The integration of active database technology into mobile database systems allows to limit the transfer of data between mobile computers and the stationary network. In order to employ such active database mechanisms, the rule processing component of traditional active database systems needs to be modified. This paper introduces a new model for event processing and presents a new algorithm for t...

Business rules can be formulated according to the eventcondition-action structure of triggers in active databases. However, delays in the execution of such rules can cause unexpected and undesired side-effects. While business rules are commonly constructed from an external user’s perspective, users often neglect to cater for the cases in which unanticipated sequences of I/O and rule activation ...

Active database systems enhance the functionality of traditional databases through the use of active rules or`triggers'. There is little consensus, though, on what components should be included in a rule system. In this paper, the expressive power of some simple active database rule systems is examined and the eeect of choosing diierent features studied. Four important parameters of variation a...

A key facility of active database management systems is their ability to detect and react to the occurrence of events. Such events can be either atomic in nature, or speciied using an event algebra to form complex events. An important role of an event algebra is to deene the semantics of when events become invalid (event consumption). In this paper, we examine a simple event algebra and provide...

The need for user-defined execution orders (or control structures) for rules is well recognized by researchers of active database management systems. Priority-based approaches (e.g., numeric priorities) have been used to specify a desired control structure among rules. However, due to the fact that fixed priorities are assigned to rules, independent of different contexts in which they may be tr...

The integrated monitoring within heterogeneous database environments can become complex, due to the particularities in the language syntax and available tools. In particular, active databases allow developing mechanisms and automation of processes involving data or objects. This work proposes the development of an architecture to identify and monitor DDL, exploring the active databases and reco...

Today, enterprises maintain many, disparate information sources over which complex business procedures and applications are executed. The informal and ad hoc characteristics of these environments make the information in them very prone to inconsistency. Yet, the exibility of application execution given to diierent parts of an organization is desirable. This paper introduces a new mechanism in w...

Although much work in the area of Active Database Management Systems (ADBMSs) has been done, it is not yet clear how the performance of an active DBMS can be evaluated systematically. In this paper, we describe the OBJECTIVE Benchmark for objectoriented ADBMSs, and present experimental results from its implementation in an active database system prototype. OBJECTIVE can be used to identify perf...

Current active database management systems (ADBMS) are typically realized as monolithic, tightly integrated software systems. Separating the active database mechanisms from the DBMS, would open the opportunity to use them in a variety of ways and environments. In order to build the respective decoupled active database facilities, construction systems are required. The realization of such a cons...