David Rowley <david.row...@2ndquadrant.com> writes: > On 23 January 2016 at 12:44, Tom Lane <t...@sss.pgh.pa.us> wrote: >> * What you did to join.sql/join.out seems a bit bizarre. The existing >> test case that you modified was meant to test something else, and >> conflating this behavior with the pre-existing one (and not documenting >> it) is confusing as can be. A bit more work on regression test cases >> seems indicated.
> The history behind that is that at one point during developing the > patch that test had started failing due to the group by item being > removed therefore allowing the join removal conditions to be met. On > testing again with the old test query I see this no longer happens, so > I've removed the change, although the expected output still differs > due to the group by item being removed. Hmm ... but ... it seems to me that the test as it stands *should* fail after this patch, because once the non-pkey grouping column is removed the join removal optimization should apply. I think we should look a bit more closely at what's happening there. (IOW, I wasn't so much unhappy with the change to that test case as that it was being used as the only test case for this new behavior. I see you added some new, separate test cases, so that's good; but there's something fishy if the existing case doesn't change behavior.) regards, tom lane -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers