by username select a.sid, a.serial#, b.sql_text from v$session a, v$sqlarea b where a.sql_address=b.address and a.username='xx' ;
by provide sid select a.sid, a.serial#, b.sql_text from v$session a, v$sqlarea b where a.sql_address=b.address and a.sid='xx' ;
find a blocking session detail
select a.blocking_session, a.sid, a.serial#, a.wait_class,
a.seconds_in_wait, b.sql_text from v$session a, v$sqlarea b where
a.blocking_session is not NULL and a.sql_address=b.address order by
a.blocking_session;