Delta Abstractions: A Technique for Managing Database States in Active Rule Processing
Taoufik Ben Abdellatif, Susan D. Urban, Amy Sundermier, Suzanne W. Dietrich
Department of Computer Science and Engineering
Arizona State University
Tempe, AZ 85287-5406
602-965-2874
{s.urban}@asu.edu
Abstract
This paper introduces the concept of delta abstractions as a mechanism for
managing database states during the execution of active database rules. At a low
level, object deltas capture changes to individual objects through a
system-supported, collapsible type structure that is implemented using
object-oriented concepts such as encapsulation and inheritance. Delta
abstractions then provide an additional layer to the database programmer for
organizing object deltas according to different language components that induce
database changes, such as methods and active rules. As with object deltas, delta
abstractions are transparently created and maintained by the active database
system. We define different types of delta abstractions as views
of object deltas and illustrate how the services of deltas abstractions can be
used to inspect the state of active rule execution. Delta abstractions can
therefore be used to provide more meaning to the context in which object deltas
have occurred, thus supporting more effective tools for run-time analysis and
debugging of active database rules.
This research was supported by NSF grant no. IRI-9109195 and NSF grant no.
IRI-9410993.