On 04/17/2012 07:43 AM, Igor Neyman wrote: >> -----Original Message----- >> From: Chris Ernst [mailto:cer...@zvelo.com] >> Sent: Monday, April 16, 2012 10:55 PM >> To: email@example.com >> Subject: Re: Recreate primary key without dropping foreign keys? >> >> On 04/16/2012 07:02 PM, amador alvarez wrote: >>> How about deferring the FK's while recreating the PK ? >>> or using a temporary parallel table to be pointed by the other tables >>> (FK) and swap it up on the recreation. >> >> Hmm.. Interesting. But it appears that you have to declare the >> foreign >> key as deferrable at creation. Is there any way to set an existing >> foreign key as deferrable? >> >> - Chris > > May be this (from the docs) would help: > > "ADD table_constraint [ NOT VALID ] > > This form adds a new constraint to a table using the same syntax as > CREATE TABLE, plus the option NOT VALID, which is currently only allowed for > foreign key constraints. If the constraint is marked NOT VALID, the > potentially-lengthy initial check to verify that all rows in the table > satisfy the constraint is skipped. The constraint will still be enforced > against subsequent inserts or updates (that is, they'll fail unless there is > a matching row in the referenced table). But the database will not assume > that the constraint holds for all rows in the table, until it is validated by > using the VALIDATE CONSTRAINT option." > > Using this option you can drop and recreate corresponding FKs in a very short > time, and start using them, while postponing to run "VALIDATE CONSTRAINT" for > later. > > It's similar to Oracle's adding FK with "NOCHECK" option, but if IRC there is > no need to run "VALIDATE CONSTRAINT" later.
Hi Igor, Oooooo... I like the sound of this. I'll give this a shot in the test environment and report back my findings. Thanks a bunch! - Chris -- Sent via pgsql-admin mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin