newgroup);
+
+    int64_t e = taosGetTimestampUs();
+    if (t++ == 1) {
+      printf("---------------elapsed:%ld\n", e - s);
+    }
+
+    if (pRes == NULL) {
+      break;
+    }
+
+    SColumnInfoData* pCol1 = static_cast<SColumnInfoData*>(taosArrayGet(pRes->pDataBlock, 0));
+//    SColumnInfoData* pCol2 = static_cast<SColumnInfoData*>(taosArrayGet(pRes->pDataBlock, 1));
+    for (int32_t i = 0; i < pRes->info.rows; ++i) {
+//      char* p = colDataGetData(pCol2, i);
+      printf("%d: %ld\n", total++, ((int64_t*)pCol1->pData)[i]);
+//      printf("%d: %d, %s\n", total++, ((int32_t*)pCol1->pData)[i], (char*)varDataVal(p));
+    }
+  }
+
+  int64_t s2 = taosGetTimestampUs();
+  printf("total:%ld\n", s2 - s1);
+
+  pOperator->cleanupFn(pOperator->info, 2);
+  tfree(exp);
+  tfree(exp1);
+  taosArrayDestroy(pExprInfo);
+  taosArrayDestroy(pOrderVal);
+}
+
 #pragma GCC diagnostic pop
diff --git a/source/libs/executor/test/lhashTests.cpp b/source/libs/executor/test/lhashTests.cpp
new file mode 100644
index 0000000000..66ef3b0877
--- /dev/null
+++ b/source/libs/executor/test/lhashTests.cpp
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <gtest/gtest.h>
+#include <iostream>
+#include "executorimpl.h"
+#include "tlinearhash.h"
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wwrite-strings"
+#pragma GCC diagnostic ignored "-Wunused-function"
+#pragma GCC diagnostic ignored "-Wunused-variable"
+#pragma GCC diagnostic ignored "-Wsign-compare"
+
+TEST(testCase, linear_hash_Tests) {
+  srand(time(NULL));
+
+  _hash_fn_t fn = taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT);
+#if 0
+  SLHashObj* pHashObj = tHashInit(256, 4096, fn, 320);
+  for(int32_t i = 0; i < 5000000; ++i) {
+    int32_t code = tHashPut(pHashObj, &i, sizeof(i), &i, sizeof(i));
+    assert(code == 0);
+  }
+
+//  tHashPrint(pHashObj, LINEAR_HASH_STATIS);
+
+//  for(int32_t i = 0; i < 10000; ++i) {
+//    char* v = tHashGet(pHashObj, &i, sizeof(i));
+//    if (v != NULL) {
+////      printf("find value: %d, key:%d\n", *(int32_t*) v, i);
+//    } else {
+//      printf("failed to found key:%d in hash\n", i);
+//    }
+//  }
+
+  tHashPrint(pHashObj, LINEAR_HASH_STATIS);
+  tHashCleanup(pHashObj);
+#endif
+
+#if 0
+  SHashObj* pHashObj = taosHashInit(1000, fn, false, HASH_NO_LOCK);
+  for(int32_t i = 0; i < 1000000; ++i) {
+    taosHashPut(pHashObj, &i, sizeof(i), &i, sizeof(i));
+  }
+
+  for(int32_t i = 0; i < 10000; ++i) {
+    void* v = taosHashGet(pHashObj, &i, sizeof(i));
+  }
+  taosHashCleanup(pHashObj);
+#endif
+
+}
\ No newline at end of file
diff --git a/source/libs/executor/test/sortTests.cpp b/source/libs/executor/test/sortTests.cpp
new file mode 100644
index 0000000000..fc366e4cc8
--- /dev/null
+++ b/source/libs/executor/test/sortTests.cpp
@@ -0,0 +1,280 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <executorimpl.h>
+#include <gtest/gtest.h>
+#include <tglobal.h>
+#include <tsort.h>
+#include <iostream>
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wwrite-strings"
+#pragma GCC diagnostic ignored "-Wunused-function"
+#pragma GCC diagnostic ignored "-Wunused-variable"
+#pragma GCC diagnostic ignored "-Wsign-compare"
+#include "os.h"
+
+#include "executor.h"
+#include "stub.h"
+#include "taos.h"
+#include "tdef.h"
+#include "tep.h"
+#include "trpc.h"
+#include "tvariant.h"
+
+namespace {
+typedef struct {
+  int32_t startVal;
+  int32_t count;
+  int32_t pageRows;
+} _info;
+
+SSDataBlock* getSingleColDummyBlock(void* param) {
+  _info* pInfo = (_info*) param;
+  if (--pInfo->count < 0) {
+    return NULL;
+  }
+
+  SSDataBlock* pBlock = static_cast<SSDataBlock*>(calloc(1, sizeof(SSDataBlock)));
+  pBlock->pDataBlock = taosArrayInit(4, sizeof(SColumnInfoData));
+
+  SColumnInfoData colInfo = {0};
+  colInfo.info.type = TSDB_DATA_TYPE_INT;
+  colInfo.info.bytes = sizeof(int32_t);
+  colInfo.info.colId = 1;
+  colInfo.pData = static_cast<char*>(calloc(pInfo->pageRows, sizeof(int32_t)));
+  colInfo.nullbitmap = static_cast<char*>(calloc(1, (pInfo->pageRows + 7) / 8));
+
+  taosArrayPush(pBlock->pDataBlock, &colInfo);
+
+  for (int32_t i = 0; i < pInfo->pageRows; ++i) {
+    SColumnInfoData* pColInfo = static_cast<SColumnInfoData*>(TARRAY_GET_ELEM(pBlock->pDataBlock, 0));
+
+    int32_t v = ++pInfo->startVal;
+    colDataAppend(pColInfo, i, reinterpret_cast<const char*>(&v), false);
+  }
+
+  pBlock->info.rows = pInfo->pageRows;
+  pBlock->info.numOfCols = 1;
+  return pBlock;
+}
+
+int32_t docomp(const void* p1, const void* p2, void* param) {
+  int32_t pLeftIdx  = *(int32_t *)p1;
+  int32_t pRightIdx = *(int32_t *)p2;
+
+  SMsortComparParam *pParam = (SMsortComparParam *)param;
+  SGenericSource** px = reinterpret_cast<SGenericSource**>(pParam->pSources);
+
+  SArray *pInfo = pParam->orderInfo;
+
+  SGenericSource* pLeftSource  = px[pLeftIdx];
+  SGenericSource* pRightSource = px[pRightIdx];
+
+  // this input is exhausted, set the special value to denote this
+  if (pLeftSource->src.rowIndex == -1) {
+    return 1;
+  }
+
+  if (pRightSource->src.rowIndex == -1) {
+    return -1;
+  }
+
+  SSDataBlock* pLeftBlock = pLeftSource->src.pBlock;
+  SSDataBlock* pRightBlock = pRightSource->src.pBlock;
+
+  for(int32_t i = 0; i < pInfo->size; ++i) {
+    SBlockOrderInfo* pOrder = (SBlockOrderInfo*)TARRAY_GET_ELEM(pInfo, i);
+
+    SColumnInfoData* pLeftColInfoData = (SColumnInfoData*)TARRAY_GET_ELEM(pLeftBlock->pDataBlock, pOrder->colIndex);
+
+    bool leftNull  = false;
+    if (pLeftColInfoData->hasNull) {
+      leftNull = colDataIsNull(pLeftColInfoData, pLeftBlock->info.rows, pLeftSource->src.rowIndex, pLeftBlock->pBlockAgg);
+    }
+
+    SColumnInfoData* pRightColInfoData = (SColumnInfoData*) TARRAY_GET_ELEM(pRightBlock->pDataBlock, pOrder->colIndex);
+    bool rightNull = false;
+    if (pRightColInfoData->hasNull) {
+      rightNull = colDataIsNull(pRightColInfoData, pRightBlock->info.rows, pRightSource->src.rowIndex, pRightBlock->pBlockAgg);
+    }
+
+    if (leftNull && rightNull) {
+      continue; // continue to next slot
+    }
+
+    if (rightNull) {
+      return pParam->nullFirst? 1:-1;
+    }
+
+    if (leftNull) {
+      return pParam->nullFirst? -1:1;
+    }
+
+    void* left1  = colDataGetData(pLeftColInfoData, pLeftSource->src.rowIndex);
+    void* right1 = colDataGetData(pRightColInfoData, pRightSource->src.rowIndex);
+
+    switch(pLeftColInfoData->info.type) {
+      case TSDB_DATA_TYPE_INT: {
+        int32_t leftv = *(int32_t*)left1;
+        int32_t rightv = *(int32_t*)right1;
+
+        if (leftv == rightv) {
+          break;
+        } else {
+          if (pOrder->order == TSDB_ORDER_ASC) {
+            return leftv < rightv? -1 : 1;
+          } else {
+            return leftv < rightv? 1 : -1;
+          }
+        }
+      }
+      default:
+        assert(0);
+    }
+  }
+
+  return 0;
+}
+}  // namespace
+
+#if 0
+TEST(testCase, inMem_sort_Test) {
+  SArray* pOrderVal = taosArrayInit(4, sizeof(SOrder));
+  SOrder o = {.order = TSDB_ORDER_ASC};
+  o.col.info.colId = 1;
+  o.col.info.type = TSDB_DATA_TYPE_INT;
+  taosArrayPush(pOrderVal, &o);
+
+  int32_t numOfRows = 1000;
+  SBlockOrderInfo oi = {0};
+  oi.order = TSDB_ORDER_ASC;
+  oi.colIndex = 0;
+  SArray* orderInfo = taosArrayInit(1, sizeof(SBlockOrderInfo));
+  taosArrayPush(orderInfo, &oi);
+
+  SSchema s = {.type = TSDB_DATA_TYPE_INT, .colId = 1, .bytes = 4, };
+  SSortHandle* phandle = tsortCreateSortHandle(orderInfo, false, SORT_SINGLESOURCE_SORT, 1024, 5, &s, 1, "test_abc");
+  tsortSetFetchRawDataFp(phandle, getSingleColDummyBlock);
+  tsortAddSource(phandle, &numOfRows);
+
+  int32_t code = tsortOpen(phandle);
+  int32_t row = 1;
+
+  while(1) {
+    STupleHandle* pTupleHandle = tsortNextTuple(phandle);
+    if (pTupleHandle == NULL) {
+      break;
+    }
+
+    void* v = tsortGetValue(pTupleHandle, 0);
+    printf("%d: %d\n", row++, *(int32_t*) v);
+
+  }
+  tsortDestroySortHandle(phandle);
+}
+
+TEST(testCase, external_mem_sort_Test) {
+  SArray* pOrderVal = taosArrayInit(4, sizeof(SOrder));
+  SOrder o = {.order = TSDB_ORDER_ASC};
+  o.col.info.colId = 1;
+  o.col.info.type = TSDB_DATA_TYPE_INT;
+  taosArrayPush(pOrderVal, &o);
+
+  SBlockOrderInfo oi = {0};
+  oi.order = TSDB_ORDER_ASC;
+  oi.colIndex = 0;
+  SArray* orderInfo = taosArrayInit(1, sizeof(SBlockOrderInfo));
+  taosArrayPush(orderInfo, &oi);
+
+  SSchema s = {.type = TSDB_DATA_TYPE_INT, .colId = 1, .bytes = 4, };
+  SSortHandle* phandle = tsortCreateSortHandle(orderInfo, false, SORT_SINGLESOURCE_SORT, 1024, 5, &s, 1, "test_abc");
+  tsortSetFetchRawDataFp(phandle, getSingleColDummyBlock);
+
+  _info* pInfo = (_info*) calloc(1, sizeof(_info));
+  pInfo->startVal = 100000;
+  pInfo->pageRows = 1000;
+  pInfo->count = 50;
+
+  SGenericSource* ps = static_cast<SGenericSource*>(calloc(1, sizeof(SGenericSource)));
+  ps->param = pInfo;
+
+  tsortAddSource(phandle, ps);
+
+  int32_t code = tsortOpen(phandle);
+  int32_t row = 1;
+
+  while(1) {
+    STupleHandle* pTupleHandle = tsortNextTuple(phandle);
+    if (pTupleHandle == NULL) {
+      break;
+    }
+
+    void* v = tsortGetValue(pTupleHandle, 0);
+    printf("%d: %d\n", row++, *(int32_t*) v);
+
+  }
+  tsortDestroySortHandle(phandle);
+}
+
+TEST(testCase, ordered_merge_sort_Test) {
+  SArray* pOrderVal = taosArrayInit(4, sizeof(SOrder));
+  SOrder o = {.order = TSDB_ORDER_ASC};
+  o.col.info.colId = 1;
+  o.col.info.type = TSDB_DATA_TYPE_INT;
+  taosArrayPush(pOrderVal, &o);
+
+  int32_t numOfRows = 1000;
+  SBlockOrderInfo oi = {0};
+  oi.order = TSDB_ORDER_ASC;
+  oi.colIndex = 0;
+  SArray* orderInfo = taosArrayInit(1, sizeof(SBlockOrderInfo));
+  taosArrayPush(orderInfo, &oi);
+
+  SSchema s = {.type = TSDB_DATA_TYPE_INT, .colId = 1, .bytes = 4};
+  SSortHandle* phandle = tsortCreateSortHandle(orderInfo, false, SORT_MULTISOURCE_MERGE, 1024, 5, &s, 1,"test_abc");
+  tsortSetFetchRawDataFp(phandle, getSingleColDummyBlock);
+  tsortSetComparFp(phandle, docomp);
+
+  for(int32_t i = 0; i < 10; ++i) {
+    SGenericSource* p = static_cast<SGenericSource*>(calloc(1, sizeof(SGenericSource)));
+    _info* c = static_cast<_info*>(calloc(1, sizeof(_info)));
+    c->count    = 1;
+    c->pageRows = 1000;
+    c->startVal = 0;
+
+    p->param = c;
+    tsortAddSource(phandle, p);
+  }
+
+  int32_t code = tsortOpen(phandle);
+  int32_t row = 1;
+
+  while(1) {
+    STupleHandle* pTupleHandle = tsortNextTuple(phandle);
+    if (pTupleHandle == NULL) {
+      break;
+    }
+
+    void* v = tsortGetValue(pTupleHandle, 0);
+    printf("%d: %d\n", row++, *(int32_t*) v);
+
+  }
+  tsortDestroySortHandle(phandle);
+}
+
+#endif
+
+#pragma GCC diagnostic pop
diff --git a/source/libs/function/src/taggfunction.c b/source/libs/function/src/taggfunction.c
index 2ff2edf84e..c36fc9c659 100644
--- a/source/libs/function/src/taggfunction.c
+++ b/source/libs/function/src/taggfunction.c
@@ -29,9 +29,10 @@
 #include "tcompression.h"
 //#include "queryLog.h"
 #include "tudf.h"
+#include "tep.h"
 
 #define GET_INPUT_DATA_LIST(x) ((char *)((x)->pInput))
-#define GET_INPUT_DATA(x, y) (GET_INPUT_DATA_LIST(x) + (y) * (x)->inputBytes)
+#define GET_INPUT_DATA(x, y) ((char*) colDataGetData((x)->pInput, (y)))
 
 #define GET_TS_LIST(x)    ((TSKEY*)((x)->ptsList))
 #define GET_TS_DATA(x, y) (GET_TS_LIST(x)[(y)])
@@ -3818,7 +3819,7 @@ static void interp_function_impl(SqlFunctionCtx *pCtx) {
             skey = ekey;
           }
         }
-        assignVal(pCtx->pOutput, pCtx->pInput, pCtx->resDataInfo.bytes, pCtx->inputType);
+//        assignVal(pCtx->pOutput, pCtx->pInput, pCtx->resDataInfo.bytes, pCtx->inputType);
       } else if (type == TSDB_FILL_NEXT) {
         TSKEY ekey = skey;
         char* val = NULL;
@@ -4395,7 +4396,7 @@ SFunctionFpSet fpSet[1] = {
       .addInput = count_function,
       .finalize = doFinalizer,
       .combine = count_func_merge,
-    }
+    },
 };
 
 SAggFunctionInfo aggFunc[35] = {{
diff --git a/source/libs/function/src/tpercentile.c b/source/libs/function/src/tpercentile.c
index 40731adc58..27cdc15d94 100644
--- a/source/libs/function/src/tpercentile.c
+++ b/source/libs/function/src/tpercentile.c
@@ -221,7 +221,7 @@ tMemBucket *tMemBucketCreate(int16_t nElemSize, int16_t dataType, double minval,
   }
 
   pBucket->numOfSlots = DEFAULT_NUM_OF_SLOT;
-  pBucket->bufPageSize = DEFAULT_PAGE_SIZE * 4;   // 4k per page
+  pBucket->bufPageSize = 16384 * 4;   // 16k per page
 
   pBucket->type  = dataType;
   pBucket->bytes = nElemSize;
@@ -254,7 +254,7 @@ tMemBucket *tMemBucketCreate(int16_t nElemSize, int16_t dataType, double minval,
 
   resetSlotInfo(pBucket);
 
-  int32_t ret = createDiskbasedBuffer(&pBucket->pBuffer, pBucket->bufPageSize, pBucket->bufPageSize * 512, 1, tsTempDir);
+  int32_t ret = createDiskbasedBuf(&pBucket->pBuffer, pBucket->bufPageSize, pBucket->bufPageSize * 512, 1, "/tmp");
   if (ret != 0) {
     tMemBucketDestroy(pBucket);
     return NULL;
@@ -269,7 +269,7 @@ void tMemBucketDestroy(tMemBucket *pBucket) {
     return;
   }
 
-  destroyResultBuf(pBucket->pBuffer);
+  destroyDiskbasedBuf(pBucket->pBuffer);
   tfree(pBucket->pSlots);
   tfree(pBucket);
 }
@@ -347,7 +347,7 @@ int32_t tMemBucketPut(tMemBucket *pBucket, const void *data, size_t size) {
         pSlot->info.data = NULL;
       }
 
-      pSlot->info.data = getNewDataBuf(pBucket->pBuffer, groupId, &pageId);
+      pSlot->info.data = getNewBufPage(pBucket->pBuffer, groupId, &pageId);
       pSlot->info.pageId = pageId;
     }
 
diff --git a/source/libs/parser/src/queryInfoUtil.c b/source/libs/parser/src/queryInfoUtil.c
index 9a2ca2da98..05aebb2cb2 100644
--- a/source/libs/parser/src/queryInfoUtil.c
+++ b/source/libs/parser/src/queryInfoUtil.c
@@ -230,7 +230,7 @@ int32_t getExprFunctionId(SExprInfo *pExprInfo) {
 }
 
 void assignExprInfo(SExprInfo* dst, const SExprInfo* src) {
-  assert(dst != NULL && src != NULL);
+  assert(dst != NULL && src != NULL/* && src->base.numOfCols > 0*/);
 
   *dst = *src;
 #if 0
@@ -241,8 +241,12 @@ void assignExprInfo(SExprInfo* dst, const SExprInfo* src) {
 #endif
 
   dst->pExpr = exprdup(src->pExpr);
-  dst->base.pColumns = calloc(src->base.numOfCols, sizeof(SColumn));
-  memcpy(dst->base.pColumns, src->base.pColumns, sizeof(SColumn) * src->base.numOfCols);
+  if (src->base.numOfCols > 0) {
+    dst->base.pColumns = calloc(src->base.numOfCols, sizeof(SColumn));
+    memcpy(dst->base.pColumns, src->base.pColumns, sizeof(SColumn) * src->base.numOfCols);
+  } else {
+    dst->base.pColumns = NULL;
+  }
 
   memset(dst->base.param, 0, sizeof(SVariant) * tListLen(dst->base.param));
   for (int32_t j = 0; j < src->base.numOfParams; ++j) {
diff --git a/source/libs/scalar/inc/filterInt.h b/source/libs/scalar/inc/filterInt.h
index a0d4bc680c..f1660aa0e8 100644
--- a/source/libs/scalar/inc/filterInt.h
+++ b/source/libs/scalar/inc/filterInt.h
@@ -306,7 +306,7 @@ typedef struct SFilterInfo {
 #define FILTER_GET_COL_FIELD_ID(fi) (((SColumnNode *)((fi)->desc))->colId)
 #define FILTER_GET_COL_FIELD_SLOT_ID(fi) (((SColumnNode *)((fi)->desc))->slotId)
 #define FILTER_GET_COL_FIELD_DESC(fi) ((SColumnNode *)((fi)->desc))
-#define FILTER_GET_COL_FIELD_DATA(fi, ri) (colDataGet(((SColumnInfoData *)(fi)->data), (ri)))
+#define FILTER_GET_COL_FIELD_DATA(fi, ri) (colDataGetData(((SColumnInfoData *)(fi)->data), (ri)))
 #define FILTER_GET_VAL_FIELD_TYPE(fi) (((SValueNode *)((fi)->desc))->node.resType.type)
 #define FILTER_GET_VAL_FIELD_DATA(fi) ((char *)(fi)->data)
 #define FILTER_GET_JSON_VAL_FIELD_DATA(fi) ((char *)(fi)->desc)
diff --git a/source/libs/scalar/src/filter.c b/source/libs/scalar/src/filter.c
index 4d6656b061..8a7d6ae910 100644
--- a/source/libs/scalar/src/filter.c
+++ b/source/libs/scalar/src/filter.c
@@ -19,6 +19,7 @@
 #include "tcompare.h"
 #include "filterInt.h"
 #include "filter.h"
+#include "tep.h"
 
 OptrStr gOptrStr[] = {
   {0,                                      "invalid"},
@@ -2776,7 +2777,7 @@ bool filterExecuteBasedOnStatisImpl(void *pinfo, int32_t numOfRows, int8_t** p,
       uint32_t unitNum = *(unitIdx++);
       for (uint32_t u = 0; u < unitNum; ++u) {
         SFilterComUnit *cunit = &info->cunits[*(unitIdx + u)];
-        void *colData = colDataGet((SColumnInfoData *)cunit->colData, i);
+        void *colData = colDataGetData((SColumnInfoData *)cunit->colData, i);
       
         //if (FILTER_UNIT_GET_F(info, uidx)) {
         //  p[i] = FILTER_UNIT_GET_R(info, uidx);
@@ -2874,7 +2875,7 @@ static FORCE_INLINE bool filterExecuteImplIsNull(void *pinfo, int32_t numOfRows,
   
   for (int32_t i = 0; i < numOfRows; ++i) {
     uint32_t uidx = info->groups[0].unitIdxs[0];
-    void *colData = colDataGet((SColumnInfoData *)info->cunits[uidx].colData, i);
+    void *colData = colDataGetData((SColumnInfoData *)info->cunits[uidx].colData, i);
     if(info->cunits[uidx].dataType == TSDB_DATA_TYPE_JSON){
       if (!colData){  // for json->'key' is null
         (*p)[i] = 1;
@@ -2908,7 +2909,7 @@ static FORCE_INLINE bool filterExecuteImplNotNull(void *pinfo, int32_t numOfRows
   
   for (int32_t i = 0; i < numOfRows; ++i) {
     uint32_t uidx = info->groups[0].unitIdxs[0];
-    void *colData = colDataGet((SColumnInfoData *)info->cunits[uidx].colData, i);
+    void *colData = colDataGetData((SColumnInfoData *)info->cunits[uidx].colData, i);
 
     if(info->cunits[uidx].dataType == TSDB_DATA_TYPE_JSON){
       if (!colData) {   // for json->'key' is not null
@@ -2949,7 +2950,7 @@ bool filterExecuteImplRange(void *pinfo, int32_t numOfRows, int8_t** p, SColumnD
   }
   
   for (int32_t i = 0; i < numOfRows; ++i) {    
-    void *colData = colDataGet((SColumnInfoData *)info->cunits[0].colData, i);
+    void *colData = colDataGetData((SColumnInfoData *)info->cunits[0].colData, i);
 
     if (colData == NULL || isNull(colData, info->cunits[0].dataType)) {
       all = false;
@@ -2980,7 +2981,7 @@ bool filterExecuteImplMisc(void *pinfo, int32_t numOfRows, int8_t** p, SColumnDa
   
   for (int32_t i = 0; i < numOfRows; ++i) {
     uint32_t uidx = info->groups[0].unitIdxs[0];
-    void *colData = colDataGet((SColumnInfoData *)info->cunits[uidx].colData, i);
+    void *colData = colDataGetData((SColumnInfoData *)info->cunits[uidx].colData, i);
     if (colData == NULL || isNull(colData, info->cunits[uidx].dataType)) {
       (*p)[i] = 0;
       all = false;
@@ -3031,7 +3032,7 @@ bool filterExecuteImpl(void *pinfo, int32_t numOfRows, int8_t** p, SColumnDataAg
       for (uint32_t u = 0; u < group->unitNum; ++u) {
         uint32_t uidx = group->unitIdxs[u];
         SFilterComUnit *cunit = &info->cunits[uidx];
-        void *colData = colDataGet((SColumnInfoData *)(cunit->colData), i);
+        void *colData = colDataGetData((SColumnInfoData *)(cunit->colData), i);
       
         //if (FILTER_UNIT_GET_F(info, uidx)) {
         //  p[i] = FILTER_UNIT_GET_R(info, uidx);
diff --git a/source/libs/scalar/src/sclvector.c b/source/libs/scalar/src/sclvector.c
index 85af663313..26ffeb2d60 100644
--- a/source/libs/scalar/src/sclvector.c
+++ b/source/libs/scalar/src/sclvector.c
@@ -226,7 +226,7 @@ void* getVectorValueAddr_default(void *src, int32_t index) {
   return src;
 }
 void* getVectorValueAddr_VAR(void *src, int32_t index) {
-  return colDataGet((SColumnInfoData *)src, index);
+  return colDataGetData((SColumnInfoData *)src, index);
 }
 
 _getValueAddr_fn_t getVectorValueAddrFn(int32_t srcType) {
diff --git a/source/util/src/tpagedbuf.c b/source/util/src/tpagedbuf.c
index a7e43cebf9..c8e5bba314 100644
--- a/source/util/src/tpagedbuf.c
+++ b/source/util/src/tpagedbuf.c
@@ -7,27 +7,22 @@
 #define GET_DATA_PAYLOAD(_p) ((char *)(_p)->pData + POINTER_BYTES)
 #define NO_IN_MEM_AVAILABLE_PAGES(_b) (listNEles((_b)->lruList) >= (_b)->inMemPages)
 
-typedef struct SFreeListItem {
-  int32_t offset;
-  int32_t len;
-} SFreeListItem;
-
 typedef struct SPageDiskInfo {
   int64_t  offset;
   int32_t  length;
-} SPageDiskInfo;
+} SPageDiskInfo, SFreeListItem;
 
-typedef struct SPageInfo {
-  SListNode*    pn;       // point to list node
+struct SPageInfo {
+  SListNode*    pn;       // point to list node struct
   void*         pData;
   int64_t       offset;
   int32_t       pageId;
-  int32_t       length:30;
+  int32_t       length:29;
   bool          used:1;     // set current page is in used
   bool          dirty:1;    // set current buffer page is dirty or not
-} SPageInfo;
+};
 
-typedef struct SDiskbasedBuf {
+struct SDiskbasedBuf {
   int32_t   numOfPages;
   int64_t   totalBufSize;
   uint64_t  fileSize;            // disk file size
@@ -36,7 +31,8 @@ typedef struct SDiskbasedBuf {
   char*     path;                // file path
   int32_t   pageSize;            // current used page size
   int32_t   inMemPages;          // numOfPages that are allocated in memory
-  SHashObj* groupSet;            // id hash table
+  SList*    freePgList;          // free page list
+  SHashObj* groupSet;            // id hash table, todo remove it
   SHashObj* all;
   SList*    lruList;
   void*     emptyDummyIdList;    // dummy id list
@@ -48,49 +44,7 @@ typedef struct SDiskbasedBuf {
   uint64_t  qId;                 // for debug purpose
   bool      printStatis;         // Print statistics info when closing this buffer.
   SDiskbasedBufStatis statis;
-} SDiskbasedBuf;
-
-static void printStatisData(const SDiskbasedBuf* pBuf);
-
-  int32_t createDiskbasedBuffer(SDiskbasedBuf** pBuf, int32_t pagesize, int32_t inMemBufSize, uint64_t qId, const char* dir) {
-  *pBuf = calloc(1, sizeof(SDiskbasedBuf));
-
-  SDiskbasedBuf* pResBuf = *pBuf;
-  if (pResBuf == NULL) {
-    return TSDB_CODE_OUT_OF_MEMORY;  
-  }
-
-  pResBuf->pageSize     = pagesize;
-  pResBuf->numOfPages   = 0;                        // all pages are in buffer in the first place
-  pResBuf->totalBufSize = 0;
-  pResBuf->inMemPages   = inMemBufSize/pagesize;    // maximum allowed pages, it is a soft limit.
-  pResBuf->allocateId   = -1;
-  pResBuf->comp         = true;
-  pResBuf->pFile        = NULL;
-  pResBuf->qId          = qId;
-  pResBuf->fileSize     = 0;
-
-  // at least more than 2 pages must be in memory
-  assert(inMemBufSize >= pagesize * 2);
-
-  pResBuf->lruList = tdListNew(POINTER_BYTES);
-
-  // init id hash table
-  pResBuf->groupSet  = taosHashInit(10, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true, false);
-  pResBuf->assistBuf = malloc(pResBuf->pageSize + 2); // EXTRA BYTES
-  pResBuf->all = taosHashInit(10, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true, false);
-
-  char path[PATH_MAX] = {0};
-  taosGetTmpfilePath(dir, "qbuf", path);
-  pResBuf->path = strdup(path);
-
-  pResBuf->emptyDummyIdList = taosArrayInit(1, sizeof(int32_t));
-
-//  qDebug("QInfo:0x%"PRIx64" create resBuf for output, page size:%d, inmem buf pages:%d, file:%s", qId, pResBuf->pageSize,
-//         pResBuf->inMemPages, pResBuf->path);
-
-  return TSDB_CODE_SUCCESS;
-}
+};
 
 static int32_t createDiskFile(SDiskbasedBuf* pBuf) {
   // pBuf->file = fopen(pBuf->path, "wb+");
@@ -121,7 +75,7 @@ static char* doDecompressData(void* data, int32_t srcSize, int32_t *dst, SDiskba
     return data;
   }
 
-  *dst = tsDecompressString(data, srcSize, 1, pBuf->assistBuf, pBuf->pageSize+sizeof(SFilePage), ONE_STAGE_COMP, NULL, 0);
+  *dst = tsDecompressString(data, srcSize, 1, pBuf->assistBuf, pBuf->pageSize, ONE_STAGE_COMP, NULL, 0);
   if (*dst > 0) {
     memcpy(data, pBuf->assistBuf, *dst);
   }
@@ -137,10 +91,10 @@ static uint64_t allocatePositionInFile(SDiskbasedBuf* pBuf, size_t size) {
     size_t num = taosArrayGetSize(pBuf->pFree);
     for(int32_t i = 0; i < num; ++i) {
       SFreeListItem* pi = taosArrayGet(pBuf->pFree, i);
-      if (pi->len >= size) {
+      if (pi->length >= size) {
         offset = pi->offset;
         pi->offset += (int32_t)size;
-        pi->len -= (int32_t)size;
+        pi->length -= (int32_t)size;
 
         return offset;
       }
@@ -151,22 +105,40 @@ static uint64_t allocatePositionInFile(SDiskbasedBuf* pBuf, size_t size) {
   }
 }
 
+static void setPageNotInBuf(SPageInfo* pPageInfo) {
+  pPageInfo->pData = NULL;
+}
+
+static FORCE_INLINE size_t getAllocPageSize(int32_t pageSize) {
+  return pageSize + POINTER_BYTES + 2;
+}
+
+/**
+ *   +--------------------------+-------------------+--------------+
+ *   | PTR to SPageInfo (8bytes)| Payload (PageSize)| 2 Extra Bytes|
+ *   +--------------------------+-------------------+--------------+
+ * @param pBuf
+ * @param pg
+ * @return
+ */
 static char* doFlushPageToDisk(SDiskbasedBuf* pBuf, SPageInfo* pg) {
   assert(!pg->used && pg->pData != NULL);
 
-  int32_t size = -1;
+  int32_t size = pBuf->pageSize;
   char*   t = NULL;
   if (pg->offset == -1 || pg->dirty) {
-    SFilePage* pPage = (SFilePage*) GET_DATA_PAYLOAD(pg);
-    t = doCompressData(pPage->data, pBuf->pageSize, &size, pBuf);
+    void* payload = GET_DATA_PAYLOAD(pg);
+    t = doCompressData(payload, pBuf->pageSize, &size, pBuf);
+    assert(size >= 0);
   }
 
   // this page is flushed to disk for the first time
-  if (pg->offset == -1) {
-    assert(pg->dirty == true);
+  if (pg->dirty) {
+    if (pg->offset == -1) {
+      assert(pg->dirty == true);
 
-    pg->offset = allocatePositionInFile(pBuf, size);
-    pBuf->nextPos += size;
+      pg->offset = allocatePositionInFile(pBuf, size);
+      pBuf->nextPos += size;
 
     int32_t ret = taosLSeekFile(pBuf->pFile, pg->offset, SEEK_SET);
     if (ret != 0) {
@@ -180,23 +152,23 @@ static char* doFlushPageToDisk(SDiskbasedBuf* pBuf, SPageInfo* pg) {
       return NULL;
     }
 
-    if (pBuf->fileSize < pg->offset + size) {
-      pBuf->fileSize = pg->offset + size;
-    }
+      if (pBuf->fileSize < pg->offset + size) {
+        pBuf->fileSize = pg->offset + size;
+      }
 
-    pBuf->statis.flushBytes += size;
-    pBuf->statis.flushPages += 1;
-  } else if (pg->dirty) {
-    // length becomes greater, current space is not enough, allocate new place, otherwise, do nothing
-    if (pg->length < size) {
-      // 1. add current space to free list
-      SPageDiskInfo dinfo = {.length = pg->length, .offset = pg->offset};
-      taosArrayPush(pBuf->pFree, &dinfo);
+      pBuf->statis.flushBytes += size;
+      pBuf->statis.flushPages += 1;
+    } else {
+      // length becomes greater, current space is not enough, allocate new place, otherwise, do nothing
+      if (pg->length < size) {
+        // 1. add current space to free list
+        SPageDiskInfo dinfo = {.length = pg->length, .offset = pg->offset};
+        taosArrayPush(pBuf->pFree, &dinfo);
 
-      // 2. allocate new position, and update the info
-      pg->offset = allocatePositionInFile(pBuf, size);
-      pBuf->nextPos += size;
-    }
+        // 2. allocate new position, and update the info
+        pg->offset = allocatePositionInFile(pBuf, size);
+        pBuf->nextPos += size;
+      }
 
     // 3. write to disk.
     int32_t ret = taosLSeekFile(pBuf->pFile, pg->offset, SEEK_SET);
@@ -211,21 +183,26 @@ static char* doFlushPageToDisk(SDiskbasedBuf* pBuf, SPageInfo* pg) {
       return NULL;
     }
 
-    if (pBuf->fileSize < pg->offset + size) {
-      pBuf->fileSize = pg->offset + size;
-    }
+      if (pBuf->fileSize < pg->offset + size) {
+        pBuf->fileSize = pg->offset + size;
+      }
 
-    pBuf->statis.flushBytes += size;
-    pBuf->statis.flushPages += 1;
+      pBuf->statis.flushBytes += size;
+      pBuf->statis.flushPages += 1;
+    }
+  } else {// NOTE: the size may be -1, the this recycle page has not been flushed to disk yet.
+    size = pg->length;
+    if (size == -1) {
+      printf("----\n");
+    }
   }
 
+  ASSERT(size > 0 || (pg->offset == -1 && pg->length == -1));
+
   char* pDataBuf = pg->pData;
-  memset(pDataBuf, 0, pBuf->pageSize + sizeof(SFilePage));
-
-  pg->pData  = NULL;  // this means the data is not in buffer
-  pg->length = size;
-  pg->dirty  = false;
+  memset(pDataBuf, 0, getAllocPageSize(pBuf->pageSize));
 
+  pg->length = size;  // on disk size
   return pDataBuf;
 }
 
@@ -240,7 +217,11 @@ static char* flushPageToDisk(SDiskbasedBuf* pBuf, SPageInfo* pg) {
     }
   }
 
-  return doFlushPageToDisk(pBuf, pg);
+  char* p = doFlushPageToDisk(pBuf, pg);
+  setPageNotInBuf(pg);
+  pg->dirty = false;
+
+  return p;
 }
 
 // load file block data in disk
@@ -251,8 +232,8 @@ static int32_t loadPageFromDisk(SDiskbasedBuf* pBuf, SPageInfo* pg) {
     return ret;
   }
 
-  SFilePage* pPage = (SFilePage*) GET_DATA_PAYLOAD(pg);
-  ret = (int32_t)taosReadFile(pBuf->pFile, pPage->data, pg->length);
+  void* pPage = (void*) GET_DATA_PAYLOAD(pg);
+  ret = (int32_t)taosReadFile(pBuf->pFile, pPage, pg->length);
   if (ret != pg->length) {
     ret = TAOS_SYSTEM_ERROR(errno);
     return ret;
@@ -262,7 +243,7 @@ static int32_t loadPageFromDisk(SDiskbasedBuf* pBuf, SPageInfo* pg) {
   pBuf->statis.loadPages += 1;
 
   int32_t fullSize = 0;
-  doDecompressData(pPage->data, pg->length, &fullSize, pBuf);
+  doDecompressData(pPage, pg->length, &fullSize, pBuf);
   return 0;
 }
 
@@ -288,7 +269,7 @@ static SPageInfo* registerPage(SDiskbasedBuf* pBuf, int32_t groupId, int32_t pag
 
   pBuf->numOfPages += 1;
 
-  SPageInfo* ppi = malloc(sizeof(SPageInfo));//{ .info = PAGE_INFO_INITIALIZER, .pageId = pageId, .pn = NULL};
+  SPageInfo* ppi = malloc(sizeof(SPageInfo));
 
   ppi->pageId = pageId;
   ppi->pData  = NULL;
@@ -306,16 +287,27 @@ static SListNode* getEldestUnrefedPage(SDiskbasedBuf* pBuf) {
 
   SListNode* pn = NULL;
   while((pn = tdListNext(&iter)) != NULL) {
-    assert(pn != NULL);
-
     SPageInfo* pageInfo = *(SPageInfo**) pn->data;
     assert(pageInfo->pageId >= 0 && pageInfo->pn == pn);
 
     if (!pageInfo->used) {
+//      printf("%d is chosen\n", pageInfo->pageId);
       break;
+    } else {
+//      printf("page %d is used, dirty:%d\n", pageInfo->pageId, pageInfo->dirty);
     }
   }
 
+//  int32_t pos = listNEles(pBuf->lruList);
+//  SListIter iter1 = {0};
+//  tdListInitIter(pBuf->lruList, &iter1, TD_LIST_BACKWARD);
+//  SListNode* pn1 = NULL;
+//  while((pn1 = tdListNext(&iter1)) != NULL) {
+//    SPageInfo* pageInfo = *(SPageInfo**) pn1->data;
+//    printf("page %d is used, dirty:%d, pos:%d\n", pageInfo->pageId, pageInfo->dirty, pos - 1);
+//    pos -= 1;
+//  }
+
   return pn;
 }
 
@@ -359,11 +351,58 @@ static void lruListMoveToFront(SList *pList, SPageInfo* pi) {
   tdListPrependNode(pList, pi->pn);
 }
 
-static FORCE_INLINE size_t getAllocPageSize(int32_t pageSize) {
-  return pageSize + POINTER_BYTES + 2 + sizeof(SFilePage);
+static SPageInfo* getPageInfoFromPayload(void* page) {
+  int32_t offset = offsetof(SPageInfo, pData);
+  char* p = page - offset;
+
+  SPageInfo* ppi = ((SPageInfo**) p)[0];
+  return ppi;
 }
 
-SFilePage* getNewDataBuf(SDiskbasedBuf* pBuf, int32_t groupId, int32_t* pageId) {
+int32_t createDiskbasedBuf(SDiskbasedBuf** pBuf, int32_t pagesize, int32_t inMemBufSize, uint64_t qId, const char* dir) {
+  *pBuf = calloc(1, sizeof(SDiskbasedBuf));
+
+  SDiskbasedBuf* pPBuf = *pBuf;
+  if (pPBuf == NULL) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  pPBuf->pageSize     = pagesize;
+  pPBuf->numOfPages   = 0;                        // all pages are in buffer in the first place
+  pPBuf->totalBufSize = 0;
+  pPBuf->inMemPages   = inMemBufSize/pagesize;    // maximum allowed pages, it is a soft limit.
+  pPBuf->allocateId   = -1;
+  pPBuf->comp         = true;
+  pPBuf->pFile        = NULL;
+  pPBuf->qId          = qId;
+  pPBuf->fileSize     = 0;
+  pPBuf->pFree        = taosArrayInit(4, sizeof(SFreeListItem));
+  pPBuf->freePgList   = tdListNew(POINTER_BYTES);
+
+  // at least more than 2 pages must be in memory
+  assert(inMemBufSize >= pagesize * 2);
+
+  pPBuf->lruList = tdListNew(POINTER_BYTES);
+
+  // init id hash table
+  _hash_fn_t fn = taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT);
+  pPBuf->groupSet  = taosHashInit(10, fn, true, false);
+  pPBuf->assistBuf = malloc(pPBuf->pageSize + 2); // EXTRA BYTES
+  pPBuf->all = taosHashInit(10, fn, true, false);
+
+  char path[PATH_MAX] = {0};
+  taosGetTmpfilePath(dir, "paged-buf", path);
+  pPBuf->path = strdup(path);
+
+  pPBuf->emptyDummyIdList = taosArrayInit(1, sizeof(int32_t));
+
+//  qDebug("QInfo:0x%"PRIx64" create resBuf for output, page size:%d, inmem buf pages:%d, file:%s", qId, pPBuf->pageSize,
+//         pPBuf->inMemPages, pPBuf->path);
+
+  return TSDB_CODE_SUCCESS;
+}
+
+void* getNewBufPage(SDiskbasedBuf* pBuf, int32_t groupId, int32_t* pageId) {
   pBuf->statis.getPages += 1;
 
   char* availablePage = NULL;
@@ -372,23 +411,34 @@ SFilePage* getNewDataBuf(SDiskbasedBuf* pBuf, int32_t groupId, int32_t* pageId)
 
     // Failed to allocate a new buffer page, and there is an error occurs.
     if (availablePage == NULL) {
+      assert(0);
       return NULL;
     }
   }
 
-  // register new id in this group
-  *pageId = (++pBuf->allocateId);
+  SPageInfo* pi = NULL;
+  if (listNEles(pBuf->freePgList) != 0) {
+    SListNode* pItem = tdListPopHead(pBuf->freePgList);
+    pi       = *(SPageInfo**) pItem->data;
+    pi->used = true;
+    *pageId  = pi->pageId;
+    tfree(pItem);
+  } else {// create a new pageinfo
+    // register new id in this group
+    *pageId = (++pBuf->allocateId);
 
-  // register page id info
-  SPageInfo* pi = registerPage(pBuf, groupId, *pageId);
+    // register page id info
+    pi = registerPage(pBuf, groupId, *pageId);
+
+    // add to hash map
+    taosHashPut(pBuf->all, pageId, sizeof(int32_t), &pi, POINTER_BYTES);
+    pBuf->totalBufSize += pBuf->pageSize;
+  }
 
   // add to LRU list
   assert(listNEles(pBuf->lruList) < pBuf->inMemPages && pBuf->inMemPages > 0);
   lruListPushFront(pBuf->lruList, pi);
 
-  // add to hash map
-  taosHashPut(pBuf->all, pageId, sizeof(int32_t), &pi, POINTER_BYTES);
-
   // allocate buf
   if (availablePage == NULL) {
     pi->pData = calloc(1, getAllocPageSize(pBuf->pageSize));  // add extract bytes in case of zipped buffer increased.
@@ -396,15 +446,11 @@ SFilePage* getNewDataBuf(SDiskbasedBuf* pBuf, int32_t groupId, int32_t* pageId)
     pi->pData = availablePage;
   }
 
-  pBuf->totalBufSize += pBuf->pageSize;
-
   ((void**)pi->pData)[0] = pi;
-  pi->used = true;
-
   return (void *)(GET_DATA_PAYLOAD(pi));
 }
 
-SFilePage* getBufPage(SDiskbasedBuf* pBuf, int32_t id) {
+void* getBufPage(SDiskbasedBuf* pBuf, int32_t id) {
   assert(pBuf != NULL && id >= 0);
   pBuf->statis.getPages += 1;
 
@@ -425,7 +471,6 @@ SFilePage* getBufPage(SDiskbasedBuf* pBuf, int32_t id) {
     (*pi)->used = true;
 
     return (void *)(GET_DATA_PAYLOAD(*pi));
-
   } else { // not in memory
     assert((*pi)->pData == NULL && (*pi)->pn == NULL && (*pi)->length >= 0 && (*pi)->offset >= 0);
 
@@ -443,6 +488,7 @@ SFilePage* getBufPage(SDiskbasedBuf* pBuf, int32_t id) {
       (*pi)->pData = availablePage;
     }
 
+    // set the ptr to the new SPageInfo
     ((void**)((*pi)->pData))[0] = (*pi);
 
     lruListPushFront(pBuf->lruList, *pi);
@@ -459,21 +505,18 @@ SFilePage* getBufPage(SDiskbasedBuf* pBuf, int32_t id) {
 
 void releaseBufPage(SDiskbasedBuf* pBuf, void* page) {
   assert(pBuf != NULL && page != NULL);
-  int32_t offset = offsetof(SPageInfo, pData);
-  char* p = page - offset;
-
-  SPageInfo* ppi = ((SPageInfo**) p)[0];
+  SPageInfo* ppi = getPageInfoFromPayload(page);
   releaseBufPageInfo(pBuf, ppi);
 }
 
 void releaseBufPageInfo(SDiskbasedBuf* pBuf, SPageInfo* pi) {
-  assert(pi->pData != NULL && pi->used);
+  assert(pi->pData != NULL && pi->used == true);
 
   pi->used = false;
   pBuf->statis.releasePages += 1;
 }
 
-size_t getNumOfResultBufGroupId(const SDiskbasedBuf* pBuf) { return taosHashGetSize(pBuf->groupSet); }
+size_t getNumOfBufGroupId(const SDiskbasedBuf* pBuf) { return taosHashGetSize(pBuf->groupSet); }
 
 size_t getTotalBufSize(const SDiskbasedBuf* pBuf) { return (size_t)pBuf->totalBufSize; }
 
@@ -488,12 +531,12 @@ SIDList getDataBufPagesIdList(SDiskbasedBuf* pBuf, int32_t groupId) {
   }
 }
 
-void destroyResultBuf(SDiskbasedBuf* pBuf) {
+void destroyDiskbasedBuf(SDiskbasedBuf* pBuf) {
   if (pBuf == NULL) {
     return;
   }
 
-  printStatisData(pBuf);
+  dBufPrintStatis(pBuf);
 
   if (pBuf->pFile != NULL) {
   uDebug("Paged buffer closed, total:%.2f Kb (%d Pages), inmem size:%.2f Kb (%d Pages), file size:%.2f Kb, page size:%.2f Kb, %"PRIx64"\n",
@@ -530,7 +573,11 @@ void destroyResultBuf(SDiskbasedBuf* pBuf) {
   }
 
   tdListFree(pBuf->lruList);
+  tdListFree(pBuf->freePgList);
+
   taosArrayDestroy(pBuf->emptyDummyIdList);
+  taosArrayDestroy(pBuf->pFree);
+
   taosHashCleanup(pBuf->groupSet);
   taosHashCleanup(pBuf->all);
 
@@ -561,15 +608,30 @@ bool isAllDataInMemBuf(const SDiskbasedBuf* pBuf) {
   return pBuf->fileSize == 0;
 }
 
-void setBufPageDirty(SFilePage* pPage, bool dirty) {
-  int32_t offset = offsetof(SPageInfo, pData);  // todo extract method
-  char* p = (char*)pPage - offset;
-
-  SPageInfo* ppi = ((SPageInfo**) p)[0];
+void setBufPageDirty(void* pPage, bool dirty) {
+  SPageInfo* ppi = getPageInfoFromPayload(pPage);
   ppi->dirty = dirty;
 }
 
-void printStatisBeforeClose(SDiskbasedBuf* pBuf) {
+void setBufPageCompressOnDisk(SDiskbasedBuf* pBuf, bool comp) {
+  pBuf->comp = comp;
+}
+
+void dBufSetBufPageRecycled(SDiskbasedBuf *pBuf, void* pPage) {
+  SPageInfo* ppi = getPageInfoFromPayload(pPage);
+
+  ppi->used  = false;
+  ppi->dirty = false;
+
+  // add this pageinfo into the free page info list
+  SListNode* pNode = tdListPopNode(pBuf->lruList, ppi->pn);
+  tfree(ppi->pData);
+  tfree(pNode);
+
+  tdListAppend(pBuf->freePgList, &ppi);
+}
+
+void dBufSetPrintInfo(SDiskbasedBuf* pBuf) {
   pBuf->printStatis = true;
 }
 
@@ -577,7 +639,7 @@ SDiskbasedBufStatis getDBufStatis(const SDiskbasedBuf* pBuf) {
   return pBuf->statis;
 }
 
-void printStatisData(const SDiskbasedBuf* pBuf) {
+void dBufPrintStatis(const SDiskbasedBuf* pBuf) {
   if (!pBuf->printStatis) {
     return;
   }
@@ -595,3 +657,4 @@ void printStatisData(const SDiskbasedBuf* pBuf) {
       ps->getPages, ps->releasePages, ps->flushBytes / 1024.0f, ps->flushPages, ps->loadBytes / 1024.0f, ps->loadPages,
       ps->loadBytes / (1024.0 * ps->loadPages));
 }
+
diff --git a/source/util/test/pageBufferTest.cpp b/source/util/test/pageBufferTest.cpp
index 8fa8216223..4b9d8c5f51 100644
--- a/source/util/test/pageBufferTest.cpp
+++ b/source/util/test/pageBufferTest.cpp
@@ -13,144 +13,144 @@ namespace {
 // simple test
 void simpleTest() {
   SDiskbasedBuf* pResultBuf = NULL;
-  int32_t ret = createDiskbasedBuffer(&pResultBuf, 1024, 4096, 1, "/tmp/");
+  int32_t ret = createDiskbasedBuf(&pResultBuf, 1024, 4096, 1, "/tmp/");
   
   int32_t pageId = 0;
   int32_t groupId = 0;
   
-  SFilePage* pBufPage = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* pBufPage = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
   ASSERT_TRUE(pBufPage != NULL);
   
   ASSERT_EQ(getTotalBufSize(pResultBuf), 1024);
   
   SIDList list = getDataBufPagesIdList(pResultBuf, groupId);
   ASSERT_EQ(taosArrayGetSize(list), 1);
-  ASSERT_EQ(getNumOfResultBufGroupId(pResultBuf), 1);
+  ASSERT_EQ(getNumOfBufGroupId(pResultBuf), 1);
 
   releaseBufPage(pResultBuf, pBufPage);
 
-  SFilePage* pBufPage1 = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* pBufPage1 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
 
-  SFilePage* t = getBufPage(pResultBuf, pageId);
+  SFilePage* t = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t == pBufPage1);
 
-  SFilePage* pBufPage2 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t1 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage2 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t1 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t1 == pBufPage2);
 
-  SFilePage* pBufPage3 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t2 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage3 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t2 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t2 == pBufPage3);
 
-  SFilePage* pBufPage4 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t3 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage4 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t3 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t3 == pBufPage4);
 
-  SFilePage* pBufPage5 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t4 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage5 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t4 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t4 == pBufPage5);
 
-  destroyResultBuf(pResultBuf);
+  destroyDiskbasedBuf(pResultBuf);
 }
 
 void writeDownTest() {
   SDiskbasedBuf* pResultBuf = NULL;
-  int32_t ret = createDiskbasedBuffer(&pResultBuf, 1024, 4*1024, 1, "/tmp/");
+  int32_t ret = createDiskbasedBuf(&pResultBuf, 1024, 4*1024, 1, "/tmp/");
 
   int32_t pageId = 0;
   int32_t writePageId = 0;
   int32_t groupId = 0;
   int32_t nx = 12345;
 
-  SFilePage* pBufPage = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* pBufPage = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
   ASSERT_TRUE(pBufPage != NULL);
 
   *(int32_t*)(pBufPage->data) = nx;
   writePageId = pageId;
   releaseBufPage(pResultBuf, pBufPage);
 
-  SFilePage* pBufPage1 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t1 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage1 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t1 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t1 == pBufPage1);
   ASSERT_TRUE(pageId == 1);
 
-  SFilePage* pBufPage2 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t2 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage2 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t2 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t2 == pBufPage2);
   ASSERT_TRUE(pageId == 2);
 
-  SFilePage* pBufPage3 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t3 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage3 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t3 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t3 == pBufPage3);
   ASSERT_TRUE(pageId == 3);
 
-  SFilePage* pBufPage4 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t4 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage4 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t4 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t4 == pBufPage4);
   ASSERT_TRUE(pageId == 4);
   releaseBufPage(pResultBuf, t4);
 
   // flush the written page to disk, and read it out again
-  SFilePage* pBufPagex = getBufPage(pResultBuf, writePageId);
+  SFilePage* pBufPagex = static_cast<SFilePage*>(getBufPage(pResultBuf, writePageId));
   ASSERT_EQ(*(int32_t*)pBufPagex->data, nx);
 
   SArray* pa = getDataBufPagesIdList(pResultBuf, groupId);
   ASSERT_EQ(taosArrayGetSize(pa), 5);
 
-  destroyResultBuf(pResultBuf);
+  destroyDiskbasedBuf(pResultBuf);
 }
 
 void recyclePageTest() {
   SDiskbasedBuf* pResultBuf = NULL;
-  int32_t ret = createDiskbasedBuffer(&pResultBuf, 1024, 4*1024, 1, "/tmp/");
+  int32_t ret = createDiskbasedBuf(&pResultBuf, 1024, 4*1024, 1, "/tmp/");
 
   int32_t pageId = 0;
   int32_t writePageId = 0;
   int32_t groupId = 0;
   int32_t nx = 12345;
 
-  SFilePage* pBufPage = getNewDataBuf(pResultBuf, groupId, &pageId);
+  SFilePage* pBufPage = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
   ASSERT_TRUE(pBufPage != NULL);
   releaseBufPage(pResultBuf, pBufPage);
 
-  SFilePage* pBufPage1 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t1 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage1 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t1 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t1 == pBufPage1);
   ASSERT_TRUE(pageId == 1);
 
-  SFilePage* pBufPage2 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t2 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage2 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t2 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t2 == pBufPage2);
   ASSERT_TRUE(pageId == 2);
 
-  SFilePage* pBufPage3 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t3 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage3 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t3 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t3 == pBufPage3);
   ASSERT_TRUE(pageId == 3);
 
-  SFilePage* pBufPage4 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t4 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage4 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t4 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t4 == pBufPage4);
   ASSERT_TRUE(pageId == 4);
   releaseBufPage(pResultBuf, t4);
 
-  SFilePage* pBufPage5 = getNewDataBuf(pResultBuf, groupId, &pageId);
-  SFilePage* t5 = getBufPage(pResultBuf, pageId);
+  SFilePage* pBufPage5 = static_cast<SFilePage*>(getNewBufPage(pResultBuf, groupId, &pageId));
+  SFilePage* t5 = static_cast<SFilePage*>(getBufPage(pResultBuf, pageId));
   ASSERT_TRUE(t5 == pBufPage5);
   ASSERT_TRUE(pageId == 5);
 
   // flush the written page to disk, and read it out again
-  SFilePage* pBufPagex = getBufPage(pResultBuf, writePageId);
+  SFilePage* pBufPagex = static_cast<SFilePage*>(getBufPage(pResultBuf, writePageId));
   *(int32_t*)(pBufPagex->data) = nx;
   writePageId = pageId;   // update the data
   releaseBufPage(pResultBuf, pBufPagex);
 
-  SFilePage* pBufPagex1 = getBufPage(pResultBuf, 1);
+  SFilePage* pBufPagex1 = static_cast<SFilePage*>(getBufPage(pResultBuf, 1));
 
   SArray* pa = getDataBufPagesIdList(pResultBuf, groupId);
   ASSERT_EQ(taosArrayGetSize(pa), 6);
 
-  destroyResultBuf(pResultBuf);
+  destroyDiskbasedBuf(pResultBuf);
 }
 } // namespace