Re: Problems with ALTER DOMAIN patch

Rod Taylor <rbt@rbt.ca> writes:
> On Tue, 2002-12-10 at 22:56, Tom Lane wrote:
>> relation's pg_class row.  We have no such locks on types at present,
>> but I think it may be time to invent 'em.

> I'd be happy to use them once created.

I think you misunderstood me ;=) ... that was a none-too-subtle
suggestion that *you* should go invent 'em, seeing as how you're the
one pushing the feature that makes 'em necessary.

The lock manager itself deals with lock tags that could be almost
anything.  We currently only use lock tags that represent relations or
specific pages in relations, but I see no reason that there couldn't
also be lock tags representing types --- or other basic catalog entries.
(I am trying hard to repress the thought that we may already need
locking on other classes of entities as well.)  What we need now is a
little thought about exactly how to represent these different lock tags
(should be easy), and about what semantics to assign to different lock
modes applied to pg_type entities (perhaps not so easy).
        regards, tom lane