Re: [GENERAL] Performance of full outer join in 8.3

From: Hannu Krosing <hannu(at)2ndQuadrant(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Simon Riggs <simon(at)2ndQuadrant(dot)com>, Christian Schröder <cs(at)deriva(dot)de>, pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: [GENERAL] Performance of full outer join in 8.3
Date: 2009-04-18 10:50:50
Message-ID: 1240051850.7401.7.camel@huvostro
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On Wed, 2009-04-15 at 18:04 -0400, Tom Lane wrote:
> Simon Riggs <simon(at)2ndQuadrant(dot)com> writes:
> > I've always been scared to ask this question, in case the answer is No,
> > but: Do we have a set of regression tests for the optimizer anywhere?
>
> Nothing beyond what is in the standard tests. While that's okay at
> catching wrong answers --- and we have memorialized a number of such
> issues in the tests --- the framework is not good for catching things
> that run slower than they ought.

Can't we make first cut at it by just running with timings on and then
compare ratios of running times - maybe with 2-3X tolerance - to catch
most obvious regressions ?

> regards, tom lane

--
Hannu Krosing http://www.2ndQuadrant.com
PostgreSQL Scalability and Availability
Services, Consulting and Training

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