On tis, 2011-04-05 at 14:47 -0400, Tom Lane wrote:
> Supporting user mappings in COMMENT, EXTENSION, etc is not so critical
> that we should push a possibly misdesigned notion of ownership into
> the system for it. Better to take our time and think about that.
>
> (BTW, it might be useful to reconsider casts while we are thinking about
> this. Those don't have a proper notion of ownership either. I'm a bit
> inclined to think that we should just bite the bullet and add owner
> columns to both these catalogs. But, again, let's not be hasty.)
As I said elsewhere, I think of user mappings as similar to role grants.
An owner there would be similar to a grantor, so it would make sense.