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Re: DBT-3 Query 2 EXPLAIN ANALYZE differences

From: Josh Berkus <josh(at)agliodbs(dot)com>
To: pgsql-hackers(at)postgresql(dot)org
Cc: Mark Wong <markw(at)osdl(dot)org>
Subject: Re: DBT-3 Query 2 EXPLAIN ANALYZE differences
Date: 2004-10-26 23:39:46
Message-ID: 200410261639.46055.josh@agliodbs.com (view raw or flat)
Thread:
Lists: pgsql-hackers
Mark,

> The plans are different and I suspect thats where the differences lie.
> For brevity (and readability) I won't copy the plans here but I'll
> provide the links.  Search for 'PERF1.POWER.Q2' in the file, it's the
> second query executed and you'll notice the differences under the
> SubPlan:

Yeah, the difference seems to be an arbitrary choice of which table to join on 
first.    The error is only +10 ms, but when it's being executed 3000 
times ...

Will delve into this when I can re-format it, and try to figure out why the 
planner is choosing what it is.

-- 
--Josh

Josh Berkus
Aglio Database Solutions
San Francisco

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