diff --git a/src/client/inc/tscUtil.h b/src/client/inc/tscUtil.h
index 950d81fb61794e99647ba0777129cebba141a8ee..7038ae004cca9141cd7aa3832c37aad86ac58184 100644
--- a/src/client/inc/tscUtil.h
+++ b/src/client/inc/tscUtil.h
@@ -217,7 +217,7 @@ void tscColumnListDestroy(SArray* pColList);
 void tscColumnListCopy(SArray* dst, const SArray* src, uint64_t tableUid);
 void tscColumnListCopyAll(SArray* dst, const SArray* src);
 
-void convertQueryResult(SSqlRes* pRes, SQueryInfo* pQueryInfo, uint64_t objId);
+void convertQueryResult(SSqlRes* pRes, SQueryInfo* pQueryInfo, uint64_t objId, bool convertNchar);
 
 void tscDequoteAndTrimToken(SStrToken* pToken);
 int32_t tscValidateName(SStrToken* pToken);
diff --git a/src/client/inc/tsclient.h b/src/client/inc/tsclient.h
index ec4bf5252783cd9df31d820bff1277fb2ba25afb..c0a1afda77fbab6dba58fe2583294e79ea081acb 100644
--- a/src/client/inc/tsclient.h
+++ b/src/client/inc/tsclient.h
@@ -319,7 +319,7 @@ void    tscRestoreFuncForSTableQuery(SQueryInfo *pQueryInfo);
 
 int32_t tscCreateResPointerInfo(SSqlRes *pRes, SQueryInfo *pQueryInfo);
 void tscSetResRawPtr(SSqlRes* pRes, SQueryInfo* pQueryInfo);
-void tscSetResRawPtrRv(SSqlRes* pRes, SQueryInfo* pQueryInfo, SSDataBlock* pBlock);
+void tscSetResRawPtrRv(SSqlRes* pRes, SQueryInfo* pQueryInfo, SSDataBlock* pBlock, bool convertNchar);
 
 void handleDownstreamOperator(SSqlObj** pSqlList, int32_t numOfUpstream, SQueryInfo* px, SSqlObj* pParent);
 void destroyTableNameList(SInsertStatementParam* pInsertParam);
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 7fc47947c85913a2f64cb8a58092d4616a4779f9..1ec006746e699058ad8e036856b183dc1b0ba9a2 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -1703,7 +1703,7 @@ int tscProcessRetrieveGlobalMergeRsp(SSqlObj *pSql) {
 
   uint64_t localQueryId = pSql->self;
   qTableQuery(pQueryInfo->pQInfo, &localQueryId);
-  convertQueryResult(pRes, pQueryInfo, pSql->self);
+  convertQueryResult(pRes, pQueryInfo, pSql->self, true);
 
   code = pRes->code;
   if (pRes->code == TSDB_CODE_SUCCESS) {
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 52d109210718fb889d5f2e04fa24a5ffce326496..c74c0fa6cfec0330798a78411eb2d035bcabd1a0 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -645,7 +645,7 @@ void tscSetResRawPtr(SSqlRes* pRes, SQueryInfo* pQueryInfo) {
   }
 }
 
-void tscSetResRawPtrRv(SSqlRes* pRes, SQueryInfo* pQueryInfo, SSDataBlock* pBlock) {
+void tscSetResRawPtrRv(SSqlRes* pRes, SQueryInfo* pQueryInfo, SSDataBlock* pBlock, bool convertNchar) {
   assert(pRes->numOfCols > 0);
 
   for (int32_t i = 0; i < pQueryInfo->fieldsInfo.numOfOutput; ++i) {
@@ -678,7 +678,7 @@ void tscSetResRawPtrRv(SSqlRes* pRes, SQueryInfo* pQueryInfo, SSDataBlock* pBloc
         }
       }
 
-    } else if (pInfo->field.type == TSDB_DATA_TYPE_NCHAR) {
+    } else if (convertNchar && pInfo->field.type == TSDB_DATA_TYPE_NCHAR) {
       // convert unicode to native code in a temporary buffer extra one byte for terminated symbol
       pRes->buffer[i] = realloc(pRes->buffer[i], pInfo->field.bytes * pRes->numOfRows);
 
@@ -1072,14 +1072,14 @@ SOperatorInfo* createJoinOperatorInfo(SOperatorInfo** pUpstream, int32_t numOfUp
   return pOperator;
 }
 
-void convertQueryResult(SSqlRes* pRes, SQueryInfo* pQueryInfo, uint64_t objId) {
+void convertQueryResult(SSqlRes* pRes, SQueryInfo* pQueryInfo, uint64_t objId, bool convertNchar) {
   // set the correct result
   SSDataBlock* p = pQueryInfo->pQInfo->runtimeEnv.outputBuf;
   pRes->numOfRows = (p != NULL)? p->info.rows: 0;
 
   if (pRes->code == TSDB_CODE_SUCCESS && pRes->numOfRows > 0) {
     tscCreateResPointerInfo(pRes, pQueryInfo);
-    tscSetResRawPtrRv(pRes, pQueryInfo, p);
+    tscSetResRawPtrRv(pRes, pQueryInfo, p, convertNchar);
   }
 
   tscDebug("0x%"PRIx64" retrieve result in pRes, numOfRows:%d", objId, pRes->numOfRows);
@@ -1199,7 +1199,7 @@ void handleDownstreamOperator(SSqlObj** pSqlObjList, int32_t numOfUpstream, SQue
 
   uint64_t qId = pSql->self;
   qTableQuery(px->pQInfo, &qId);
-  convertQueryResult(pOutput, px, pSql->self);
+  convertQueryResult(pOutput, px, pSql->self, false);
 }
 
 static void tscDestroyResPointerInfo(SSqlRes* pRes) {
diff --git a/src/query/inc/qTableMeta.h b/src/query/inc/qTableMeta.h
index 4fc252b644efab0c6bfdb97b19c3af3ef9c68920..7ec6dfbcf908c6100aedfc704dde32212e6b4347 100644
--- a/src/query/inc/qTableMeta.h
+++ b/src/query/inc/qTableMeta.h
@@ -118,7 +118,6 @@ typedef struct SQueryInfo {
   int64_t          vgroupLimit;    // table limit in case of super table projection query + global order + limit
 
   int32_t          udColumnId;    // current user-defined constant output field column id, monotonically decreases from TSDB_UD_COLUMN_INDEX
-  int16_t          resColumnId;   // result column id
   bool             distinctTag;   // distinct tag or not
   int32_t          round;         // 0/1/....
   int32_t          bufLen;