Re: CLUSTER FREEZE

On 2013-10-29 11:29:24 -0400, Robert Haas wrote:
> On Tue, Oct 29, 2013 at 10:32 AM, Andres Freund <andres@2ndquadrant.com> wrote:
> > On 2013-10-25 09:26:29 -0400, Robert Haas wrote:
> >> > In any case, it's very far from obvious to me that CLUSTER ought
> >> > to throw away information by default, which is what you're proposing.
> >>
> >> I find it odd to referring to this as throwing away information.  I
> >> know that you have a general concern about throwing away XIDs that are
> >> still needed for forensic purposes, but that is clearly the ONLY
> >> purpose that those XIDs serve, and the I/O advantages of freezing by
> >> default could be massive for many of our users.  What's going to
> >> happen in practice is that experienced users will simply recommend
> >> CLUSTER FREEZE rather than plain CLUSTER, and you won't have the
> >> forensic information *anyway*.
> >
> > I think we should just apply your "preserve forensic information when
> > freezing" patch. Then we're good to go without big arguments ;)
> 
> Well, I'm happy with that, too.  But you wanted it significantly
> reworked and I haven't had time to do that.

I did? I only seem to remember suggesting to introduce
HeapTupleHeaderGetRawXmin() and some bugfix around rewriteheap.c? I
think the RawXmin() thing is a judgement call...

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
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