On Tue, 23 Apr 2019 at 04:54, Bruce Momjian <bruce@momjian.us> wrote:
>
> We had a discussion in October about adding more optimizer items to the
> release notes:
>
>
https://www.postgresql.org/message-id/flat/20181010220601.GA7807%40momjian.us#11d805ea0b0fcd0552dfa99251417cc1
>
> There was no agreement on a change, but if people want to propose a
> change, please post here and we can discuss it.
I'd say these sorts of changes are important. TBH, these days, I think
query planner smarts are arguably one of our weakest areas when
compared to the big commercial databases. The more we can throw in
there about this sort of thing the better. The strange thing about
making improvements to the planner is often that the benefits of doing
so can range massively. e.g has zero effect all the way up to perhaps
thousands or even millions of times faster. The users that get the 1
million times speedup will likely want to know that more than some
executor speedup that gets them 5% across the board. I believe these
are useful to keep in the release notes to catch the eye of all those
people blocked from upgrading from <commercial database> due to us not
optimising their queries the same way as they and their applications
are accustomed to.
I see from the v11 release notes that we have "E.3.3.1.4. Optimizer",
it seems fairly simple for someone to skip this if they happen not to
be interested in what's been changed in that area.
--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services