Cascading deletes in PostgreSQL

Question

I have a database with a few dozen tables interlinked with foreign keys. Under normal circumstances, I want the default ON DELETE RESTRICT behavior for those co

Answer 1

You do not need to dump and restore. You should be able to just drop the constraint, rebuild it with cascade, do your deletes, drop it again, and the rebuild it with restrict.

CREATE TABLE "header"
(
  header_id serial NOT NULL,
  CONSTRAINT header_pkey PRIMARY KEY (header_id)
);

CREATE TABLE detail
(
  header_id integer,
  stuff text,
  CONSTRAINT detail_header_id_fkey FOREIGN KEY (header_id)
      REFERENCES "header" (header_id) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE NO ACTION
);
insert into header values(1);
insert into detail values(1,'stuff');
delete from header where header_id=1;
alter table detail drop constraint detail_header_id_fkey;
alter table detail add constraint detail_header_id_fkey FOREIGN KEY (header_id)
      REFERENCES "header" (header_id) on delete cascade;
delete from header where header_id=1;
alter table detail add constraint detail_header_id_fkey FOREIGN KEY (header_id)
      REFERENCES "header" (header_id) on delete restrict;