ARCHITECTURE AND IMPLEMENTATION OF AN INTERACTIVE TOOL FOR THE DESIGN AND VISUALIZATION OF ACTIVE CAPABILITY

摘要

Active capability has been proposed as a paradigm to meet the demands of many database and other applications that require a timely response to situations. Event ― Condition ― Action (or ECA) rules are used to support active capability in a system. The design of an active DBMS for a particular application entails the design of schema for that application as well as ECA rules that correspond to business rules, constraints, invariants, and situations to be monitored in that application. This paper concentrates on: ⅰ) architecture and development of a general-purpose lightweight proxy that enables us to support interfaces on distributed or web-based environment uniformly and ⅱ) design and implementation of an interactive visualization tool for Active Database systems (ADBs). The tool is intended both as a debugging tool and a visualization tool based on the proposed architecture. The tool allows the designer/user to set breakpoints on event occurrences and rule execution or to enable/disable events and rules at run time. The priority and other attributes of rules can be changed interactively to study the behavior of rule interaction among themselves and with transaction/applications.