Re: optimizing LIKE '%2345' queries - Mailing list pgsql-performance

From Chris
Subject Re: optimizing LIKE '%2345' queries
Date
Msg-id 44AB0652.2080606@gmail.com
Whole thread Raw
In response to Re: optimizing LIKE '%2345' queries  (Gene <genekhart@gmail.com>)
List pgsql-performance
Gene wrote:
> Thanks for the suggestion. Actually I went ahead and created a reverse
> function using plpgsql, created an index using reverse column and now
> my queries use "where reverse(column) like reverse('%2345') and it's
> using the index like i hoped it would! Now if I could figure out how
> to optimize like  '%2345%' queries. I don't want to create many
> indexes though the table is very write heavy.

You can't because that text can be anywhere inside the database field,
so the whole field basically has to be checked to see if it's there.

You could check out full text indexing (tsearch2).

<shameless plug>
http://www.designmagick.com/article/27/PostgreSQL/Introduction-to-Full-Text-Indexing

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