Conventional concurrency control protocols are inapplicable in mobile broadcast environments due to a number of constraints of wireless communications. Previous studies are focused on efficient processing of read-only transactions at the mobile clients, neglecting update transactions. In this paper, we design a new protocol for processing both read-only and update mobile transactions. The proto...

Studies in [7, 8, 91 concluded that for a variety of reasons, optimistic concurrency control appears well-suited to real-time database systems. Especially, they showed that in a real-time database system that discards tardy transactions, optimistic concurrency control outperforms locking. In this paper, we show that the optimistic algorithms used in those studies incur restarts unnecessary to e...

Multi-versioned database systems have the potential to significantly increase the amount of concurrency in transaction processing because they can avoid read-write conflicts. Unfortunately, the increase in concurrency usually comes at the cost of transaction serializability. If a database user requests full serializability, modern multi-versioned systems significantly constrain read-write concu...

Research on real-time database systems (RTDBS) has been underway for close to a decade now. So far, this research has focused mainly o11 identifying the appropriate choice, with respect to meeting the real-time goals, for the various database system policies such as priority assignment, transaction concurrency control, memory management, etc. (see [16] for a recent survey). However, the design ...

A problem with Speculative Concurrency Control algorithms and other common concurrency control schemes using forward validation is that committing a transaction as soon as it nishes validating, may result in a value loss to the system. Haritsa showed that by making a lower priority transaction wait after it is validated, the number of transactions meeting their deadlines is increased, which may...

In this paper, it combines the dynamic nature of grid services with the capabilities alternative of real-time transactions. First of all, the grid real-time transaction model based on function equivalent service is defined .The model supports the joint implementation by a number of function equivalent services which own the same transaction, and allows grid services to join or exit the transact...

The concurrency control lock (e.g. file lock, table lock) has long been used as a canonical example of a covert channel in a database system. Locking is a fundamental concurrency control technique used in many kinds of computer systems besides database systems.Locking is generally considered to be interfering and hence unsuitable for multilevel systems. In this paper we show how such locks can ...

A federated database is comprised of multiple interconnected databases that cooperate in an autonomous fashion. Global integrity constraints are very useful in federated databases, but the lack of global queries, global transaction mechanisms, and global concurrency control renders traditional constraint management techniques inapplicable. This paper presents a threefold contribution to integri...