I noticed in the Oracle 10gR2 New Features Guide a piece on the Rules Manager. I have not yet figured out what it does exactly. But it certainly sounds interesting enough to return to later on. Perhaps it intrigues you as well:
Rules Manager is a new feature of Oracle Database 10g Release 2. It enables developers to create applications that process and respond to events of any complexity using rules and policies defined in the database. It can evaluate events using data from the application and from database tables. It stores intermediate results to quickly evaluate the next event in a long running composite event (an event made up of two or more simple events). Rules are defined using XML and SQL and can have complex conditions using conjunctions and disjunctions, and specify a set of events, time, and non-occurrence of events with or without a deadline. Event policies control how rules are processed and the duration of an event. Rules can trigger actions that are user-defined procedures running inside an Oracle Database or actions in another application.
The benefit of this feature is that rules that are managed in Oracle Database keep pace with changing business conditions and are always up-to-date; rules are easily changed with SQL and are not included in your application or loaded into a memory-based rules repository. Rules can be evaluated efficiently with the complete business context stored in your Oracle Database and data provided by your application. Event response is flexible; rules can trigger actions in Oracle Database or your application.
Additional advantages of Oracle Database over other approaches include:
* Manageability, by storing rules and event policies with your application data.
* Performance, by evaluating rules and coordinating multiple events and application threads with the full capabilities of Oracle Database.
* Scalability, by evaluating sets of rules of any size.