Extendible Hashing for Concurrent Operations and Distributed Data

The extendible hash file is a dynamic data structure that is an alternative to B-trees for use as a database index. While there have been many algorithms proposed to allow concurrent access to B-trees, similar solutions for extendible hash files have not appeared. In this paper, we present solutions to allow for concurrency that are based on locking protocols and minor modifications in the data structure. Another question that deserves consideration is whether these indexing structures can be adapted for use in a distributed database. Among the motivations for distributing data are increased availability and ease of growth; however, unless data structures in the access path are designed to support those goals, they may not be realized. We describe some first attempts at adapting extendible hash files for distributed data