text: --  @testpoint:opengauss关键字position(非保留)，自定义数据类型名为position
  --关键字position作为数据类型不带引号，创建成功
  drop type if exists position;
  CREATE TYPE position AS (f1 int, f2 text);
  select typname from pg_type where typname ='position';
  drop type position;
  
  
  --关键字position作为数据类型加双引号，创建成功
  drop type if exists "position";
  CREATE TYPE "position" AS (f1 int, f2 text);
  select typname from pg_type where typname ='position';
  drop type "position";
  
  --关键字position作为数据类型加单引号，合理报错
  drop type if exists 'position';
  CREATE TYPE 'position' AS (f1 int, f2 text);
  select * from pg_type where typname ='position';
  drop type 'position';
  
  --关键字position作为数据类型加反引号，合理报错
  drop type if exists `position`;
  CREATE TYPE `position` AS (f1 int, f2 text);
  select * from pg_type where typname =`position`;
  drop type `position`;