From: Stephan Szabo <sszabo@megazone.bigpanda.com>
To: Andrea Arcangeli <andrea@cpushare.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-performance@postgresql.org
Subject: Re: NOT LIKE much faster than LIKE?
Date: Mon, 9 Jan 2006 18:54:57 -0800 (PST)
Message-ID: <20060109185355.S36990@megazone.bigpanda.com> (raw)
In-Reply-To: <20060110022303.GA20168@opteron.random>
References: <20060110014447.GB18474@opteron.random>
<24021.1136858688@sss.pgh.pa.us>
<20060110022303.GA20168@opteron.random>
On Tue, 10 Jan 2006, Andrea Arcangeli wrote:
> I see. I can certainly fix it by stopping using LIKE. But IMHO this
> remains a bug, since until the statistics about the numberof matching
> rows isn't estimated well, you should not make assumptions on LIKE/NOT
> LIKE. I think you can change the code in a way that I won't have to
> touch anything, and this will lead to fewer surprises in the future IMHO.
I doubt it, since I would expect that this would be as large a
pessimization for a larger fraction of people than it is an optimization
for you.
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To: pgsql-performance@postgresql.org
Cc: sszabo@megazone.bigpanda.com, andrea@cpushare.com, tgl@sss.pgh.pa.us
Subject: Re: NOT LIKE much faster than LIKE?
In-Reply-To: <20060109185355.S36990@megazone.bigpanda.com>
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