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