There are many different types of Oracle backups. First, you have logical and physical backups. Logical backups are taken with Oracle's export utilities. Physical backups are performed either hot or cold. With cold backups, you shut down the database and then you use OS copy commands to copy the database datafiles to your backup destination. Hot backups are best performed by using RMAN (which can also do cold backups). RMAN offers different types of backups as well. With RMAN, you can back up the entire database, back up certain tablespaces, and perform incremental backups as well. If this sounds like there is a lot of things to consider with backing up your Oracle database, that's because there is! Oracle has provided many different backup and recovery methodologies to handle a great many different situations. The only way to understand which method is best for you is to figure out how they all work. This document is Oracle's start at teaching you backup and recovery from an Oracle perspective.
Additionally, you may want to pick up any of the fine books from Oracle Press concerning Oracle backups. These are great books which can enhance your library and your skill set. You can pick up Oracle Press books on Amazon, or your local Barnes & Noble or Borders, here in the United States. I'm sure other countries have similar outlets.
This was first published in January 2006