Re: Optimise default partition scanning while adding new partition

On Sat, Sep 16, 2017 at 12:59 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Fri, Sep 15, 2017 at 2:00 AM, Amit Langote
> <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
>> I wonder if we should call check_default_allows_bound() from
>> ATExecAttachPartition(), too, instead of validating updated default
>> partition constraint using ValidatePartitionConstraints()? That is, call
>> the latter only to validate the partition constraint of the table being
>> attached and call check_default_allows_bound() to validate the updated
>> default partition constraint. That way, INFO/ERROR messages related to
>> default partition constraint are consistent across the board.
>
> I believe the intended advantage of the current system is that if you
> specify multiple operations in a single ALTER TABLE command, you only
> do one scan rather than having a second scan per operation. If that's
> currently working, we probably don't want to make it stop working.

OK.

How about squash Jeevan's and my patch, so both
check_default_allows_bound() and ValidatePartitionConstraints() know
to scan default partition's children and there won't be any surprises
in the regression test output as you found after applying just the
Jeevan's patch. Unfortunately, I'm not able to post such a patch
right now.

Thanks,
Amit