Re: Very slow queries w/ NOT IN preparation (seems like a bug, test case)

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Richard Huxton <dev(at)archonet(dot)com>
Cc: Sergey Konoplev <gray(dot)ru(at)gmail(dot)com>, pgsql-general(at)postgreSQL(dot)org
Subject: Re: Very slow queries w/ NOT IN preparation (seems like a bug, test case)
Date: 2008-11-11 13:22:36
Message-ID: 14698.1226409756@sss.pgh.pa.us
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Richard Huxton <dev(at)archonet(dot)com> writes:
> I've never heard of EXPLAIN ANALYSE being *faster* than the actual
> query, it's usually slower due to all the timing calls. The only thing
> it doesn't do is actually send the results over the connection to the
> client. In your case, you're not actually selecting any columns, so that
> can't be it.

If I'm reading it right the query returns 5000 instances of "1". So
there's definitely scope for the client side to pose a performance
issue.

regards, tom lane

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