An important part of developing a backup plan is determining how often to back up your databases.
The frequency of your backups determines how much work you lose in the event of a media failure.
Dump each user database immediately after you create it, to provide a base point, and on a fixed schedule thereafter.
SAP recommends a minimum of daily backups of the transaction log and weekly backups of the database. Many installations with large and active databases make database dumps every day and transaction log dumps every half hour or hour.
Interdependent databases—databases where there are cross-database transactions, triggers, or referential integrity—should be backed up at the same time, during a period when there is no cross-database data modification activity. If one of these databases fails and requires reloading, reload them all from these simultaneous dumps.