Re: [HACKERS] relation ### modified while in use

[Vadim Mikheev]

> > > In my understanding,locking levels you provided contains > > > an implicit share/exclusive lock on the corrsponding > > > pg_class tuple i.e. AccessExclusive Lock acquires an > > > exclusive lock on the corresping pg_class tuple and > > > other locks acquire a share lock, Is it right ? > > > > No. Access...Locks are acquired over target table > > (table' oid is used as key for lmgr hash table), > > not over corresponding pg_class tuple, in what case > > we would use pg_clas' oid + table' oid as key > > (possibility I've described below). > > > > Yes,I know that "lock table" doesn't touch the correpon > ding pg_class tuple at all. However isn't it equivalent ? >From what POV? Lock manager will allow two simultaneous exclusive locks using these different methods (keys) and so we can interpret (use) them differently. Vadim