(2014/09/11 4:32), Heikki Linnakangas wrote:
> I had a cursory look at this patch and the discussions around this.
Thank you!
> ISTM there are actually two new features in this: 1) allow CHECK
> constraints on foreign tables, and 2) support inheritance for foreign
> tables. How about splitting it into two?
That's right. There are the two in this patch.
I'm not sure if I should split the patch into the two, because 1) won't
make sense without 2). As described in the following note added to the
docs on CREATE FOREIGN TABLE, CHECK constraints on foreign tables are
intended to support constraint exclusion for partitioned foreign tables:
+ Constraints on foreign tables are not enforced on insert or update.
+ Those definitions simply declare the constraints hold for all rows
+ in the foreign tables. It is the user's responsibility to ensure
+ that those definitions match the remote side. Such constraints are
+ used for some kind of query optimization such as constraint exclusion
+ for partitioned tables
Thanks,
Best regards,
Etsuro Fujita