Re: TRUNCATE question

Rod Taylor wrote:
> 
> Makes for a real pain when the nice and safe foreign keys aren't
> really nice and safe anymore.
> >
> > It's supposed to work that way - same as Oracle.

TRUNCATE TABLE is essentially short-hand for DROP/CREATE, but preserves
GRANT permissions, associations from its oid in functions, views, etc.
Oracle disallows TRUNCATE on a table involved in a referential integrity
relationship, but doesn't disallow the behavior for a normal ON DELETE
trigger. According to previous discussions, PostgreSQL should behave
similarly. If it does not, its a bug. I haven't checked the status since
7.1.0, so I don't know.

Accordingly, as of 7.1.0, nothing stops you in PostgreSQL from
performing a DROP/CREATE on a table involved in a referential integrity
relationship. Now your foreign keys are completely gone. I haven't
checked that behavior in later versions, however. Oracle requires DROP
TABLE <table> CASCADE CONSTRAINTS to force a DROP of a table involved in
a primary/foreign key relationship.

Mike Mascari
mascarm@mascari.com