[TD-4199]<feature> enhance performance

src/client/src/tscServer.c

@@ -2845,10 +2845,8 @@ int32_t tscGetTableMetaImpl(SSqlObj* pSql, STableMetaInfo *pTableMetaInfo, bool
 
   size_t len = strlen(name);
   // just make runtime happy
-  if (pTableMetaInfo->tableMetaCapacity != 0) {
-    if (pTableMetaInfo->pTableMeta != NULL) {
-      memset(pTableMetaInfo->pTableMeta, 0, pTableMetaInfo->tableMetaCapacity);
-    }
+  if (pTableMetaInfo->tableMetaCapacity != 0 && pTableMetaInfo->pTableMeta != NULL) {
+    memset(pTableMetaInfo->pTableMeta, 0, pTableMetaInfo->tableMetaCapacity);
   } 
   taosHashGetCloneExt(tscTableMetaMap, name, len, NULL, (void **)&(pTableMetaInfo->pTableMeta), &pTableMetaInfo->tableMetaCapacity);
   

src/util/src/hash.c

@@ -18,7 +18,7 @@
 #include "tulog.h"
 #include "taosdef.h"
 
-#define EXT_SIZE 0 
+#define EXT_SIZE 1024 
 
 #define HASH_NEED_RESIZE(_h) ((_h)->size >= (_h)->capacity * HASH_DEFAULT_LOAD_FACTOR)