| From: | Kovacs Zoltan <kovacsz(at)pc10(dot)radnoti-szeged(dot)sulinet(dot)hu> |
|---|---|
| To: | Zeugswetter Andreas SB SD <ZeugswetterA(at)spardat(dot)at> |
| Cc: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: slow UNIONing |
| Date: | 2001-09-21 06:50:57 |
| Message-ID: | Pine.LNX.4.21.0109210850090.8015-100000@pc10.radnoti-szeged.sulinet.hu |
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| Lists: | pgsql-hackers |
> > For me it seems to be slow due to the sorting. Is this right?
> > Is this normal at all? Is it possible to make it faster?
>
> If you know, that your result does not produce duplicates
> (which are filtered away with "union") you can use a
> "union all" which should be substantially faster, since it does
> not need to sort.
Thank you to all who helped. I knew nothing about UNION ALL, but now it's
OK. Regards, Zoltan
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