On Wed, Apr 29, 2020 at 8:29 AM David Rowley <dgrowle...@gmail.com> wrote:
> On Thu, 16 Apr 2020 at 14:17, Andy Fan <zhihui.fan1...@gmail.com> wrote: > > V6 also includes: > > 1. Fix the comment misleading you mentioned above. > > 2. Fixed a concern case for `relation_has_uniquekeys_for` function. > > Over on [1], Richard highlights a problem in the current join removals > lack of ability to remove left joins unless the min_righthand side of > the join is a singleton rel. It's my understanding that the reason the > code checks for this is down to the fact that join removals used > unique indexed to prove the uniqueness of the relation and obviously, > those can only exist on base relations. I wondered if you might want > to look into a 0003 patch which removes that restriction? I think this > can be done now since we no longer look at unique indexes to provide > the proves that the join to be removed won't duplicate outer side > rows. > Yes, I think that would be another benefit of UniqueKey, but it doesn't happen until now. I will take a look of it today and fix it in a separated commit. Best Regards Andy Fan
