Oracle — 11g

SELECT sql_id, sql_text FROM v$sql WHERE sql_id = (SELECT sql_id FROM v$session WHERE sid = <blocking_sid>); This will help you identify poorly written transactions or missing COMMIT statements.

ALTER SYSTEM KILL SESSION 'sid,serial#' IMMEDIATE; Example: oracle 11g

ALTER SYSTEM KILL SESSION '142,3892' IMMEDIATE; Sometimes the killed session lingers. Use this to force cleanup: SELECT sql_id, sql_text FROM v$sql WHERE sql_id =