Garfield Lewis <garfield.lewis@lzlabs.com> writes:
> I need the page and possibly row of the data location to be stored as an element of the new type. This is to simulate
astructure from another database system.
You need to rethink. The datatype input function cannot know even that
the value is going to be stored anywhere, let alone exactly where.
Moreover, what would happen if the row is moved somewhere else due
to an update of some other column?
You might be able to build something for cross-linking by putting
the logic in AFTER INSERT/UPDATE/DELETE triggers, but I think a
custom datatype is not going to be helpful for that.
regards, tom lane