From: Tom Lane <tgl@sss.pgh.pa.us>
To: Josh Berkus <josh@agliodbs.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Issue for partitioning with extra check constriants
Date: Fri, 01 Oct 2010 19:56:17 -0400
Message-ID: <1548.1285977377@sss.pgh.pa.us> (raw)
In-Reply-To: <4CA672D7.3070405@agliodbs.com>
References: <4CA672D7.3070405@agliodbs.com>
Josh Berkus <josh@agliodbs.com> writes:
> The issue is this: when a partitioned table is evaluated by the planner
> for constraint exclusion, it evaluates ALL check constraints on each
> partition, regardless of whether or not they include a referenced column
> in the query (and whether or not they relate to partitioning).
[ shrug ... ] We do not promise that the current partitioning scheme
scales to the number of partitions where this is likely to be an
interesting concern.
*After* we have a real partitioning scheme, it might be worth worrying
about this sort of problem, if it's still a problem then.
> Are we talking "moderate", "hard" or "nearly impossible"?
We're talking "wasted effort on a dead-end situation". The time that
would go into this would be much better spent on real partitioning.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, josh@agliodbs.com
Subject: Re: Issue for partitioning with extra check constriants
In-Reply-To: <1548.1285977377@sss.pgh.pa.us>
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