The two types of backups can be categorized as either physical backups or logical backups. The table mode export processes specific tables. The user mode export is used to export all of a user's objects. The last mode, full database, exports all data relevant to the database including datafiles, tablespace and rollback segments. Import then can be used in either table, user or full database mode to recover the data from the point in time it was exported.
Image backups can backup all or specific control files, redo logs and datafiles in two modes.
This process involves performing backups while the database is running. Once the backup has been performed, the control file is backed up. This process involves identifying not only the image backup that was used, but the correct archived redo log. There is no doubt that the import, export and image backup facilities in Oracle provide a basic means of ensuring that database objects can be backed up and restored. For example, SQL-BackTrack has a feature to perform physical incremental backups that backs up only the data blocks that have changed since the last physical backup.