Re: CLUSTER FREEZE

On 2013-10-24 17:17:22 -0700, Josh Berkus wrote:
> On 10/24/2013 04:55 PM, Robert Haas wrote:
> > On Thu, Oct 24, 2013 at 1:09 PM, Josh Berkus <josh@agliodbs.com> wrote:
> >> On 10/23/2013 09:58 PM, Amit Kapila wrote:
> >>> I wonder why anyone would like to freeze during CLUSTER command when
> >>> they already have separate way (VACUUM FREEZE) to achieve it, do you
> >>> know or can think of any case where user wants to do it along with
> >>> Cluster command?
> >>
> >> "If I'm rewriting the table anyway, let's freeze it".
> >>
> >> Otherwise, you have to write the same pages twice, if both CLUSTER and
> >> FREEZE are required.
> > 
> > I wonder if we should go so far as to make this the default behavior,
> > instead of just making it an option.
> 
> +1 from me.  Can you think of a reason you *wouldn't* want to freeze?

It makes content from the future appear when you start using the
relation in a query/session with an older snapshot. Currently CLUSTER is
safe against that.

Greetings,

Andres Freund

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