From: | mark(at)mark(dot)mielke(dot)cc |
---|---|
To: | Ibrahim Tekin <itekin(at)gmail(dot)com> |
Cc: | pgsql-performance(at)postgresql(dot)org |
Subject: | Re: LIKE query on indexes |
Date: | 2006-02-21 17:40:48 |
Message-ID: | 20060221174048.GA8108@mark.mielke.cc |
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Lists: | pgsql-performance |
On Tue, Feb 21, 2006 at 05:57:12PM +0200, Ibrahim Tekin wrote:
> i have btree index on a text type field. i want see rows which starts with
> certain characters on that field. so i write a query like this:
> SELECT * FROM mytable WHERE myfield LIKE 'john%'
> since this condition is from start of the field, query planner should use
> index to find such elements but explain command shows me it will do a
> sequential scan.
> is this lack of a feature or i am wrong somewhere?
Is the query fast enough? How big is your table? What does explain
analyze select tell you?
Cheers,
mark
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