diff --git a/source/libs/executor/src/tsort.c b/source/libs/executor/src/tsort.c
index 272629627a..2ef40cd738 100644
--- a/source/libs/executor/src/tsort.c
+++ b/source/libs/executor/src/tsort.c
@@ -1243,7 +1243,9 @@ static int32_t tsortFinalizeRegions(SSortHandle* pHandle) {
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t saveBlockRowToExtRowsMemFile(SSortHandle* pHandle, SSDataBlock* pBlock, int32_t rowIdx, int32_t* pRegionId, int32_t* pOffset, int32_t* pLength) {
+static int32_t saveBlockRowToExtRowsMemFile(SSortHandle* pHandle, SSDataBlock* pBlock, int32_t rowIdx,
+                                            int32_t* pRegionId, int32_t* pOffset, int32_t* pLength) {
+
   SSortMemFile* pMemFile = pHandle->pExtRowsMemFile;
   SSortMemFileRegion* pRegion = taosArrayGet(pMemFile->aFileRegions, pMemFile->currRegionId);
   {
@@ -1257,11 +1259,13 @@ static int32_t saveBlockRowToExtRowsMemFile(SSortHandle* pHandle, SSDataBlock* p
       pMemFile->writeFileOffset = pRegion->fileOffset + pMemFile->currRegionOffset;
     }
   }
+
   *pRegionId = pMemFile->currRegionId;
   *pOffset = pMemFile->currRegionOffset;
   int32_t writeBufOffset = pMemFile->currRegionOffset - (pMemFile->writeFileOffset - pRegion->fileOffset);
   int32_t blockLen = blockRowToBuf(pBlock, rowIdx, pMemFile->writeBuf + writeBufOffset);
   *pLength = blockLen;
+
   pMemFile->currRegionOffset += blockLen;
   pMemFile->bRegionDirty = true;
   return TSDB_CODE_SUCCESS;
@@ -1324,6 +1328,7 @@ static void initRowIdSort(SSortHandle* pHandle) {
     pkCol = createColumnInfoData(extPkCol->info.type, extPkCol->info.bytes, 5);
     blockDataAppendColInfo(pSortInput, &pkCol);
   }
+
   blockDataDestroy(pHandle->pDataBlock);
   pHandle->pDataBlock = pSortInput;
 
@@ -1444,32 +1449,61 @@ static int32_t appendDataBlockToPageBuf(SSortHandle* pHandle, SSDataBlock* blk,
   return 0;
 }
 
-static int32_t getPageBufIncForRow(SSDataBlock* blk, int32_t row, int32_t rowIdxInPage) {
-  int32_t sz = 0;
-  int32_t numCols = taosArrayGetSize(blk->pDataBlock);
-  if (!blk->info.hasVarCol) {
-    sz += numCols * ((rowIdxInPage & 0x7) == 0 ? 1: 0);
-    sz += blockDataGetRowSize(blk);
+static int32_t getPageBufIncForRow(SSDataBlock* pSrcBlock, int32_t srcRowIndex, int32_t dstRowIndex) {
+  int32_t size = 0;
+  int32_t numCols = taosArrayGetSize(pSrcBlock->pDataBlock);
+
+  if (!pSrcBlock->info.hasVarCol) {
+    size += numCols * ((dstRowIndex & 0x7) == 0 ? 1: 0);
+    size += blockDataGetRowSize(pSrcBlock);
   } else {
     for (int32_t i = 0; i < numCols; ++i) {
-      SColumnInfoData* pColInfoData = TARRAY_GET_ELEM(blk->pDataBlock, i);
+      SColumnInfoData* pColInfoData = TARRAY_GET_ELEM(pSrcBlock->pDataBlock, i);
       if (IS_VAR_DATA_TYPE(pColInfoData->info.type)) {
-        if ((pColInfoData->varmeta.offset[row] != -1) && (pColInfoData->pData)) {
-          char* p = colDataGetData(pColInfoData, row);
-          sz += varDataTLen(p);
+        if ((pColInfoData->varmeta.offset[srcRowIndex] != -1) && (pColInfoData->pData)) {
+          char* p = colDataGetData(pColInfoData, srcRowIndex);
+          size += varDataTLen(p);
         }
 
-        sz += sizeof(pColInfoData->varmeta.offset[0]);
+        size += sizeof(pColInfoData->varmeta.offset[0]);
       } else {
-        sz += pColInfoData->info.bytes;
+        size += pColInfoData->info.bytes;
 
-        if (((rowIdxInPage) & 0x07) == 0) {
-          sz += 1; // bitmap
+        if (((dstRowIndex) & 0x07) == 0) {
+          size += 1; // bitmap
         }
       }
     }    
   }
-  return sz;
+
+  return size;
+}
+
+static int32_t getPageBufIncForRowIdSort(SSDataBlock* pDstBlock, int32_t srcRowIndex, int32_t dstRowIndex, SColumnInfoData* pPkCol) {
+  int32_t size = 0;
+  int32_t numOfCols = blockDataGetNumOfCols(pDstBlock);
+
+  if (pPkCol == NULL) {
+    ASSERT(!pDstBlock->info.hasVarCol);
+    size += numOfCols * ((dstRowIndex & 0x7) == 0 ? 1: 0);
+    size += blockDataGetRowSize(pDstBlock);
+  } else {
+    if (IS_VAR_DATA_TYPE(pPkCol->info.type)) {
+      if ((pPkCol->varmeta.offset[srcRowIndex] != -1) && (pPkCol->pData)) {
+        char* p = colDataGetData(pPkCol, srcRowIndex);
+        size += varDataTLen(p);
+      }
+
+      size += sizeof(pPkCol->varmeta.offset[0]);
+    } else {
+      size += pPkCol->info.bytes;
+      if (((dstRowIndex) & 0x07) == 0) {
+        size += 1; // bitmap
+      }
+    }
+  }
+
+  return size;
 }
 
 static int32_t sortBlocksToExtSource(SSortHandle* pHandle, SArray* aBlk, SArray* aExtSrc) {
@@ -1533,8 +1567,19 @@ static int32_t sortBlocksToExtSource(SSortHandle* pHandle, SArray* aBlk, SArray*
     int32_t      minIdx = tMergeTreeGetChosenIndex(pTree);
     SSDataBlock* minBlk = taosArrayGetP(aBlk, minIdx);
     int32_t      minRow = sup.aRowIdx[minIdx];
-    SSDataBlock* incBlock = (pHandle->bSortByRowId) ? pHandle->pDataBlock : minBlk;
-    int32_t      bufInc = getPageBufIncForRow(incBlock, minRow, pHandle->pDataBlock->info.rows);
+
+    int32_t bufInc = 0;
+    if (pHandle->bSortByRowId) {
+      if (!pHandle->bSortPk) {
+        bufInc = getPageBufIncForRowIdSort(pHandle->pDataBlock, minRow, pHandle->pDataBlock->info.rows, NULL);
+      } else { // there may be varchar column exists, so we need to get the pk info, and then calculate the row length
+        SBlockOrderInfo* extRowsPkOrder = taosArrayGet(pHandle->aExtRowsOrders, 1);
+        SColumnInfoData* pPkCol = taosArrayGet(minBlk->pDataBlock, extRowsPkOrder->slotId);
+        bufInc = getPageBufIncForRowIdSort(pHandle->pDataBlock, minRow, pHandle->pDataBlock->info.rows, pPkCol);
+      }
+    } else {
+      bufInc = getPageBufIncForRow(minBlk, minRow, pHandle->pDataBlock->info.rows);
+    }
 
     if (blkPgSz <= pHandle->pageSize && blkPgSz + bufInc > pHandle->pageSize) {
       SColumnInfoData* tsCol = taosArrayGet(pHandle->pDataBlock->pDataBlock, pHandleBlockTsOrder->slotId);
@@ -1552,7 +1597,8 @@ static int32_t sortBlocksToExtSource(SSortHandle* pHandle, SArray* aBlk, SArray*
       nMergedRows += pHandle->pDataBlock->info.rows;
       blockDataCleanup(pHandle->pDataBlock);
       blkPgSz = pgHeaderSz;
-      incBlock = (pHandle->bSortByRowId) ? pHandle->pDataBlock : minBlk;
+
+      SSDataBlock* incBlock = (pHandle->bSortByRowId) ? pHandle->pDataBlock : minBlk;
       bufInc = getPageBufIncForRow(incBlock, minRow, 0);
 
       if ((pHandle->mergeLimit != -1) && (nMergedRows >= pHandle->mergeLimit)) {
@@ -1566,10 +1612,10 @@ static int32_t sortBlocksToExtSource(SSortHandle* pHandle, SArray* aBlk, SArray*
     }
 
     blockDataEnsureCapacity(pHandle->pDataBlock, pHandle->pDataBlock->info.rows + 1);
-    if (!pHandle->bSortByRowId) {
-      appendOneRowToDataBlock(pHandle->pDataBlock, minBlk, &minRow);
-    } else {
+    if (pHandle->bSortByRowId) {
       appendToRowIndexDataBlock(pHandle, minBlk, &minRow);
+    } else {
+      appendOneRowToDataBlock(pHandle->pDataBlock, minBlk, &minRow);
     }
 
     blkPgSz += bufInc;