Below is where I am confused. While I have used EMC MirrorView and Snapview to do just this, I am curious as to where the 'cheaper' comparison comes in? From a licensing cost standpoint, whether I'm using some SAN vendor's disk tool, Some Oracle technology or home-grown database cloning technique, or some other third-parties software, I will need to license the test database. Maybe it is our contracts at my particular company. If I have EE licensed in production, I will have EE licensed in test. (Granted, we don't have to license per-cpu, and can do the minimum named user per our contract). Now, from a time and effort standpoint, I have found SAN replication to be easier and quicker for me, the DBA. (maybe not so for the SAN administrator, you'd have to ask him :) ). It might be nice to get to the core of the question rather than getting on a tangent. Not only does the original poster what to duplicate a 500+GB database, they want to be able to make changes to it during the day, and then have it re-synced with production nightly. I think some valid solutions to this question have been posted. 1. Use your SAN vendor's tools to do fancy things at the disk level. 2. Refresh from a known backup nightly from prod. 3. Use RMAN duplicate. etc. YMMV Bradd Piontek piontekdd@xxxxxxxxx On Tue, Mar 18, 2008 at 9:29 AM, Nuno Souto <dbvision@xxxxxxxxxxxx> wrote: > Exactly. Let's recap for a second: > > Point is simple: done in a sensible manner, > SAN replication is much cheaper for non-critical > test database duplication than the current > Oracle EE+DG licensing. > > That may not be the case in future or may > not have been in the past. It is now. > > -- > Cheers > Nuno Souto > dbvision@xxxxxxxxxxxx > > <//www.freelists.org/webpage/oracle-l> > > >