Hi I have a rac oracle 9204 ,IBM p570 aix5304 And I tried to delete a foreign key by ALTER TABLE BN_MAINS DROP CONSTRAINT BN_MAINS_FOR I don’t know what was happened It’s possible the delete operation have not completed The table bn_mains cannot be access For example , when I run Desc bn_mains In sqlplus, then sqlplus hang How can I return it? Thanks