Richard Guo <guofengli...@gmail.com> writes: > On Thu, Apr 9, 2020 at 1:07 AM Tom Lane <t...@sss.pgh.pa.us> wrote: >> I have hopes of being able to incorporate outer >> joins into the EC logic in a less squishy way in the future, by making >> the representation of Vars distinguish explicitly between >> value-before-outer-join and value-after-outer-join, after which we could >> make bulletproof assertions about what is equal to what, even with outer >> joins in the mix. If that works out it might produce a cleaner answer >> in this area too.
> This is very appealing. Do we have ongoing discussions/threads about > this idea? There's some preliminary noodling in this thread: https://www.postgresql.org/message-id/flat/15848.1576515643%40sss.pgh.pa.us I've pushed the earlier work discussed there, but stalled out due to the call of other responsibilities after posting the currently-last message in the thread. Hoping to get back into that over the summer. regards, tom lane