Delta abstractions: a technique for managing database states in runtime debugging of active database rules

Abstract

Delta abstractions are introduced as a mechanism for managing database states during the execution of active database rules. Delta abstractions build upon the use of object deltas, capturing changes to individual objects through a system-supported, collapsible type structure. The object delta structure is implemented using object-oriented concepts such as encapsulation and inheritance so that all database objects inherit the ability to transparently create and manage delta values. Delta abstractions 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 delta abstractions can be used to inspect the state of active rule execution. An active rule analysis and debugging tool has been implemented to demonstrate the use of object deltas and delta abstractions for dynamic analysis of active rules at runtime.Index Terms-Active database systems, object deltas, rule analysis and debugging.

Monitoring data dependencies in concurrent process execution through delta-enabled grid services

“…Based on the concept of object deltas, delta abstractions were defined in (Ben Abdellatif, 1999) to establish a run-time, interactive analysis and debugging tool for active rules. A delta abstraction provides a view of the object deltas associated with an ADOOD language component, such as an active rule, an update method, or a transaction (Urban et al, 2003). Thus the changes made by the specific instance of a language component can be used to observe the dynamic execution of active rules, to rollback rule execution in the context of different language components, to modify rule execution sequences, and to compare the results of different rule execution orders.…”

“…Delta-Enabled Grid Services (DEGS) (Blake, 2005) are a foundational aspect of the DeltaGrid environment, extending Grid Services with the capability of recording incremental data changes, known as deltas. The design of a DEGS is based on the concept of object deltas (Sundermier et al 1997) and delta abstractions (Ben Abdellatif 1999;Urban et al, 2003), which were originally introduced to capture the incremental data changes made to the properties of objects in an object-oriented database. The deltas generated by DEGS are sent to a DeltaGrid Event Processor and then forwarded to a Process History Capture System that organizes deltas from distributed sources into a global, time-sequenced schedule of data changes.…”

A database approach for information communication in a peer‐to‐peer collaborative CAD environment

“…In our system, P2P database facilities [11] in addition provide a decentralized architecture where changes are detected by database procedures and active rules, and then propagated between peers. The work on object deltas in [24] describes representation of changes in an object-oriented database as first-class objects for debugging active rules. Our work is similar in that we also determine changes in object values and store them in an object-oriented database.…”