How to see lock on table and query?

Question

Hi All,
How do we see lock on table and query?
Thanks,
Rafi

Answer 1

Yes Rafi,
It is working fine at my end. See below:
Opened Session 1 with scott/tiger and:
update emp set ename='xx' where empno=7499;
Opened Session 2 with scott/tiger and:
update emp set ename='xx' where empno=7499;
<<Its lock here>> This session is locked by above one.
Opened Session 3 with sys/pw as sysdba and:
SQL> set serveroutput on
SQL> BEGIN
  2  dbms_output.enable(1000000);
  3  for do_loop in (select session_id, a.object_id, xidsqn, oracle_username, b.owner owner,
  4  b.object_name object_name, b.object_type object_type
  5  FROM v$locked_object a, dba_objects b
  6  WHERE xidsqn != 0
  7  and b.object_id = a.object_id)
  8  loop
  9  dbms_output.put_line('.');
10  dbms_output.put_line('Blocking Session : '||do_loop.session_id);
11  dbms_output.put_line('Object (Owner/Name): '||do_loop.owner||'.'||do_loop.object_name);
12  dbms_output.put_line('Object Type : '||do_loop.object_type);
13  for next_loop in (select sid from v$lock
14  where id2 = do_loop.xidsqn
15  and sid != do_loop.session_id)
16  LOOP
17  dbms_output.put_line('Sessions being blocked : '||next_loop.sid);
18  end loop;
19  end loop;
20  END;
21  /
Blocking Session : 139
Object (Owner/Name): SCOTT.EMP
Object Type : TABLE
Sessions being blocked : 134
PL/SQL procedure successfully completed.HTH
Girish Sharma