Re: pruning disabled for array, enum, record, range type partition keys

Hi.

On 2018/04/19 6:45, Alvaro Herrera wrote:
> Amit Langote wrote:
>> On Thu, Apr 19, 2018 at 12:01 AM, Alvaro Herrera
>> <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
>
>>> Makes sense. Still, I was expecting that pruning of hash partitioning
>>> would also work for pseudotypes, yet it doesn't.
>>
>> It does?
>
> Aha, so it does.
>
> While staring at this new code, I was confused as to why we didn't use
> the commutator if the code above had determined one. I was unable to
> cause a test to fail, so I put that thought aside.

Oops, you're right. Shouldn't have ignored the commutator.

> Some time later, after restructuring the code in a way that seemed to
> make more sense to me (and saving one get_op_opfamily_properties call
> for the case of the not-equals operator), I realized that with the new
> code we can store the opstrategy in the PartClause instead of leaving it
> as Invalid and look it up again later, so I did that. And lo and
> behold, the tests that used commutators started failing! So I fixed
> that one in the obvious way, and the tests work fully again.
>
> Please give this version another look. I also rewrote a couple of
> comments.

Thanks, your rewritten version looks much better.

> I now wonder if there's anything else that equivclass.c or indxpath.c
> can teach us on this topic.

I have referenced indxpath.c number of times when writing this code (for
example, match_clause_to_indexcol), but never equivclass.c.

Thanks,
Amit