Re: Optimze usage of immutable functions as relation

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Antonin Houska <ah@cybertec.at>, Aleksandr Parfenov <asp437@gmail.com>, a.bykov@postgrespro.ru, pgsql-hackers@lists.postgresql.org
Date: 2019-02-18T00:20:25Z
Lists: pgsql-hackers
Andres Freund <andres@anarazel.de> writes:
> Given this I think the appropriate state of the CF entry would have been
> waiting-for-author, not needs review. Or alternatively
> returned-with-feedback or rejected.  I'm a bit confused as to why the
> patch was moved to the next CF twice?

We have this review from Antonin, and mine in
https://www.postgresql.org/message-id/2906.1542395026%40sss.pgh.pa.us
and there's the cfbot report that the patch doesn't even apply anymore.

The dummy-relation stuff I referred to has now been merged, so there's
really no good reason not to revise the patch along that line.

I'm going to go set this CF entry to waiting-for-author, but unless
a rewritten patch appears soon, I think we should close it
returned-with-feedback.  I think the idea is potentially good, but
as I said in my review, I don't like this implementation; it has the
potential to be a net loss in some cases.

			regards, tom lane


Commits

  1. Prevent bogus pullup of constant-valued functions returning composite.

  2. Allow functions-in-FROM to be pulled up if they reduce to constants.