Monitoring full table scans in DB

Hello -

Apart from OEM tool, can someone tell me how else can I monitor long running transactions and full table-scans in an oracle database? Any scripts?

Thanks

select sw.sid,s.serial#,sa.sql_text,sw.event,s.schemaname "oracle user",s.osuser "os user",s.machine from v$session_Wait
sw,v$sqlarea sa,v$session s where s.status='ACTIVE' and sw.event like '%db file sca%' and s.sql_hash_value=sa.hash_value
and s.sid = sw.sid;

This will give complete SQL and the SESSION doing full table scan

regards
anandkl

Thank you very much! Any other suggestions welcome!