0

Advances in the area of active database management systems require the development of a trigger design theory, which guides the user in the deenition oo well-behaving trigger based applications. The development of such a theory requires a formal deenition of trigger semantics. This paper describes a framework for such a formalisation of triggers. That is, the parameters of trigger execution and...

Although there are a number of issues to resolve, active databases, object-oriented databases, and deductive databases can be smoothly integrated. We present the integration challenges, provide a resolution to the issues, and show a way to achieve this integration by describing the active, object-oriented, and deductive features of a model/language called Harmony. Harmony lets us see the integr...

Learning from Past Query Processing— In today’s databases, the answers to past queries barely benefit processing future queries. The query answers and the work performed for processing queries—such as I/O and computations—are no longer used after returning query answers. Database Learning (DBL) [4] proposes to change this paradigm in an approximate query processing (AQP) context. DBL uses its k...

Integrating a production rules facility into a database system provides a uniform mechanism for a number of advanced database features including integrity constraint enforcement, derived data maintenance, triggers, alerters, protection, version control, and others. In addition, a database system with rule processing capabilities provides a useful platform for large and e cient knowledge-base an...

An active database rulebase is a set of ECA rules that can be manipulated by an active database. Thus, an ADB rulebase is not static, but it evolves over time. Typically, ECA rules can be added, deleted, modified, enabled, and disabled. Each update of the ADB rulebase can potentially lead to different behaviors of the ECA rules at run time, in particular with respect to termination and confluen...

Active real-time databases have emerged as a research area in which concepts of active databases and real-time databases are combined into a real-time database with reactive behavior. However, this marriage is not free from complications. The main problem is that timeliness, i.e., predictability and eeciency, is of paramount importance in real-time databases, while reactive behavior may add to ...

We propose a visualization tool to help application developers in understand-ing/debugging the execution of event-based applications. Vizar allows applications to record and then replay executions of event-based systems. It is a general purpose visualization service. It is not intended or linked in any way to any speciic system { eventhough it was rst targeted for active databases. Also we inve...