Re: select where id=random()*something returns two results
Ulrich Meis <u.meis@gmx.de>
From: Ulrich Meis <u.meis@gmx.de>
To:
Cc: pgsql-bugs@postgresql.org
Date: 2003-09-21T12:21:20Z
Lists: pgsql-bugs
> -----Original Message----- > From: pgsql-bugs-owner@postgresql.org [mailto:pgsql-bugs- > owner@postgresql.org] On Behalf Of Jean-Luc Lachance > Sent: Friday, September 19, 2003 4:44 PM > To: Rod Taylor > Cc: Ulrich Meis; pgsql-bugs@postgresql.org > Subject: Re: [BUGS] select where id=random()*something returns two results > > Rod, > > If the table has 100,000 tupples your query is generating 100,000 new > tupples... > Try: > > select * from quotes where id = ( > select int8( 1 + random() * ( > select id from quotes order by id desc limit 1))); > How about select * from quotes where id=1+int8((select random())*(select max(id) from quotes)); It works, but is it more or less efficient?