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
