Thread: Hot standby, xlog_xact_assignment and unreported subxids.

In the hot standby patch, we have this comment in procarray.c:

> It is
>  * important that the XLOG_XACT_ASSIGNMENT record contain *all* subxids 
>  * not just those so far unreported because the sole purpose is to ensure
>  * we can remove the xids from KnownAssignedXids. 

As the patch stands, that's not what we do. We only include new subxids
in the XLOG_XACT_ASSIGNMENT record that we haven't included in any
previous ones. I think that comment is just obsolete and should be
removed, but am I missing something?

--  Heikki Linnakangas EnterpriseDB   http://www.enterprisedb.com

On Wed, 2009-10-14 at 14:43 +0300, Heikki Linnakangas wrote:
> In the hot standby patch, we have this comment in procarray.c:
> 
> > It is
> >  * important that the XLOG_XACT_ASSIGNMENT record contain *all* subxids 
> >  * not just those so far unreported because the sole purpose is to ensure
> >  * we can remove the xids from KnownAssignedXids. 
> 
> As the patch stands, that's not what we do. We only include new subxids
> in the XLOG_XACT_ASSIGNMENT record that we haven't included in any
> previous ones. 

That's the correct handling, in my view.

> I think that comment is just obsolete and should be
> removed, but am I missing something?

I agree it looks wrong. (Did I write that??)

-- Simon Riggs           www.2ndQuadrant.com