diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index 9545ded9273137271e3fe7ff74dd48e81c943177..47511cce984fda9eda6ae654e775e57a30c0406f 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -2126,6 +2126,10 @@ int32_t doMergeRowsInBuf(SIterInfo* pIter, uint64_t uid, int64_t ts, SArray* pDe
     }
 
     tRowMergerAdd(pMerger, pRow, pTSchema);
+
+    if (sversion != pReader->pSchema->version) {
+      taosMemoryFree(pTSchema);
+    }
   }
 
   return TSDB_CODE_SUCCESS;
@@ -2262,6 +2266,10 @@ void doMergeMultiRows(TSDBROW* pRow, uint64_t uid, SIterInfo* pIter, SArray* pDe
   doMergeRowsInBuf(pIter, uid, k.ts, pDelList, &merge, pReader);
   tRowMergerGetRow(&merge, pTSRow);
   tRowMergerClear(&merge);
+
+  if (sversion != pReader->pSchema->version) {
+    taosMemoryFree(pTSchema);
+  }
 }
 
 void doMergeMemIMemRows(TSDBROW* pRow, TSDBROW* piRow, STableBlockScanInfo* pBlockScanInfo, STsdbReader* pReader,
diff --git a/source/dnode/vnode/src/tsdb/tsdbUtil.c b/source/dnode/vnode/src/tsdb/tsdbUtil.c
index 211a33059993437df38334136e41c4ea84a4652e..ae9f3ae7c31ad2c51336455391b6c64192a5ac28 100644
--- a/source/dnode/vnode/src/tsdb/tsdbUtil.c
+++ b/source/dnode/vnode/src/tsdb/tsdbUtil.c
@@ -575,7 +575,7 @@ int32_t tRowMergerInit2(SRowMerger *pMerger, STSchema *pResTSchema, TSDBROW *pRo
   TSDBKEY   key = TSDBROW_KEY(pRow);
   SColVal  *pColVal = &(SColVal){0};
   STColumn *pTColumn;
-  int32_t   iCol = 0;
+  int32_t   iCol, jCol = 0;
 
   pMerger->pTSchema = pResTSchema;
   pMerger->version = key.version;
@@ -587,7 +587,7 @@ int32_t tRowMergerInit2(SRowMerger *pMerger, STSchema *pResTSchema, TSDBROW *pRo
   }
 
   // ts
-  pTColumn = &pTSchema->columns[iCol++];
+  pTColumn = &pTSchema->columns[jCol++];
 
   ASSERT(pTColumn->type == TSDB_DATA_TYPE_TIMESTAMP);
 
@@ -598,14 +598,18 @@ int32_t tRowMergerInit2(SRowMerger *pMerger, STSchema *pResTSchema, TSDBROW *pRo
   }
 
   // other
-  for (; iCol < pTSchema->numOfCols && iCol < pResTSchema->numOfCols; ++iCol) {
+  for (iCol = 1; jCol < pTSchema->numOfCols && iCol < pResTSchema->numOfCols; ++iCol) {
     pTColumn = &pResTSchema->columns[iCol];
-    if (pTSchema->columns[iCol].colId != pTColumn->colId) {
+    if (pTSchema->columns[jCol].colId < pTColumn->colId) {
+      ++jCol;
+      --iCol;
+      continue;
+    } else if (pTSchema->columns[jCol].colId > pTColumn->colId) {
       taosArrayPush(pMerger->pArray, &COL_VAL_NONE(pTColumn->colId, pTColumn->type));
       continue;
     }
 
-    tsdbRowGetColVal(pRow, pTSchema, iCol, pColVal);
+    tsdbRowGetColVal(pRow, pTSchema, jCol++, pColVal);
     if (taosArrayPush(pMerger->pArray, pColVal) == NULL) {
       code = TSDB_CODE_OUT_OF_MEMORY;
       goto _exit;
@@ -626,17 +630,21 @@ int32_t tRowMergerAdd(SRowMerger *pMerger, TSDBROW *pRow, STSchema *pTSchema) {
   TSDBKEY   key = TSDBROW_KEY(pRow);
   SColVal  *pColVal = &(SColVal){0};
   STColumn *pTColumn;
-  int32_t   iCol;
+  int32_t   iCol, jCol = 1;
 
   ASSERT(((SColVal *)pMerger->pArray->pData)->value.ts == key.ts);
 
-  for (iCol = 1; iCol < pMerger->pTSchema->numOfCols && iCol < pTSchema->numOfCols; ++iCol) {
+  for (iCol = 1; iCol < pMerger->pTSchema->numOfCols && jCol < pTSchema->numOfCols; ++iCol) {
     pTColumn = &pMerger->pTSchema->columns[iCol];
-    if (pTSchema->columns[iCol].colId != pTColumn->colId) {
+    if (pTSchema->columns[jCol].colId < pTColumn->colId) {
+      ++jCol;
+      --iCol;
+      continue;
+    } else if (pTSchema->columns[jCol].colId > pTColumn->colId) {
       continue;
     }
 
-    tsdbRowGetColVal(pRow, pMerger->pTSchema, iCol, pColVal);
+    tsdbRowGetColVal(pRow, pTSchema, jCol++, pColVal);
 
     if (key.version > pMerger->version) {
       if (!pColVal->isNone) {