diff --git a/source/libs/command/inc/commandInt.h b/source/libs/command/inc/commandInt.h
index 2ae4666ff6c20580c63034ad368e5d038a1ccd96..c53d464eab9bc719ca140556fe4e74924d76b3d4 100644
--- a/source/libs/command/inc/commandInt.h
+++ b/source/libs/command/inc/commandInt.h
@@ -49,6 +49,7 @@ extern "C" {
 #define EXPLAIN_PARITION_FORMAT "Partition on Column %s"
 #define EXPLAIN_ORDER_FORMAT "Order: %s"
 #define EXPLAIN_FILTER_FORMAT "Filter: "
+#define EXPLAIN_MERGEBLOCKS_FORMAT "Merge ResBlocks: %s"
 #define EXPLAIN_FILL_VALUE_FORMAT "Fill Values: "
 #define EXPLAIN_ON_CONDITIONS_FORMAT "Join Cond: "
 #define EXPLAIN_TIMERANGE_FORMAT "Time Range: [%" PRId64 ", %" PRId64 "]"
@@ -56,7 +57,7 @@ extern "C" {
 #define EXPLAIN_TIME_WINDOWS_FORMAT "Time Window: interval=%" PRId64 "%c offset=%" PRId64 "%c sliding=%" PRId64 "%c"
 #define EXPLAIN_WINDOW_FORMAT "Window: gap=%" PRId64
 #define EXPLAIN_RATIO_TIME_FORMAT "Ratio: %f"
-#define EXPLAIN_MERGE_FORMAT "Merge"
+#define EXPLAIN_MERGE_FORMAT "SortMerge"
 #define EXPLAIN_MERGE_KEYS_FORMAT "Merge Key: "
 
 #define EXPLAIN_PLANNING_TIME_FORMAT "Planning Time: %.3f ms"
diff --git a/source/libs/command/src/explain.c b/source/libs/command/src/explain.c
index c080b666cc5ac2e6dc4628e4ccf916ffc7735e47..2836bd7acdc5d24c24ebbe369842f7f4d633ee20 100644
--- a/source/libs/command/src/explain.c
+++ b/source/libs/command/src/explain.c
@@ -702,7 +702,11 @@ int32_t qExplainResNodeToRowsImpl(SExplainResNode *pResNode, SExplainCtx *ctx, i
                                      TSDB_EXPLAIN_RESULT_ROW_SIZE, &tlen));
           EXPLAIN_ROW_END();
           QRY_ERR_RET(qExplainResAppendRow(ctx, tbuf, tlen, level + 1));
-        }     
+        }
+
+        EXPLAIN_ROW_NEW(level + 1, EXPLAIN_MERGEBLOCKS_FORMAT, pAggNode->mergeDataBlock? "True":"False");
+        EXPLAIN_ROW_END();
+        QRY_ERR_RET(qExplainResAppendRow(ctx, tbuf, tlen, level + 1));
       }
       break;
     }
@@ -901,7 +905,11 @@ int32_t qExplainResNodeToRowsImpl(SExplainResNode *pResNode, SExplainCtx *ctx, i
                                      TSDB_EXPLAIN_RESULT_ROW_SIZE, &tlen));
           EXPLAIN_ROW_END();
           QRY_ERR_RET(qExplainResAppendRow(ctx, tbuf, tlen, level + 1));
-        }      
+        }
+
+        EXPLAIN_ROW_NEW(level + 1, EXPLAIN_MERGEBLOCKS_FORMAT, pIntNode->window.mergeDataBlock? "True":"False");
+        EXPLAIN_ROW_END();
+        QRY_ERR_RET(qExplainResAppendRow(ctx, tbuf, tlen, level + 1));
       }
       break;
     }
@@ -945,7 +953,11 @@ int32_t qExplainResNodeToRowsImpl(SExplainResNode *pResNode, SExplainCtx *ctx, i
                                      TSDB_EXPLAIN_RESULT_ROW_SIZE, &tlen));
           EXPLAIN_ROW_END();
           QRY_ERR_RET(qExplainResAppendRow(ctx, tbuf, tlen, level + 1));
-        }        
+        }
+
+        EXPLAIN_ROW_NEW(level + 1, EXPLAIN_MERGEBLOCKS_FORMAT, pIntNode->window.mergeDataBlock? "True":"False");
+        EXPLAIN_ROW_END();
+        QRY_ERR_RET(qExplainResAppendRow(ctx, tbuf, tlen, level + 1));
       }
       break;
     }
diff --git a/source/libs/executor/inc/executorimpl.h b/source/libs/executor/inc/executorimpl.h
index d24156bc60c09b40c8571cbde2793af53ac57ce3..6383ba06b333dbeccefce65e7aa4c9e16e0566c9 100644
--- a/source/libs/executor/inc/executorimpl.h
+++ b/source/libs/executor/inc/executorimpl.h
@@ -908,10 +908,10 @@ SOperatorInfo* createMergeIntervalOperatorInfo(SOperatorInfo* downstream, SExprI
 
 SOperatorInfo* createMergeAlignedIntervalOperatorInfo(SOperatorInfo* downstream, SExprInfo* pExprInfo, int32_t numOfCols,
                                           SSDataBlock* pResBlock, SInterval* pInterval, int32_t primaryTsSlotId,
-                                          SNode* pCondition, SExecTaskInfo* pTaskInfo);
+                                          SNode* pCondition, bool mergeResultBlocks, SExecTaskInfo* pTaskInfo);
 
-SOperatorInfo* createStreamFinalIntervalOperatorInfo(SOperatorInfo* downstream,
-    SPhysiNode* pPhyNode, SExecTaskInfo* pTaskInfo, int32_t numOfChild);
+SOperatorInfo* createStreamFinalIntervalOperatorInfo(SOperatorInfo* downstream, SPhysiNode* pPhyNode,
+                                                     SExecTaskInfo* pTaskInfo, int32_t numOfChild);
 SOperatorInfo* createStreamIntervalOperatorInfo(SOperatorInfo* downstream, SExprInfo* pExprInfo, int32_t numOfCols,
                                                 SSDataBlock* pResBlock, SInterval* pInterval, int32_t primaryTsSlotId,
                                                 STimeWindowAggSupp *pTwAggSupp, SExecTaskInfo* pTaskInfo);
diff --git a/source/libs/executor/src/executorimpl.c b/source/libs/executor/src/executorimpl.c
index 794e751dd27908a8ceb270c53b95fbadc668bb45..112b6ebc99ca967b5d3d2ce0dd769701c5ae92c5 100644
--- a/source/libs/executor/src/executorimpl.c
+++ b/source/libs/executor/src/executorimpl.c
@@ -4131,7 +4131,7 @@ SOperatorInfo* createOperatorTree(SPhysiNode* pPhyNode, SExecTaskInfo* pTaskInfo
 
     int32_t tsSlotId = ((SColumnNode*)pIntervalPhyNode->window.pTspk)->slotId;
     pOptr = createMergeAlignedIntervalOperatorInfo(ops[0], pExprInfo, num, pResBlock, &interval, tsSlotId,
-                                                   pPhyNode->pConditions, pTaskInfo);
+                                                   pPhyNode->pConditions, pIntervalPhyNode->window.mergeDataBlock, pTaskInfo);
   } else if (QUERY_NODE_PHYSICAL_PLAN_MERGE_INTERVAL == type) {
     SMergeIntervalPhysiNode* pIntervalPhyNode = (SMergeIntervalPhysiNode*)pPhyNode;
 
diff --git a/source/libs/executor/src/timewindowoperator.c b/source/libs/executor/src/timewindowoperator.c
index 5dcfb400d9495fc1d143f4b96f19b9a53eeb78e8..aaa7a1ea8ddef24b32ae6369900addbe993aa456 100644
--- a/source/libs/executor/src/timewindowoperator.c
+++ b/source/libs/executor/src/timewindowoperator.c
@@ -4762,7 +4762,7 @@ static SSDataBlock* mergeAlignedIntervalAgg(SOperatorInfo* pOperator) {
   if (iaInfo->binfo.mergeResultBlock) {
     while(1) {
       if (pOperator->status == OP_EXEC_DONE) {
-        return NULL;
+        break;
       }
 
       if (pRes->info.rows >= pOperator->resultInfo.threshold) {
@@ -4782,7 +4782,7 @@ static SSDataBlock* mergeAlignedIntervalAgg(SOperatorInfo* pOperator) {
 
 SOperatorInfo* createMergeAlignedIntervalOperatorInfo(SOperatorInfo* downstream, SExprInfo* pExprInfo,
                                                       int32_t numOfCols, SSDataBlock* pResBlock, SInterval* pInterval,
-                                                      int32_t primaryTsSlotId, SNode* pCondition,
+                                                      int32_t primaryTsSlotId, SNode* pCondition, bool mergeResultBlock,
                                                       SExecTaskInfo* pTaskInfo) {
   SMergeAlignedIntervalAggOperatorInfo* miaInfo = taosMemoryCalloc(1, sizeof(SMergeAlignedIntervalAggOperatorInfo));
   SOperatorInfo*                        pOperator = taosMemoryCalloc(1, sizeof(SOperatorInfo));
@@ -4806,6 +4806,7 @@ SOperatorInfo* createMergeAlignedIntervalOperatorInfo(SOperatorInfo* downstream,
   iaInfo->interval = *pInterval;
   iaInfo->execModel = pTaskInfo->execModel;
   iaInfo->primaryTsIndex = primaryTsSlotId;
+  iaInfo->binfo.mergeResultBlock = mergeResultBlock;
 
   size_t keyBufSize = sizeof(int64_t) + sizeof(int64_t) + POINTER_BYTES;
   initResultSizeInfo(&pOperator->resultInfo, 4096);