Re: Reduce heap tuple header size

From: Jan Wieck <JanWieck(at)Yahoo(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>, Manfred Koizar <mkoi-pg(at)aon(dot)at>, pgsql-patches(at)postgresql(dot)org
Subject: Re: Reduce heap tuple header size
Date: 2002-06-21 14:03:54
Message-ID: 3D13324A.1C126728@Yahoo.com
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Tom Lane wrote:
>
> Jan Wieck <JanWieck(at)Yahoo(dot)com> writes:
> > Do we have any hard numbers on that? Is it just access to the header
> > fields, or do we loose the offset cacheability of all fixed size fields
> > at the beginning of a row? In the latter case count me into the
> > slowness-believer camp.
>
> I don't believe the patch would have made the header variable size,
> only changed what the fixed size is. The slowdown I was worried about
> was just a matter of a couple extra tests and branches in the tqual.c
> routines; which would be negligible if they weren't such hotspots.

Did someone run at least pgbench with/without that patch applied?

Jan

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