Http://www.dba-oracle.com/t_rman_export_expdp.htm
Question: I 've been using data pump (the export utility) to backup my database, but I wonder if I shocould be using RMAN instead. they both do backups, so what's the advantages of each?
Answer: Yes, RMAN and export both backup tables, and they both support flashback database, but there are some important differences:
- Data Pump Export (expdp)-The Export Utility is a "logical" backup, usually done by specifying specific tables. if you fail to do a "consistent" export, or if you fail to include related tables and use restricted and consistent mode (with referential integrity constraints ), you may not be able to recover properly. export is often used as a supplement to rman, usually for the restore of specific tables.
- Recovery Manager (RMAN)-RMAN is designed for backup and recovery, a extension of the enterprise backup utility (EBU). RMAN takes full, physical, consistent backups of your database files ..
Advantages & disadvantages of export:
- Free, and easy to use
- Very slow, compared to RMAN (examines every data block)
- Easy restore of a specific table
- Does not require archivelog Mode
Advantages & disadvantages of RMAN:
- RMAN has block-level media recovery
- has a catalog for backup tracking and a report utility
- fast-if you dedicate a backup device for each production disk, You can backup terabytes in the time it takes to backup any single disk.
- does hot or cold backups
- backups and restores can be done in parallel
- allows incremental backups (block change tracking)
- interfaces with media management systems (TMS)
