Re: immutable functions vs. join for lookups ?

* Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Enrico Weigelt <weigelt(at)metux(dot)de> writes:
> > c) CREATE FUNCTION id2username(oid) RETURNS text
> > LANGUAGE 'SQL' IMMUTABLE AS '
> > SELECT username AS RESULT FROM users WHERE uid = $1';
>
> This is simply dangerous. The function is *NOT* immutable (it is
> stable though). When ... not if ... your application breaks because
> you got the wrong answers, you'll get no sympathy from anyone.

In my case it is immutable. The username never changes.

cu
--
---------------------------------------------------------------------
Enrico Weigelt == metux IT service

phone: +49 36207 519931 www: http://www.metux.de/
fax: +49 36207 519932 email: contact(at)metux(dot)de
cellphone: +49 174 7066481
---------------------------------------------------------------------
-- DSL ab 0 Euro. -- statische IP -- UUCP -- Hosting -- Webshops --
---------------------------------------------------------------------