In this article we extend previous work on the development of logical foundations for the specification of the dynamics of databases. In particular, we deal with two problems. Firstly, the derivation of active rules that maintain the consistency of the database by triggering repairing actions. Secondly, we deal with the correct integration of the specification of the derived rules into the orig...

In an active database, triggers are red in response to the occurrence of events. Events may have attributes, and the values of these attributes may be used as parameters to functions invoked in the action part. Composite events may be speciied as the composition of primitive events in the database system. The attributes of a composite event are derived from the attributes of its constituent pri...

Different rule execution semantics may be available in the same active database system. We perform several simulation experiments t o evaluate the performance trade-offs yielded b y different execution semantics in various operating conditions. In particular, we evaluate the eflect of executing transaction and rule statements that a f f ec t a varying number of data instances, and applications ...

We introduce an active data mining paradigm that combines the recent work in data mining with the rich literature on active database systems. In this paradigm, data is continuously mined at a desired frequency. As rules are discovered, they are added to a rulebase, and if they already exist, the history of the statistical parameters associated with the rules is updated. When the history starts ...

Business rules are statements about business policies and can be formulated according to the event-condition-action structure of rules in active database systems. However, modeling business rules at the conceptual level from an external user's perspective requires a diierent set of concepts than currently provided by active database systems. This paper identiies requirements on the event langua...

Whenever technologies converge there exists the potential for huge benefits but also the risk of failure. The main pitfall when combining technologies that evolved independently consists in attempting to provide the union of features without properly considering the often incompatible assumptions and the crosseffects. In this paper real-time databases, active databases, and distributed object s...

Change definition and computation is an essential component in several capabilities of an active database, such as integrity constraints checking, materialized view maintenance and condition monitoring. We describe a method for change definition and computation, which is general and flexible. The method can be implemented easily in most active databases systems.

We refine an active-database application taxonomy, proposed by Stonebraker, to include monotonic log monitoring applications (MLM). MLMs are a subclass of hard rule systems where triggering events are restricted to monotonic relations. We develop a formal semantic model for the MLM class. We then prove the correctness of concurrency schemes for applications within the model. Our results demonst...

Active systems are emerging in many fields, being particularly interesting those like Active Database Management Systems which always provide some kind of reactive capabilities. In this paper, starting from the assumption that activity is an important notion not only for database systems, but also for capturing semantics in the Requirements Analysis and Specification field, we present a model o...

As XML is becoming widely accepted as a mean of storing, searching and extracting information, a larger number of Web applications will require conceptual models and administrative tools to organize their collections of documents. Recently, event-condition-action (ECA) rules have been proposed to provide reactive functionality into XML document databases. However, logical inference mechanisms t...