For cold backups, the database must be down for the time it takes to back up the entire database. For sites that have an availability requirement, this may not be viable. Unless you are in archivelog mode, the entire database must be backed up at the same time and restored as a whole. Oracle refers to this operation as a full backup .
In our discussion, the assumption is generally that you want to recover the entire database. However, it is possible to recover a subset of the tablespaces. A procedure for doing this is provided in the following sections.