Please add this patch to the commitfest so that it's not forgotten. On Fri, Feb 3, 2017 at 6:10 PM, Ashutosh Bapat <ashutosh.ba...@enterprisedb.com> wrote: > The patch applies cleanly. No regression test fails. > > On Thu, Feb 2, 2017 at 6:57 PM, Alexey Bashtanov <bashta...@imap.cc> wrote: >> Hello hackers, >> >> The view information_schema.constraint_column_usage becomes slow when the >> number of columns and constraints raise to substantial values. >> This is because of a join condition that allows only join filter to enforce. >> The patch is to optimize it. > > Right. Because there are three relations involved in the condition, > it's evaluation is delayed till all three of them are joined, thus > increasing the sizes of minion joins. With this change, the size of > minion joins reduces. Since this is an all INNER join, splitting the > condition should be fine. > >> See many_constraints.sql file attached for a performance test: create 3000 >> tables with 10 columns and a PK each and select * from the view. >> The last statement works for 22 seconds on master branch, 34 milliseconds >> optimized on my laptop. > > Yes, that's a lot of improvement. I can reproduce similar results on my > laptop. > > -- > Best Wishes, > Ashutosh Bapat > EnterpriseDB Corporation > The Postgres Database Company
-- Best Wishes, Ashutosh Bapat EnterpriseDB Corporation The Postgres Database Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
