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