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Re: OOM Errors as a result of table inheritance and a bad plan(?)

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Arctic Toucan <arctic_toucan(at)hotmail(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: OOM Errors as a result of table inheritance and a bad plan(?)
Date: 2007-09-28 20:56:49
Message-ID: 19037.1191013009@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-performance
Arctic Toucan <arctic_toucan(at)hotmail(dot)com> writes:
> -- Is there something magical about the hash aggregate estimate of 200 rows?

Yeah, it's the default :-(

> Is this a bug, or some subtlety of the Postgres query planner?

It's an, um, known deficiency --- the planner hasn't got any idea how to
construct aggregated statistics for an inheritance tree.

			regards, tom lane

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