MAKING SYBASE FULLY ACTIVE: SUPPORTING COMPOSITE EVENTS AND PRIORITIZED RULES
A database management system (DBMS) is a software system for reliably and efficiently creating, maintaining, and operating large information repositories that can be accessed concurrently by a large number of users. Commercial RDBMSs used to be passive earlier, but currently support limited active capability. Active database management system is one that extends the passive DBMS with the ability to react to set of pre-defined situations or conditions (induced by the changes applied to the database). Event Condition and Action (ECA) rules are typically used to enhance the native active capability present in the RDBMS.
The goal of this thesis is to generalize the mediated approach to support active capability. Introducing a generalized ECA agent between the Database Server and the client permits us to enhance the native active capability of RDBMSs. The architecture, design, and implementation of this approach are explained in this thesis. The system developed supports primitive and composite events in different contexts. The mediated approach used in this thesis is in contrast to the integrated approach for supporting active capability. This approach is useful when it is not possible to change or add code to the underlying system.
This approach provides an alternative way to support complete ECA paradigm using a mediated approach by using the "trigger" capability available in the underlying DBMS.