diff --git a/include/libs/executor/storageapi.h b/include/libs/executor/storageapi.h
index 712ae7c95b..2402182eae 100644
--- a/include/libs/executor/storageapi.h
+++ b/include/libs/executor/storageapi.h
@@ -153,7 +153,8 @@ typedef struct {
 // clang-format off
 /*-------------------------------------------------new api format---------------------------------------------------*/
 typedef enum {
-  TSD_READER_NOTIFY_DURATION_START
+  TSD_READER_NOTIFY_DURATION_START,
+  TSD_READER_NOTIFY_NEXT_DURATION_BLOCK,
 } ETsdReaderNotifyType;
 
 typedef union {
diff --git a/source/dnode/vnode/src/tsdb/tsdbRead2.c b/source/dnode/vnode/src/tsdb/tsdbRead2.c
index e1dc226bb9..6f9f81773a 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead2.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead2.c
@@ -4332,12 +4332,7 @@ static int32_t buildFromPreFilesetBuffer(STsdbReader* pReader) {
       STsdReaderNotifyInfo info = {0};
       info.duration.filesetId = fid;
       pReader->notifyFn(TSD_READER_NOTIFY_DURATION_START, &info, pReader->notifyParam);
-      tsdbDebug("new duration %d start notification when no buffer preceeding fileset, %s", fid, pReader->idStr);
-    }
-    if (pStatus->pNextFilesetBlock && pStatus->pNextFilesetBlock->info.rows > 0) {
-      tsdbDebug("return the saved block from fileset %d files, %s", fid, pReader->idStr);
-      copyDataBlock(pBlock, pStatus->pNextFilesetBlock);
-      blockDataDestroy(pStatus->pNextFilesetBlock);
+      tsdbDebug("new duration %d start notification when buffer pre-fileset, %s", fid, pReader->idStr);
     }
   }
   return code;
@@ -4364,12 +4359,12 @@ static int32_t doTsdbNextDataBlockFilesetDelimited(STsdbReader* pReader) {
     tsdbTrace("block from file rows: %"PRId64", will process pre-file set buffer: %d. %s", 
             pBlock->info.rows, pStatus->bProcMemFirstFileset, pReader->idStr);
     if (pStatus->bProcMemPreFileset) {
-      if ( pBlock->info.rows > 0) {
-        pStatus->pNextFilesetBlock = createOneDataBlock(pBlock, true);
-        blockDataCleanup(pBlock);
-        code = buildFromPreFilesetBuffer(pReader);
-        if (code != TSDB_CODE_SUCCESS || pBlock->info.rows > 0) {
-          return code;
+      if (pBlock->info.rows > 0) {
+        if (pReader->notifyFn) {
+          int32_t        fid = pReader->status.pCurrentFileset->fid;
+          STsdReaderNotifyInfo info = {0};
+          info.duration.filesetId = fid;
+          pReader->notifyFn(TSD_READER_NOTIFY_NEXT_DURATION_BLOCK, &info, pReader->notifyParam);
         }
       } else {
         pStatus->bProcMemPreFileset = false;
diff --git a/source/dnode/vnode/src/tsdb/tsdbReadUtil.h b/source/dnode/vnode/src/tsdb/tsdbReadUtil.h
index fe3441d058..3679015e9c 100644
--- a/source/dnode/vnode/src/tsdb/tsdbReadUtil.h
+++ b/source/dnode/vnode/src/tsdb/tsdbReadUtil.h
@@ -220,7 +220,6 @@ typedef struct SReaderStatus {
   bool                  bProcMemFirstFileset;
   STableUidList         procMemUidList;
   STableBlockScanInfo** pProcMemTableIter;
-  SSDataBlock*           pNextFilesetBlock;
 } SReaderStatus;
 
 struct STsdbReader {
diff --git a/source/libs/executor/inc/executorInt.h b/source/libs/executor/inc/executorInt.h
index f7e55b71be..e3e504cdbc 100644
--- a/source/libs/executor/inc/executorInt.h
+++ b/source/libs/executor/inc/executorInt.h
@@ -298,9 +298,14 @@ typedef struct STableMergeScanInfo {
   SHashObj*        mSkipTables;
   int64_t          mergeLimit;
   SSortExecInfo   sortExecInfo;
-  bool             bNewFileset;
-  bool             bOnlyRetrieveBlock;
+
   bool             filesetDelimited;
+  bool             bNewFilesetEvent;
+  bool             bNextDurationBlockEvent;
+  int32_t          numNextDurationBlocks;
+  SSDataBlock*     nextDurationBlocks[2];
+  bool             rtnNextDurationBlocks;
+  int32_t          nextDurationBlocksIdx;
 } STableMergeScanInfo;
 
 typedef struct STagScanFilterContext {
diff --git a/source/libs/executor/src/scanoperator.c b/source/libs/executor/src/scanoperator.c
index ea73f60468..bce8325195 100644
--- a/source/libs/executor/src/scanoperator.c
+++ b/source/libs/executor/src/scanoperator.c
@@ -3240,6 +3240,53 @@ static int32_t tableMergeScanDoSkipTable(STableMergeScanInfo* pInfo, SSDataBlock
   return TSDB_CODE_SUCCESS;
 }
 
+static void doGetBlockForTableMergeScan(SOperatorInfo* pOperator, bool* pFinished, bool* pSkipped) {
+  STableMergeScanInfo*            pInfo = pOperator->info;
+  SExecTaskInfo*                  pTaskInfo = pOperator->pTaskInfo;
+  SStorageAPI* pAPI = &pTaskInfo->storageAPI;
+
+  SSDataBlock*                    pBlock = pInfo->pReaderBlock;
+  int32_t                         code = 0;
+  bool hasNext = false;
+  STsdbReader* reader = pInfo->base.dataReader;
+
+  code = pAPI->tsdReader.tsdNextDataBlock(reader, &hasNext);
+  if (code != 0) {
+    pAPI->tsdReader.tsdReaderReleaseDataBlock(reader);
+    qError("table merge scan fetch next data block error code: %d, %s", code, GET_TASKID(pTaskInfo));
+    T_LONG_JMP(pTaskInfo->env, code);
+  }
+
+  if (!hasNext || isTaskKilled(pTaskInfo)) {
+    if (isTaskKilled(pTaskInfo)) {
+      qInfo("table merge scan fetch next data block found task killed. %s", GET_TASKID(pTaskInfo));
+      pAPI->tsdReader.tsdReaderReleaseDataBlock(reader);
+    }
+    *pFinished = true;
+    return;
+  }
+
+  uint32_t status = 0;
+  code = loadDataBlock(pOperator, &pInfo->base, pBlock, &status);
+
+  if (code != TSDB_CODE_SUCCESS) {
+    qInfo("table merge scan load datablock code %d, %s", code, GET_TASKID(pTaskInfo));
+    T_LONG_JMP(pTaskInfo->env, code);
+  }
+
+  if (status == FUNC_DATA_REQUIRED_ALL_FILTEROUT) {
+    *pFinished = true;
+    return;
+  }
+
+  // current block is filter out according to filter condition, continue load the next block
+  if (status == FUNC_DATA_REQUIRED_FILTEROUT || pBlock->info.rows == 0) {
+    *pSkipped = true;
+    return;
+  }
+  return;
+}
+
 static SSDataBlock* getBlockForTableMergeScan(void* param) {
   STableMergeScanSortSourceParam* source = param;
   SOperatorInfo*                  pOperator = source->pOperator;
@@ -3255,53 +3302,42 @@ static SSDataBlock* getBlockForTableMergeScan(void* param) {
 
   STsdbReader* reader = pInfo->base.dataReader;
   while (true) {
-    if (!pInfo->bOnlyRetrieveBlock) {
-      code = pAPI->tsdReader.tsdNextDataBlock(reader, &hasNext);
-      if (code != 0) {
-        pAPI->tsdReader.tsdReaderReleaseDataBlock(reader);
-        qError("table merge scan fetch next data block error code: %d, %s", code, GET_TASKID(pTaskInfo));
-        T_LONG_JMP(pTaskInfo->env, code);
-      }
-
-      if (!hasNext || isTaskKilled(pTaskInfo)) {
-        pInfo->bNewFileset = false;
-        if (isTaskKilled(pTaskInfo)) {
-          qInfo("table merge scan fetch next data block found task killed. %s", GET_TASKID(pTaskInfo));
-          pAPI->tsdReader.tsdReaderReleaseDataBlock(reader);
+    if (pInfo->rtnNextDurationBlocks) {
+      if (pInfo->nextDurationBlocksIdx < pInfo->numNextDurationBlocks) {
+        copyDataBlock(pBlock, pInfo->nextDurationBlocks[pInfo->nextDurationBlocksIdx]);
+        blockDataDestroy(pInfo->nextDurationBlocks[pInfo->nextDurationBlocksIdx]);
+        ++pInfo->nextDurationBlocksIdx;
+        if (pInfo->nextDurationBlocksIdx >= pInfo->numNextDurationBlocks) {
+          pInfo->rtnNextDurationBlocks = false;
+          pInfo->nextDurationBlocksIdx = 0;
         }
+      }
+    } else {
+      bool bFinished = false;
+      bool bSkipped = false;
+      doGetBlockForTableMergeScan(pOperator, &bFinished, &bSkipped);
+      if (bFinished) {
+        pInfo->bNewFilesetEvent = false;
         break;
       }
 
-      if (pInfo->bNewFileset) {
-        pInfo->bOnlyRetrieveBlock = true;
-        return NULL;
+      if (pInfo->bNextDurationBlockEvent || pInfo->bNewFilesetEvent) {
+        if (!bSkipped) {
+          pInfo->nextDurationBlocks[pInfo->numNextDurationBlocks] = createOneDataBlock(pBlock, true);
+          ++pInfo->numNextDurationBlocks;
+          ASSERT(pInfo->numNextDurationBlocks <= 2);
+        }
+        if (pInfo->bNewFilesetEvent) {
+          pInfo->rtnNextDurationBlocks = true;
+          return NULL;
+        }
+        if (pInfo->bNextDurationBlockEvent) {
+          pInfo->bNextDurationBlockEvent = false;
+          continue;
+        }
       }
+      if (bSkipped) continue;
     }
-    // process this data block based on the probabilities
-    bool processThisBlock = processBlockWithProbability(&pInfo->sample);
-    if (!processThisBlock) {
-      continue;
-    }
-
-    uint32_t status = 0;
-    code = loadDataBlock(pOperator, &pInfo->base, pBlock, &status);
-    if (pInfo->bOnlyRetrieveBlock) {
-      pInfo->bOnlyRetrieveBlock = false;
-    }
-    if (code != TSDB_CODE_SUCCESS) {
-      qInfo("table merge scan load datablock code %d, %s", code, GET_TASKID(pTaskInfo));
-      T_LONG_JMP(pTaskInfo->env, code);
-    }
-
-    if (status == FUNC_DATA_REQUIRED_ALL_FILTEROUT) {
-      break;
-    }
-
-    // current block is filter out according to filter condition, continue load the next block
-    if (status == FUNC_DATA_REQUIRED_FILTEROUT || pBlock->info.rows == 0) {
-      continue;
-    }
-
     pBlock->info.id.groupId = tableListGetTableGroupId(pInfo->base.pTableListInfo, pBlock->info.id.uid);
 
     if (pInfo->mergeLimit != -1) {
@@ -3317,6 +3353,7 @@ static SSDataBlock* getBlockForTableMergeScan(void* param) {
   return NULL;
 }
 
+
 SArray* generateSortByTsInfo(SArray* colMatchInfo, int32_t order) {
   int32_t tsTargetSlotId = 0;
   for (int32_t i = 0; i < taosArrayGetSize(colMatchInfo); ++i) {
@@ -3348,7 +3385,11 @@ int32_t dumpQueryTableCond(const SQueryTableDataCond* src, SQueryTableDataCond*
 
 void tableMergeScanTsdbNotifyCb(ETsdReaderNotifyType type, STsdReaderNotifyInfo* info, void* param) {
   STableMergeScanInfo* pTmsInfo = param;
-  pTmsInfo->bNewFileset = true;
+  if (type == TSD_READER_NOTIFY_DURATION_START) {
+    pTmsInfo->bNewFilesetEvent = true;
+  } else if (type == TSD_READER_NOTIFY_NEXT_DURATION_BLOCK) {
+    pTmsInfo->bNextDurationBlockEvent = true;
+  }
   return;
 }
 
@@ -3358,7 +3399,11 @@ int32_t startDurationForGroupTableMergeScan(SOperatorInfo* pOperator) {
   int32_t code = TSDB_CODE_SUCCESS;
   int32_t numOfTable = pInfo->tableEndIndex - pInfo->tableStartIndex + 1;
 
-  pInfo->bNewFileset = false;
+  pInfo->bNewFilesetEvent = false;
+  pInfo->bNextDurationBlockEvent = false;
+  pInfo->numNextDurationBlocks = 0;
+  pInfo->nextDurationBlocksIdx = 0;
+  pInfo->rtnNextDurationBlocks = false;
 
   pInfo->sortBufSize = 2048 * pInfo->bufPageSize;
   int32_t numOfBufPage = pInfo->sortBufSize / pInfo->bufPageSize;
@@ -3535,7 +3580,7 @@ SSDataBlock* doTableMergeScan(SOperatorInfo* pOperator) {
       pOperator->resultInfo.totalRows += pBlock->info.rows;
       return pBlock;
     } else {
-      if (pInfo->bNewFileset) {
+      if (pInfo->bNewFilesetEvent) {
         stopDurationForGroupTableMergeScan(pOperator);
         startDurationForGroupTableMergeScan(pOperator);
       } else {