John, You did not mention the Database version, but if it is 10g, then the *spread* of timings for various events is provided in snapshots of V$EVENT_HISTOGRAM. Look for skews in snapshots of this view. Unfortunately, STATSPACK in 10g records this while AWR does not. -- John Kanagaraj <>< DB Soft Inc http://www.linkedin.com/in/johnkanagaraj http://jkanagaraj.wordpress.com (Sorry - not an Oracle blog!) ** The opinions and facts contained in this message are entirely mine and do not reflect those of my employer or customers ** -- //www.freelists.org/webpage/oracle-l