Intelligent Caching for Information Mediators: A KR Based Approach

We present a semantic caching approach for optimizing the performance of information mediators. A critical problem with information mediators, particularly those gathering and integrating information from Web sources is a high query response time. This is because the data needed to answer user queries is present across several differentWeb sources (and in several pages within a source) and retrieving, extracting and integrating the data is time consuming. We address this problem using a semantic caching approach, where we cache useful classes of information and define them as auxiliary data sources for the information mediator. The key challenge here is to identify the contentandschema of the classes of information that would be useful to cache as the auxiliary sources. We present an algorithm that identifies such classes by analyzing patterns in user queries. The algorithm utilizes the kr system loom to reason about classes of information to cache. We describe an implementation of our caching approach and experiments in progress. We also discuss several other important problems that must be addressed in building a complete and effeciv