enh(query): support multi-groups result merge into one datablock.

source/libs/executor/src/timewindowoperator.c

@@ -4685,20 +4685,16 @@ static void doMergeAlignedIntervalAggImpl(SOperatorInfo* pOperatorInfo, SResultR
                    tsCols, pBlock->info.rows, numOfOutput, iaInfo->inputOrder);
 }
 
-static SSDataBlock* doMergeAlignedIntervalAgg(SOperatorInfo* pOperator) {
+
+static void doMergeAlignedIntervalAgg(SOperatorInfo* pOperator) {
   SExecTaskInfo* pTaskInfo = pOperator->pTaskInfo;
 
   SMergeAlignedIntervalAggOperatorInfo* miaInfo = pOperator->info;
   SIntervalAggOperatorInfo*             iaInfo = miaInfo->intervalAggOperatorInfo;
-  if (pOperator->status == OP_EXEC_DONE) {
-    return NULL;
-  }
 
   SExprSupp*   pSup = &pOperator->exprSupp;
   SSDataBlock* pRes = iaInfo->binfo.pRes;
 
-  blockDataCleanup(pRes);
-
   SOperatorInfo* downstream = pOperator->pDownstream[0];
   int32_t        scanFlag = MAIN_SCAN;
 
@@ -4749,6 +4745,35 @@ static SSDataBlock* doMergeAlignedIntervalAgg(SOperatorInfo* pOperator) {
 
   pRes->info.groupId = miaInfo->groupId;
   miaInfo->hasGroupId = false;
+}
+
+static SSDataBlock* mergeAlignedIntervalAgg(SOperatorInfo* pOperator) {
+  SExecTaskInfo* pTaskInfo = pOperator->pTaskInfo;
+
+  SMergeAlignedIntervalAggOperatorInfo* pMiaInfo = pOperator->info;
+  SIntervalAggOperatorInfo*             iaInfo = pMiaInfo->intervalAggOperatorInfo;
+  if (pOperator->status == OP_EXEC_DONE) {
+    return NULL;
+  }
+
+  SSDataBlock* pRes = iaInfo->binfo.pRes;
+  blockDataCleanup(pRes);
+
+  if (iaInfo->binfo.mergeResultBlock) {
+    while(1) {
+      if (pOperator->status == OP_EXEC_DONE) {
+        return NULL;
+      }
+
+      if (pRes->info.rows >= pOperator->resultInfo.threshold) {
+        break;
+      }
+
+      doMergeAlignedIntervalAgg(pOperator);
+    }
+  } else {
+    doMergeAlignedIntervalAgg(pOperator);
+  }
 
   size_t rows = pRes->info.rows;
   pOperator->resultInfo.totalRows += rows;
@@ -4812,7 +4837,7 @@ SOperatorInfo* createMergeAlignedIntervalOperatorInfo(SOperatorInfo* downstream,
   pOperator->exprSupp.numOfExprs = numOfCols;
   pOperator->info = miaInfo;
 
-  pOperator->fpSet = createOperatorFpSet(operatorDummyOpenFn, doMergeAlignedIntervalAgg, NULL, NULL,
+  pOperator->fpSet = createOperatorFpSet(operatorDummyOpenFn, mergeAlignedIntervalAgg, NULL, NULL,
                                          destroyMergeAlignedIntervalOperatorInfo, NULL, NULL, NULL);
 
   code = appendDownstream(pOperator, &downstream, 1);