Methods for returning a corrupted database to a known, correct state by selectively using redo and undo operations

摘要

Both redo operations and undo operations are provided for returning a database that is corrupted to a correct state. When corruption of the database is detected, an automatic selection is made of one or more operations from the redo operations and undo operations for returning the database that is corrupted to a correct state. The selected one or more redo and undo operations are then performed on the database, thereby returning the database that is corrupted to a correct state.

主权项

1. A method of returning a database that is corrupted to a correct state, the database allowing for a plurality of transactions which operate upon the database, at least some of the transactions including a plurality of operations, the method comprising:
(a) providing both redo operations and undo operations for returning a database that is corrupted to a correct state; (b) detecting corruption of the database; (c) automatically selecting for each operation in a transaction that includes a plurality of operations at least one redo operation and at least one undo operation for returning the database that is corrupted to a correct state; and (d) performing the selected at least one redo operation and at least one undo operation on the operations in the transaction, thereby returning the database that is corrupted to a correct state, wherein the at least one redo operation and at least one undo operation are performed on operations of the same transaction.