Tom Lane wrote: > Michael Gould <mgo...@intermodalsoftwaresolutions.net> writes: > > It would be nice if we could enable and disable column and table > > constraints. I believe that you can do this in Oracle but this is very > > handy for testing stored procedures and other external processes. > > Drop the constraint and re-add it later...
That's not very useful when adding it later means grabbing an exclusive lock on the table for the whole duration of the full table scan required to check the table. Actually something in this area is on my plate too -- a customer of ours wants to be able to define constraints but not have it checked immediately. I envision it similar to how concurrent index creation works: the constraint is created as "not checked" and the transaction is committed; new insertions are checked against the constraint. Then the table is scanned to verify that extant tuples pass the constraint, _without_ the exclusive lock on the table. Both DB2 and Oracle have an ENFORCE setting for constraints, and a MySQL blog hinted some time ago that it might be in SQL 201x. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers