The database must exist and be open to perform full database recovery using import. As well, at least one non-system rollback segment must be online to perform this activity. If time does not permit, or your database is just too big to permit writing a full database export every night, you need to design a strategy that exports components of your dynamic database files in a cycle. Look at table 1 to see a sample of what to do when using export against a very large database. Parameter files used in 4-cycle export routine Note that there are two parameter files in cycles 3 and 4.
Export is run once using each file.
Say cycle 2 was supposed to run on a Tuesday night and aborted. Repeat cycle 2 on Wednesday and delay running cycle 3 until Thursday. Backup Using Image Backups Image backups involve copying whole or part of the database o a secondary storage device, usually tape. Most installations, disk space permitting, copy the database files to disk, then put that disk copy to tape. In this section, I will discuss offline and online image backups and the protection they can provide.