Patent ID: 8725693

Claim:
A method of reinstating an unreinstated database system which has become unreinstated as a result of a reinstatement event in a failover configuration, the method comprising: receiving a reinstatement descriptor from a primary database system, the primary database system having made the reinstatement descriptor in response to the reinstatement event; and performing the reinstatement as indicated by the reinstatement descriptor on a database of the unreinstated database system, in which the reinstatement descriptor specifies a redo divergence point in a redo data of the unreinstated database system, in which the redo divergence point is a point such that when the database of the unreinstated database system is restored no further than to the redo divergence point and a redo data from the primary database system is applied to the restored database of the unreinstated database system after reinstatement, the restored database does not diverge from the database of the primary database system; wherein: the reinstatement event has one of a plurality of types; the reinstatement descriptor includes the type of the reinstatement event to which the primary database system was responding when the primary database system made the reinstatement descriptor; and in the act of performing, the reinstatement is performed as indicated by the type of the reinstatement event.