Re: Docs off on ILIKE indexing?

From: "Magnus Hagander" <mha(at)sollentuna(dot)net>
To: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: "pgsql-hackers" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Docs off on ILIKE indexing?
Date: 2006-01-17 14:44:30
Message-ID: 6BCB9D8A16AC4241919521715F4D8BCE6C7EB6@algol.sollentuna.se
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> > http://www.postgresql.org/docs/8.1/static/indexes-types.html
> > says:
> > The optimizer can also use a B-tree index for queries involving the
> > pattern matching operators LIKE, ILIKE, ~, and ~*, if the
> pattern is a
> > constant and is anchored to the beginning of the string -
> for example,
> > col LIKE 'foo%' or col ~ '^foo', but not col LIKE '%bar'.
>
> > But really, does it use indexes for ILIKE?
>
> That's pretty poorly phrased. For ILIKE it'll only work if
> there's a prefix of the pattern that's not letters (and hence
> is unaffected by the case-folding issue).

Ahh. That explains it. Perfectly logical.
And yes, that's pretty poorly phrased - at least I didn't understand it
:-)

//Magnus

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