[TD-4199]<feature> enhance performance

src/client/src/tscSQLParser.c

@@ -8145,6 +8145,7 @@ int32_t loadAllTableMeta(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       void* pVgroupIdList = NULL;
       if (pTableMeta->tableType == TSDB_CHILD_TABLE) {
         code = tscCreateTableMetaFromSTableMeta((STableMeta **)(&pTableMeta), name, &tableMetaCapacity, (STableMeta **)(&pSTMeta));
+        pSql->pBuf = (void *)pSTMeta; 
 
         // create the child table meta from super table failed, try load it from mnode
         if (code != TSDB_CODE_SUCCESS) {

src/client/src/tscServer.c

@@ -2856,6 +2856,7 @@ int32_t tscGetTableMetaImpl(SSqlObj* pSql, STableMetaInfo *pTableMetaInfo, bool
     // in case of child table, here only get the
     if (pMeta->tableType == TSDB_CHILD_TABLE) {
       int32_t code = tscCreateTableMetaFromSTableMeta(&pTableMetaInfo->pTableMeta, name, &pTableMetaInfo->tableMetaCapacity, (STableMeta **)(&pSTMeta));
+      pSql->pBuf   = (void *)(pSTMeta); 
       if (code != TSDB_CODE_SUCCESS) {
         return getTableMetaFromMnode(pSql, pTableMetaInfo, autocreate);
       }

src/client/src/tscUtil.c

@@ -4456,8 +4456,8 @@ int32_t tscCreateTableMetaFromSTableMeta(STableMeta** ppChild, const char* name,
   if (p != NULL && sz != 0) {
     memset((char *)p, 0, sz);
   }
-  taosHashGetCloneExt(tscTableMetaMap, pChild->sTableName, strnlen(pChild->sTableName, TSDB_TABLE_FNAME_LEN), NULL, (void **)ppSTable, &sz);
-  p = *ppSTable; 
+  taosHashGetCloneExt(tscTableMetaMap, pChild->sTableName, strnlen(pChild->sTableName, TSDB_TABLE_FNAME_LEN), NULL, (void **)&p, &sz);
+  *ppSTable = p; 
 
   // tableMeta exists, build child table meta according to the super table meta
   // the uid need to be checked in addition to the general name of the super table.