Message-ID: <51717928.2010602@ca.afilias.info>
Date: Fri, 19 Apr 2013 13:04:40 -0400
From: Steve Singer <ssinger@ca.afilias.info>
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To: Jeff Janes <jeff.janes@gmail.com>
CC: "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Subject: Re: slow bitmap heap scans on pg 9.2
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On 13-04-14 08:06 PM, Steve Singer wrote:
> On 13-04-13 04:54 PM, Jeff Janes wrote:

>>
>> If you are trying to make your own private copy of 9.2, then removing
>> the fudge factor altogether is probably the way to go.  But if you want
>> to help improve future versions, you probably need to test with the most
>> up-to-date dev version.
>
> I will do that in a few days.  I don't have enough disk space on this
> dev server to have a 9.2 datadir and a 9.3 one for this database.  Once
> I have a solution that I can use with 9.2 firmed up I can upgrade the
> datadir to 9.3 and test this.  I am hoping I can get a set of partial
> indexes that will give good results with an unmodified 9.2, so far that
> looks promising but I still have more cases to verify (these indexes
> take a while to build).
>

I've run these queries against a recent master/9.3 and the planner is 
picking the nested-loop plan for using the full index. This is with 
random_page_cost=2.


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