diff --git a/source/dnode/vnode/src/inc/tsdb.h b/source/dnode/vnode/src/inc/tsdb.h
index d8c84e952b43a5c0f0cfa64058d8f4a6fb77ca3e..bbf100cf3a09b2de97a55807c54f3d5ccc2a075f 100644
--- a/source/dnode/vnode/src/inc/tsdb.h
+++ b/source/dnode/vnode/src/inc/tsdb.h
@@ -90,6 +90,9 @@ int32_t tsdbRowCmprFn(const void *p1, const void *p2);
 void     tRowIterInit(SRowIter *pIter, TSDBROW *pRow, STSchema *pTSchema);
 SColVal *tRowIterNext(SRowIter *pIter);
 // SRowMerger
+int32_t tRowMergerInit2(SRowMerger *pMerger, STSchema *pResTSchema, TSDBROW *pRow, STSchema *pTSchema);
+int32_t tRowMergerAdd(SRowMerger *pMerger, TSDBROW *pRow, STSchema *pTSchema);
+
 int32_t tRowMergerInit(SRowMerger *pMerger, TSDBROW *pRow, STSchema *pTSchema);
 void    tRowMergerClear(SRowMerger *pMerger);
 int32_t tRowMerge(SRowMerger *pMerger, TSDBROW *pRow);
diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index 0eec715bd11de12a611036c6527269b469dac1ff..9545ded9273137271e3fe7ff74dd48e81c943177 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -143,7 +143,7 @@ static int      buildDataBlockFromBufImpl(STableBlockScanInfo* pBlockScanInfo, i
 static TSDBROW* getValidRow(SIterInfo* pIter, const SArray* pDelList, STsdbReader* pReader);
 static int32_t  doMergeRowsInFileBlocks(SBlockData* pBlockData, STableBlockScanInfo* pScanInfo, STsdbReader* pReader,
                                         SRowMerger* pMerger);
-static int32_t  doMergeRowsInBuf(SIterInfo* pIter, int64_t ts, SArray* pDelList, SRowMerger* pMerger,
+static int32_t  doMergeRowsInBuf(SIterInfo* pIter, uint64_t uid, int64_t ts, SArray* pDelList, SRowMerger* pMerger,
                                  STsdbReader* pReader);
 static int32_t  doAppendOneRow(SSDataBlock* pBlock, STsdbReader* pReader, STSRow* pTSRow);
 static void     setComposedBlockFlag(STsdbReader* pReader, bool composed);
@@ -1230,7 +1230,7 @@ static int32_t doMergeBufAndFileRows(STsdbReader* pReader, STableBlockScanInfo*
       doMergeRowsInFileBlocks(pBlockData, pBlockScanInfo, pReader, &merge);
 
       tRowMerge(&merge, pRow);
-      doMergeRowsInBuf(pIter, k.ts, pBlockScanInfo->delSkyline, &merge, pReader);
+      doMergeRowsInBuf(pIter, pBlockScanInfo->uid, k.ts, pBlockScanInfo->delSkyline, &merge, pReader);
 
       tRowMergerGetRow(&merge, &pTSRow);
     }
@@ -1246,7 +1246,7 @@ static int32_t doMergeBufAndFileRows(STsdbReader* pReader, STableBlockScanInfo*
       updateSchema(pRow, pBlockScanInfo->uid, pReader);
 
       tRowMergerInit(&merge, pRow, pReader->pSchema);
-      doMergeRowsInBuf(pIter, k.ts, pBlockScanInfo->delSkyline, &merge, pReader);
+      doMergeRowsInBuf(pIter, pBlockScanInfo->uid, k.ts, pBlockScanInfo->delSkyline, &merge, pReader);
 
       tRowMerge(&merge, &fRow);
       doMergeRowsInFileBlocks(pBlockData, pBlockScanInfo, pReader, &merge);
@@ -1291,12 +1291,12 @@ static int32_t doMergeThreeLevelRows(STsdbReader* pReader, STableBlockScanInfo*
 
       if (ik.ts == key) {
         tRowMerge(&merge, piRow);
-        doMergeRowsInBuf(&pBlockScanInfo->iiter, key, pBlockScanInfo->delSkyline, &merge, pReader);
+        doMergeRowsInBuf(&pBlockScanInfo->iiter, uid, key, pBlockScanInfo->delSkyline, &merge, pReader);
       }
 
       if (k.ts == key) {
         tRowMerge(&merge, pRow);
-        doMergeRowsInBuf(&pBlockScanInfo->iter, key, pBlockScanInfo->delSkyline, &merge, pReader);
+        doMergeRowsInBuf(&pBlockScanInfo->iter, uid, key, pBlockScanInfo->delSkyline, &merge, pReader);
       }
 
       tRowMergerGetRow(&merge, &pTSRow);
@@ -1336,11 +1336,11 @@ static int32_t doMergeThreeLevelRows(STsdbReader* pReader, STableBlockScanInfo*
       updateSchema(pRow, uid, pReader);
 
       tRowMergerInit(&merge, pRow, pReader->pSchema);
-      doMergeRowsInBuf(&pBlockScanInfo->iter, key, pBlockScanInfo->delSkyline, &merge, pReader);
+      doMergeRowsInBuf(&pBlockScanInfo->iter, uid, key, pBlockScanInfo->delSkyline, &merge, pReader);
 
       if (ik.ts == k.ts) {
         tRowMerge(&merge, piRow);
-        doMergeRowsInBuf(&pBlockScanInfo->iiter, key, pBlockScanInfo->delSkyline, &merge, pReader);
+        doMergeRowsInBuf(&pBlockScanInfo->iiter, uid, key, pBlockScanInfo->delSkyline, &merge, pReader);
       }
 
       if (k.ts == key) {
@@ -2097,7 +2097,8 @@ TSDBROW* getValidRow(SIterInfo* pIter, const SArray* pDelList, STsdbReader* pRea
   }
 }
 
-int32_t doMergeRowsInBuf(SIterInfo* pIter, int64_t ts, SArray* pDelList, SRowMerger* pMerger, STsdbReader* pReader) {
+int32_t doMergeRowsInBuf(SIterInfo* pIter, uint64_t uid, int64_t ts, SArray* pDelList, SRowMerger* pMerger,
+                         STsdbReader* pReader) {
   while (1) {
     pIter->hasVal = tsdbTbDataIterNext(pIter->iter);
     if (!pIter->hasVal) {
@@ -2116,7 +2117,15 @@ int32_t doMergeRowsInBuf(SIterInfo* pIter, int64_t ts, SArray* pDelList, SRowMer
       break;
     }
 
-    tRowMerge(pMerger, pRow);
+    int32_t   sversion = TSDBROW_SVERSION(pRow);
+    STSchema* pTSchema = NULL;
+    if (sversion != pReader->pSchema->version) {
+      metaGetTbTSchemaEx(pReader->pTsdb->pVnode->pMeta, pReader->suid, uid, sversion, &pTSchema);
+    } else {
+      pTSchema = pReader->pSchema;
+    }
+
+    tRowMergerAdd(pMerger, pRow, pTSchema);
   }
 
   return TSDB_CODE_SUCCESS;
@@ -2229,7 +2238,7 @@ void updateSchema(TSDBROW* pRow, uint64_t uid, STsdbReader* pReader) {
 
   if (pReader->pSchema == NULL) {
     metaGetTbTSchemaEx(pReader->pTsdb->pVnode->pMeta, pReader->suid, uid, sversion, &pReader->pSchema);
-  } else if (pReader->pSchema->version < sversion) {
+  } else if (pReader->pSchema->version != sversion) {
     taosMemoryFreeClear(pReader->pSchema);
     metaGetTbTSchemaEx(pReader->pTsdb->pVnode->pMeta, pReader->suid, uid, sversion, &pReader->pSchema);
   }
@@ -2240,10 +2249,17 @@ void doMergeMultiRows(TSDBROW* pRow, uint64_t uid, SIterInfo* pIter, SArray* pDe
   SRowMerger merge = {0};
 
   TSDBKEY k = TSDBROW_KEY(pRow);
-  updateSchema(pRow, uid, pReader);
+  // updateSchema(pRow, uid, pReader);
+  int32_t   sversion = TSDBROW_SVERSION(pRow);
+  STSchema* pTSchema = NULL;
+  if (sversion != pReader->pSchema->version) {
+    metaGetTbTSchemaEx(pReader->pTsdb->pVnode->pMeta, pReader->suid, uid, sversion, &pTSchema);
+  } else {
+    pTSchema = pReader->pSchema;
+  }
 
-  tRowMergerInit(&merge, pRow, pReader->pSchema);
-  doMergeRowsInBuf(pIter, k.ts, pDelList, &merge, pReader);
+  tRowMergerInit2(&merge, pReader->pSchema, pRow, pTSchema);
+  doMergeRowsInBuf(pIter, uid, k.ts, pDelList, &merge, pReader);
   tRowMergerGetRow(&merge, pTSRow);
   tRowMergerClear(&merge);
 }
@@ -2259,18 +2275,18 @@ void doMergeMemIMemRows(TSDBROW* pRow, TSDBROW* piRow, STableBlockScanInfo* pBlo
     updateSchema(piRow, pBlockScanInfo->uid, pReader);
 
     tRowMergerInit(&merge, piRow, pReader->pSchema);
-    doMergeRowsInBuf(&pBlockScanInfo->iiter, ik.ts, pBlockScanInfo->delSkyline, &merge, pReader);
+    doMergeRowsInBuf(&pBlockScanInfo->iiter, pBlockScanInfo->uid, ik.ts, pBlockScanInfo->delSkyline, &merge, pReader);
 
     tRowMerge(&merge, pRow);
-    doMergeRowsInBuf(&pBlockScanInfo->iter, k.ts, pBlockScanInfo->delSkyline, &merge, pReader);
+    doMergeRowsInBuf(&pBlockScanInfo->iter, pBlockScanInfo->uid, k.ts, pBlockScanInfo->delSkyline, &merge, pReader);
   } else {
     updateSchema(pRow, pBlockScanInfo->uid, pReader);
 
     tRowMergerInit(&merge, pRow, pReader->pSchema);
-    doMergeRowsInBuf(&pBlockScanInfo->iter, k.ts, pBlockScanInfo->delSkyline, &merge, pReader);
+    doMergeRowsInBuf(&pBlockScanInfo->iter, pBlockScanInfo->uid, k.ts, pBlockScanInfo->delSkyline, &merge, pReader);
 
     tRowMerge(&merge, piRow);
-    doMergeRowsInBuf(&pBlockScanInfo->iiter, k.ts, pBlockScanInfo->delSkyline, &merge, pReader);
+    doMergeRowsInBuf(&pBlockScanInfo->iiter, pBlockScanInfo->uid, k.ts, pBlockScanInfo->delSkyline, &merge, pReader);
   }
 
   tRowMergerGetRow(&merge, pTSRow);
diff --git a/source/dnode/vnode/src/tsdb/tsdbUtil.c b/source/dnode/vnode/src/tsdb/tsdbUtil.c
index 3e05b75dd010ec2336115efa8354e2892c07afa7..211a33059993437df38334136e41c4ea84a4652e 100644
--- a/source/dnode/vnode/src/tsdb/tsdbUtil.c
+++ b/source/dnode/vnode/src/tsdb/tsdbUtil.c
@@ -13,6 +13,7 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "tdataformat.h"
 #include "tsdb.h"
 
 // SMapData =======================================================================
@@ -568,6 +569,95 @@ SColVal *tRowIterNext(SRowIter *pIter) {
 }
 
 // SRowMerger ======================================================
+
+int32_t tRowMergerInit2(SRowMerger *pMerger, STSchema *pResTSchema, TSDBROW *pRow, STSchema *pTSchema) {
+  int32_t   code = 0;
+  TSDBKEY   key = TSDBROW_KEY(pRow);
+  SColVal  *pColVal = &(SColVal){0};
+  STColumn *pTColumn;
+  int32_t   iCol = 0;
+
+  pMerger->pTSchema = pResTSchema;
+  pMerger->version = key.version;
+
+  pMerger->pArray = taosArrayInit(pResTSchema->numOfCols, sizeof(SColVal));
+  if (pMerger->pArray == NULL) {
+    code = TSDB_CODE_OUT_OF_MEMORY;
+    goto _exit;
+  }
+
+  // ts
+  pTColumn = &pTSchema->columns[iCol++];
+
+  ASSERT(pTColumn->type == TSDB_DATA_TYPE_TIMESTAMP);
+
+  *pColVal = COL_VAL_VALUE(pTColumn->colId, pTColumn->type, (SValue){.ts = key.ts});
+  if (taosArrayPush(pMerger->pArray, pColVal) == NULL) {
+    code = TSDB_CODE_OUT_OF_MEMORY;
+    goto _exit;
+  }
+
+  // other
+  for (; iCol < pTSchema->numOfCols && iCol < pResTSchema->numOfCols; ++iCol) {
+    pTColumn = &pResTSchema->columns[iCol];
+    if (pTSchema->columns[iCol].colId != pTColumn->colId) {
+      taosArrayPush(pMerger->pArray, &COL_VAL_NONE(pTColumn->colId, pTColumn->type));
+      continue;
+    }
+
+    tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
+    if (taosArrayPush(pMerger->pArray, pColVal) == NULL) {
+      code = TSDB_CODE_OUT_OF_MEMORY;
+      goto _exit;
+    }
+  }
+
+  for (; iCol < pResTSchema->numOfCols; ++iCol) {
+    pTColumn = &pResTSchema->columns[iCol];
+    taosArrayPush(pMerger->pArray, &COL_VAL_NONE(pTColumn->colId, pTColumn->type));
+  }
+
+_exit:
+  return code;
+}
+
+int32_t tRowMergerAdd(SRowMerger *pMerger, TSDBROW *pRow, STSchema *pTSchema) {
+  int32_t   code = 0;
+  TSDBKEY   key = TSDBROW_KEY(pRow);
+  SColVal  *pColVal = &(SColVal){0};
+  STColumn *pTColumn;
+  int32_t   iCol;
+
+  ASSERT(((SColVal *)pMerger->pArray->pData)->value.ts == key.ts);
+
+  for (iCol = 1; iCol < pMerger->pTSchema->numOfCols && iCol < pTSchema->numOfCols; ++iCol) {
+    pTColumn = &pMerger->pTSchema->columns[iCol];
+    if (pTSchema->columns[iCol].colId != pTColumn->colId) {
+      continue;
+    }
+
+    tsdbRowGetColVal(pRow, pMerger->pTSchema, iCol, pColVal);
+
+    if (key.version > pMerger->version) {
+      if (!pColVal->isNone) {
+        taosArraySet(pMerger->pArray, iCol, pColVal);
+      }
+    } else if (key.version < pMerger->version) {
+      SColVal *tColVal = (SColVal *)taosArrayGet(pMerger->pArray, iCol);
+      if (tColVal->isNone && !pColVal->isNone) {
+        taosArraySet(pMerger->pArray, iCol, pColVal);
+      }
+    } else {
+      ASSERT(0);
+    }
+  }
+
+  pMerger->version = key.version;
+
+_exit:
+  return code;
+}
+
 int32_t tRowMergerInit(SRowMerger *pMerger, TSDBROW *pRow, STSchema *pTSchema) {
   int32_t   code = 0;
   TSDBKEY   key = TSDBROW_KEY(pRow);
@@ -1401,7 +1491,7 @@ void tsdbCalcColDataSMA(SColData *pColData, SColumnDataAgg *pColAgg) {
           break;
         case TSDB_DATA_TYPE_BOOL:
           break;
-        case TSDB_DATA_TYPE_TINYINT:{
+        case TSDB_DATA_TYPE_TINYINT: {
           pColAgg->sum += colVal.value.i8;
           if (pColAgg->min > colVal.value.i8) {
             pColAgg->min = colVal.value.i8;
@@ -1411,7 +1501,7 @@ void tsdbCalcColDataSMA(SColData *pColData, SColumnDataAgg *pColAgg) {
           }
           break;
         }
-        case TSDB_DATA_TYPE_SMALLINT:{
+        case TSDB_DATA_TYPE_SMALLINT: {
           pColAgg->sum += colVal.value.i16;
           if (pColAgg->min > colVal.value.i16) {
             pColAgg->min = colVal.value.i16;
@@ -1441,7 +1531,7 @@ void tsdbCalcColDataSMA(SColData *pColData, SColumnDataAgg *pColAgg) {
           }
           break;
         }
-        case TSDB_DATA_TYPE_FLOAT:{
+        case TSDB_DATA_TYPE_FLOAT: {
           pColAgg->sum += colVal.value.f;
           if (pColAgg->min > colVal.value.f) {
             pColAgg->min = colVal.value.f;
@@ -1451,7 +1541,7 @@ void tsdbCalcColDataSMA(SColData *pColData, SColumnDataAgg *pColAgg) {
           }
           break;
         }
-        case TSDB_DATA_TYPE_DOUBLE:{
+        case TSDB_DATA_TYPE_DOUBLE: {
           pColAgg->sum += colVal.value.d;
           if (pColAgg->min > colVal.value.d) {
             pColAgg->min = colVal.value.d;
@@ -1463,7 +1553,7 @@ void tsdbCalcColDataSMA(SColData *pColData, SColumnDataAgg *pColAgg) {
         }
         case TSDB_DATA_TYPE_VARCHAR:
           break;
-        case TSDB_DATA_TYPE_TIMESTAMP:{
+        case TSDB_DATA_TYPE_TIMESTAMP: {
           if (pColAgg->min > colVal.value.i64) {
             pColAgg->min = colVal.value.i64;
           }
@@ -1474,7 +1564,7 @@ void tsdbCalcColDataSMA(SColData *pColData, SColumnDataAgg *pColAgg) {
         }
         case TSDB_DATA_TYPE_NCHAR:
           break;
-        case TSDB_DATA_TYPE_UTINYINT:{
+        case TSDB_DATA_TYPE_UTINYINT: {
           pColAgg->sum += colVal.value.u8;
           if (pColAgg->min > colVal.value.u8) {
             pColAgg->min = colVal.value.u8;
@@ -1484,7 +1574,7 @@ void tsdbCalcColDataSMA(SColData *pColData, SColumnDataAgg *pColAgg) {
           }
           break;
         }
-        case TSDB_DATA_TYPE_USMALLINT:{
+        case TSDB_DATA_TYPE_USMALLINT: {
           pColAgg->sum += colVal.value.u16;
           if (pColAgg->min > colVal.value.u16) {
             pColAgg->min = colVal.value.u16;
@@ -1494,7 +1584,7 @@ void tsdbCalcColDataSMA(SColData *pColData, SColumnDataAgg *pColAgg) {
           }
           break;
         }
-        case TSDB_DATA_TYPE_UINT:{
+        case TSDB_DATA_TYPE_UINT: {
           pColAgg->sum += colVal.value.u32;
           if (pColAgg->min > colVal.value.u32) {
             pColAgg->min = colVal.value.u32;
@@ -1504,7 +1594,7 @@ void tsdbCalcColDataSMA(SColData *pColData, SColumnDataAgg *pColAgg) {
           }
           break;
         }
-        case TSDB_DATA_TYPE_UBIGINT:{
+        case TSDB_DATA_TYPE_UBIGINT: {
           pColAgg->sum += colVal.value.u64;
           if (pColAgg->min > colVal.value.u64) {
             pColAgg->min = colVal.value.u64;