From: Tom Lane <tgl@sss.pgh.pa.us>
To: Ehab Galal <ehabgalal123@hotmail.com>
Cc: pgsql-sql@postgresql.org <pgsql-sql@postgresql.org>
Subject: Re: materialize
Date: Mon, 26 Nov 2007 16:53:45 -0500
Message-ID: <4140.1196114025@sss.pgh.pa.us> (raw)
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<14450.1194194136@sss.pgh.pa.us>
<BAY138-W1297C42D3E676BE815771E96750@phx.gbl>
Ehab Galal <ehabgalal123@hotmail.com> writes:
> I was wondering why do we need the Materialize node in the plan below when i explain a query?
It's cheaper to scan a materialized rowset many times than a raw table
--- we don't need to re-access shared memory nor re-check row visibility.
regards, tom lane
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To: pgsql-sql@postgresql.org
Cc: tgl@sss.pgh.pa.us, ehabgalal123@hotmail.com
Subject: Re: materialize
In-Reply-To: <4140.1196114025@sss.pgh.pa.us>
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