Re: WIP: Upper planner pathification
| От | Oleg Bartunov |
|---|---|
| Тема | Re: WIP: Upper planner pathification |
| Дата | |
| Msg-id | CAF4Au4zFmFOogc2dgBBN8ZZjPWCj9Q7jYb0DBqEePt7pgYT+JQ@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: WIP: Upper planner pathification (Teodor Sigaev <teodor@sigaev.ru>) |
| Список | pgsql-hackers |
On Tue, Mar 1, 2016 at 3:11 PM, Teodor Sigaev <teodor@sigaev.ru> wrote:
The basic point of this patch is to apply the generate-and-compare-Paths...
paradigm to the planning steps after query_planner(), which only covers
> The present patch addresses this problem by inventing Path nodes to
> represent every post-scan/join step
I'm really glad to see that. Separating path nodes for later steps opens a new ways to optimize queries. For first glance, consider
select * from a left outer join b on a.i = b.i limit 1;
Limit node could be pushed down to scan over 'a' table if b.i is unique.
This patch opens a lot of possibilities to our ongoing project on indexing subselects, which we plan to use for jsonb. Having it in 9.6 will certainly facilitate this. So, I'm +1 for this patch, even if we have to postpone 9.6 a bit. Hope, Robert, Teodor and other reviewers could help Tom with this patch.
--
Teodor Sigaev E-mail: teodor@sigaev.ru
WWW: http://www.sigaev.ru/
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
В списке pgsql-hackers по дате отправления: