Why and how the record is locked by another user in Oracle

Prompt for "record locked by another user" workaround when deleting data in Oracle data:

1, check the database lock, the source and type of diagnostic lock:

Select Object_id,session_id,locked_mode from V$locked_object;

or use the following command: Select B.owner,b.object_name,l.session_id,l.locked_mode from V$locked_object l, dba_objects b where b.object_ id=l.object_id

2. Find out the serial# of the database for killing:

Select T2.username,t2.sid,t2.serial#,t2.logon_time from V$locked_object t1,v$session T2 where T1.session_id=t2.sid Order BY T2.logon_time;

3. Kill the session alter system kill session ' sid,serial# '