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Re: plan time of MASSIVE partitioning ...

From: Boszormenyi Zoltan <zb(at)cybertec(dot)at>
To: Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Alvaro Herrera <alvherre(at)commandprompt(dot)com>, Stephen Frost <sfrost(at)snowman(dot)net>, Hans-Jürgen Schönig <postgres(at)cybertec(dot)at>, Robert Haas <robertmhaas(at)gmail(dot)com>, pgsql-hackers Hackers <pgsql-hackers(at)postgresql(dot)org>, Josh Berkus <josh(at)agliodbs(dot)com>
Subject: Re: plan time of MASSIVE partitioning ...
Date: 2010-10-28 09:33:22
Message-ID: 4CC94362.1000402@cybertec.at (view raw or flat)
Thread:
Lists: pgsql-hackers
Heikki Linnakangas írta:
> On 26.10.2010 18:34, Boszormenyi Zoltan wrote:
>> thank you very much for pointing me to dynahash, here is the
>> next version that finally seems to work.
>>
>> Two patches are attached, the first is the absolute minimum for
>> making it work, this still has the Tree type for canon_pathkeys
>> and eq_classes got the same treatment as join_rel_list/join_rel_hash
>> has in the current sources: if the list grows larger than 32, a hash
>> table
>> is created. It seems to be be enough for doing in for
>>       get_eclass_for_sort_expr()
>> only, the other users of eq_classes aren't bothered by this change.
>
> That's better, but can't you use dynahash for canon_pathkeys as well?

Here's a purely dynahash solution. It's somewhat slower than
the tree version, 0.45 vs 0.41 seconds in the cached case for the
previously posted test case.

Best regards,
Zoltán Böszörményi

-- 
----------------------------------
Zoltán Böszörményi
Cybertec Schönig & Schönig GmbH
Gröhrmühlgasse 26
A-2700 Wiener Neustadt, Austria
Web: http://www.postgresql-support.de
     http://www.postgresql.at/


Attachment: 9.1-planner-speedup-v6.patch
Description: text/x-patch (15.5 KB)

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