diff --git a/source/common/src/tglobal.c b/source/common/src/tglobal.c
index fa8fdb19d4..09f5d4b4b2 100644
--- a/source/common/src/tglobal.c
+++ b/source/common/src/tglobal.c
@@ -58,7 +58,7 @@ int32_t tsNumOfMnodeFetchThreads = 1;
 int32_t tsNumOfMnodeReadThreads = 1;
 int32_t tsNumOfVnodeQueryThreads = 4;
 int32_t tsNumOfVnodeStreamThreads = 2;
-int32_t tsNumOfVnodeFetchThreads = 4;
+int32_t tsNumOfVnodeFetchThreads = 1;
 int32_t tsNumOfVnodeWriteThreads = 2;
 int32_t tsNumOfVnodeSyncThreads = 2;
 int32_t tsNumOfVnodeRsmaThreads = 2;
@@ -165,8 +165,8 @@ int32_t tsMqRebalanceInterval = 2;
 int32_t tsTtlUnit = 86400;
 int32_t tsTtlPushInterval = 86400;
 int32_t tsGrantHBInterval = 60;
-int32_t tsUptimeInterval = 300;  // seconds
-char    tsUdfdResFuncs[1024] = ""; // udfd resident funcs that teardown when udfd exits
+int32_t tsUptimeInterval = 300;     // seconds
+char    tsUdfdResFuncs[1024] = "";  // udfd resident funcs that teardown when udfd exits
 
 #ifndef _STORAGE
 int32_t taosSetTfsCfg(SConfig *pCfg) {
@@ -371,9 +371,8 @@ static int32_t taosAddServerCfg(SConfig *pCfg) {
   tsNumOfVnodeStreamThreads = TMAX(tsNumOfVnodeStreamThreads, 4);
   if (cfgAddInt32(pCfg, "numOfVnodeStreamThreads", tsNumOfVnodeStreamThreads, 4, 1024, 0) != 0) return -1;
 
-  tsNumOfVnodeFetchThreads = tsNumOfCores / 4;
-  tsNumOfVnodeFetchThreads = TMAX(tsNumOfVnodeFetchThreads, 4);
-  if (cfgAddInt32(pCfg, "numOfVnodeFetchThreads", tsNumOfVnodeFetchThreads, 4, 1024, 0) != 0) return -1;
+  tsNumOfVnodeFetchThreads = 1;
+  if (cfgAddInt32(pCfg, "numOfVnodeFetchThreads", tsNumOfVnodeFetchThreads, 1, 1024, 0) != 0) return -1;
 
   tsNumOfVnodeWriteThreads = tsNumOfCores;
   tsNumOfVnodeWriteThreads = TMAX(tsNumOfVnodeWriteThreads, 1);
diff --git a/source/dnode/vnode/src/tq/tq.c b/source/dnode/vnode/src/tq/tq.c
index 29217e29a4..76f3c1b12d 100644
--- a/source/dnode/vnode/src/tq/tq.c
+++ b/source/dnode/vnode/src/tq/tq.c
@@ -479,6 +479,9 @@ int32_t tqProcessPollReq(STQ* pTq, SRpcMsg* pMsg) {
     tqInitDataRsp(&dataRsp, pReq, pHandle->execHandle.subType);
     tqScanData(pTq, pHandle, &dataRsp, &fetchOffsetNew);
 
+#if 1
+
+#endif
     if (tqSendDataRsp(pTq, pMsg, pReq, &dataRsp) < 0) {
       code = -1;
     }
diff --git a/source/libs/executor/src/executor.c b/source/libs/executor/src/executor.c
index 45b88ec6a5..be8bdf7308 100644
--- a/source/libs/executor/src/executor.c
+++ b/source/libs/executor/src/executor.c
@@ -49,6 +49,7 @@ static int32_t doSetStreamBlock(SOperatorInfo* pOperator, void* input, size_t nu
 
     SStreamScanInfo* pInfo = pOperator->info;
 
+#if 0
     // TODO: if a block was set but not consumed,
     // prevent setting a different type of block
     pInfo->validBlockIndex = 0;
@@ -57,6 +58,10 @@ static int32_t doSetStreamBlock(SOperatorInfo* pOperator, void* input, size_t nu
     } else {
       taosArrayClear(pInfo->pBlockLists);
     }
+#endif
+
+    ASSERT(pInfo->validBlockIndex == 0);
+    ASSERT(taosArrayGetSize(pInfo->pBlockLists) == 0);
 
     if (type == STREAM_INPUT__MERGED_SUBMIT) {
       // ASSERT(numOfBlocks > 1);
@@ -79,7 +84,9 @@ static int32_t doSetStreamBlock(SOperatorInfo* pOperator, void* input, size_t nu
     } else if (type == STREAM_INPUT__DATA_BLOCK) {
       for (int32_t i = 0; i < numOfBlocks; ++i) {
         SSDataBlock* pDataBlock = &((SSDataBlock*)input)[i];
+        taosArrayPush(pInfo->pBlockLists, &pDataBlock);
 
+#if 0
         // TODO optimize
         SSDataBlock* p = createOneDataBlock(pDataBlock, false);
         p->info = pDataBlock->info;
@@ -87,6 +94,7 @@ static int32_t doSetStreamBlock(SOperatorInfo* pOperator, void* input, size_t nu
         taosArrayClear(p->pDataBlock);
         taosArrayAddAll(p->pDataBlock, pDataBlock->pDataBlock);
         taosArrayPush(pInfo->pBlockLists, &p);
+#endif
       }
       pInfo->blockType = STREAM_INPUT__DATA_BLOCK;
     } else {
@@ -100,6 +108,7 @@ static int32_t doSetStreamBlock(SOperatorInfo* pOperator, void* input, size_t nu
 static FORCE_INLINE void streamInputBlockDataDestory(void* pBlock) { blockDataDestroy((SSDataBlock*)pBlock); }
 
 void tdCleanupStreamInputDataBlock(qTaskInfo_t tinfo) {
+#if 0
   SExecTaskInfo* pTaskInfo = (SExecTaskInfo*)tinfo;
   if (!pTaskInfo || !pTaskInfo->pRoot || pTaskInfo->pRoot->numOfDownstream <= 0) {
     return;
@@ -116,6 +125,7 @@ void tdCleanupStreamInputDataBlock(qTaskInfo_t tinfo) {
   } else {
     ASSERT(0);
   }
+#endif
 }
 
 int32_t qSetMultiStreamInput(qTaskInfo_t tinfo, const void* pBlocks, size_t numOfBlocks, int32_t type) {
diff --git a/source/libs/executor/src/scanoperator.c b/source/libs/executor/src/scanoperator.c
index 5293e23fa7..6c5c33ae29 100644
--- a/source/libs/executor/src/scanoperator.c
+++ b/source/libs/executor/src/scanoperator.c
@@ -920,6 +920,19 @@ _error:
 }
 
 static void doClearBufferedBlocks(SStreamScanInfo* pInfo) {
+#if 0
+  if (pInfo->blockType == STREAM_INPUT__DATA_BLOCK) {
+    size_t total = taosArrayGetSize(pInfo->pBlockLists);
+    for (int32_t i = 0; i < total; i++) {
+      SSDataBlock* p = taosArrayGetP(pInfo->pBlockLists, i);
+      taosArrayDestroy(p->pDataBlock);
+      taosMemoryFree(p);
+    }
+  }
+#endif
+  taosArrayClear(pInfo->pBlockLists);
+  pInfo->validBlockIndex = 0;
+#if 0
   size_t total = taosArrayGetSize(pInfo->pBlockLists);
 
   pInfo->validBlockIndex = 0;
@@ -928,6 +941,7 @@ static void doClearBufferedBlocks(SStreamScanInfo* pInfo) {
     blockDataDestroy(p);
   }
   taosArrayClear(pInfo->pBlockLists);
+#endif
 }
 
 static bool isSessionWindow(SStreamScanInfo* pInfo) {
@@ -1580,9 +1594,10 @@ static SSDataBlock* doStreamScan(SOperatorInfo* pOperator) {
 
   size_t total = taosArrayGetSize(pInfo->pBlockLists);
   // TODO: refactor
+FETCH_NEXT_BLOCK:
   if (pInfo->blockType == STREAM_INPUT__DATA_BLOCK) {
     if (pInfo->validBlockIndex >= total) {
-      /*doClearBufferedBlocks(pInfo);*/
+      doClearBufferedBlocks(pInfo);
       /*pOperator->status = OP_EXEC_DONE;*/
       return NULL;
     }
@@ -1606,27 +1621,40 @@ static SSDataBlock* doStreamScan(SOperatorInfo* pOperator) {
       } break;
       case STREAM_DELETE_DATA: {
         printDataBlock(pBlock, "stream scan delete recv");
+        SSDataBlock* pDelBlock = NULL;
         if (pInfo->tqReader) {
-          SSDataBlock* pDelBlock = createSpecialDataBlock(STREAM_DELETE_DATA);
+          pDelBlock = createSpecialDataBlock(STREAM_DELETE_DATA);
           filterDelBlockByUid(pDelBlock, pBlock, pInfo);
-          pBlock = pDelBlock;
+        } else {
+          pDelBlock = pBlock;
         }
         printDataBlock(pBlock, "stream scan delete recv filtered");
         if (!isIntervalWindow(pInfo) && !isSessionWindow(pInfo) && !isStateWindow(pInfo)) {
-          generateDeleteResultBlock(pInfo, pBlock, pInfo->pDeleteDataRes);
+          generateDeleteResultBlock(pInfo, pDelBlock, pInfo->pDeleteDataRes);
           pInfo->pDeleteDataRes->info.type = STREAM_DELETE_RESULT;
-          printDataBlock(pBlock, "stream scan delete result");
-          return pInfo->pDeleteDataRes;
+          printDataBlock(pDelBlock, "stream scan delete result");
+          if (pInfo->pDeleteDataRes->info.rows > 0) {
+            return pInfo->pDeleteDataRes;
+          } else {
+            goto FETCH_NEXT_BLOCK;
+          }
         } else {
           pInfo->blockType = STREAM_INPUT__DATA_SUBMIT;
           pInfo->updateResIndex = 0;
-          generateScanRange(pInfo, pBlock, pInfo->pUpdateRes);
+          generateScanRange(pInfo, pDelBlock, pInfo->pUpdateRes);
           prepareRangeScan(pInfo, pInfo->pUpdateRes, &pInfo->updateResIndex);
           copyDataBlock(pInfo->pDeleteDataRes, pInfo->pUpdateRes);
           pInfo->pDeleteDataRes->info.type = STREAM_DELETE_DATA;
           pInfo->scanMode = STREAM_SCAN_FROM_DATAREADER_RANGE;
-          printDataBlock(pBlock, "stream scan delete data");
-          return pInfo->pDeleteDataRes;
+          printDataBlock(pDelBlock, "stream scan delete data");
+          if (pInfo->tqReader) {
+            blockDataDestroy(pDelBlock);
+          }
+          if (pInfo->pDeleteDataRes->info.rows > 0) {
+            return pInfo->pDeleteDataRes;
+          } else {
+            goto FETCH_NEXT_BLOCK;
+          }
         }
       } break;
       default:
@@ -1688,10 +1716,12 @@ static SSDataBlock* doStreamScan(SOperatorInfo* pOperator) {
 
     int32_t totBlockNum = taosArrayGetSize(pInfo->pBlockLists);
 
+  NEXT_SUBMIT_BLK:
     while (1) {
       if (pInfo->tqReader->pMsg == NULL) {
         if (pInfo->validBlockIndex >= totBlockNum) {
           updateInfoDestoryColseWinSBF(pInfo->pUpdateInfo);
+          doClearBufferedBlocks(pInfo);
           return NULL;
         }
 
@@ -1763,7 +1793,12 @@ static SSDataBlock* doStreamScan(SOperatorInfo* pOperator) {
     }
 
     qDebug("scan rows: %d", pBlockInfo->rows);
-    return (pBlockInfo->rows == 0) ? NULL : pInfo->pRes;
+    if (pBlockInfo->rows > 0) {
+      return pInfo->pRes;
+    } else {
+      goto NEXT_SUBMIT_BLK;
+    }
+    /*return (pBlockInfo->rows == 0) ? NULL : pInfo->pRes;*/
   } else {
     ASSERT(0);
     return NULL;
diff --git a/source/libs/executor/src/timewindowoperator.c b/source/libs/executor/src/timewindowoperator.c
index b5ad3f9270..9e51f3638e 100644
--- a/source/libs/executor/src/timewindowoperator.c
+++ b/source/libs/executor/src/timewindowoperator.c
@@ -5658,7 +5658,6 @@ static void doStreamIntervalAggImpl2(SOperatorInfo* pOperatorInfo, SSDataBlock*
   TSKEY*          tsCols = NULL;
   SResultRow*     pResult = NULL;
   int32_t         forwardRows = 0;
-  int32_t         aa = 4;
 
   ASSERT(pSDataBlock->pDataBlock != NULL);
   SColumnInfoData* pColDataInfo = taosArrayGet(pSDataBlock->pDataBlock, pInfo->primaryTsIndex);