On Thu, Jan 10, 2019 at 6:10 PM, Imai, Yoshikazu wrote: > > Does that not mean that the if (parent->top_parent_relids) will always > > be false in build_dummy_partition_rel() and it'll only ever get > > rtekind == RTE_RELATION? > > At least, I checked if (parent->top_parent_relids) can be true if I > execute below SQL. > > select * from parent p1 inner join parent p2 on p1.a=p2.a where p1.id < 15;
Sorry, I also made mistake. I was executed: select * from parent p1 inner join parent p2 on p1.a=p2.a where p1.a < 15; -- Yoshikazu Imai > -----Original Message----- > From: Imai, Yoshikazu [mailto:imai.yoshik...@jp.fujitsu.com] > Sent: Friday, January 11, 2019 3:10 PM > To: 'David Rowley' <david.row...@2ndquadrant.com>; Amit Langote > <langote_amit...@lab.ntt.co.jp> > Cc: Amit Langote <amitlangot...@gmail.com>; Alvaro Herrera > <alvhe...@2ndquadrant.com>; Pg Hackers <pgsql-hack...@postgresql.org> > Subject: RE: speeding up planning with partitions > > Hi David, > > On Thu, Jan 10, 2019 at 4:02 PM, David Rowley wrote: > > 3. I wonder if there's a better way to handle what > > build_dummy_partition_rel() does. I see the child's relid to the > > parent's relid and makes up a fake AppendRelInfo and puts it in the > > parent's slot. What's going to happen when the parent is not the > > top-level parent? It'll already have a AppendRelInfo set. > ... > > > > select * from parent p1 inner join parent p2 on p1.a=p2.a where p1.id > > < 10; > > I think there is a mistake in the select SQL. > "p1.id < 10" doesn't prune any partition because tables are partitioned > by column "a" in your definition. Isn't it? > > > Does that not mean that the if (parent->top_parent_relids) will always > > be false in build_dummy_partition_rel() and it'll only ever get > > rtekind == RTE_RELATION? > > At least, I checked if (parent->top_parent_relids) can be true if I > execute below SQL. > > select * from parent p1 inner join parent p2 on p1.a=p2.a where p1.id > < 15; > > I couldn't check other points you mentioned, but I also think > build_dummy_partition_rel() needs more consideration because I felt it > has complicated logic when I was checking around here. > > > Amit, > I also realized there are some mistakes in the comments around this > function. > > + * build_dummy_partition_rel > + * Build a RelOptInfo and AppendRelInfo for a pruned > partition > s/and AppendRelInfo/and an AppendRelInfo/ > > + * Now we'll need a (no-op) AppendRelInfo for parent, because > we're > + * setting the dummy partition's relid to be same as the parent's. > s/a \(no-op\) AppendRelInfo/an \(no-op\) AppendRelInfo/ > > -- > Yoshikazu Imai
