Re: slow UNIONing

From: Peter Eisentraut <peter_e(at)gmx(dot)net>
To: Kovacs Zoltan <kovacsz(at)pc10(dot)radnoti-szeged(dot)sulinet(dot)hu>
Cc: <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: slow UNIONing
Date: 2001-09-19 10:22:19
Message-ID: Pine.LNX.4.30.0109191221210.1053-100000@peter.localdomain
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Kovacs Zoltan writes:

> I experienced that UNIONs in 7.1.1 are rather slow:
>
> tir=# explain (select nev from cikk) union (select tevekenyseg from log);

Try UNION ALL. Plain UNION will eliminate duplicates, so it becomes
slower.

--
Peter Eisentraut peter_e(at)gmx(dot)net http://funkturm.homeip.net/~peter

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Haller Christoph 2001-09-19 11:36:51 Where are the ERROR: Messages
Previous Message Zeugswetter Andreas SB SD 2001-09-19 07:15:52 Re: slow UNIONing