Re: [HACKERS] Partition-wise join for join between (declaratively) partitioned tables

Robert Haas <robertmhaas@gmail.com> writes:
> I don't understand why you think that partition-wise join needs any
> new logic here; if this were a non-partitionwise join, we'd similarly
> need to use the correct operator, but the existing code handles that
> just fine.  If the join is performed partition-wise, it should use the
> same operators that would have been used by a non-partitionwise join
> between the same tables.

More to the point, the appropriate operator was chosen by parse analysis.
The planner has *zero* flexibility as to which operator is involved.

BTW, I remain totally mystified as to what people think the semantics of
partitioning ought to be.  Child columns can have a different type from
parent columns?  Really?  Why is this even under discussion?  We don't
allow that in old-school inheritance, and I cannot imagine a rational
argument why partitioning should allow it.
        regards, tom lane