You *might* just possibly be able to upgrade your own in-house written software without downtime. You *cannot* maintain Oracle software without downtime - 11g promises the actual shipping of 'rolling upgrades' just about 1/2 a decade after Larry first mentioned them. Until then (and it would be a brave person who relied on that particular feature in it's first release) then you cannot achieve 24*7 without either
Well, what 11g is *promising* (or was it Tom Kite's *prediction*?) is online evolution of APPLICATION schema. This doesn't mean that we will be able to do the same online evolution for sys schema. In fact, I can bet that it won't make patchset installation any more online than now. -- Best regards, Alex Gorbachev The Pythian Group Sr. Oracle DBA http://www.pythian.com/blogs/author/alex/ http://blog.oracloid.com -- //www.freelists.org/webpage/oracle-l