diff --git a/source/libs/executor/inc/executorInt.h b/source/libs/executor/inc/executorInt.h
index 98e96bb250..1c55da412b 100644
--- a/source/libs/executor/inc/executorInt.h
+++ b/source/libs/executor/inc/executorInt.h
@@ -302,11 +302,13 @@ typedef struct STmsSubTableInput {
 
   int32_t rowIdx;
   int64_t* aTs;
+  SSDataBlock* pInputBlock;
 } STmsSubTableInput;
 
 typedef struct SBlockOrderInfo SBlockOrderInfo;
 typedef struct STmsSubTablesMergeInfo {
-  SBlockOrderInfo* pOrderInfo;
+  SBlockOrderInfo* pTsOrderInfo;
+  SBlockOrderInfo* pPkOrderInfo;
 
   int32_t numSubTables;
   STmsSubTableInput* aInputs;
diff --git a/source/libs/executor/inc/tsort.h b/source/libs/executor/inc/tsort.h
index 852e59aa80..b9118cf00d 100644
--- a/source/libs/executor/inc/tsort.h
+++ b/source/libs/executor/inc/tsort.h
@@ -212,6 +212,9 @@ int32_t tsortCompAndBuildKeys(const SArray* pSortCols, char* keyBuf, int32_t* ke
  * @brief set the merge limit reached callback. it calls mergeLimitReached param with tableUid and param
 */
 void tsortSetMergeLimitReachedFp(SSortHandle* pHandle, void (*mergeLimitReached)(uint64_t tableUid, void* param), void* param);
+
+int tsortComparBlockCell(SSDataBlock* pLeftBlock, SSDataBlock* pRightBlock,
+                      int32_t leftRowIndex, int32_t rightRowIndex, void* pOrder);
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/libs/executor/src/scanoperator.c b/source/libs/executor/src/scanoperator.c
index 6c697a6fc3..5c02dce53c 100644
--- a/source/libs/executor/src/scanoperator.c
+++ b/source/libs/executor/src/scanoperator.c
@@ -3440,9 +3440,7 @@ _error:
 
 // table merge scan operator
 
-// table merge scan operator
-
-static int32_t subTblRowCompareFn(const void* pLeft, const void* pRight, void* param) {
+static int32_t subTblRowCompareTsFn(const void* pLeft, const void* pRight, void* param) {
   int32_t left = *(int32_t*)pLeft;
   int32_t right = *(int32_t*)pRight;
   STmsSubTablesMergeInfo* pInfo = (STmsSubTablesMergeInfo*)param;
@@ -3459,12 +3457,39 @@ static int32_t subTblRowCompareFn(const void* pLeft, const void* pRight, void* p
   int64_t leftTs = pInfo->aInputs[left].aTs[leftIdx];
   int64_t rightTs = pInfo->aInputs[right].aTs[rightIdx];
   int32_t ret = leftTs>rightTs ? 1 : ((leftTs < rightTs) ? -1 : 0);
-  if (pInfo->pOrderInfo->order == TSDB_ORDER_DESC) {
+  if (pInfo->pTsOrderInfo->order == TSDB_ORDER_DESC) {
     ret = -1 * ret;
   }
   return ret;
 }
 
+static int32_t subTblRowCompareTsPkFn(const void* pLeft, const void* pRight, void* param) {
+  int32_t left = *(int32_t*)pLeft;
+  int32_t right = *(int32_t*)pRight;
+  STmsSubTablesMergeInfo* pInfo = (STmsSubTablesMergeInfo*)param;
+
+  int32_t leftIdx = pInfo->aInputs[left].rowIdx;
+  int32_t rightIdx = pInfo->aInputs[right].rowIdx;
+
+  if (leftIdx == -1) {
+    return 1;
+  } else if (rightIdx == -1) {
+    return -1;
+  }
+
+  int64_t leftTs = pInfo->aInputs[left].aTs[leftIdx];
+  int64_t rightTs = pInfo->aInputs[right].aTs[rightIdx];
+  int32_t ret = leftTs>rightTs ? 1 : ((leftTs < rightTs) ? -1 : 0);
+  if (pInfo->pTsOrderInfo->order == TSDB_ORDER_DESC) {
+    ret = -1 * ret;
+  }
+  if (ret == 0 && pInfo->pPkOrderInfo) {                               
+    ret = tsortComparBlockCell(pInfo->aInputs[left].pInputBlock, pInfo->aInputs[right].pInputBlock, 
+                              leftIdx, rightIdx, pInfo->pPkOrderInfo);
+  }
+  return ret;
+}
+
 int32_t dumpQueryTableCond(const SQueryTableDataCond* src, SQueryTableDataCond* dst) {
   memcpy((void*)dst, (void*)src, sizeof(SQueryTableDataCond));
   dst->colList = taosMemoryCalloc(src->numOfCols, sizeof(SColumnInfo));
@@ -3573,11 +3598,12 @@ static int32_t openSubTablesMergeSort(STmsSubTablesMergeInfo* pSubTblsInfo) {
       pInput->rowIdx = 0;
       pInput->pageIdx = -1;
     }
-    SSDataBlock* pInputBlock = (pInput->type == SUB_TABLE_MEM_BLOCK) ? pInput->pReaderBlock : pInput->pPageBlock;
-    SColumnInfoData* col = taosArrayGet(pInputBlock->pDataBlock, pSubTblsInfo->pOrderInfo->slotId);
+    pInput->pInputBlock = (pInput->type == SUB_TABLE_MEM_BLOCK) ? pInput->pReaderBlock : pInput->pPageBlock;
+    SColumnInfoData* col = taosArrayGet(pInput->pInputBlock->pDataBlock, pSubTblsInfo->pTsOrderInfo->slotId);
     pInput->aTs = (int64_t*)col->pData;
   }
-  tMergeTreeCreate(&pSubTblsInfo->pTree, pSubTblsInfo->numSubTables, pSubTblsInfo, subTblRowCompareFn);
+  __merge_compare_fn_t mergeCompareFn = (!pSubTblsInfo->pPkOrderInfo) ? subTblRowCompareTsFn : subTblRowCompareTsPkFn;
+  tMergeTreeCreate(&pSubTblsInfo->pTree, pSubTblsInfo->numSubTables, pSubTblsInfo, mergeCompareFn);
   return  TSDB_CODE_SUCCESS;
 }
 
@@ -3587,7 +3613,12 @@ static int32_t initSubTablesMergeInfo(STableMergeScanInfo* pInfo) {
   if (pSubTblsInfo == NULL) {
     return TSDB_CODE_OUT_OF_MEMORY;
   }
-  pSubTblsInfo->pOrderInfo = taosArrayGet(pInfo->pSortInfo, 0);
+  pSubTblsInfo->pTsOrderInfo = taosArrayGet(pInfo->pSortInfo, 0);
+  if (taosArrayGetSize(pInfo->pSortInfo) == 2) {
+    pSubTblsInfo->pPkOrderInfo = taosArrayGet(pInfo->pSortInfo, 1);
+  } else {
+    pSubTblsInfo->pPkOrderInfo = NULL;
+  }
   pSubTblsInfo->numSubTables = pInfo->tableEndIndex - pInfo->tableStartIndex + 1;
   pSubTblsInfo->aInputs = taosMemoryCalloc(pSubTblsInfo->numSubTables, sizeof(STmsSubTableInput));
   if (pSubTblsInfo->aInputs == NULL) {
@@ -3679,7 +3710,8 @@ static int32_t adjustSubTableForNextRow(SOperatorInfo* pOperatorInfo, STmsSubTab
       adjustSubTableFromMemBlock(pOperatorInfo, pSubTblsInfo);
     }
     if (pInput->rowIdx != -1) {
-      SColumnInfoData* col = taosArrayGet(pInputBlock->pDataBlock, pSubTblsInfo->pOrderInfo->slotId);
+      SColumnInfoData* col = taosArrayGet(pInputBlock->pDataBlock, pSubTblsInfo->pTsOrderInfo->slotId);
+      pInput->pInputBlock = pInputBlock;
       pInput->aTs = (int64_t*)col->pData;
     }
   }
diff --git a/source/libs/executor/src/tsort.c b/source/libs/executor/src/tsort.c
index 0c0c83da6b..678d757e68 100644
--- a/source/libs/executor/src/tsort.c
+++ b/source/libs/executor/src/tsort.c
@@ -636,7 +636,8 @@ static SSDataBlock* getSortedBlockDataInner(SSortHandle* pHandle, SMsortComparPa
 // TODO: improve this function performance
 
 int tsortComparBlockCell(SSDataBlock* pLeftBlock, SSDataBlock* pRightBlock,
-                      int32_t leftRowIndex, int32_t rightRowIndex, SBlockOrderInfo* pOrder) {
+                      int32_t leftRowIndex, int32_t rightRowIndex, void* pCompareOrder) {
+  SBlockOrderInfo* pOrder = pCompareOrder;
   SColumnInfoData* pLeftColInfoData = TARRAY_GET_ELEM(pLeftBlock->pDataBlock, pOrder->slotId);
   SColumnInfoData* pRightColInfoData = TARRAY_GET_ELEM(pRightBlock->pDataBlock, pOrder->slotId);
 
@@ -1534,6 +1535,7 @@ static int32_t sortBlocksToExtSource(SSortHandle* pHandle, SArray* aBlk, SArray*
           taosArrayDestroy(aPgId);
           taosMemoryFree(sup.aRowIdx);
           taosMemoryFree(sup.aTs);
+          taosMemoryFree(sup.aBlks);
           return code;
         }
         nMergedRows += pHandle->pDataBlock->info.rows;
@@ -1578,6 +1580,7 @@ static int32_t sortBlocksToExtSource(SSortHandle* pHandle, SArray* aBlk, SArray*
         taosMemoryFree(pTree);
         taosMemoryFree(sup.aRowIdx);
         taosMemoryFree(sup.aTs);
+        taosMemoryFree(sup.aBlks);
         return code;
       }      
       nMergedRows += pHandle->pDataBlock->info.rows;
@@ -1597,6 +1600,7 @@ static int32_t sortBlocksToExtSource(SSortHandle* pHandle, SArray* aBlk, SArray*
 
   taosMemoryFree(sup.aRowIdx);
   taosMemoryFree(sup.aTs);
+  taosMemoryFree(sup.aBlks);
 
   tMergeTreeDestroy(&pTree);