text: -- @testpoint: opengauss关键字symmetric(保留)，作为函数名,部分测试点合理报错
  
  --关键字不带引号-失败
  drop function if exists symmetric;
  create function symmetric(i integer)
  returns integer
  as $$
  begin
      return i+1;
  end;
  $$ language plpgsql;
  /
  
  --关键字带双引号-成功
  drop function if exists "symmetric";
  create function "symmetric"(i integer)
  returns integer
  as $$
  begin
      return i+1;
  end;
  $$ language plpgsql;
  /
  drop function "symmetric";
  
  --关键字带单引号-合理报错
  drop function if exists 'symmetric';
  create function 'symmetric'(i integer)
  returns integer
  as $$
  begin
      return i+1;
  end;
  $$ language plpgsql;
  /
  --关键字带反引号-合理报错
  drop function if exists `symmetric`;
  create function `symmetric`(i integer)
  returns integer
  as $$
  begin
      return i+1;
  end;
  $$ language plpgsql;
  /