diff --git a/source/common/src/tdatablock.c b/source/common/src/tdatablock.c
index a0f795a729ae5af42f683c7fea5adad36fd4241b..20eda52aacbc55ff1a439ce7b36c87234d091bd4 100644
--- a/source/common/src/tdatablock.c
+++ b/source/common/src/tdatablock.c
@@ -1139,6 +1139,9 @@ int32_t blockDataSort_rv(SSDataBlock* pDataBlock, SArray* pOrderInfo, bool nullF
 void blockDataCleanup(SSDataBlock* pDataBlock) {
   SDataBlockInfo* pInfo = &pDataBlock->info;
 
+  int32_t existedRows = pInfo->rows;
+  ASSERT(existedRows <= pDataBlock->info.capacity);
+
   pInfo->rows = 0;
   pInfo->id.uid = 0;
   pInfo->id.groupId = 0;
@@ -1152,7 +1155,7 @@ void blockDataCleanup(SSDataBlock* pDataBlock) {
   size_t numOfCols = taosArrayGetSize(pDataBlock->pDataBlock);
   for (int32_t i = 0; i < numOfCols; ++i) {
     SColumnInfoData* p = taosArrayGet(pDataBlock->pDataBlock, i);
-    colInfoDataCleanup(p, pInfo->capacity);
+    colInfoDataCleanup(p, existedRows);
   }
 }
 
diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index 4ba311212a49e36095c27d113f09491991a4c9bc..660d1894514a2a1015ba6f4dc5a462a9deb4c8b7 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -3589,7 +3589,7 @@ int32_t doAppendRowFromFileBlock(SSDataBlock* pResBlock, STsdbReader* pReader, S
 
   SColumnInfoData* pColData = taosArrayGet(pResBlock->pDataBlock, i);
   if (pColData->info.colId == PRIMARYKEY_TIMESTAMP_COL_ID) {
-    colDataAppendInt64(pColData, outputRowIndex, &pBlockData->aTSKEY[rowIndex]);
+    ((int64_t*)pColData->pData)[outputRowIndex] = pBlockData->aTSKEY[rowIndex];
     i += 1;
   }
 
diff --git a/source/libs/executor/src/sortoperator.c b/source/libs/executor/src/sortoperator.c
index 0287af62d25613dedd9b8ea5076c4bcdd9ca121f..b355b8586121558a14d18047d168e88d3106ffdc 100644
--- a/source/libs/executor/src/sortoperator.c
+++ b/source/libs/executor/src/sortoperator.c
@@ -720,7 +720,6 @@ SSDataBlock* doMultiwayMerge(SOperatorInfo* pOperator) {
   }
 
   qDebug("start to merge final sorted rows, %s", GET_TASKID(pTaskInfo));
-
   SSDataBlock* pBlock = getMultiwaySortedBlockData(pInfo->pSortHandle, pInfo->binfo.pRes, pInfo->matchInfo.pList, pOperator);
   if (pBlock != NULL) {
     pOperator->resultInfo.totalRows += pBlock->info.rows;
@@ -787,7 +786,7 @@ SOperatorInfo* createMultiwayMergeOperatorInfo(SOperatorInfo** downStreams, size
   SPhysiNode*  pChildNode = (SPhysiNode*)nodesListGetNode(pPhyNode->pChildren, 0);
   SSDataBlock* pInputBlock = createDataBlockFromDescNode(pChildNode->pOutputDataBlockDesc);
 
-  initResultSizeInfo(&pOperator->resultInfo, 4096);
+  initResultSizeInfo(&pOperator->resultInfo, 1024);
   blockDataEnsureCapacity(pInfo->binfo.pRes, pOperator->resultInfo.capacity);
 
   pInfo->groupSort = pMergePhyNode->groupSort;