DBA_DDL_LOCKS lists all DDL locks held in the database and all outstanding requests for a DDL lock.
| Column | Datatype | NULL | Description | 
|---|---|---|---|
| SESSION_ID | NUMBER | Session identifier | |
| OWNER | VARCHAR2(30) | Owner of the lock | |
| NAME | VARCHAR2(30) | Name of the lock | |
| TYPE | VARCHAR2(40) | Lock type: 
 | |
| MODE_HELD | VARCHAR2(9) | Lock mode: 
 | |
| MODE_REQUESTED | VARCHAR2(9) | Lock request type: 
 |