PrefetchGuide: Capturing Navigational Access Patterns for Prefetching in Client/Server Object-Oriented/Object-Relational DBMSs

Abstract

In prefetching, the objects that are expected to be accessed in the future are fetched from the server to the client in advance. Prefetching reduces the number of round-trips and increases the system performance. To prefetch object effectively, we need to correctly predict the future navigational patterns. In this paper, we propose the PrefetchGuide, a novel data structure that captures the navigational access patterns. We also formally define the notion of the attribute access log set and analyze the navigational access patterns that can be captured by the PrefetchGuide. We then present an prefetching algorithm using the PrefetchGuide. To show effectiveness of our algorithm, we have conducted extensive experiments in a prototype object-relational database management systems (DBMS). The results show that our method significantly outperforms the state-of-the-art prefetching method. These results indicate that our approach provides a practical method that can be implemented in commercial object-oriented/object-relationaI DBMSs. We believe our method is practically usable for object-oriented programmers and DBMS implementors. (C) 2002 Elsevier Science Inc. All rights reserved.