Here's another case that is broken in 7.4, but works when SET WITHOUT
OIDs is reimplemented as a full-fledged DROP:
regression=# create table foo1(f1 int, unique(oid));
NOTICE: CREATE TABLE / UNIQUE will create implicit index "foo1_oid_key" for table "foo1"
CREATE TABLE
regression=# create table foo2(f1 oid references foo1(oid));
CREATE TABLE
regression=# alter table foo1 set without oids;
NOTICE: constraint $1 on table foo2 depends on table foo1 column oid
ERROR: cannot drop table foo1 column oid because other objects depend on it
HINT: Use DROP ... CASCADE to drop the dependent objects too.
regression=# alter table foo1 drop column oid;
NOTICE: constraint $1 on table foo2 depends on table foo1 column oid
ERROR: cannot drop table foo1 column oid because other objects depend on it
HINT: Use DROP ... CASCADE to drop the dependent objects too.
regression=# alter table foo1 drop column oid cascade;
NOTICE: drop cascades to constraint $1 on table foo2
ALTER TABLE
regression=#
regards, tom lane