pg.ddx.io  pgsql-hackers@postgresql.org mailing list archive  

help / color / mirror / Atom feed

From: Robert Treat <xzilla@users.sourceforge.net>
To: pgsql-docs@postgresql.org
Cc: Neil Conway <neilc@samurai.com>
Cc: Guillaume Lelarge <guillaume@lelarge.info>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Subject: Re: row-level stats and last analyze time
Date: Tue, 24 Apr 2007 22:07:10 -0400
Message-ID: <200704242207.11093.xzilla@users.sourceforge.net> (raw)
In-Reply-To: <1177450739.16415.249.camel@localhost.localdomain>
References: <462B6CEB.4010109@lelarge.info>
	<1177450739.16415.249.camel@localhost.localdomain>

On Tuesday 24 April 2007 17:38, Neil Conway wrote:
> [ CC'ing -hackers ]
>
> On Sun, 2007-04-22 at 16:10 +0200, Guillaume Lelarge wrote:
> > This patch adds a sentence on monitoring.sgml explaining that
> > stats_row_level needs to be enabled if user wants to get last
> > vacuum/analyze execution time.
>
> This behavior was introduced in r1.120 of postmaster/pgstat.c:
>
>     Modify pgstats code to reduce performance penalties from
>     oversized stats data files: avoid creating stats
>     hashtable entries for tables that aren't being touched
>     except by vacuum/analyze [...]
>
> which included other modifications to reduce the pgstat I/O volume in
> 8.1. I don't think this particular change was wise: the reduction in
> pgstat volume is pretty marginal, and it is counter-intuitive for
> stats_row_level to effect whether the last ANALYZE / VACUUM is recorded.
> (Plus, the optimization is not even enabled with the default
> postgresql.conf settings.)
>

+1

-- 
Robert Treat
Build A Brighter LAMP :: Linux Apache {middleware} PostgreSQL

view thread (7+ messages)  latest in thread

Message-ID: <200704242207.11093.xzilla@users.sourceforge.net>
Permalink:  ../200704242207.11093.xzilla@users.sourceforge.net/
Also on:    postgresql.org/message-id/200704242207.11093.xzilla@users.sourceforge.net

copy link · copy postgr.es

reply

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-hackers@postgresql.org
  Cc: xzilla@users.sourceforge.net, pgsql-docs@postgresql.org, neilc@samurai.com, guillaume@lelarge.info, tgl@sss.pgh.pa.us
  Subject: Re: row-level stats and last analyze time
  In-Reply-To: <200704242207.11093.xzilla@users.sourceforge.net>

* 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