Hi,
On 2019-07-18 11:29:37 +1200, David Rowley wrote:
> On Wed, 17 Jul 2019 at 06:46, Andres Freund <andres@anarazel.de> wrote:
> > 1) Have ExecFindPartition() return via a bool* whether the partition is
> > being accessed for the first time. In copy.c push the partition onto
> > a list of to-be-bulk-finished tables.
> > 2) Add a execPartition.c function that returns all the used tables from
> > a PartitionTupleRouting*.
>
> #2 seems better than #1 as it does not add overhead to ExecFindPartition().
I don't see how #1 would add meaningful overhead compared to the other
costs of that function. Wouldn't it just be adding if (isnew) *isnew =
false; to the "/* ResultRelInfo already built */" branch, and the
reverse to the else? That got to be several orders of magnitude cheaper
than e.g. FormPartitionKeyDatum() which is unconditionally executed?
> Are you thinking this should go back into v12, or just for v13 only?
Not sure, tbh. Probably depends a bit on how complicated it'd look?
Greetings,
Andres Freund