Re: Improve OR conditions on joined columns (common star schema problem)

Hi,

On 2017-02-14 14:18:54 -0500, Tom Lane wrote:
> I think this might be code-complete, modulo the question of whether we
> want an enabling GUC for it. I'm still concerned about the question
> of whether it adds more planning time than it's worth for most users.
> (Obviously it needs some regression test cases too, and a lot more
> real-world testing than I've given it.)

> One point that could use further review is whether the de-duplication
> algorithm is actually correct. I'm only about 95% convinced by the
> argument I wrote in planunionor.c's header comment.
>
> Potential future work includes finding join ORs in upper-level INNER JOIN
> ON clauses, and improving matters so we can do the unique-ification with
> hashing as well as sorting. I don't think either of those things has to
> be in the first commit, though.

Are you planning to push this into v10? Given the looming freeze I'm
inclined to bump this to the next CF.

- Andres