diff --git a/source/libs/executor/src/scanoperator.c b/source/libs/executor/src/scanoperator.c
index 16780a9402ffbbff90bfb1624a4727c58edad94a..90dfbd5599cc609b8186df58914335a10a355bff 100644
--- a/source/libs/executor/src/scanoperator.c
+++ b/source/libs/executor/src/scanoperator.c
@@ -55,7 +55,6 @@ typedef struct STableMergeScanSortSourceParam {
   int32_t        readerIdx;
   uint64_t       uid;
   SSDataBlock*   inputBlock;
-  bool           multiReader;
   STsdbReader*   dataReader;
 } STableMergeScanSortSourceParam;
 
@@ -2658,8 +2657,7 @@ static SSDataBlock* getTableDataBlockImpl(void* param) {
   int64_t      st = taosGetTimestampUs();
   void*        p = tableListGetInfo(pInfo->base.pTableListInfo, readIdx + pInfo->tableStartIndex);
   SReadHandle* pHandle = &pInfo->base.readHandle;
-
-  if (NULL == source->dataReader || !source->multiReader) {
+  if (NULL == source->dataReader) {
     code = pAPI->tsdReader.tsdReaderOpen(pHandle->vnode, pQueryCond, p, 1, pBlock, (void**)&source->dataReader, GET_TASKID(pTaskInfo), false, NULL);
     if (code != 0) {
       T_LONG_JMP(pTaskInfo->env, code);
@@ -2723,19 +2721,14 @@ static SSDataBlock* getTableDataBlockImpl(void* param) {
     pInfo->base.readRecorder.elapsedTime += (taosGetTimestampUs() - st) / 1000.0;
 
     qTrace("tsdb/read-table-data: %p, close reader", reader);
-    if (!source->multiReader) {
-      pAPI->tsdReader.tsdReaderClose(pInfo->base.dataReader);
-      source->dataReader = NULL;
-    }
     pInfo->base.dataReader = NULL;
     return pBlock;
   }
 
-  if (!source->multiReader) {
-    pAPI->tsdReader.tsdReaderClose(pInfo->base.dataReader);
-    source->dataReader = NULL;
-  }
+  pAPI->tsdReader.tsdReaderClose(source->dataReader);
+  source->dataReader = NULL;
   pInfo->base.dataReader = NULL;
+
   return NULL;
 }
 
@@ -2791,7 +2784,8 @@ int32_t startGroupTableMergeScan(SOperatorInfo* pOperator) {
 
   // todo the total available buffer should be determined by total capacity of buffer of this task.
   // the additional one is reserved for merge result
-  pInfo->sortBufSize = pInfo->bufPageSize * (tableEndIdx - tableStartIdx + 1 + 1);
+  // pInfo->sortBufSize = pInfo->bufPageSize * (tableEndIdx - tableStartIdx + 1 + 1);
+  pInfo->sortBufSize = pInfo->bufPageSize * (256 + 1);
   int32_t numOfBufPage = pInfo->sortBufSize / pInfo->bufPageSize;
   pInfo->pSortHandle = tsortCreateSortHandle(pInfo->pSortInfo, SORT_MULTISOURCE_MERGE, pInfo->bufPageSize, numOfBufPage,
                                              pInfo->pSortInputBlock, pTaskInfo->id.str);
@@ -2806,7 +2800,6 @@ int32_t startGroupTableMergeScan(SOperatorInfo* pOperator) {
     STableMergeScanSortSourceParam param = {0};
     param.readerIdx = i;
     param.pOperator = pOperator;
-    param.multiReader = (numOfTable <= MULTI_READER_MAX_TABLE_NUM) ? true : false;
     param.inputBlock = createOneDataBlock(pInfo->pResBlock, false);
     blockDataEnsureCapacity(param.inputBlock, pOperator->resultInfo.capacity);
 
diff --git a/source/libs/executor/src/tsort.c b/source/libs/executor/src/tsort.c
index 783597df6705af50017312095ede318707a2dd01..3033441aadf5b94c8cfb8f3ce29ac0a09b1b9907 100644
--- a/source/libs/executor/src/tsort.c
+++ b/source/libs/executor/src/tsort.c
@@ -101,7 +101,11 @@ static int32_t sortComparCleanup(SMsortComparParam* cmpParam) {
   for (int32_t i = 0; i < cmpParam->numOfSources; ++i) {
     SSortSource* pSource = cmpParam->pSources[i];
     blockDataDestroy(pSource->src.pBlock);
+    if (pSource->pageIdList) {
+      taosArrayDestroy(pSource->pageIdList);
+    }
     taosMemoryFreeClear(pSource);
+    cmpParam->pSources[i] = NULL;
   }
 
   cmpParam->numOfSources = 0;
@@ -123,9 +127,11 @@ void tsortClearOrderdSource(SArray* pOrderedSource, int64_t *fetchUs, int64_t *f
     // release pageIdList
     if ((*pSource)->pageIdList) {
       taosArrayDestroy((*pSource)->pageIdList);
+      (*pSource)->pageIdList = NULL;
     }
     if ((*pSource)->param && !(*pSource)->onlyRef) {
       taosMemoryFree((*pSource)->param);
+      (*pSource)->param = NULL;
     }
 
     if (!(*pSource)->onlyRef && (*pSource)->src.pBlock) {