Four different hosts (Windows 2003 and Windows 2008): Oracle 9.2 STARTED DAYS ------------------- ---------- 21/11/2011 08:19:55 297,21 Oracle 10.2: STARTED DAYS ------------------- ---------- 23/10/2011 07:12:17 326,26 Oracle 11.1: STARTED DAYS ------------------- ---------- 30/07/2012 07:27:56 45,25 Oracle 11.2: STARTED DAYS ------------------- ---------- 19/04/2012 18:24:15 146,79 All machines get OS patches monthly (not listed here) or once a year. The supported versions also receive Oracle patches occasionally. In most cases these are the only downtimes. Best regards Ingrid -- //www.freelists.org/webpage/oracle-l