select sid,serial#,event,BLOCKING_SESSION from v$session where event like '%TX%';

select sid,serial#,username,machine,blocking_session from v$session where sid=<SID>;

ALTER SYSTEM DISCONNECT SESSION '<SID>,<SERIAL>' IMMEDIATE;

ALTER SYSTEM KILL SESSION '<SID>,<SERIAL>';

col waiting_session for a20col lock_type for a15col mode_requested for a10col mode_held for a10col lock_id1 for a10col lock_id2 for a10set linesize 120set pagesize 999with dba_locks_cust as (SELECT  inst_id||'_'||sid session_id,      DECODE (TYPE,          'MR', 'Media Recovery',          'RT', 'Redo Thread',          'UN', 'User Name',          'TX', 'Transaction',          'TM', 'DML',          'UL', 'PL/SQL User Lock',          'DX', 'Distributed Xaction',          'CF', 'Control File',          'IS', 'Instance State',          'FS', 'File Set',          'IR', 'Instance Recovery',          'ST', 'Disk Space Transaction',          'TS', 'Temp Segment',          'IV', 'Library Cache Invalidation',          'LS', 'Log Start or Switch',          'RW', 'Row Wait',          'SQ', 'Sequence Number',          'TE', 'Extend Table',          'TT', 'Temp Table',          TYPE)        lock_type,      DECODE (lmode,          0, 'None',            /* Mon Lock equivalent */          1, 'Null',                     /* N */          2, 'Row-S (SS)',                  /* L */          3, 'Row-X (SX)',                  /* R */          4, 'Share',                    /* S */          5, 'S/Row-X (SSX)',                /* C */          6, 'Exclusive',                  /* X */          TO_CHAR (lmode))        mode_held,      DECODE (request,          0, 'None',            /* Mon Lock equivalent */          1, 'Null',                     /* N */          2, 'Row-S (SS)',                  /* L */          3, 'Row-X (SX)',                  /* R */          4, 'Share',                    /* S */          5, 'S/Row-X (SSX)',                /* C */          6, 'Exclusive',                  /* X */          TO_CHAR (request))        mode_requested,      TO_CHAR (id1) lock_id1,      TO_CHAR (id2) lock_id2,      ctime last_convert,      DECODE (block,          0, 'Not Blocking', /* Not blocking any other processes */          1, 'Blocking',   /* This lock blocks other processes */          2, 'Global',  /* This lock is global, so we can't tell */          TO_CHAR (block))        blocking_others   FROM gv$lock),lock_temp as(select * from dba_locks_cust),lock_holder as ( select w.session_id waiting_session,    h.session_id holding_session,    w.lock_type,    h.mode_held,    w.mode_requested,    w.lock_id1,    w.lock_id2 from lock_temp w, lock_temp h where h.blocking_others in ('Blocking','Global') and h.mode_held   != 'None' and h.mode_held   != 'Null' and w.mode_requested != 'None' and w.lock_type    = h.lock_type and w.lock_id1    = h.lock_id1 and w.lock_id2    = h.lock_id2),lock_holders as(select waiting_session,holding_session,lock_type,mode_held,mode_requested,lock_id1,lock_id2 from lock_holder union all select holding_session, null, 'None', null, null, null, null   from lock_holder minus select waiting_session, null, 'None', null, null, null, null  from lock_holder  )select lpad(' ',3*(level-1)) || waiting_session waiting_session,    lock_type,    mode_requested,    mode_held,    lock_id1,    lock_id2 from lock_holdersconnect by prior waiting_session = holding_session start with holding_session is null;