Predicate-based Cache Management for Continuous Partial Match Queries in . . .

The continuous partial match query is a partial match query whose result continues to exist consistently in the client's memory. Conventional cache management methods for mobile clients are record ID-based. However, since the partial match query uses a content-based retrieval, the conventional record ID-based approach cannot properly manage cache consistency. Therefore, in the paper, we propose a predicate-based cache management scheme for continuous partial match queries in mobile database systems. In the proposed cache management scheme, we represent the cache state of a mobile client as a predicate, and construct a cache invalidation report (CIR), which the server broadcasts to clients for cache management, with predicates. We show the predicate-based approach is an effective cache management method in mobile database systems. For reducing the amount of information that is needed in cache management, we propose a set of methods for CIR construction (in the server) and identi cation of invalidated data (in the client)