diff --git a/source/libs/executor/src/tsort.c b/source/libs/executor/src/tsort.c
index ebce48a068..363125c216 100644
--- a/source/libs/executor/src/tsort.c
+++ b/source/libs/executor/src/tsort.c
@@ -13,6 +13,8 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#define ALLOW_FORBID_FUNC
+
 #include "query.h"
 #include "tcommon.h"
 
@@ -46,7 +48,10 @@ typedef struct SSortMemPageEntry {
 typedef struct SSortMemFile {
   int32_t pageSize;
   int32_t cacheSize;
-  char*   pageBuf;
+  
+  char*   writePageBuf;
+  int32_t startPageId;
+  int32_t numWritePages;
   
   int32_t currPageId;
   int32_t currPageOffset;
@@ -58,7 +63,7 @@ typedef struct SSortMemFile {
   int32_t numMemPages;
   SSHashObj* mActivePages;
 
-  TdFilePtr pTdFile;
+  FILE* pTdFile;
   char memFilePath[PATH_MAX];
 } SSortMemFile;
 
@@ -121,7 +126,7 @@ struct SSortHandle {
 static int32_t destroySortMemFile(SSortHandle* pHandle);
 static int32_t getPageFromExtMemFile(SSortHandle* pHandle, int32_t pageId, char** ppPage);
 static void    setExtMemFilePageUnused(SSortMemFile* pMemFile, int32_t pageId);
-static int32_t saveLastPageToExtRowsMemFile(SSortHandle* pHandle);
+static int32_t saveDirtyPagesToExtRowsMemFile(SSortHandle* pHandle);
 
 void tsortSetSingleTableMerge(SSortHandle* pHandle) {
   pHandle->singleTableMerge = true;
@@ -1024,8 +1029,6 @@ static int32_t getPageFromExtMemFile(SSortHandle* pHandle, int32_t pageId, char*
       }
       pEntry->prev->next = pEntry->next;
       pEntry->next->prev = pEntry->prev;
-      taosLSeekFile(pMemFile->pTdFile, pageId * pMemFile->pageSize, SEEK_SET);
-      taosReadFile(pMemFile->pTdFile, pEntry->data, pMemFile->pageSize);
       pEntry->active = false;
     } else if (pMemFile->numMemPages < pMemFile->totalMemPages) {
       pEntry = taosMemoryCalloc(1, sizeof(SSortMemPageEntry));
@@ -1033,6 +1036,8 @@ static int32_t getPageFromExtMemFile(SSortHandle* pHandle, int32_t pageId, char*
       ++pMemFile->numMemPages;
     }
     {
+      fseek(pMemFile->pTdFile, pageId * pMemFile->pageSize, SEEK_SET);
+      fread(pEntry->data, pMemFile->pageSize, 1, pMemFile->pTdFile);      
       SSortMemPageEntry* tail = pMemFile->pagesTail;
       tail->next = pEntry;
       pEntry->next = NULL;
@@ -1076,13 +1081,14 @@ static int32_t createSortMemFile(SSortHandle* pHandle) {
 
   taosGetTmpfilePath(tsTempDir, "sort-ext-mem", pMemFile->memFilePath);
   pMemFile->pTdFile =
-      taosOpenFile(pMemFile->memFilePath, TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_READ | TD_FILE_TRUNC);
+      fopen(pMemFile->memFilePath, "wb+");
   pMemFile->currPageId = -1;
   pMemFile->currPageOffset = -1;
 
   pMemFile->pageSize = pHandle->extRowsPageSize;
   pMemFile->cacheSize = pHandle->extRowsMemSize;
-  pMemFile->pageBuf = taosMemoryMalloc(pMemFile->pageSize);
+  pMemFile->numWritePages = pMemFile->cacheSize/pMemFile->pageSize;
+  pMemFile->writePageBuf = taosMemoryMalloc(pMemFile->pageSize * pMemFile->numWritePages);
   pMemFile->bDirty = false;
 
   pMemFile->mActivePages = tSimpleHashInit(8192, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT));
@@ -1110,8 +1116,11 @@ static int32_t destroySortMemFile(SSortHandle* pHandle) {
     taosMemoryFree(pCurr);
   }
   tSimpleHashCleanup(pMemFile->mActivePages);
-  taosMemoryFree(pMemFile->pageBuf);
-  taosCloseFile(pMemFile->pTdFile);
+  taosMemoryFree(pMemFile->writePageBuf);
+  fclose(pMemFile->pTdFile);
+  taosRemoveFile(pMemFile->memFilePath);
+  taosMemoryFree(pMemFile);
+  pHandle->pExtRowsMemFile = NULL;
   return TSDB_CODE_SUCCESS;
 }
 
@@ -1120,32 +1129,41 @@ static int32_t saveBlockRowToExtRowsMemFile(SSortHandle* pHandle, SSDataBlock* p
   if (pMemFile->currPageId == -1) {
     pMemFile->currPageId = 0;
     pMemFile->currPageOffset = 0;
+    pMemFile->startPageId = 0;
   } else {
     if (pMemFile->currPageOffset + pHandle->extRowBytes >= pMemFile->pageSize) {
-      taosLSeekFile(pMemFile->pTdFile, pMemFile->currPageId * pMemFile->pageSize, SEEK_SET);
-      taosWriteFile(pMemFile->pTdFile, pMemFile->pageBuf, pMemFile->currPageOffset + 1);
 
       ++pMemFile->currPageId;
       pMemFile->currPageOffset = 0;
+
+      if (pMemFile->currPageId - pMemFile->startPageId >= pMemFile->numWritePages) {
+        fseeko(pMemFile->pTdFile, ((int64_t)pMemFile->startPageId) * pMemFile->pageSize, SEEK_SET);
+        fwrite(pMemFile->writePageBuf, pMemFile->pageSize * pMemFile->numWritePages, 1, pMemFile->pTdFile);
+
+        pMemFile->startPageId = pMemFile->currPageId;
+      }
     }
   }
 
   *pPageId = pMemFile->currPageId;
   *pOffset = pMemFile->currPageOffset;
-  int32_t blockLen = blockRowToBuf(pBlock, rowIdx, pMemFile->pageBuf + pMemFile->currPageOffset);
+  int32_t offsetPages = (pMemFile->currPageId - pMemFile->startPageId) * pMemFile->pageSize;
+  int32_t blockLen = blockRowToBuf(pBlock, rowIdx, 
+                  pMemFile->writePageBuf + offsetPages + pMemFile->currPageOffset);
   *pLength = blockLen;
   pMemFile->currPageOffset += blockLen;
   pMemFile->bDirty = true;
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t saveLastPageToExtRowsMemFile(SSortHandle* pHandle) {
+static int32_t saveDirtyPagesToExtRowsMemFile(SSortHandle* pHandle) {
   SSortMemFile* pMemFile = pHandle->pExtRowsMemFile;
   if (!pMemFile->bDirty) {
     return TSDB_CODE_SUCCESS;
   }
-  taosLSeekFile(pMemFile->pTdFile, pMemFile->currPageId * pMemFile->pageSize, SEEK_SET);
-  taosWriteFile(pMemFile->pTdFile, pMemFile->pageBuf, pMemFile->currPageOffset + 1);
+  fseeko(pMemFile->pTdFile, ((int64_t)pMemFile->startPageId) * pMemFile->pageSize, SEEK_SET);
+  int32_t numWriteBytes = pMemFile->pageSize * (pMemFile->currPageId - pMemFile->startPageId) + pMemFile->currPageOffset + 1;
+  fwrite(pMemFile->writePageBuf, numWriteBytes, 1, pMemFile->pTdFile);
   pMemFile->bDirty = false;
   return TSDB_CODE_SUCCESS;
 }
@@ -1406,7 +1424,7 @@ static int32_t sortBlocksToExtSource(SSortHandle* pHandle, SArray* aBlk, SArray*
     blockDataCleanup(pHandle->pDataBlock);
   }
 
-  saveLastPageToExtRowsMemFile(pHandle);
+  saveDirtyPagesToExtRowsMemFile(pHandle);
 
   SSDataBlock* pMemSrcBlk = createOneDataBlock(pHandle->pDataBlock, false);
   doAddNewExternalMemSource(pHandle->pBuf, aExtSrc, pMemSrcBlk, &pHandle->sourceId, aPgId);