The architecture of an active database management system

Abstract

The HiPAC project is investigating active, time-constrained database managment. An active DBMS is one which automatically executes specified actions when speciifed conditions arise. HiPAC has proposed Event-Condition-Action (ECA) rules as a formalism for active database capabilities. We have also developed an execution model that speicifes how these rules are processed in the context of database transactions. The additional functionality provided by ECA rules makes new demands on the design of an active DBMS. In this paper we propose an architecture for an active DBMS that supports ECA rules. This architecture provides new forms of interaction, in support of ECA rules, between application programs and thDBMS.This leads to a new paradigm for constructing database applications.

Mobility in Publish/Subscribe Systems

“…In a database, data are persisted in a database and queries retrieve these data, whereas in the publish/subscribe model, the queries (subscriptions) are stored at the broker, and the data (publications) are pushed to the subscribers. A subscription can be thought of as a long running query, so it may be helpful to think of publish/subscribe model as being similar to database triggers [18]. It is important to note that in most publish/subscribe systems, subscriptions only match future publications.…”

Leveraging information sharing to configure supply chains

“…First, the ERP systems or supply chain applications feed planning, transactional and processrelated data into a database which stores shared data objects. Second, an information flow engine based on ECA rules (McCarthy and Dayal 1989) is used to facilitate information flows exchanged between partners. Third, to build "sense-and-respond" capabilities (Kapoor et al 2005) in a supply chain, an event engine (Liu et al 2007) is included to detect, analyze, and respond to events in real time.…”

A UML-based approach for the development of shop floor control systems

“…A state is shown as a rectangle with rounded corners whereas a transition is drawn as a line between two states, with an arrowhead pointing to the destination state. The transition can be labelled with the ECA (event-condition-action) rule (McCarthy and Dayal 1989) in the form of E[C]A, where E is the event, C is the guard condition and A is an action expression. An ECA rule represents the fact: the associated transition is triggered and the action A is then executed when the object being in the source state receives the event E and the guard conditions C are satisfied.…”