From: Simon Riggs <simon@2ndQuadrant.com>
To: Xiao Meng <mx.cogito@gmail.com>
Cc: pgsql-patches@postgresql.org, "Jonah H. Harris" <jonah.harris@gmail.com>
Subject: Re: hash index improving v3
Date: Thu, 04 Sep 2008 03:06:42 +0100
Message-ID: <1220494002.4371.813.camel@ebony.2ndQuadrant> (raw)
In-Reply-To: <ded849dd0808171846g2c6c65adub942bd2510a6c94f@mail.gmail.com>
References: <ded849dd0808171846g2c6c65adub942bd2510a6c94f@mail.gmail.com>
On Mon, 2008-08-18 at 09:46 +0800, Xiao Meng wrote:
> There's minor change against the previous
> one( http://archives.postgresql.org/pgsql-hackers/2008-07/msg01183.php ).
> * merge branch master(Aug 16) into the patch
> * clean code and make some comment
> Performance result is here
> http://wiki.postgresql.org/wiki/Gsoc08-hashindex
>
> It seems hash index is a little better on index creation and
> selection.
> But maybe it's in the range of noise, I'm not sure.
> I'd like to try it with a bigger dataset (e.g. table with 10GB) but
> there is not enough space in my computer.
> Anyone interest can make a test on a bigger data set.
You don't give the text of the query used to do these performance tests,
so I can't validate your test results.
Right now it seems strange that the index is larger than a btree, yet
the performance tests show that 3 times as much I/O was used accessing
the btree.
--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Training, Services and Support
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To: pgsql-patches@postgresql.org
Cc: simon@2ndQuadrant.com, mx.cogito@gmail.com, jonah.harris@gmail.com
Subject: Re: hash index improving v3
In-Reply-To: <1220494002.4371.813.camel@ebony.2ndQuadrant>
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