From: daveg <daveg@sonic.net>
To: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Cc: Greg Stark <gsstark@mit.edu>
Subject: Re: Re: PD_ALL_VISIBLE flag was incorrectly set happend during repeatable vacuum
Date: Tue, 8 Mar 2011 00:49:56 -0800
Message-ID: <20110308084956.GE21941@sonic.net> (raw)
In-Reply-To: <4D75EAC4.7090008@enterprisedb.com>
References: <AANLkTi=xq4SV6jwA7txvrbEWocyeiU6XiTG=-zVy+7Dq@mail.gmail.com>
<AANLkTi=Ye7AoF7_uVQfPVn-ok2VOp65mi0xU3H7kCke3@mail.gmail.com>
<20110303071208.GA4053@sonic.net>
<4D6F4E5D.6080507@enterprisedb.com>
<20110304090031.GE4053@sonic.net>
<4D710ABD.5090103@enterprisedb.com>
<20110307235340.GA21941@sonic.net>
<AANLkTi=54GF1MJN3FSXL2gr9xG_aB09y_taT8daUwz4Z@mail.gmail.com>
<4D75E201.20402@enterprisedb.com>
<4D75EAC4.7090008@enterprisedb.com>
On Tue, Mar 08, 2011 at 10:37:24AM +0200, Heikki Linnakangas wrote:
> On 08.03.2011 10:00, Heikki Linnakangas wrote:
> >Another idea is to give up on the warning when it appears that
> >oldestxmin has moved backwards, and assume that it's actually fine. We
> >could still warn in other cases where the flag appears to be incorrectly
> >set, like if there is a deleted tuple on the page.
>
> This is probably a better idea at least in back-branches. It also
> handles the case of twiddling vacuum_defer_cleanup_age, which tracking
> two xmins per transactions would not handle.
>
> Here's a patch. I also changed the warning per Robert's suggestion.
> Anyone see a hole in this?
It would be helpful to have the dbname and schema in the message in addition
to the relname. I added those to the original diagnostic patch as it was not
clear that the messages were all related to the same page/table/dg.
Also, in your comment you might mention that multiple databases are one way
we could see oldestxmin move backwards.
-dg
--
David Gould daveg@sonic.net 510 536 1443 510 282 0869
If simplicity worked, the world would be overrun with insects.
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-admin@postgresql.org
Cc: daveg@sonic.net, heikki.linnakangas@enterprisedb.com, pgsql-hackers@postgresql.org, gsstark@mit.edu
Subject: Re: Re: PD_ALL_VISIBLE flag was incorrectly set happend during repeatable vacuum
In-Reply-To: <20110308084956.GE21941@sonic.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