Protecting Database Integrity Protecting Database Integrity The InterSystems recovery process is designed to provide maximal protection: It uses the “roll forward” approach. If a system crash occurs, the recovery mechanism completes the updates that were in progress. By contrast, other systems employ a “roll back” approach, undoing updates to recover. While both approaches protect internal integrity, the roll forward approach used by InterSystems IRIS does so with reduced data loss. It protects the sequence of updates; if an update is present in the database following recovery, all preceding updates are also present. Other systems which do not correctly preserve update sequence may yield a database that is internally consistent but logically invalid. It protects the incremental backup file structures, as well as the database. You can run a valid incremental backup following recovery from a crash.
