From: Tom Lane <tgl@sss.pgh.pa.us>
To: henk de wit <henk53602@hotmail.com>
Cc: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: How to speed up min/max(id) in 50M rows table?
Date: Fri, 12 Oct 2007 18:51:03 -0400
Message-ID: <6275.1192229463@sss.pgh.pa.us> (raw)
In-Reply-To: <BAY124-W124912A351A1628891721FF5A00@phx.gbl>
References: <BAY124-W503931258D0AE13AF37546F5A00@phx.gbl>
<5754.1192226626@sss.pgh.pa.us>
<BAY124-W124912A351A1628891721FF5A00@phx.gbl>
henk de wit <henk53602@hotmail.com> writes:
> I see, that sounds very interesting too. As you might have noticed, I'm not=
> an expert on this field but I'm trying to learn. I was under the impressio=
> n that the last few incarnations of postgresql automatically combined singl=
> e column indexes for cases where a multi-column index would be needed in ea=
> rlier releases.
It's possible to combine independent indexes for resolving AND-type
queries, but the combination process does not preserve ordering, so
it's useless for this type of situation.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, henk53602@hotmail.com
Subject: Re: How to speed up min/max(id) in 50M rows table?
In-Reply-To: <6275.1192229463@sss.pgh.pa.us>
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