Oracle Database has information on the table locking stored in few Oracle table.

If you have encountered some error in the front end which was due to database table locking, then you can either check the table locking via Oracle Application Management or Oracle Enterprise Manager.

For a quick way, you can login to Oracle Database to execute the SQL script to detect which table locked.

Problem is when you run in the RAC environment database, you will have more than 1 Oracle Database machine to check on locking.

The Oracle Database SQL script as below can be execute in 1 single Oracle Database machine but it shows the total table locking in all the Oracle Database.

RAC Database Table Lock Checking Script

SQL> SELECT b.sid, b.serial#, a.spid, b.program, b.osuser, b.machine, 
b.type, b.event, b.action, b.p1text, b.p2text, b.p3text, 
b.state, c.sql_text,b.logon_time, 
b.STATUS,  e.owner, e.object_name "Table Lock"
FROM
gv$process a,
gv$session b,
gv$sqltext c,
gv$locked_object d,
dba_objects e
WHERE a.addr=b.paddr
AND b.sql_address = c.address
AND b.sid = d.session_id
AND d.object_id = e.object_id
AND b.STATUS = 'ACTIVE'
ORDER BY a.spid, c.piece