Robert Haas wrote: > On Sun, Dec 31, 2017 at 2:43 PM, Alvaro Herrera > <alvhe...@2ndquadrant.com> wrote: > > This patch removes all the ONLY markers from queries in ri_triggers.c. > > That makes the queries work for the new use case, but I haven't figured > > if it breaks things for other use cases. I suppose not, since regular > > inheritance isn't supposed to allow foreign keys in the first place, but > > I haven't dug any further. > > I suspect that this leads to bugs under concurrency, something to do > with crosscheck_snapshot, but I couldn't say exactly what the problem > is off the top of my head. My hope is that partitioning might be > immune on the strength of knowing that any given tuple could only be > present in one particular partition, but that might be wishful > thinking.
I think you're thinking of this problem: if I insert a row in partitioned table F, and simultaneously remove the referenced row from table P, it is possible that we fail to reject the insertion in some corner-case scenario. I suppose it's not completely far-fetched, if P is partitioned. I don't see any way in which it could be a problem if only F is partitioned. For the record: in the patch I'm about to push, I did not implement foreign key references to partitioned tables. So it should be safe. More thought may be needed to implement the other direction. Offhand, I don't see a problem, but I may well be wrong. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
