Subject: Re: Small Bug in GetConflictingVirtualXIDs
From: Simon Riggs <simon@2ndQuadrant.com>
To: Andres Freund <af@cybertec.de>
Cc: pgsql-hackers@postgresql.org, Tom Lane <tgl@sss.pgh.pa.us>,
	Alvaro Herrera <alvherre@commandprompt.com>
In-Reply-To: <200912272011.27003.af@cybertec.de>
References: <200912210402.37850.andres@anarazel.de>
	<200912220319.10264.af@cybertec.de> <1261478551.7442.4332.camel@ebony>
	<200912272011.27003.af@cybertec.de>
Content-Type: text/plain
Date: Sun, 10 Jan 2010 15:49:00 +0000
Message-Id: <1263138541.19367.142097.camel@ebony>
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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.

I've committed a slightly modified form of this patch.

It was an outstanding bug, so delaying fix at this stage not worth it. I
had in mind a slightly grander fix, but it's hardly a priority to polish
the chrome on this one.

Thanks for the bug report and fix.

-- 
 Simon Riggs           www.2ndQuadrant.com