On Sat, Mar 27, 2021 at 11:44 AM Andy Fan <zhihui.fan1213@gmail.com> wrote:
>
>
>
> On Sat, Mar 27, 2021 at 3:07 AM Dmitry Dolgov <9erthalion6@gmail.com> wrote:
>>
>> > On Sat, Feb 20, 2021 at 10:25:59AM +0800, Andy Fan wrote:
>> >
>> > The attached is a UnqiueKey with EquivalenceClass patch, I just complete the
>> > single relation part and may have bugs. I just attached it here for design
>> > review only. and the not-null-attrs is just v1 which we can continue
>> > discussing on the original thread[2].
>>
>> Thanks for the patch. After a short look through it I'm a bit confused
>> and wanted to clarify, now uniquekeys list could contain both Expr and
>> EquivalenceClass?
>
>
> Yes, That's because I don't want to create a new EquivalenceClass (which
> would make the PlannerInfo->eq_classes longer) if we don't have
> one , then I just used one Expr instead for this case.
> However during the
> test, I found some EquivalenceClass with only 1 EquivalenceMember
> unexpectedly.
>
Pathkeys may induce single member ECs. Why UniqueKeys are an exception?
--
Best Wishes,
Ashutosh Bapat