text: --  @testpoint:opengauss关键字Large(非保留)，作为角色名
  
  
  --关键字不带引号-成功
  drop role if exists Large;
  create role Large with password 'Gauss@123' valid until '2020-12-31';
  drop role Large;
  
  --关键字带双引号-成功
  drop role if exists "Large";
  create role "Large" with password 'Gauss@123' valid until '2020-12-31';
  drop role "Large";
  
  --关键字带单引号-合理报错
  drop role if exists 'Large';
  create role 'Large' with password 'Gauss@123' valid until '2020-12-31';
  
  --关键字带反引号-合理报错
  drop role if exists `Large`;
  create role `Large` with password 'Gauss@123' valid until '2020-12-31';
  