Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> Obviously not. We don't need to acquire an AccessExclusiveLock to
> comment on an object - just something that will CONFLICT WITH an
> AccessExclusiveLock. So, use the same locking rules, perhaps, but
> take a much weaker lock, like AccessShareLock.
Well, it probably needs to be a self-conflicting lock type, so that
two COMMENTs on the same object can't run concurrently. But I agree
AccessExclusiveLock is too strong: that implies locking out read-only
examination of the object, which we don't want.
regards, tom lane