diff --git a/source/libs/executor/src/timesliceoperator.c b/source/libs/executor/src/timesliceoperator.c
index 7a4b9014bc..78aabb5c26 100644
--- a/source/libs/executor/src/timesliceoperator.c
+++ b/source/libs/executor/src/timesliceoperator.c
@@ -39,7 +39,7 @@ typedef struct STimeSliceOperatorInfo {
   int64_t              prevTs;
   bool                 prevTsSet;
   uint64_t             groupId;
-  SSDataBlock*         pPrevGroupRes;
+  SGroupKeys*          pPrevGroupKey;
   SSDataBlock*         pNextGroupRes;
 } STimeSliceOperatorInfo;
 
@@ -227,16 +227,26 @@ static bool genInterpolationResult(STimeSliceOperatorInfo* pSliceInfo, SExprSupp
       continue;
     } else if (!isInterpFunc(pExprInfo)) {
       if (isGroupKeyFunc(pExprInfo)) {
-        int32_t       srcSlot = pExprInfo->base.pParam[0].pCol->slotId;
-        SColumnInfoData* pSrc = taosArrayGet(pSrcBlock->pDataBlock, srcSlot);
+        if (pSrcBlock != NULL) {
+          int32_t       srcSlot = pExprInfo->base.pParam[0].pCol->slotId;
+          SColumnInfoData* pSrc = taosArrayGet(pSrcBlock->pDataBlock, srcSlot);
 
-        if (colDataIsNull_s(pSrc, index)) {
-          colDataSetNULL(pDst, pResBlock->info.rows);
-          continue;
+          if (colDataIsNull_s(pSrc, index)) {
+            colDataSetNULL(pDst, pResBlock->info.rows);
+            continue;
+          }
+
+          char* v = colDataGetData(pSrc, index);
+          colDataSetVal(pDst, pResBlock->info.rows, v, false);
+        } else {
+          // use stored group key
+          SGroupKeys* pkey = pSliceInfo->pPrevGroupKey;
+          if (pkey->isNull == false) {
+            colDataSetVal(pDst, rows, pkey->pData, false);
+          } else {
+            colDataSetNULL(pDst, rows);
+          }
         }
-
-        char* v = colDataGetData(pSrc, index);
-        colDataSetVal(pDst, pResBlock->info.rows, v, false);
       }
       continue;
     }
@@ -464,7 +474,31 @@ static int32_t initFillLinearInfo(STimeSliceOperatorInfo* pInfo, SSDataBlock* pB
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t initKeeperInfo(STimeSliceOperatorInfo* pInfo, SSDataBlock* pBlock) {
+static int32_t initGroupKeyKeeper(STimeSliceOperatorInfo* pInfo, SExprSupp* pExprSup) {
+  if (pInfo->pPrevGroupKey != NULL) {
+    return TSDB_CODE_SUCCESS;
+  }
+
+  pInfo->pPrevGroupKey = taosMemoryCalloc(1, sizeof(SGroupKeys));
+  if (pInfo->pPrevGroupKey == NULL) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  for (int32_t i = 0; i < pExprSup->numOfExprs; ++i) {
+    SExprInfo* pExprInfo = &pExprSup->pExprInfo[i];
+
+    if (isGroupKeyFunc(pExprInfo)) {
+      pInfo->pPrevGroupKey->bytes = pExprInfo->base.resSchema.bytes;
+      pInfo->pPrevGroupKey->type = pExprInfo->base.resSchema.type;
+      pInfo->pPrevGroupKey->isNull = false;
+      pInfo->pPrevGroupKey->pData = taosMemoryCalloc(1, pInfo->pPrevGroupKey->bytes);
+    }
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static int32_t initKeeperInfo(STimeSliceOperatorInfo* pInfo, SSDataBlock* pBlock, SExprSupp* pExprSup) {
   int32_t code;
   code = initPrevRowsKeeper(pInfo, pBlock);
   if (code != TSDB_CODE_SUCCESS) {
@@ -481,6 +515,12 @@ static int32_t initKeeperInfo(STimeSliceOperatorInfo* pInfo, SSDataBlock* pBlock
     return TSDB_CODE_FAILED;
   }
 
+  code = initGroupKeyKeeper(pInfo, pExprSup);
+  if (code != TSDB_CODE_SUCCESS) {
+    return TSDB_CODE_FAILED;
+  }
+
+
   return TSDB_CODE_SUCCESS;
 }
 
@@ -627,22 +667,42 @@ static void doTimesliceImpl(SOperatorInfo* pOperator, STimeSliceOperatorInfo* pS
   }
 }
 
-static void genInterpAfterDataBlock(STimeSliceOperatorInfo* pSliceInfo, SOperatorInfo* pOperator, SSDataBlock* pSrcBlock,
-                                    int32_t index) {
+static void genInterpAfterDataBlock(STimeSliceOperatorInfo* pSliceInfo, SOperatorInfo* pOperator, int32_t index) {
   SSDataBlock* pResBlock = pSliceInfo->pRes;
   SInterval*   pInterval = &pSliceInfo->interval;
 
   while (pSliceInfo->current <= pSliceInfo->win.ekey && pSliceInfo->fillType != TSDB_FILL_NEXT &&
          pSliceInfo->fillType != TSDB_FILL_LINEAR) {
-    genInterpolationResult(pSliceInfo, &pOperator->exprSupp, pResBlock, pSrcBlock, index, false);
+    genInterpolationResult(pSliceInfo, &pOperator->exprSupp, pResBlock, NULL, index, false);
     pSliceInfo->current =
         taosTimeAdd(pSliceInfo->current, pInterval->interval, pInterval->intervalUnit, pInterval->precision);
   }
 }
 
-static void copyPrevGroupDataBlock(SSDataBlock* pDstBlock, SSDataBlock* pSrcBlock) {
-  blockDataCleanup(pDstBlock);
-  assignOneDataBlock(pDstBlock, pSrcBlock);
+static void copyPrevGroupKey(SExprSupp* pExprSup, SGroupKeys* pGroupKey, SSDataBlock* pSrcBlock) {
+  for (int32_t j = 0; j < pExprSup->numOfExprs; ++j) {
+    SExprInfo* pExprInfo = &pExprSup->pExprInfo[j];
+
+    if (isGroupKeyFunc(pExprInfo)) {
+      int32_t       srcSlot = pExprInfo->base.pParam[0].pCol->slotId;
+      SColumnInfoData* pSrc = taosArrayGet(pSrcBlock->pDataBlock, srcSlot);
+
+      if (colDataIsNull_s(pSrc, 0)) {
+        pGroupKey->isNull = true;
+        break;
+      }
+
+      char* v = colDataGetData(pSrc, 0);
+      if (IS_VAR_DATA_TYPE(pGroupKey->type)) {
+        memcpy(pGroupKey->pData, v, varDataTLen(v));
+      } else {
+        memcpy(pGroupKey->pData, v, pGroupKey->bytes);
+      }
+
+      pGroupKey->isNull = false;
+      break;
+    }
+  }
 }
 
 static void resetTimesliceInfo(STimeSliceOperatorInfo* pSliceInfo) {
@@ -672,7 +732,7 @@ static SSDataBlock* doTimeslice(SOperatorInfo* pOperator) {
     if (pSliceInfo->pNextGroupRes != NULL) {
       setInputDataBlock(pSup, pSliceInfo->pNextGroupRes, order, MAIN_SCAN, true);
       doTimesliceImpl(pOperator, pSliceInfo, pSliceInfo->pNextGroupRes, pTaskInfo);
-      copyPrevGroupDataBlock(pSliceInfo->pPrevGroupRes, pSliceInfo->pNextGroupRes);
+      copyPrevGroupKey(&pOperator->exprSupp, pSliceInfo->pPrevGroupKey, pSliceInfo->pNextGroupRes);
       pSliceInfo->pNextGroupRes = NULL;
     }
 
@@ -698,7 +758,7 @@ static SSDataBlock* doTimeslice(SOperatorInfo* pOperator) {
         projectApplyFunctions(pExprSup->pExprInfo, pBlock, pBlock, pExprSup->pCtx, pExprSup->numOfExprs, NULL);
       }
 
-      int32_t code = initKeeperInfo(pSliceInfo, pBlock);
+      int32_t code = initKeeperInfo(pSliceInfo, pBlock, &pOperator->exprSupp);
       if (code != TSDB_CODE_SUCCESS) {
         T_LONG_JMP(pTaskInfo->env, code);
       }
@@ -706,13 +766,12 @@ static SSDataBlock* doTimeslice(SOperatorInfo* pOperator) {
       // the pDataBlock are always the same one, no need to call this again
       setInputDataBlock(pSup, pBlock, order, MAIN_SCAN, true);
       doTimesliceImpl(pOperator, pSliceInfo, pBlock, pTaskInfo);
-      copyPrevGroupDataBlock(pSliceInfo->pPrevGroupRes, pBlock);
+      copyPrevGroupKey(&pOperator->exprSupp, pSliceInfo->pPrevGroupKey, pBlock);
     }
 
     // check if need to interpolate after last datablock
     // except for fill(next), fill(linear)
-    genInterpAfterDataBlock(pSliceInfo, pOperator, pSliceInfo->pPrevGroupRes,
-                            pSliceInfo->pPrevGroupRes->info.rows - 1);
+    genInterpAfterDataBlock(pSliceInfo, pOperator, 0);
 
     doFilter(pResBlock, pOperator->exprSupp.pFilterInfo, NULL);
     if (pOperator->status == OP_EXEC_DONE) {
@@ -776,7 +835,7 @@ SOperatorInfo* createTimeSliceOperatorInfo(SOperatorInfo* downstream, SPhysiNode
   pInfo->prevTsSet = false;
   pInfo->prevTs = 0;
   pInfo->groupId = 0;
-  pInfo->pPrevGroupRes = createDataBlock();
+  pInfo->pPrevGroupKey = NULL;
   pInfo->pNextGroupRes = NULL;
 
   if (downstream->operatorType == QUERY_NODE_PHYSICAL_PLAN_TABLE_SCAN) {
@@ -806,7 +865,6 @@ void destroyTimeSliceOperatorInfo(void* param) {
   STimeSliceOperatorInfo* pInfo = (STimeSliceOperatorInfo*)param;
 
   pInfo->pRes = blockDataDestroy(pInfo->pRes);
-  pInfo->pPrevGroupRes = blockDataDestroy(pInfo->pPrevGroupRes);
 
   for (int32_t i = 0; i < taosArrayGetSize(pInfo->pPrevRow); ++i) {
     SGroupKeys* pKey = taosArrayGet(pInfo->pPrevRow, i);
@@ -826,6 +884,10 @@ void destroyTimeSliceOperatorInfo(void* param) {
     taosMemoryFree(pKey->end.val);
   }
   taosArrayDestroy(pInfo->pLinearInfo);
+
+  taosMemoryFree(pInfo->pPrevGroupKey->pData);
+  taosMemoryFree(pInfo->pPrevGroupKey);
+
   cleanupExprSupp(&pInfo->scalarSup);
 
   for (int32_t i = 0; i < pInfo->pFillColInfo->numOfFillExpr; ++i) {