Re: [COMMITTERS] pgsql: Don't scan partitioned tables.

On Tue, Mar 21, 2017 at 10:01 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> On 21 March 2017 at 13:48, Robert Haas <rhaas@postgresql.org> wrote:
>> Don't scan partitioned tables.
>
> Sounds good.
>
>> Aside from the obvious advantage of avoiding some work at execution
>> time, this has two other advantages.  First, it may improve the
>> planner's decision-making in some cases since the empty relation
>> might throw things off.
>
> I was surprised to see that an Append node still exists when there is
> only one child plan to be appended. I thought removing that was the
> whole point of the patch?

No, that was discussed on-thread.

http://postgr.es/m/b7f2d81d-9c9b-ba4e-5e00-edf626567256@lab.ntt.co.jp

It's not a bad idea, but it would require further work on top of what
this patch already does.

>> Second, it paves the way to getting rid of
>> the storage for partitioned tables altogether.
>
> I thought we already discussed that. Seems strange to mention
> something not very important that might happen in the future. We could
> save much more space by optimising FSM.

Sure, that's possible.  I didn't think it was strange to mention it,
but you're welcome to have a different opinion.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company