Re: Idea for getting rid of VACUUM FREEZE on cold pages

Excerpts from Bruce Momjian's message of vie jun 04 15:39:07 -0400 2010:
> Tom Lane wrote:
> > Bruce Momjian <bruce@momjian.us> writes:
> > > With in-place VACUUM FULL gone in 9.0, will there be as much need for
> > > xmin/xmax forensics?
> > 
> > You know perfectly well that no one could answer that question.
> > (Or at least not answer it on the basis of facts available today.)
> 
> Well, guess then.  In the past, how many forensic cases were needed for
> in-place VACUUM FULL bugs, vs. other cases?

I don't understand the question.  I know I have debugged a bunch of
cases of data corruption, and having xmin/xmax around has been truly
useful.  VACUUM FULL has never been involved (that I know of -- most of
our customers tend not to run it AFAIK), so why would I care about
whether it's gone in 9.0?  Note that it's not always about PG bugs; but
in the cases where xmin=FrozenXid for all/most involved tuples, the
problems are more difficult to track down.

Yes, VACUUM FULL had bugs too -- I, for one, welcome our new
not-in-place VACUUM FULL overlord.

-- 
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
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