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List:       pgsql-performance
Subject:    Re: [PERFORM] efficient pattern queries (using LIKE, ~)
From:       Mario Weilguni <mweilguni () sime ! com>
Date:       2007-09-11 19:08:37
Message-ID: 46E6E7B5.8000807 () sime ! com
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Fernan Aguero schrieb:
> Hi,
> 
> I have a table containing some ~13 million rows. Queries on
> indexed fields run fast, but unanchored pattern queries on a
> text column are slooooow. Indexing the column doesn't help
> (this is already mentioned in the manual).
> http://www.postgresql.org/docs/8.2/interactive/indexes-types.html
> 
> However, no alternative solution is mentioned for indexing
> and/or optimizing queries based on unanchored patterns: 
> i.e. description LIKE '%kinase%'.

Maybe trigram search might help you? Never tried it myself, but it seems 
to be able to handle substring searches.


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