From: Tom Lane <tgl@sss.pgh.pa.us>
To: Thom Brown <thom@linux.com>
Cc: pgsql-performance <pgsql-performance@postgresql.org>
Subject: Re: Partial index slower than regular index
Date: Wed, 06 Apr 2011 00:44:22 -0400
Message-ID: <4331.1302065062@sss.pgh.pa.us> (raw)
In-Reply-To: <BANLkTimFZjYve4GDOXQJ6VjRO1pOQEwp4w@mail.gmail.com>
References: <BANLkTimFZjYve4GDOXQJ6VjRO1pOQEwp4w@mail.gmail.com>
Thom Brown <thom@linux.com> writes:
> The index doesn't get used. There's probably a logical explanation,
> which is what I'm curious about.
Er ... it's broken?
It looks like the index predicate expression isn't getting the right
collation assigned, so predtest.c decides the query doesn't imply the
index's predicate. Too tired to look into exactly why right now, but
it's clearly bound up in all the recent collation changes.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, thom@linux.com
Subject: Re: Partial index slower than regular index
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