From: | Alexander Jerusalem <alexander(dot)jerusalem(at)pop(dot)chello(dot)at> |
---|---|
To: | adb <adb(at)Beast(dot)COM> |
Cc: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: LIKE and indexes? |
Date: | 2001-03-15 01:39:27 |
Message-ID: | 4.3.2.7.0.20010315023628.00cf9100@pop.chello.at |
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Thread: | |
Lists: | pgsql-general |
Thanks for your answer, Alex!
I've done an EXPLAIN and I saw that no index was used although my SQL
statement had a wild card only at the end as you pointed out ('blah%'). My
guess is that this is because of the locale support.
Regards,
Alexander Jerusalem
At 01:22 15.03.01, adb wrote:
>When in doubt, try the explain command
>
>Not exactly sure about postgres but in general LIKE can
>only use an index in the case of LIKE "Something%"
>
>LIKE "%Something" or LIKE "%Something%"
>won't use an index since it would have to scan the entire
>index to find all matches.
>
>Alex.
>
>
>
>On Wed, 14 Mar 2001, Alexander Jerusalem wrote:
>
> > Hi,
> >
> > Can anyone telle me if and when a LIKE query uses an index? I've compiled
> > postgres with locale support. Does that have any influence indexes?
> >
> > thanks,
> >
> > Alexander Jerusalem
> >
> >
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