Subject: Re: Hot Standby on git
From: Simon Riggs <simon@2ndQuadrant.com>
To: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
In-Reply-To: <4AC5DB71.7000105@enterprisedb.com>
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Date: Fri, 02 Oct 2009 13:40:47 +0100
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On Fri, 2009-10-02 at 13:52 +0300, Heikki Linnakangas wrote:
> Simon Riggs wrote:
> > I'd rather just skip this for now. It's a minor case anyway and there's
> > nothing stopping writing their own RunningXactData records with a
> > function, if it is needed. I can add a function for that.
> 
> That won't help. There's no way to have it in a right place wrt. the
> shutdown checkpoint if it's triggered by a user-callable function.

I notice that you avoid saying "yes, I agree we should remove the two
checks".

I will add code to make a shutdown checkpoint be a valid starting place
for Hot Standby, as long as there are no in-doubt prepared transactions.
That way we know there are no xids still running and no locks, without
needing to write a record to say so.

-- 
 Simon Riggs           www.2ndQuadrant.com