Subject: Re: WIP: Transportable Optimizer Mode
From: Simon Riggs <simon@2ndquadrant.com>
To: chris <cbbrowne@ca.afilias.info>
Cc: pgsql-patches@postgresql.org
In-Reply-To: <1217704370.3934.132.camel@ebony.t-mobile.de.>
References: <1217023107.3894.1053.camel@ebony.2ndQuadrant>
	<87myjzp5as.fsf@dba2.int.libertyrms.com>
	<1217704370.3934.132.camel@ebony.t-mobile.de.>
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Date: Wed, 06 Aug 2008 23:32:02 +0100
Message-Id: <1218061922.4549.296.camel@ebony.2ndQuadrant>
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On Sat, 2008-08-02 at 20:12 +0100, Simon Riggs wrote:
> Chris,
> 
> Thanks for all of those changes... added as suggested (in next version)
> 
> On Wed, 2008-07-30 at 14:58 -0400, chris wrote:
> 
> > It's not clear to me that the plugin is actually working.
> > 
> > When I run EXPLAIN against tables in "tomtestdb", I get results
> > consistent with an unanalyzed table.  So possibly the "hook" isn't
> > being used.  Perhaps I'm using it wrongly; perhaps what I have
> > documented above may suggest to you what's broken.
> 
> The plugin works, but it currently extracts 0 for number of tuples. So
> you need to override that to give a different answer.
> 
> I was going to add an SQL function to estimate the number of tuples in
> the same way as the optimizer does. That way we get the same answer from
> the EXPLAIN as we would have got on the main server and we don't need to
> run select count(*) against each table (unless we want to).

New version submitted together with stats hook patch on other thread.

-- 
 Simon Riggs           www.2ndQuadrant.com
 PostgreSQL Training, Services and Support