A semantic-based transaction model for active heterogeneous database systems

Presents a framework to process transactions in active heterogeneous database systems. In order to schedule the transactions correctly with high performance, the framework provides semantic-based concurrency control on the global level. It relaxes the correct criterion (global serializability) to allow the global sub-transactions on each site to execute in a different order. The global transactions include data transactions and rule transactions. A data transaction is a general database transaction. A rule transaction is formed by active rules during the data transaction. During the global transaction process, both data and rule transactions are managed by different control modules. The data transaction is decomposed into several global sub-transactions. The global semantic-based transaction module produces a correct parallel schedule for the global sub-transactions. The rule transaction may generate new global transactions during rule inference. The advantages of providing semantic-based transactions on the global level are that they reduce the number of aborts produced by the incorrect global ordering of the local database schedules and they improve the performance of the global transactions.