Re: CLUSTER FREEZE

On Thu, Oct 24, 2013 at 10:28:43AM +0530, Amit Kapila wrote:
> On Thu, Oct 24, 2013 at 4:58 AM, Thomas Munro <munro(at)ip9(dot)org> wrote:
> > Hi
> > I noticed that CLUSTER doesn't have a FREEZE option. Here is a patch to add
> > that, for consistency with VACUUM. Is it useful?
>
> 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?
>
> Anyway code side, I think you need to set both feeze_min_age as well
> as freeze_table_age, see VACUUM command in gram.y
>
> CLUSTER opt_freeze opt_verbose qualified_name cluster_index_specification
>
> {
> ClusterStmt *n = makeNode(ClusterStmt);
> - n->relation = $3;
> - n->indexname = $4;
> - n->verbose = $2;
> + n->relation = $4;
> + n->freeze_min_age = $2 ? 0 : -1;
> + n->indexname = $5;
> + n->verbose = $3;
> ..
>
> With Regards,
> Amit Kapila.
> EnterpriseDB: http://www.enterprisedb.com
>

Hi Amit,

If the FREEZE is part of the CLUSTER, you would only read/write the table
once. With a follow-up VACUUM FREEZE, you would re-read/write a second time.
I, for one, would appreciate being able to perform both in the same run. (+1)

Regards,
Ken