diff --git a/source/libs/executor/inc/executorimpl.h b/source/libs/executor/inc/executorimpl.h
index 4f02c559b1..5dd349f4ab 100644
--- a/source/libs/executor/inc/executorimpl.h
+++ b/source/libs/executor/inc/executorimpl.h
@@ -895,6 +895,9 @@ int64_t getSmaWaterMark(int64_t interval, double filesFactor);
 bool isSmaStream(int8_t triggerType);
 
 int32_t compareTimeWindow(const void* p1, const void* p2, const void* param);
+int32_t finalizeResultRowIntoSDataBlock(SDiskbasedBuf* pBuf, SResultRowPosition* resultRowPosition,
+                                       SqlFunctionCtx* pCtx, SExprInfo* pExprInfo, int32_t numOfExprs, const int32_t* rowCellOffset,
+                                       SSDataBlock* pBlock, SExecTaskInfo* pTaskInfo);
 
 #ifdef __cplusplus
 }
diff --git a/source/libs/executor/src/executorimpl.c b/source/libs/executor/src/executorimpl.c
index 7b73fd8ae9..5bd9044167 100644
--- a/source/libs/executor/src/executorimpl.c
+++ b/source/libs/executor/src/executorimpl.c
@@ -1955,6 +1955,51 @@ static void doUpdateNumOfRows(SResultRow* pRow, int32_t numOfExprs, const int32_
   }
 }
 
+int32_t finalizeResultRowIntoSDataBlock(SDiskbasedBuf* pBuf, SResultRowPosition* resultRowPosition,
+                                       SqlFunctionCtx* pCtx, SExprInfo* pExprInfo, int32_t numOfExprs, const int32_t* rowCellOffset,
+                                       SSDataBlock* pBlock, SExecTaskInfo* pTaskInfo) {
+  SFilePage*  page = getBufPage(pBuf, resultRowPosition->pageId);
+  SResultRow* pRow = (SResultRow*)((char*)page + resultRowPosition->offset);
+
+  doUpdateNumOfRows(pRow, numOfExprs, rowCellOffset);
+  if (pRow->numOfRows == 0) {
+    releaseBufPage(pBuf, page);
+    return 0;
+  }
+
+  if (pBlock->info.rows + pRow->numOfRows > pBlock->info.capacity) {
+    releaseBufPage(pBuf, page);
+    return -1;
+  }
+
+  for (int32_t j = 0; j < numOfExprs; ++j) {
+    int32_t slotId = pExprInfo[j].base.resSchema.slotId;
+
+    pCtx[j].resultInfo = getResultCell(pRow, j, rowCellOffset);
+    if (pCtx[j].fpSet.finalize) {
+      int32_t code = pCtx[j].fpSet.finalize(&pCtx[j], pBlock);
+      if (TAOS_FAILED(code)) {
+        qError("%s build result data block error, code %s", GET_TASKID(pTaskInfo), tstrerror(code));
+        longjmp(pTaskInfo->env, code);
+      }
+    } else if (strcmp(pCtx[j].pExpr->pExpr->_function.functionName, "_select_value") == 0) {
+      // do nothing, todo refactor
+    } else {
+      // expand the result into multiple rows. E.g., _wstartts, top(k, 20)
+      // the _wstartts needs to copy to 20 following rows, since the results of top-k expands to 20 different rows.
+      SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, slotId);
+      char*            in = GET_ROWCELL_INTERBUF(pCtx[j].resultInfo);
+      for (int32_t k = 0; k < pRow->numOfRows; ++k) {
+        colDataAppend(pColInfoData, pBlock->info.rows + k, in, pCtx[j].resultInfo->isNullRes);
+      }
+    }
+  }
+
+  releaseBufPage(pBuf, page);
+
+  return 0;
+}
+
 int32_t doCopyToSDataBlock(SExecTaskInfo* pTaskInfo, SSDataBlock* pBlock, SExprInfo* pExprInfo, SDiskbasedBuf* pBuf,
                            SGroupResInfo* pGroupResInfo, const int32_t* rowCellOffset, SqlFunctionCtx* pCtx,
                            int32_t numOfExprs) {
diff --git a/source/libs/executor/src/timewindowoperator.c b/source/libs/executor/src/timewindowoperator.c
index b309478556..696b9139cf 100644
--- a/source/libs/executor/src/timewindowoperator.c
+++ b/source/libs/executor/src/timewindowoperator.c
@@ -3175,3 +3175,229 @@ _error:
   pTaskInfo->code = code;
   return NULL;
 }
+
+typedef struct SMergeIntervalAggOperatorInfo {
+  SIntervalAggOperatorInfo intervalAggOperatorInfo;
+
+  SHashObj*         groupIntervalHash;
+} SMergeIntervalAggOperatorInfo;
+
+void destroyMergeIntervalOperatorInfo(void* param, int32_t numOfOutput) {
+  SMergeIntervalAggOperatorInfo* pInfo = (SMergeIntervalAggOperatorInfo*)param;
+  taosHashCleanup(pInfo->groupIntervalHash);
+  destroyIntervalOperatorInfo(&pInfo->intervalAggOperatorInfo, numOfOutput);
+}
+
+static void doMergeIntervalAggImpl(SOperatorInfo* pOperatorInfo, SResultRowInfo* pResultRowInfo, SSDataBlock* pBlock,
+                            int32_t scanFlag, SSDataBlock* pResultBlock) {
+  SMergeIntervalAggOperatorInfo *miaInfo = pOperatorInfo->info;
+  SIntervalAggOperatorInfo * pInfo = &miaInfo->intervalAggOperatorInfo;
+
+  SExecTaskInfo* pTaskInfo = pOperatorInfo->pTaskInfo;
+
+  int32_t     startPos = 0;
+  int32_t     numOfOutput = pOperatorInfo->numOfExprs;
+  int64_t*    tsCols = extractTsCol(pBlock, pInfo);
+  uint64_t    tableGroupId = pBlock->info.groupId;
+  bool        ascScan = (pInfo->order == TSDB_ORDER_ASC);
+  TSKEY       blockStartTs = getStartTsKey(&pBlock->info.window, tsCols);
+  SResultRow* pResult = NULL;
+
+  STimeWindow win = getActiveTimeWindow(pInfo->aggSup.pResultBuf, pResultRowInfo, blockStartTs, &pInfo->interval,
+                                        pInfo->interval.precision, &pInfo->win);
+  //TODO: pResultBlock full
+  //TODO: pBlock not process not finished
+  //TODO: different block group id or no group id
+  //TODO: lastWin may be none, p1 shall not be null
+  //TODO: the last datablock
+  //TODO: blockDataUpdateTsWindow(pBlock, 0);
+
+  int32_t ret =
+      setTimeWindowOutputBuf(pResultRowInfo, &win, (scanFlag == MAIN_SCAN), &pResult, tableGroupId, pInfo->binfo.pCtx,
+                             numOfOutput, pInfo->binfo.rowCellInfoOffset, &pInfo->aggSup, pTaskInfo);
+  if (ret != TSDB_CODE_SUCCESS || pResult == NULL) {
+    longjmp(pTaskInfo->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
+  }
+
+  TSKEY   ekey = ascScan ? win.ekey : win.skey;
+  int32_t forwardRows =
+      getNumOfRowsInTimeWindow(&pBlock->info, tsCols, startPos, ekey, binarySearchForKey, NULL, pInfo->order);
+  ASSERT(forwardRows > 0);
+
+  // prev time window not interpolation yet.
+  if (pInfo->timeWindowInterpo) {
+    SResultRowPosition pos = addToOpenWindowList(pResultRowInfo, pResult);
+    doInterpUnclosedTimeWindow(pOperatorInfo, numOfOutput, pResultRowInfo, pBlock, scanFlag, tsCols, &pos);
+
+    // restore current time window
+    ret =
+        setTimeWindowOutputBuf(pResultRowInfo, &win, (scanFlag == MAIN_SCAN), &pResult, tableGroupId, pInfo->binfo.pCtx,
+                               numOfOutput, pInfo->binfo.rowCellInfoOffset, &pInfo->aggSup, pTaskInfo);
+    if (ret != TSDB_CODE_SUCCESS) {
+      longjmp(pTaskInfo->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
+    }
+
+    // window start key interpolation
+    doWindowBorderInterpolation(pInfo, pBlock, numOfOutput, pInfo->binfo.pCtx, pResult, &win, startPos, forwardRows);
+  }
+
+  updateTimeWindowInfo(&pInfo->twAggSup.timeWindowData, &win, true);
+  doApplyFunctions(pTaskInfo, pInfo->binfo.pCtx, &win, &pInfo->twAggSup.timeWindowData, startPos, forwardRows, tsCols,
+                   pBlock->info.rows, numOfOutput, pInfo->order);
+
+  doCloseWindow(pResultRowInfo, pInfo, pResult);
+  STimeWindow *lastWin = taosHashGet(miaInfo->groupIntervalHash, &tableGroupId, sizeof(tableGroupId));
+  if (ascScan && win.skey > lastWin->ekey || (!ascScan) && win.skey < lastWin->ekey) {
+    SET_RES_WINDOW_KEY(pInfo->aggSup.keyBuf, &lastWin->skey, TSDB_KEYSIZE, tableGroupId);
+    SResultRowPosition* p1 =
+        (SResultRowPosition*)taosHashGet(pInfo->aggSup.pResultRowHashTable, pInfo->aggSup.keyBuf, GET_RES_WINDOW_KEY_LEN(TSDB_KEYSIZE));
+    finalizeResultRowIntoSDataBlock(pInfo->aggSup.pResultBuf, p1,
+                                    pInfo->binfo.pCtx, pOperatorInfo->pExpr, pOperatorInfo->numOfExprs, pInfo->binfo.rowCellInfoOffset,
+                                    pResultBlock, pTaskInfo);
+    taosHashRemove(pInfo->aggSup.pResultRowHashTable, pInfo->aggSup.keyBuf, GET_RES_WINDOW_KEY_LEN(TSDB_KEYSIZE));
+
+    taosHashPut(miaInfo->groupIntervalHash, &tableGroupId, sizeof(tableGroupId), &win, sizeof(STimeWindow));
+  }
+
+  STimeWindow nextWin = win;
+  while (1) {
+    int32_t prevEndPos = forwardRows - 1 + startPos;
+    startPos = getNextQualifiedWindow(&pInfo->interval, &nextWin, &pBlock->info, tsCols, prevEndPos, pInfo->order);
+    if (startPos < 0) {
+      break;
+    }
+
+    // null data, failed to allocate more memory buffer
+    int32_t code = setTimeWindowOutputBuf(pResultRowInfo, &nextWin, (scanFlag == MAIN_SCAN), &pResult, tableGroupId,
+                                          pInfo->binfo.pCtx, numOfOutput, pInfo->binfo.rowCellInfoOffset,
+                                          &pInfo->aggSup, pTaskInfo);
+    if (code != TSDB_CODE_SUCCESS || pResult == NULL) {
+      longjmp(pTaskInfo->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
+    }
+
+    ekey = ascScan ? nextWin.ekey : nextWin.skey;
+    forwardRows =
+        getNumOfRowsInTimeWindow(&pBlock->info, tsCols, startPos, ekey, binarySearchForKey, NULL, pInfo->order);
+
+    // window start(end) key interpolation
+    doWindowBorderInterpolation(pInfo, pBlock, numOfOutput, pInfo->binfo.pCtx, pResult, &nextWin, startPos,
+                                forwardRows);
+
+    updateTimeWindowInfo(&pInfo->twAggSup.timeWindowData, &nextWin, true);
+    doApplyFunctions(pTaskInfo, pInfo->binfo.pCtx, &nextWin, &pInfo->twAggSup.timeWindowData, startPos, forwardRows,
+                     tsCols, pBlock->info.rows, numOfOutput, pInfo->order);
+    doCloseWindow(pResultRowInfo, pInfo, pResult);
+  }
+
+  if (pInfo->timeWindowInterpo) {
+    saveDataBlockLastRow(pInfo->pPrevValues, pBlock, pInfo->pInterpCols);
+  }
+}
+
+static SSDataBlock* doMergeIntervalAgg(SOperatorInfo* pOperator) {
+
+  SExecTaskInfo*            pTaskInfo = pOperator->pTaskInfo;
+
+  SMergeIntervalAggOperatorInfo* miaInfo = pOperator->info;
+  SIntervalAggOperatorInfo *pInfo = &miaInfo->intervalAggOperatorInfo;
+  if (pOperator->status == OP_EXEC_DONE) {
+    return NULL;
+  }
+
+  SSDataBlock* pRes = pInfo->binfo.pRes;
+  blockDataCleanup(pRes);
+
+  int32_t scanFlag = MAIN_SCAN;
+
+  SOperatorInfo* downstream = pOperator->pDownstream[0];
+
+  while (1) {
+    SSDataBlock* pBlock = downstream->fpSet.getNextFn(downstream);
+    if (pBlock == NULL) {
+      break;
+    }
+
+    getTableScanInfo(pOperator, &pInfo->order, &scanFlag);
+
+    // the pDataBlock are always the same one, no need to call this again
+    setInputDataBlock(pOperator, pInfo->binfo.pCtx, pBlock, pInfo->order, scanFlag, true);
+    STableQueryInfo* pTableQueryInfo = pInfo->pCurrent;
+
+    setIntervalQueryRange(pTableQueryInfo, pBlock->info.window.skey, &pTaskInfo->window);
+    doMergeIntervalAggImpl(pOperator, &pInfo->binfo.resultRowInfo, pBlock, scanFlag, pRes);
+  }
+
+  if (pRes->info.rows == 0) {
+    doSetOperatorCompleted(pOperator);
+  }
+
+  size_t rows = pRes->info.rows;
+  pOperator->resultInfo.totalRows += rows;
+  return (rows == 0) ? NULL : pRes;
+}
+
+SOperatorInfo* createMergeIntervalOperatorInfo(SOperatorInfo* downstream, SExprInfo* pExprInfo, int32_t numOfCols,
+                                          SSDataBlock* pResBlock, SInterval* pInterval, int32_t primaryTsSlotId,
+                                          STimeWindowAggSupp* pTwAggSupp, SExecTaskInfo* pTaskInfo) {
+  SMergeIntervalAggOperatorInfo* miaInfo = taosMemoryCalloc(1, sizeof(SMergeIntervalAggOperatorInfo));
+  SOperatorInfo*            pOperator = taosMemoryCalloc(1, sizeof(SOperatorInfo));
+  if (miaInfo == NULL || pOperator == NULL) {
+    goto _error;
+  }
+  SIntervalAggOperatorInfo *pInfo = &miaInfo->intervalAggOperatorInfo;
+
+  pInfo->win = pTaskInfo->window;
+  pInfo->order = TSDB_ORDER_ASC;
+  pInfo->interval = *pInterval;
+  pInfo->execModel = pTaskInfo->execModel;
+  pInfo->twAggSup = *pTwAggSupp;
+
+  pInfo->primaryTsIndex = primaryTsSlotId;
+  miaInfo->groupIntervalHash = taosHashInit(10, taosGetDefaultHashFunction(TSDB_DATA_TYPE_UBIGINT), true, HASH_NO_LOCK);
+
+  size_t keyBufSize = sizeof(int64_t) + sizeof(int64_t) + POINTER_BYTES;
+  initResultSizeInfo(pOperator, 4096);
+
+  int32_t code =
+      initAggInfo(&pInfo->binfo, &pInfo->aggSup, pExprInfo, numOfCols, pResBlock, keyBufSize, pTaskInfo->id.str);
+
+  initExecTimeWindowInfo(&pInfo->twAggSup.timeWindowData, &pInfo->win);
+
+  pInfo->timeWindowInterpo = timeWindowinterpNeeded(pInfo->binfo.pCtx, numOfCols, pInfo);
+  if (pInfo->timeWindowInterpo) {
+    pInfo->binfo.resultRowInfo.openWindow = tdListNew(sizeof(SResultRowPosition));
+  }
+
+  //  pInfo->pTableQueryInfo = initTableQueryInfo(pTableGroupInfo);
+  if (code != TSDB_CODE_SUCCESS /* || pInfo->pTableQueryInfo == NULL*/) {
+    goto _error;
+  }
+
+  initResultRowInfo(&pInfo->binfo.resultRowInfo, (int32_t)1);
+
+  pOperator->name = "TimeMergeIntervalAggOperator";
+  pOperator->operatorType = QUERY_NODE_PHYSICAL_PLAN_MERGE_INTERVAL;
+  pOperator->blocking = false;
+  pOperator->status = OP_NOT_OPENED;
+  pOperator->pExpr = pExprInfo;
+  pOperator->pTaskInfo = pTaskInfo;
+  pOperator->numOfExprs = numOfCols;
+  pOperator->info = pInfo;
+
+  pOperator->fpSet = createOperatorFpSet(operatorDummyOpenFn, doMergeIntervalAgg, doStreamIntervalAgg, NULL,
+                                         destroyIntervalOperatorInfo, NULL, NULL, NULL);
+
+  code = appendDownstream(pOperator, &downstream, 1);
+  if (code != TSDB_CODE_SUCCESS) {
+    goto _error;
+  }
+
+  return pOperator;
+
+_error:
+  destroyMergeIntervalOperatorInfo(pInfo, numOfCols);
+  taosMemoryFreeClear(pInfo);
+  taosMemoryFreeClear(pOperator);
+  pTaskInfo->code = code;
+  return NULL;
+}