diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index ee93756f0e..85282a2340 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -1758,11 +1758,14 @@ static int32_t doMergeBufAndFileRows(STsdbReader* pReader, STableBlockScanInfo*
     }
 
     if (minKey == k.ts) {
+      STSchema* pSchema = doGetSchemaForTSRow(TSDBROW_SVERSION(pRow), pReader, pBlockScanInfo->uid);
+      if (pSchema == NULL) {
+        return terrno;
+      }
       if (init) {
-        tRowMerge(&merge, pRow);
+        tRowMergerAdd(&merge, pRow, pSchema);
       } else {
         init = true;
-        STSchema* pSchema = doGetSchemaForTSRow(TSDBROW_SVERSION(pRow), pReader, pBlockScanInfo->uid);
         int32_t   code = tRowMergerInit(&merge, pRow, pSchema);
         if (code != TSDB_CODE_SUCCESS) {
           return code;
diff --git a/source/dnode/vnode/src/tsdb/tsdbUtil.c b/source/dnode/vnode/src/tsdb/tsdbUtil.c
index 86adc1dc80..ab10960970 100644
--- a/source/dnode/vnode/src/tsdb/tsdbUtil.c
+++ b/source/dnode/vnode/src/tsdb/tsdbUtil.c
@@ -731,6 +731,7 @@ int32_t tRowMergerAdd(SRowMerger *pMerger, TSDBROW *pRow, STSchema *pTSchema) {
     tsdbRowGetColVal(pRow, pTSchema, jCol++, pColVal);
 
     if (key.version > pMerger->version) {
+#if 0
       if (!COL_VAL_IS_NONE(pColVal)) {
         if ((!COL_VAL_IS_NULL(pColVal)) && IS_VAR_DATA_TYPE(pColVal->type)) {
           SColVal *tColVal = taosArrayGet(pMerger->pArray, iCol);
@@ -746,6 +747,28 @@ int32_t tRowMergerAdd(SRowMerger *pMerger, TSDBROW *pRow, STSchema *pTSchema) {
           taosArraySet(pMerger->pArray, iCol, pColVal);
         }
       }
+#endif
+      if (!COL_VAL_IS_NONE(pColVal)) {
+        if (IS_VAR_DATA_TYPE(pColVal->type)) {
+          SColVal *pTColVal = taosArrayGet(pMerger->pArray, iCol);
+          if (!COL_VAL_IS_NULL(pColVal)) {
+            code = tRealloc(&pTColVal->value.pData, pColVal->value.nData);
+            if (code) return code;
+
+            pTColVal->value.nData = pColVal->value.nData;
+            if (pTColVal->value.nData) {
+              memcpy(pTColVal->value.pData,  pColVal->value.pData, pTColVal->value.nData);
+            }
+            pTColVal->flag = 0;
+          } else {
+            tFree(pTColVal->value.pData);
+            pTColVal->value.pData = NULL;
+            taosArraySet(pMerger->pArray, iCol, pColVal);
+          }
+        } else {
+          taosArraySet(pMerger->pArray, iCol, pColVal);
+        }
+      }
     } else if (key.version < pMerger->version) {
       SColVal *tColVal = (SColVal *)taosArrayGet(pMerger->pArray, iCol);
       if (COL_VAL_IS_NONE(tColVal) && !COL_VAL_IS_NONE(pColVal)) {