Skip site navigation (1) Skip section navigation (2)

Re: Hot standby and b-tree killed items

From: Simon Riggs <simon(at)2ndQuadrant(dot)com>
To: Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
Cc: Greg Stark <greg(dot)stark(at)enterprisedb(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Hot standby and b-tree killed items
Date: 2008-12-31 10:12:40
Message-ID: 1230718360.4032.39.camel@ebony.2ndQuadrant (view raw or flat)
Thread:
Lists: pgsql-hackers
On Tue, 2008-12-30 at 18:31 +0200, Heikki Linnakangas wrote:
> Simon Riggs wrote:
> > (a) always ignore LP_DEAD flags we see when reading index during
> > recovery.
> 
> This sounds simplest, and it's nice to not clear the flags for the 
> benefit of transactions running after the recovery is done.

Agreed.

(Also: Transaction hint bits are always set correctly, because we would
only ever see a full page write with hints set after the commit/abort
record was processed. So I continue to honour transaction hint bit
reading and setting during recovery).

> You have to be careful to ignore the flags in read-only transactions 
> that started in hot standby mode, even if recovery has since ended and 
> we're in normal operation now.

Got that.

I'm setting ignore_killed_tuples = false at the start of any index scan
during recovery. And kill_prior_tuples is never set true when in
recovery. Both measures are AM-agnostic.

-- 
 Simon Riggs           www.2ndQuadrant.com
 PostgreSQL Training, Services and Support


In response to

pgsql-hackers by date

Next:From: Oleksiy ShchukinDate: 2008-12-31 10:14:58
Subject: BUG #4599: bugfix for contrib/dblink module
Previous:From: Laurent CoustetDate: 2008-12-31 09:30:45
Subject: Re: parallel restore

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group