How to find active SQL statements in Oracle

Everyone has a favorite script to find the active SQL statements. Here is one of mine, it’s RAC friendly too..

     set serverout on size 999999
     declare
     begin
     dbms_output.put_line(' ');
     dbms_output.put_line('************* Start report for WAITING sessions with current SQL ***************');
     for x in (select vs.inst_id, vs.sid || ',' || vs.serial# sidser, vs.sql_address, vs.sql_hash_value,
     vs.last_call_et, vsw.seconds_in_wait, vsw.event, vsw.state
     from gv$session_wait vsw, gv$session vs
     where vsw.sid = vs.sid
     and vsw.inst_id = vs.inst_id
     and vs.type <> 'BACKGROUND'
     and vsw.event NOT IN ('rdbms ipc message'
     ,'smon timer'
     ,'pmon timer'
     ,'SQL*Net message from client'
     ,'lock manager wait for remote message'
     ,'ges remote message'
     ,'gcs remote message'
     ,'gcs for action'
     ,'client message'
     ,'pipe get'
     ,'Null event'
     ,'PX Idle Wait'
     ,'single-task message'
     ,'PX Deq: Execution Msg'
     ,'KXFQ: kxfqdeq - normal deqeue'
     ,'listen endpoint status'
     ,'slave wait'
     ,'wakeup time manager'))
     loop
     begin
     dbms_output.put_line('Event WaitState InstID SidSerial LastCallEt SecondsInWait');
     dbms_output.put_line('************************* ******************** ****** *********** ********** *************');
     dbms_output.put_line(rpad(x.event,25) ||' '|| rpad(x.state,20) ||' '|| lpad(x.inst_id,6) ||' '|| lpad(x.sidser,11) ||'
     '|| lpad(x.last_call_et,10) ||' '|| lpad(x.seconds_in_wait,13));
     dbms_output.put_line(' SQLText ');
     dbms_output.put_line('****************************************************************');
     for y in (select sql_text
     from gv$sqltext
     where address = x.sql_address
     and hash_value = x.sql_hash_value
     and inst_id = x.inst_id
     order by piece)
     loop
     dbms_output.put_line(y.sql_text);
     end loop;
     end;
     end loop;
     dbms_output.put_line('************** End re! port for sessions waiting with current SQL ****************');
     dbms_output.put_line(' ');
     end;
     /

http://www.oracle.com/technology/oramag/code/tips2004/062104.html