• The KIPS Transactions:PartD
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• v.8D no.1
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• pp.10-23
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• 2001

Transactions in real-time active databases have the notion of activeness where transactions are generated by external effects and another transaction. In this paper, we propose the multi version concurrency control algorithm for real-time active transactions. A real-time active transaction has a timing constraint in the form of a deadline until which the user wants to complete the transaction, and is characterized by triggering relationships which mean that association between a transaction that triggers the execution of another transaction and the triggered transaction. The triggering relationship is an important factor to resolve data conflicts among real-time active transactions. The proposed concurrency control mechanism resolves data conflicts by considering triggering relationships between conflicting transactions as well as priorities and precedence relationships. The conflict resolution mechanism considers association types of the triggering relationship such as abort and commit dependency, and then resolves data conflicts in favor of higher priority transactions. We also present the experimental results of our algorithm comparing other real-time active concurrency control algorithms.