From: | "Michael Ryan S(dot) Puncia" <mpuncia(at)census(dot)gov(dot)ph> |
---|---|
To: | <pgsql-performance(at)postgresql(dot)org> |
Subject: | Re: best practices with index on varchar column |
Date: | 2005-03-23 04:11:56 |
Message-ID: | 200503230402.j2N42ax1022249@mail.census.gov.ph |
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Thread: | |
Lists: | pgsql-performance |
I have an experience using LIKE in a VARCHAR column and select statement
suffers a lot so I decided to go back in CHAR
Note: my database has about 50 millions records a b tree index
> Can I use an index on a varchar column to optimize the SELECT queries
> that
> use " column LIKE 'header%' "?
Yes
> If yes what is the best tree algotithm to use ?
Btree
Note that if you want case insensitive matching you need to make an
index
on lower(column) and SELECT WHERE lower(column) LIKE 'header%'
Locales may bite you.
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