Events in an Active Object-Oriented Database System.
Styliani Gatziu · 1994
In this paper we investigate the definition, detection, and management of events in the active object-oriented database system SAMOS. First, we present various event specification facilities based on simple but nevertheless powerful constructs which support the modelling of time aspects as well. Second we show how events can be detected in an efficient way. Finally, we deal with the internal representation of events using the benefits of the underlying data model. 1 Introduction Most new developments in database technology aim at representing more real-world semantics in the database which would otherwise be hidden in applications. Active database systems (aDBS) are able to recognize specific situations (in the database and beyond) and to react to them without immediate, explicit user or application requests. In addition to the functionalities supported by a passive DBS, an aDBS registers events, conditions, actions and the association between them by means of ECA-rules (Event-Condit...