Philip de Nier <philip.denier@xxxxxxxxxxxx> writes: > The solutions I could find in the mailing lists were either to upgrade to > version 8.1 which uses "SELECT ... FOR SHARE" (I'm currently using 8.0), > stop using foreign keys or add "DEFERRABLE INITIALLY DEFERRED" to the > constraints. For now I'd prefer to use the last option. > Does using "DEFERRABLE INITIALLY DEFERRED" completely solve the problem of > transactions waiting for each other to release locks resulting from "SELECT > ... FOR UPDATE"? It doesn't eliminate the problem, but it does narrow the window in which the lock is held by quite a bit, by postponing the FK checks until just before transaction commit. > How are the deferred foreign key constraints checked - are they checked one > at a time? Yeah. regards, tom lane
