"Jenny -" <nat_lazy@hotmail.com> writes:
> Iam trying to acquire rowlevel locks in postgresql. I try doing this:
> 'select * from students where name='Larry' for update;
> But by looking at the holding array of proclock , I've noticed that by doing
> this only
> AccessShareLock gets acquired which is a table level lock.
Row-level locks are not recorded in proclock --- they are implemented by
marking the individual tuple on-disk. If we tried to record them in
shared memory, it'd be very easy to run out of shared memory, because
you could be holding row locks on a large number of tuples.
regards, tom lane