The index_name column of DBA_CONSTRAINTS was new with version 9 and only contains an entry when the constraint_type = 'P' for primary key or = 'U' for unique constraint. In other words this column shows you the index that supports a PK or UK constraint. See the Oracle 9.x or 10.x Reference Manaul for more information about DBA_CONSTRAINTS. HTH -- Mark D Powell -- -----Original Message----- From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of nn20002@xxxxxxxxxxxx Sent: Thursday, September 30, 2004 7:51 PM To: oracle-l@xxxxxxxxxxxxx Subject: foreign key constraint and the index_name in user_constraint table Hi, Could you please help me in this issue. I have a foreign key on a child table referencing the primary key of the parent table. I have created the index on the foreign key on the child table. Now, how do I know that the foreign key constraint is using the index or not. I tried to see the index name from user_constarints table, but it always shows empty. When index_name is empty, what does it mean, even though I have it. Thanks nagu -- //www.freelists.org/webpage/oracle-l