A correctness criterion for advanced transaction models

Abstract

The transaction concept was originally applied to database applications. Serializability theory captured transaction correctness and database objects consistency properties in a single notion. Today, increasingly sophisticated information requires new correctness criteria due to the limitation of classical serialisability theory which allows only a limited cooperation between its components. Several models relaxing the ACID (Atomicity, Consistency, Isolation, Durability) properties in a controlled manner have been developed. These approaches exploit separately the semantics properties of operations (object semantic approach) and application semantics (transaction interleaving approach). The notion of correctness can be refined with the help of the two previous approaches whilst increasing concurrency. In this paper, we will the gap between transaction and object semantic correctness criteria. We define a new class of schedule called Multilevel Relative Serialisability (MLRS) to combine the two approaches. This class of schedule preserve correctness properties defined in terms of object and transaction semantics. We use ACTA formalism to express object consistency, transaction correctness and MLRS. This work merges existing /spl Lt/relaxed/spl Gt/ transaction models into a unified concept. This concept is useful for long-lived, cooperative and hierarchical transaction models.