From: Jim C. Nasby <jnasby@pervasive.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: PFC <lists@peufeu.com>
Cc: Mitchell Skinner <mitch@arctur.us>
Cc: pgsql-performance@postgresql.org
Cc: pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] Big IN() clauses etc : feature proposal
Date: Wed, 10 May 2006 14:00:11 -0500
Message-ID: <20060510190011.GO99570@pervasive.com> (raw)
In-Reply-To: <16680.1147201981@sss.pgh.pa.us>
References: <op.s89zl30wcigqcu@apollo13>
<20060509105214.P90693@vesihiisi.cksoft.de>
<op.s8916gm6cigqcu@apollo13>
<20060509113337.M90693@vesihiisi.cksoft.de>
<op.s893vzcpcigqcu@apollo13>
<20060509103632.GD29652@svana.org>
<op.s897j60qcigqcu@apollo13>
<1147190285.32304.43.camel@firebolt>
<op.s9alu1vhcigqcu@apollo13>
<16680.1147201981@sss.pgh.pa.us>
On Tue, May 09, 2006 at 03:13:01PM -0400, Tom Lane wrote:
> PFC <lists@peufeu.com> writes:
> > Fun thing is, the rowcount from a temp table (which is the problem here)
> > should be available without ANALYZE ; as the temp table is not concurrent,
> > it would be simple to inc/decrement a counter on INSERT/DELETE...
>
> No, because MVCC rules still apply.
But can anything ever see more than one version of what's in the table?
Even if you rollback you should still be able to just update a row
counter because nothing else would be able to see what was rolled back.
Speaking of which, if a temp table is defined as ON COMMIT DROP or
DELETE ROWS, there shouldn't be any need to store xmin/xmax, only
cmin/cmax, correct?
--
Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: jnasby@pervasive.com, tgl@sss.pgh.pa.us, lists@peufeu.com, mitch@arctur.us, pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] Big IN() clauses etc : feature proposal
In-Reply-To: <20060510190011.GO99570@pervasive.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox