Re: index scan with functional indexes -- solved

From: Dave Cramer <pg(at)fastcrypt(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, "Marc G(dot) Fournier" <scrappy(at)hub(dot)org>
Cc: "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: index scan with functional indexes -- solved
Date: 2004-01-27 19:09:13
Message-ID: 1075230553.21166.311.camel@localhost.localdomain
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Interesting it works now, and the good news is it is *WAY* faster, this
might be able to speed up marc's doc search by orders of magnitude

this is searching 100536 rows

select * from url where fn_strrev(url) like fn_strrev('%beta12.html');
1.57ms

explain select * from url where url like '%beta12.html';
3310.38 ms

Dave

On Tue, 2004-01-27 at 13:48, Tom Lane wrote:
> Dave Cramer <pg(at)fastcrypt(dot)com> writes:
> > I'm using 7.4.1, the db was initdb --locale='C'
> > and no I don't get them on plain indexes ????
>
> Oh? If it's 7.4 then you can confirm the locale selection with
> "show lc_collate" and "show lc_ctype" (I think the first of these
> is what the LIKE optimization checks).
>
> regards, tom lane
>
--
Dave Cramer
519 939 0336
ICQ # 1467551

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