enh: add local forbidden cfg processing

include/common/tglobal.h

@@ -146,6 +146,7 @@ struct SConfig *taosGetCfg();
 void    taosSetAllDebugFlag(int32_t flag);
 void    taosSetDebugFlag(int32_t *pFlagPtr, const char *flagName, int32_t flagVal);
 int32_t taosSetCfg(SConfig *pCfg, char *name);
+void    taosLocalCfgForbiddenToChange(char* name, bool* forbidden);
 
 #ifdef __cplusplus
 }

source/common/src/tglobal.c

@@ -594,6 +594,20 @@ static int32_t taosSetServerCfg(SConfig *pCfg) {
   return 0;
 }
 
+void taosLocalCfgForbiddenToChange(char* name, bool* forbidden) {
+  int32_t len = strlen(name);
+  char    lowcaseName[CFG_NAME_MAX_LEN + 1] = {0};
+  strntolower(lowcaseName, name, TMIN(CFG_NAME_MAX_LEN, len));
+
+  if (strcasecmp("charset", name) == 0) {
+    *forbidden = true;
+    return;
+  }
+
+  *forbidden = false;
+}
+
+
 int32_t taosSetCfg(SConfig *pCfg, char *name) {
   int32_t len = strlen(name);
   char    lowcaseName[CFG_NAME_MAX_LEN + 1] = {0};

source/libs/command/src/command.c

@@ -517,6 +517,13 @@ static int32_t execAlterLocal(SAlterLocalStmt* pStmt) {
     goto _return;
   }
 
+  bool forbidden = false;
+  taosLocalCfgForbiddenToChange(pStmt->config, &forbidden);
+  if (forbidden) {
+    terrno = TSDB_CODE_OPS_NOT_SUPPORT;
+    return terrno;
+  }
+
   if (cfgSetItem(tsCfg, pStmt->config, pStmt->value, CFG_STYPE_ALTER_CMD)) {
     return terrno;
   }