kingbase alter_sys_guid函数

create or replace function pg_catalog.alter_sys_guid() returns void as
declare
return_type text;
stmt text;
begin
select setting into return_type from pg_catalog.pg_settings where name = 'guid_default_return_type';
if lower(return_type) = 'bytea' then
stmt = 'DROP FUNCTION IF EXISTS pg_catalog.sys_guid(); CREATE OR REPLACE FUNCTION pg_catalog.sys_guid() RETURNS BYTEA AS $$SELECT pg_catalog.sys_guid_bytea()$$ LANGUAGE sql;';
else
stmt = 'DROP FUNCTION IF EXISTS pg_catalog.sys_guid(); CREATE OR REPLACE FUNCTION pg_catalog.sys_guid() RETURNS NAME AS $$SELECT pg_catalog.sys_guid_name()$$ LANGUAGE sql;';
end if;
execute stmt;
return;
end;