Find locked objects

If a table used by an user A is locked by User B then A needs to wait until B unlocks it. By issuing this query, User A can find which tables in his schema are locked and which session has locked it. It has been tested on versions 8 and up.

SQL>select a.sid,a.serial#,c.object_name 
 from V$session a, 
 V$locked_object b, 
 user_objects c 
 where a.sid=b.session_id 
 and b.object_id=c.object_id; 
 

Output:

 SID SERIAL# OBJECT_NAME 
 ---- ------- ------------ 
 7 36 emp 
 9 58 dept 
 
 2 rows selected. 

Now you can release the lock:

 
 SQL>alter system kill session '7,36'; 
 
 System Altered. 
 
 SQL>alter system kill session '9,58'; 
 
 System Altered. 
 

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