"M.D.G. Lange" <mlange@dltmedia.nl> writes:
> No matter what ON DELETE constraint I created, the system will not allow
> me to create a foreign key, as pg_shadow is a system catalog.
We do not support foreign keys (or indeed triggers of any kind) on
system catalogs. I don't foresee that happening in the near future
either, though I think there is something about it on the TODO list.
regards, tom lane