Erik Jones <mage2k@xxxxxxxxx> writes: > I've seen locks with mode of AccessExclusiveLock and locktype of tuple a > few times now but have never been able to reproduce one nor had a chance to > dig into them and now have a couple questions on them: > * When is this kind of heavy lock on a row/tuple taken out? I've done some > code spelunking but have yet to find anything. It's a transient state while waiting to acquire a "normal" tuple lock, that is one recorded in the tuple header. The explanation can be found in src/backend/access/heap/README.tuplock, and the relevant code is mostly in heap_lock_tuple(). regards, tom lane
