text: --  @testpoint:opengauss关键字cursor_name(非保留)，作为用户名
  
  --关键字cursor_name作为用户名不带引号，创建成功
  drop user if exists cursor_name;
  CREATE USER cursor_name PASSWORD 'Bigdata@123';
  drop user cursor_name;
  
  --关键字cursor_name作为用户名加双引号，创建成功
  drop user if exists "cursor_name";
  CREATE USER "cursor_name" PASSWORD 'Bigdata@123';
  drop user "cursor_name";
   
  --关键字cursor_name作为用户名加单引号，合理报错
  CREATE USER 'cursor_name' PASSWORD 'Bigdata@123';
  
  --关键字cursor_name作为用户名加反引号，合理报错
  CREATE USER `cursor_name` PASSWORD 'Bigdata@123';
  