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Re: Bug #474: Index using problem

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: joe78(at)freemail(dot)hu, pgsql-bugs(at)postgresql(dot)org
Subject: Re: Bug #474: Index using problem
Date: 2001-10-05 13:48:50
Message-ID: 6987.1002289730@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-bugs
pgsql-bugs(at)postgresql(dot)org writes:
>   explain select * from cim where utod_cim_id=0;
>   NOTICE:  QUERY PLAN:
>   Seq Scan on cim  (cost=0.00..6555.41 rows=253633 width=118)
  
>   The query optimizer does not use my index..

How many rows are there where utod_cim_id=0?  The planner guesses that
there are a lot (253633, to be exact) and concludes that using the index
is not profitable for this query.

			regards, tom lane

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