Ref

• Is it possible to define global variables in postgresql - Stack Overflow

함수 선언

drop function if exists glb;
create function glb(val text)
returns text language sql as $$
    select current_setting('glb.' || val)::text;
$$;

변수 저장

SET glb.myVar = 'val';

변수 불러오기

SHOW glb.myVar;
SELECT glb('myVar');