From: Andrew Sullivan <ajs@crankycanuck.ca>
To: pgsql-sql@postgresql.org
Subject: Re: best index for ~ ordering?
Date: Tue, 6 Mar 2007 17:28:02 -0500
Message-ID: <20070306222802.GA16606@phlogiston.dyndns.org> (raw)
In-Reply-To: <45EDDE5F.2030303@fmed.uba.ar>
References: <45EDDE5F.2030303@fmed.uba.ar>
On Tue, Mar 06, 2007 at 06:34:23PM -0300, Gerardo Herzig wrote:
> Hi all, i have a large table with one varchar field, and im triyng to
> get information about what index should i use in order to using that
> index (if this is possible) for ~ searching, and/or using LIKE searching.
What sort of match are you doing? If you're doing left-anchored
searches (LIKE 'blah%') then your standard btree is good. If you're
doing unanchored searches (LIKE '%blah%' or similar) you're best doing
tsearch. If it's right-anchored, you can do an index on the reverse
of the string.
A
--
Andrew Sullivan | ajs@crankycanuck.ca
Unfortunately reformatting the Internet is a little more painful
than reformatting your hard drive when it gets out of whack.
--Scott Morris
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To: pgsql-sql@postgresql.org
Cc: ajs@crankycanuck.ca
Subject: Re: best index for ~ ordering?
In-Reply-To: <20070306222802.GA16606@phlogiston.dyndns.org>
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