Re: postmaster consuming /lots/ of memory with hash aggregate. why?

From: Jon Nelson <jnelson+pgsql(at)jamponi(dot)net>
To:
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: postmaster consuming /lots/ of memory with hash aggregate. why?
Date: 2010-11-12 04:33:06
Message-ID: AANLkTim6CnN1ubjnuRahV3p-UBaMUzD5nMWtQQ3batCE@mail.gmail.com
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On Thu, Nov 11, 2010 at 10:26 PM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> wrote:
> Hello
>
> look on EXPLAIN ANALYZE command. Probably your statistic are out, and
> then planner can be confused. EXPLAIN ANALYZE statement show it.

As I noted earlier, I did set statistics to 1000 an re-ran vacuum
analyze and the plan did not change.

What other diagnostics can I provide? This still doesn't answer the
40000 row question, though. It seems absurd to me that the planner
would give up and just use 40000 rows (0.02 percent of the actual
result).

--
Jon

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