Re: [COMMITTERS] pgsql: Fix TransactionIdIsCurrentTransactionId() to use binary search

From: Robert Treat <xzilla(at)users(dot)sourceforge(dot)net>
To: pgsql-hackers(at)postgresql(dot)org
Cc: Tom Lane <tgl(at)postgresql(dot)org>
Subject: Re: [COMMITTERS] pgsql: Fix TransactionIdIsCurrentTransactionId() to use binary search
Date: 2008-03-27 20:56:45
Message-ID: 200803271656.45574.xzilla@users.sourceforge.net
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On Sunday 16 March 2008 22:18, Tom Lane wrote:
> Log Message:
> -----------
> Fix TransactionIdIsCurrentTransactionId() to use binary search instead of
> linear search when checking child-transaction XIDs. This makes for an
> important speedup in transactions that have large numbers of children,
> as in a recent example from Craig Ringer. We can also get rid of an
> ugly kluge that represented lists of TransactionIds as lists of OIDs.
>

Are there any plans to backpatch this into REL8_3_STABLE? It looks like I am
hitting a pretty serious performance regression on 8.3 with a stored
procedure that grabs a pretty big recordset, and loops through doing
insert....update on unique failures. The procedure get progressivly slower
the more records involved... and dbx shows me stuck in
TransactionIdIsCurrentTransactionId(). I can provide provide more details if
needed (lmk what your looking for) but it certainly looks like the issue
discussed here:
http://archives.postgresql.org/pgsql-performance/2008-03/msg00191.php

--
Robert Treat
Build A Brighter LAMP :: Linux Apache {middleware} PostgreSQL

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