Hi There, we are doing a major upgrade to one of our systems which involves application/dbase upgrade and then a client roll out/upgrade.

Before the upgrade we will shutdown the database and take an offline backup of the datafiles to get a consistent database backup.
I was wondering if after the upgrade i can restart dbase in read only mode and and do the post upgrade backup this way. I presume this will still be a consistent database backup?
If so it will allow us to proceed with the client roll out while the database is being backed up but still being able to test connectivty of the client saving us some time.