Coordinating distributed executions is achieved by two widely used approaches: process groups and transactions. Typically, the two represent a trade-oo in terms of the degrees of consistency and performance. By applying transaction concurrency control techniques to characterize and design process group multicast orderings, we aim to provide aspects of both ends of the trade-oo. In particular, w...

Since long-lived computations (e.g. workflow systems) cannot be realized with classical transactions, extended models have been developed to support this special class of executions with proper semantics. The main problem with these new models is the lack of an extended concurrency control mechanism which makes it possible to use all advanced features of the new methods. This article presents a...

This paper describes the integration of concurrency control in BALLOON, an object-oriented language that separates the concepts of type and class as well of subtyping and subclassing. Types are interface specifications enriched with concurrency control annotations. Classes are used to implement the operational functionality of types as well as concurrency control mechanisms. Types, classes and ...

In this paper, we propose a new class of Concurrency Control Algorithms that is especially suited for real-time database applications. Our approach relies on the use of (potentially) redundant computations to ensure that serializable schedules are found and executed as early as possible, thus, increasing the chances of a timely commitment of transactions with strict timing constraints. Due to i...

Optimistic concurrency control highly takes advantage of parallelism because there is no delay by lock. Unfortunately, I/O operations by transactions and cache operations are delayed in the optimistic concurrency control. In order to reduce such delay, we combine cache coherency control and optimistic concurrency control rather than they operate in separate. In this paper, we propose optimistic...

We consider a finitary procedural programming language (finite data-types, no recursion) extended with parallel composition and binary semaphores. Having first shown that may-equivalence of second-order open terms is undecidable we set out to find a framework in which decidability can be regained with minimum loss of expressivity. To that end we define an annotated type system that controls the...

In many database applications, incoming transactions are a mixed load of conventional (non real-time) and real-time (typically soft and rm) transactions. In this environment, transactions can even be changed dynamically from non real-time to soft or rm, or from soft to rm deadline transactions according to their execution paths. In this paper we show how lock based approach can handle these sit...

Functions which control the access to data in groupware should be flexibly designed by offering different options to the end users. However, conflicts might arise among different end users in the process of selecting one of these options. To support users in finding a consentaneous solution for these conflicts, we propose a metafunction called "negotiability". We propose to define and explore t...