Making constraints deferrable or enabling them with novalidate can be useful during data migration time. However, we need to ensure constraints are validated as this provides the cost based optimizer with additional information regarding the columns that it might just put to good use;
http://richardfoote.files.wordpress.com/2007/12/not-nulls-in-10g.txt
http://richardfoote.files.wordpress.com/2007/12/check-constraints-with-10g.txt
So my question is on 10gR2 during 7*24 applications running what is the best strategy to VALIDATE constraints which are left as ENABLED NOVALIDATE after a data migration?
SQL> ALTER TABLE .. MODIFY CONSTRAINT .. ENABLE VALIDATE PARALLEL 2 NOLOGGING ONLINE ;
ORA-00933: SQL command not properly ended
Thank you.