修复以'pg_temp_'为命名前缀的模式可以创建成功的问题

src/gausskernel/optimizer/commands/schemacmds.cpp

@@ -133,6 +133,17 @@ Oid CreateSchemaCommand(CreateSchemaStmt* stmt, const char* queryString)
                 errdetail("The prefix \"gs_role_\" is reserved.")));
     }
 
+#ifndef ENABLE_MULTIPLE_NODES
+    if (!g_instance.attr.attr_common.allowSystemTableMods &&
+        stmt->temptype == Temp_None &&
+        (isTempNamespaceName(stmt->schemaname) || isToastTempNamespaceName(stmt->schemaname))) {
+        ereport(ERROR,
+            (errcode(ERRCODE_RESERVED_NAME),
+                errmsg("unacceptable schema name \"%s\"", schemaName),
+                errdetail("The prefix \"pg_temp_\" is reserved.")));
+    }
+#endif
+
     /*
      * Who is supposed to own the new schema?
      */

src/gausskernel/process/postmaster/twophasecleaner.cpp

@@ -841,7 +841,9 @@ static void DropTempSchemas(PGconn* conn)
         if (thirdLastPos == NULL) {
             PQfinish(conn);
             conn = NULL;
-            elog(ERROR, "strrchr failed, can't find '%c' in '%s'\n", '_', tempBuffer2);
+            elog(ERROR, "strrchr failed, can't find '%c' in '%s'. "
+                "the schema name '%s' is reserved, advise to delete manually\n",
+                '_', tempBuffer2, tempSchema->tempSchemaName);
         }
         uint32 timeLineID = strtol(thirdLastPos + 1, NULL, 10);