AGILE - Adaptive Indexing for Context-Aware Information Filters Jens-Peter Dittrich, Peter M. Fischer, and Donald Kossmann   View Paper (PDF)   Return to Adaptive, Automatic, Autonomic Systems (Research) Abstract Information filtering has become a key technology for modern information systems. The goal of an information filter is to route messages to the right recipients (possibly none) according to declarative rules called profiles. In order to deal with high volumes of messages, several index structures have been proposed in the past. The challenge addressed in this paper is to carry out stateful information filtering in which profiles refer to values in a database or to previous messages. The difficulty is that database update streams need to be processed in addition to messages. This paper presents AGILE, a way to extend existing index structures so that the indexes adapt to the message/update workload and show good performance in all situations. Performance experiments show that AGILE is overall the clear winner as compared to the best existing approaches. In extreme situations in which it is not the winner, the overheads are small. ©2006 Association for Computing Machinery