Reliable and Recoverable Transactions in Object-Based Systems

Object based systems store information as objects; a storage format that intuitively reflects "real world" requirements. Users access the objects with transactions that take the object base from one stable state to another. Without failures, such as transaction aborts or system crashes, serializability theory and concurrency control algorithms are sufficient to provide correct transaction execution. If failures are present, transaction execution must be controlled so that transaction updates can be undone without affecting the consistency of the database. This thesis provides reliability definitions that govern transaction execution such that correct failure recovery is always possible. The recovery related components of the object based system architecture are depicted. Scheduler algorithms that satisfy the operation ordering criteria of the reliability definitions, are given. To support the reliable schedulers, a novel logging mechanism is introduced. This thesis shows that the datab..