So I was about ready to get these patches pushed, when I noticed that in REPEATABLE READ isolation mode it is possible to insert rows violating an FK referencing the partition that is being detached. I'm not sure what is a good solution to this problem.
The problem goes like this: /* setup */ drop table if exists d4_primary, d4_primary1, d4_fk; create table d4_primary (a int primary key) partition by list (a); create table d4_primary1 partition of d4_primary for values in (1); insert into d4_primary values (1); create table d4_fk (a int references d4_primary); /* session 1 */ begin isolation level repeatable read; select * from d4_primary; /* session 2 */ alter table d4_primary detach partition d4_primary1 concurrently; -- blocks -- Cancel wait: Ctrl-c /* session 1 */ insert into d4_fk values (1); commit; At this point, d4_fk contains the value (1) which is not present in d4_primary. This doesn't happen in READ COMMITTED mode; the INSERT at the final step fails with "insert or update in table f4_fk violates the foreign key", which is what I expected to happen here too. I had the idea that the RI code, in REPEATABLE READ mode, used a different snapshot for the RI queries than the transaction snapshot. Maybe I'm wrong about that. I'm looking into that now. -- Álvaro Herrera Valdivia, Chile "Cuando mañana llegue pelearemos segun lo que mañana exija" (Mowgli)