Online Backups

The best practice for backing up the master index database is an online backup during which the database is not shut down. (Note that this does require an offline backup as a starting point to which any online changes can be applied in the event the database must be restored). An online backup will always take a consistent snapshot, though it might not backup all transactions in progress.

Each transaction in the master index application is saved under one commit command, so the state of the database is always consistent when a backup is performed. The history tables always match the transactions in the current tables and no partial transactions are committed. Even if a transaction is underway at the time of the backup, the database is consistent.

For the most reliable backups for Oracle databases, Oracle recommends running the Oracle database in ARCHIVELOG mode. ARCHIVE mode ensures that your database is protected from both instance and media failure and, because all changes made to the database are saved in a redo log, all database updates are available for recovery rather than just the most recent changes. For SQL Server, Microsoft recommends running the SQL Server database using the full recovery model, which allows a database to be recovered to the point of failure. Online backups are available for Oracle and SQL Server databases running in these modes.