Oracle RMAN — A Practical Guide to Backup and Recovery

Oracle Recovery Manager is the only correct way to back up an Oracle database. But configuring and testing it properly requires experience. Here are our best practices after three years in production.

Backup Types¶

Full backup (level 0): a complete copy of all data blocks. Incremental (level 1): only changed blocks since the last backup. Cumulative incremental: changed blocks since the last full backup. Our strategy: full on Sunday, incremental every day.

Block Change Tracking¶

Without BCT, RMAN must read every block to determine if it changed. With BCT, a map of changed blocks is maintained — incremental backups are orders of magnitude faster. Enable it with: ALTER DATABASE ENABLE BLOCK CHANGE TRACKING.

Point-in-Time Recovery¶

With archive logs, you can restore the database to any point in time. RMAN RESTORE DATABASE, RECOVER DATABASE UNTIL TIME ‘2013-01-27 14:30:00’. A safety net for human errors (DROP TABLE) and corruption.

Catalog vs. Control File¶

RMAN can store metadata in the control file or in a separate RMAN catalog (another Oracle schema). For production, we recommend the catalog — a central location for backup metadata across multiple databases, with better reporting.

Testing¶

RMAN VALIDATE checks backup integrity without an actual restore. RESTORE DATABASE VALIDATE simulates a restore. Quarterly, we perform an actual restore to a test server.

Rules¶

1. Full weekly, incremental daily. 2. Block Change Tracking enabled. 3. Archive logs on separate storage. 4. RMAN catalog for multi-DB environments. 5. Test recovery regularly.