diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index bfdfd7ec87..ec4b438b2b 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -151,7 +151,7 @@ static int32_t doLoadRowsOfIdenticalTsInFileBlock(SBlockData* pBlockData, STable
 static int32_t doLoadRowsOfIdenticalTsInBuf(STbDataIter *pIter, bool* hasVal, int64_t ts, SRowMerger* pMerger, STsdbReader* pReader);
 static int32_t doAppendOneRow(SSDataBlock* pBlock, STsdbReader* pReader, STSRow* pTSRow);
 static void    setComposedBlockFlag(STsdbReader* pReader, bool composed);
-static void    checkUpdateSchema(TSDBROW* pRow, uint64_t uid, STsdbReader* pReader);
+static void    updateSchema(TSDBROW* pRow, uint64_t uid, STsdbReader* pReader);
 
 static void    doMergeMultiRows(TSDBROW* pRow, uint64_t uid, STbDataIter* dIter, bool* hasVal, STSRow **pTSRow, STsdbReader* pReader);
 static void    doMergeMemIMemRows(TSDBROW* pRow, TSDBROW* piRow, STableBlockScanInfo *pBlockScanInfo, STsdbReader* pReader, STSRow** pTSRow);
@@ -2063,7 +2063,14 @@ static bool fileBlockShouldLoad(STsdbReader* pReader, SFileDataBlockInfo *pFBloc
     overlapWithNeighbor = overlapWithNeighborBlock(pBlock, pNeighbor, pReader->order);
   }
 
-  return (overlapWithNeighbor ||
+  bool hasDup = false;
+  if (pBlock->nSubBlock == 1) {
+    hasDup = pBlock->hasDup;
+  } else {
+    hasDup = true;
+  }
+
+  return (overlapWithNeighbor || hasDup ||
           dataBlockPartialRequired(&pReader->window, &pReader->verRange, pBlock) ||
           keyOverlapFileBlock(key, pBlock, &pReader->verRange) ||
           (pBlock->nRow > pReader->capacity));
@@ -2478,7 +2485,6 @@ static int32_t buildBlockFromFiles(STsdbReader* pReader) {
   } else {
     SFileDataBlockInfo*  pFBlock = getCurrentBlockInfo(&pReader->status.blockIter);
     STableBlockScanInfo* pScanInfo = taosHashGet(pReader->status.pTableMap, &pFBlock->uid, sizeof(pFBlock->uid));
-    SBlock*              pBlock = taosArrayGet(pScanInfo->pBlockList, pFBlock->tbBlockIdx);
 
     // current block are exhausted, try the next file block
     if (pReader->status.fBlockDumpInfo.allDumped) {
@@ -2674,7 +2680,7 @@ int32_t doLoadRowsOfIdenticalTsInFileBlock(SBlockData* pBlockData, STableBlockSc
 
   if (asc) {
     pDumpInfo->rowIndex += step;
-    if (pDumpInfo->rowIndex < pBlockData->nRow - 1) {
+    if (pDumpInfo->rowIndex <= pBlockData->nRow - 1) {
       pDumpInfo->rowIndex = doMergeRowsInFileBlockImpl(pBlockData, pDumpInfo->rowIndex, key, pMerger, &pReader->verRange, step);
     }
 
@@ -2703,7 +2709,7 @@ int32_t doLoadRowsOfIdenticalTsInFileBlock(SBlockData* pBlockData, STableBlockSc
   return TSDB_CODE_SUCCESS;
 }
 
-void checkUpdateSchema(TSDBROW* pRow, uint64_t uid, STsdbReader* pReader) {
+void updateSchema(TSDBROW* pRow, uint64_t uid, STsdbReader* pReader) {
   int32_t sversion = TSDBROW_SVERSION(pRow);
 
   if (pReader->pSchema == NULL) {
@@ -2718,7 +2724,7 @@ void doMergeMultiRows(TSDBROW* pRow, uint64_t uid, STbDataIter* dIter, bool* has
   SRowMerger merge = {0};
 
   TSDBKEY k = TSDBROW_KEY(pRow);
-  checkUpdateSchema(pRow, uid, pReader);
+  updateSchema(pRow, uid, pReader);
 
   tRowMergerInit(&merge, pRow, pReader->pSchema);
   doLoadRowsOfIdenticalTsInBuf(dIter, hasVal, k.ts, &merge, pReader);
@@ -2732,7 +2738,7 @@ void doMergeMemIMemRows(TSDBROW* pRow, TSDBROW* piRow, STableBlockScanInfo *pBlo
   TSDBKEY ik = TSDBROW_KEY(piRow);
   ASSERT(k.ts == ik.ts);
 
-  checkUpdateSchema(piRow, pBlockScanInfo->uid, pReader);
+  updateSchema(piRow, pBlockScanInfo->uid, pReader);
 
   tRowMergerInit(&merge, piRow, pReader->pSchema);
   doLoadRowsOfIdenticalTsInBuf(pBlockScanInfo->iiter, &pBlockScanInfo->imemHasVal, ik.ts, &merge, pReader);