On Mon, May 25, 2015 at 1:28 AM, Simon Riggs <si...@2ndquadrant.com> wrote: > My earlier summary was that the support for multiple constraints has been > poorly thought through. This is an example of the breakage I have been > complaining about when we are forced to specify the constraint > (conflict-target). > > This is not just related to FDWs and should not be fixed solely for FDWs. > This was already an open item for me in 9.5, now even more so.
I agree that the decision to change the current behavior has nothing to do with FDWs. There is no reason to treat foreign tables differently to local ones in this regard, which implies that ON CONFLICT DO UPDATE cannot work with postgres_fdw unless and until someone invents foreign constraints on foreign tables (I think), or unless we change our mind generally (for other reasons). So, certainly, the rationale for mandating (or not mandating) an inference specification with ON CONFLICT DO UPDATE ought to come from balancing concerns about safety, compatibility, flexibility, and so on. I did not mean to imply that your comments were unreasonable/too late. However, I don't see a lot of demand for changing the behavior. There is at least some demand for accepting as arbiters multiple unique constraints (that are not more or less equivalent), from Andres for example, but that's a different question. It's also something that could reasonably be added later. -- Peter Geoghegan -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
