text: -- @testpoint: opengauss关键字free(非保留)，作为同义词对象名，合理报错
  
  --前置条件
  drop table if exists explain_test;
  create table explain_test(id int,name varchar(10));
  
  --关键字不带引号-成功
  drop synonym if exists free;
  create synonym free for explain_test;
  insert into free values (1,'ada'),(2, 'bob');
  update free set free.name='cici' where free.id=2;
  select * from free;
  drop synonym if exists free;
  
  --关键字带双引号-成功
  drop synonym if exists "free";
  create synonym "free" for explain_test;
  drop synonym if exists "free";
  
  
  --关键字带单引号-合理报错
  drop synonym if exists 'free';
  create synonym 'free' for explain_test;
  insert into 'free' values (1,'ada'),(2, 'bob');
  update 'free' set 'free'.name='cici' where 'free'.id=2;
  select * from 'free';
  
  --关键字带反引号-合理报错
  drop synonym if exists `free`;
  create synonym `free` for explain_test;
  insert into `free` values (1,'ada'),(2, 'bob');
  update `free` set `free`.name='cici' where `free`.id=2;
  select * from `free`;
  
  --清理环境
  drop table if exists explain_test;