From: Yeb Havinga <yebhavinga@gmail.com>
To: Kevin Grittner <Kevin.Grittner@wicourts.gov>
Cc: Greg Smith <greg@2ndquadrant.com>
Cc: Matthew Wakeling <matthew@flymine.org>
Cc: Eliot Gable <egable+pgsql-performance@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: B-Heaps
Date: Fri, 18 Jun 2010 22:18:41 +0200
Message-ID: <4C1BD4A1.4070406@gmail.com> (raw)
In-Reply-To: <4C1B783602000025000325CE@gw.wicourts.gov>
References: <AANLkTinsmWw4w2m2fyjord30seNfn7Ww1arKew5EttQG@mail.gmail.com>
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<AANLkTik-81bRcl1tle10YvsdY1F6MwF4SFZErKOZa5LA@mail.gmail.com>
<alpine.DEB.2.00.1006181722050.2534@aragorn.flymine.org>
<4C1BB294.8070806@2ndquadrant.com>
<4C1BBB39.10308@gmail.com>
<4C1B783602000025000325CE@gw.wicourts.gov>
Kevin Grittner wrote:
> Yeb Havinga <yebhavinga@gmail.com> wrote:
>
>
>> concerning gist indexes:
>>
>> 1) with larger block sizes and hence, larger # entries per gist
>> page, results in more generic keys of those pages. This in turn
>> results in a greater number of hits, when the index is queried, so
>> a larger part of the index is scanned. NB this has nothing to do
>> with caching / cache sizes; it holds for every IO model. Tests
>> performed by me showed performance improvements of over 200%.
>> Since then implementing a speedup has been on my 'want to do
>> list'.
>>
>
> As I recall, the better performance in your tests was with *smaller*
> GiST pages, right? (The above didn't seem entirely clear on that.)
>
Yes, making pages smaller made index scanning faster.
-- Yeb
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To: pgsql-performance@postgresql.org
Cc: yebhavinga@gmail.com, Kevin.Grittner@wicourts.gov, greg@2ndquadrant.com, matthew@flymine.org, egable+pgsql-performance@gmail.com, robertmhaas@gmail.com
Subject: Re: B-Heaps
In-Reply-To: <4C1BD4A1.4070406@gmail.com>
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