diff --git a/source/common/src/tdatablock.c b/source/common/src/tdatablock.c
index e748cce643..69b2a2e6a3 100644
--- a/source/common/src/tdatablock.c
+++ b/source/common/src/tdatablock.c
@@ -535,8 +535,8 @@ int32_t blockDataUpdatePkRange(SSDataBlock* pDataBlock, int32_t pkColumnIndex, b
 
   if (asc) {
     if (IS_NUMERIC_TYPE(pColInfoData->info.type)) {
-      pDataBlock->info.pks[0].val = *(int32_t*) skey;
-      pDataBlock->info.pks[1].val = *(int32_t*) ekey;
+      GET_TYPED_DATA(pDataBlock->info.pks[0].val, int64_t, pColInfoData->info.type, skey);
+      GET_TYPED_DATA(pDataBlock->info.pks[1].val, int64_t, pColInfoData->info.type, ekey);
     } else {  // todo refactor
       memcpy(pDataBlock->info.pks[0].pData, varDataVal(skey), varDataLen(skey));
       pDataBlock->info.pks[0].nData = varDataLen(skey);
@@ -546,8 +546,8 @@ int32_t blockDataUpdatePkRange(SSDataBlock* pDataBlock, int32_t pkColumnIndex, b
     }
   } else {
     if (IS_NUMERIC_TYPE(pColInfoData->info.type)) {
-      pDataBlock->info.pks[0].val = *(int32_t*) ekey;
-      pDataBlock->info.pks[1].val = *(int32_t*) skey;
+      GET_TYPED_DATA(pDataBlock->info.pks[0].val, int64_t, pColInfoData->info.type, ekey);
+      GET_TYPED_DATA(pDataBlock->info.pks[1].val, int64_t, pColInfoData->info.type, skey);
     } else {  // todo refactor
       memcpy(pDataBlock->info.pks[0].pData, varDataVal(ekey), varDataLen(ekey));
       pDataBlock->info.pks[0].nData = varDataLen(ekey);
@@ -1491,6 +1491,18 @@ SSDataBlock* createOneDataBlock(const SSDataBlock* pDataBlock, bool copyData) {
     blockDataAppendColInfo(pBlock, &colInfo);
   }
 
+  // prepare the pk buffer if necessary
+  if (IS_VAR_DATA_TYPE(pDataBlock->info.pks[0].type)) {
+    SValue* pVal = &pBlock->info.pks[0];
+
+    pVal->type = pDataBlock->info.pks[0].type;
+    pVal->pData = taosMemoryCalloc(1, pDataBlock->info.pks[0].nData);
+
+    pVal = &pBlock->info.pks[1];
+    pVal->type = pDataBlock->info.pks[1].type;
+    pVal->pData = taosMemoryCalloc(1, pDataBlock->info.pks[1].nData);
+  }
+
   if (copyData) {
     int32_t code = blockDataEnsureCapacity(pBlock, pDataBlock->info.rows);
     if (code != TSDB_CODE_SUCCESS) {
diff --git a/source/dnode/vnode/src/tsdb/tsdbRead2.c b/source/dnode/vnode/src/tsdb/tsdbRead2.c
index 57d4121880..a8a4ced517 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead2.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead2.c
@@ -1678,11 +1678,9 @@ static int32_t doMergeBufAndFileRows(STsdbReader* pReader, STableBlockScanInfo*
   __compar_fn_t       compFn = pReader->pkComparFn;
   int32_t             pkSrcSlot = pReader->suppInfo.pkSrcSlot;
 
-  SRowKey* pSttKey = &(SRowKey){0};
+  SRowKey* pSttKey = NULL;
   if (hasDataInSttBlock(pBlockScanInfo) && (!pBlockScanInfo->cleanSttBlocks)) {
     pSttKey = getCurrentKeyInSttBlock(pSttBlockReader);
-  } else {
-    pSttKey = NULL;
   }
 
   SRowKey k;
@@ -1714,10 +1712,8 @@ static int32_t doMergeBufAndFileRows(STsdbReader* pReader, STableBlockScanInfo*
     }
   }
 
-  SRowKey minKey;
+  SRowKey minKey = k;
   if (pReader->info.order == TSDB_ORDER_ASC) {
-    minKey = k;  // chosen the minimum value
-
     if (pfKey != NULL && pkCompEx(compFn, pfKey, &minKey) < 0) {
       minKey = *pfKey;
     }
@@ -1726,8 +1722,6 @@ static int32_t doMergeBufAndFileRows(STsdbReader* pReader, STableBlockScanInfo*
       minKey = *pSttKey;
     }
   } else {
-    minKey = k;
-
     if (pfKey != NULL && pkCompEx(compFn, pfKey, &minKey) > 0) {
       minKey = *pfKey;
     }
@@ -1882,11 +1876,9 @@ static int32_t doMergeMultiLevelRows(STsdbReader* pReader, STableBlockScanInfo*
   TSDBROW* pRow = getValidMemRow(&pBlockScanInfo->iter, pDelList, pReader);
   TSDBROW* piRow = getValidMemRow(&pBlockScanInfo->iiter, pDelList, pReader);
 
-  SRowKey* pSttKey = &(SRowKey){0};
+  SRowKey* pSttKey = NULL;
   if (hasDataInSttBlock(pBlockScanInfo) && (!pBlockScanInfo->cleanSttBlocks)) {
-    tRowKeyAssign(pSttKey, getCurrentKeyInSttBlock(pSttBlockReader));
-  } else {
-    pSttKey = NULL;
+    pSttKey = getCurrentKeyInSttBlock(pSttBlockReader);
   }
 
   SRowKey* pfKey = &(SRowKey){0};
diff --git a/source/libs/executor/inc/executil.h b/source/libs/executor/inc/executil.h
index 1c70fd8bb6..55b803f6d4 100644
--- a/source/libs/executor/inc/executil.h
+++ b/source/libs/executor/inc/executil.h
@@ -162,6 +162,7 @@ bool hasRemainResults(SGroupResInfo* pGroupResInfo);
 int32_t getNumOfTotalRes(SGroupResInfo* pGroupResInfo);
 
 SSDataBlock* createDataBlockFromDescNode(SDataBlockDescNode* pNode);
+int32_t      prepareDataBlockBuf(SSDataBlock* pDataBlock, SColMatchInfo* pMatchInfo);
 
 EDealRes doTranslateTagExpr(SNode** pNode, void* pContext);
 int32_t  getGroupIdFromTagsVal(void* pVnode, uint64_t uid, SNodeList* pGroupNode, char* keyBuf, uint64_t* pGroupId, SStorageAPI* pAPI);
diff --git a/source/libs/executor/src/executil.c b/source/libs/executor/src/executil.c
index 97b9b00efb..9749dffc13 100644
--- a/source/libs/executor/src/executil.c
+++ b/source/libs/executor/src/executil.c
@@ -250,6 +250,34 @@ SSDataBlock* createDataBlockFromDescNode(SDataBlockDescNode* pNode) {
   return pBlock;
 }
 
+int32_t prepareDataBlockBuf(SSDataBlock* pDataBlock, SColMatchInfo* pMatchInfo) {
+  SDataBlockInfo* pBlockInfo = &pDataBlock->info;
+
+  for (int32_t i = 0; i < taosArrayGetSize(pMatchInfo->pList); ++i) {
+    SColMatchItem* pItem = taosArrayGet(pMatchInfo->pList, i);
+    if (pItem->isPk) {
+      SColumnInfoData* pInfoData = taosArrayGet(pDataBlock->pDataBlock, pItem->dstSlotId);
+      pBlockInfo->pks[0].type = pInfoData->info.type;
+      pBlockInfo->pks[1].type = pInfoData->info.type;
+
+      if (IS_VAR_DATA_TYPE(pItem->dataType.type)) {
+        pBlockInfo->pks[0].pData = taosMemoryCalloc(1, pInfoData->info.bytes);
+        if (pBlockInfo->pks[0].pData == NULL) {
+          return TSDB_CODE_OUT_OF_MEMORY;
+        }
+
+        pBlockInfo->pks[1].pData = taosMemoryCalloc(1, pInfoData->info.bytes);
+        if (pBlockInfo->pks[1].pData == NULL) {
+          taosMemoryFreeClear(pBlockInfo->pks[0].pData);
+          return TSDB_CODE_OUT_OF_MEMORY;
+        }
+      }
+    }
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
 EDealRes doTranslateTagExpr(SNode** pNode, void* pContext) {
   SMetaReader* mr = (SMetaReader*)pContext;
   if (nodeType(*pNode) == QUERY_NODE_COLUMN) {
diff --git a/source/libs/executor/src/scanoperator.c b/source/libs/executor/src/scanoperator.c
index a51e627272..0d4c536dec 100644
--- a/source/libs/executor/src/scanoperator.c
+++ b/source/libs/executor/src/scanoperator.c
@@ -1196,23 +1196,8 @@ SOperatorInfo* createTableScanOperatorInfo(STableScanPhysiNode* pTableScanNode,
   pInfo->base.readerAPI = pTaskInfo->storageAPI.tsdReader;
   initResultSizeInfo(&pOperator->resultInfo, 4096);
   pInfo->pResBlock = createDataBlockFromDescNode(pDescNode);
+  prepareDataBlockBuf(pInfo->pResBlock, &pInfo->base.matchInfo);
 
-  {  // todo :refactor:
-    SDataBlockInfo* pBlockInfo = &pInfo->pResBlock->info;
-    for(int32_t i = 0; i < taosArrayGetSize(pInfo->base.matchInfo.pList); ++i) {
-      SColMatchItem* pItem = taosArrayGet(pInfo->base.matchInfo.pList, i);
-      if (pItem->isPk) {
-        SColumnInfoData* pInfoData = taosArrayGet(pInfo->pResBlock->pDataBlock, pItem->dstSlotId);
-        pBlockInfo->pks[0].type = pInfoData->info.type;
-        pBlockInfo->pks[1].type = pInfoData->info.type;
-
-        if (IS_VAR_DATA_TYPE(pItem->dataType.type)) {
-          pBlockInfo->pks[0].pData = taosMemoryCalloc(1, pInfoData->info.bytes);
-          pBlockInfo->pks[1].pData = taosMemoryCalloc(1, pInfoData->info.bytes);
-        }
-      }
-    }
-  }
   code = filterInitFromNode((SNode*)pTableScanNode->scan.node.pConditions, &pOperator->exprSupp.pFilterInfo, 0);
   if (code != TSDB_CODE_SUCCESS) {
     goto _error;
@@ -4418,6 +4403,8 @@ SOperatorInfo* createTableMergeScanOperatorInfo(STableScanPhysiNode* pTableScanN
     pInfo->bSortRowId = false;
   }
 
+  prepareDataBlockBuf(pInfo->pResBlock, &pInfo->base.matchInfo);
+
   pInfo->pSortInfo = generateSortByTsPkInfo(pInfo->base.matchInfo.pList, pInfo->base.cond.order);
   pInfo->pReaderBlock = createOneDataBlock(pInfo->pResBlock, false);