Re: relation ### modified while in use

> > > 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