A uniform indexing scheme for object-oriented databases

Object-oriented databases (OODB) have received considerable attention in recent years. Their performance is a critical factor hindering their current use. Several indexing schemes have been proposed in the literature for enhancing OODB performance and they are briefly reviewed here. In this paper a new and uniform indexing scheme is proposed. This scheme is based on a single B-tree and combines both the hierarchical and nested indexing schemes. The uniformity of this scheme enables compact and optimized code for dealing with a large range of queries on the one hand, and flexibility in adding and removing indexed paths on the other hand. The performance of the scheme is discussed and an extensive experimental analysis for the class-hierarchy case is presented. The results show the advantages of the scheme for small range, clustered sets queries. (C) 1997 Elsevier Science Ltd.