How to Check Running Jobs in Oracle Database

The DBA scripts to query currently running Jobs in Oracle Database :

SELECT R.SID,U.USERNAME,J.JOB,R.THIS_DATE,J.WHAT
   FROM DBA_JOBS J, DBA_USERS U, DBA_JOBS_RUNNING R
   WHERE J.JOB=R.JOB
   AND J.LOG_USER=U.USERNAME;