Re: [HACKERS] advanced partition matching algorithm for partition-wise join

On Mon, Jul 8, 2019 at 5:03 PM Etsuro Fujita <etsuro(dot)fujita(at)gmail(dot)com>
wrote:

> On Wed, Jul 3, 2019 at 3:44 PM Etsuro Fujita <etsuro(dot)fujita(at)gmail(dot)com>
> wrote:
> > On Tue, Jul 2, 2019 at 1:47 PM amul sul <sulamul(at)gmail(dot)com> wrote:
> > > Attached version is rebase atop of the latest master head(c74d49d41c),
> thanks.
> >
> > Thanks! Will review.
>
> I started reviewing this. Here is my initial review comments:
>
> * 0001-Hash-partition-bound-equality-refactoring-v22.patch
>
> First of all, I agree with your view on hash partitioning:
>
> "3. For hash partitioned tables however, we support partition-wise join
> only when the bounds exactly match. For hash partitioning it's unusual
> to have missing partitions and hence generic partition matching is not
> required."
>
> which is cited from the commit message for the main patch
> "0002-Partition-wise-join-for-1-1-1-0-0-1-partition-matchi-v22.patch".
> (I think it would be better if we can extend the partition matching to
> the hash-partitioning case where there are missing partitions in
> future, though.) However, I don't think it's a good idea to do this
> refactoring, because that would lead to duplicating the code to check
> whether two given hash bound collections are equal in
> partition_bounds_equal() and partition_hash_bounds_merge() that will
> be added by the main patch, after all. To avoid that, how about
> calling partition_bounds_equal() from partition_hash_bounds_merge() in
> the main patch, like the attached?

Agree, your changes look good to me, thanks for working on it.

Regards,
Amul