Please don’t top-post replies on these lists.
It is already deferrable:
ALTER TABLE doc.book ADD CONSTRAINT fk_book_display_mode_id FOREIGN KEY (display_mode_id) REFERENCES doc.display_mode(id) DEFERRABLE
Ignoring the question of why you want to do things this way it seems you need to provide a self-contained, complete, test case to get a sound answer. Though I suspect it may have to do with an on delete clause you haven’t shown.
David J.
