Re: NOT IN subquery optimization
Richard Guo <riguo@pivotal.io>
From: Richard Guo <riguo@pivotal.io>
To: David Rowley <david.rowley@2ndquadrant.com>
Cc: Jim Finnerty <jfinnert@amazon.com>,
PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-02-27T06:14:16Z
Lists: pgsql-hackers
On Wed, Feb 27, 2019 at 4:52 AM David Rowley <david.rowley@2ndquadrant.com> wrote: > On Wed, 27 Feb 2019 at 03:07, Jim Finnerty <jfinnert@amazon.com> wrote: > > If you're proposing to do that for this thread then I can take my > planner only patch somewhere else. I only posted my patch as I pretty > much already had what I thought you were originally talking about. > However, please be aware there are current patents around adding > execution time smarts in this area, so it's probably unlikely you'll > find a way to do this in the executor that does not infringe on those. > Probably no committer would want to touch it. I think my patch covers > a good number of use cases and as far as I understand, does not go > near any current patents. > > Thanks for pointing out the patent concerns. I was not aware of that before. Could you please provide some clue where I can find more info about the patents? Thanks Richard
Commits
-
Check we don't misoptimize a NOT IN where the subquery returns no rows.
- 3396138a6de3 12.0 landed