Re: Index oddity

From: Christopher Kings-Lynne <chriskl(at)familyhealth(dot)com(dot)au>
To: ken <southerland(at)samsixedd(dot)com>
Cc: Postgresql Performance <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Index oddity
Date: 2004-06-10 01:45:14
Message-ID: 40C7BD2A.70604@familyhealth.com.au
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> If I take away the diagonalSize condition in my query I find that there
> are 225 rows that satisfy the other conditions. 155 of these have a
> diagonalSize value of exactly 50.000, while the remaining 70 rows all
> have values larger than 50. Thus there is a big discrete jump in the
> number of rows at a diagonalSize of 50. However, the statistics are off
> by two orders of magnitude in guessing how many rows there are going to
> be in this case and thus is not using my index. How can I fix that?

Maybe you should drop your random_page_cost to something less than 4,
eg. 3 or even 2...

Chris

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