From: Andres Freund <af@cybertec.de>
To: pgsql-hackers@postgresql.org
Subject: Re: Small Bug in GetConflictingVirtualXIDs
Date: Sun, 27 Dec 2009 21:20:01 +0100
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Cc: Simon Riggs <simon@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>,
	Alvaro Herrera <alvherre@commandprompt.com>
References: <200912210402.37850.andres@anarazel.de>
	<200912272011.27003.af@cybertec.de>
	<1261944283.18116.24.camel@ebony>
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Message-Id: <200912272120.02171.af@cybertec.de>

On Sunday 27 December 2009 21:04:43 Simon Riggs wrote:
> On Sun, 2009-12-27 at 20:11 +0100, Andres Freund wrote:
> > On Tuesday 22 December 2009 11:42:30 Simon Riggs wrote:
> > > On Tue, 2009-12-22 at 03:19 +0100, Andres Freund wrote:
> > > > On Monday 21 December 2009 16:48:52 Simon Riggs wrote:
> > > > > Giving the drop database a snapshot is not the answer. I expect
> > > > > Andres to be able to fix this with a simple patch that would not
> > > > > effect the case of normal running.
> > > >
> > > > Actually its less simply than I had thought at first - I don't think
> > > > the code ever handled that correctly.
> > > > I might be wrong there, my knowledge of the involved code is a bit
> > > > sparse... The whole conflict resolution builds on the concept of
> > > > waiting for an VXid, but an idle backend does not have a valid vxid.
> > > > Thats correct, right?
> > >
> > > I don't see any mileage in making Startup process wait for an idle
> > > session, so no real reason to wait for others either.
> >
> > So here is a small patch implementing that behaviour.
> 
> OK, thanks. I have also written something, as mentioned. Will review.
Thats why I had asked in another mail ;-) But I have learned a bit more about 
pg while writing that patch so its fine for me at least ;-)

Andres