A join algorithm utilizing multiple path indexes in object-oriented database systems

Although various types of path indexes-indexes on path expressions-have been proposed for efficient processing of object-oriented queries, conventional join algorithms do not effectively utilize them. We propose a new join algorithm called OID join algorithm that effectively utilizes (multiple) path indexes in object-oriented databases. When (multiple) path indexes are available for a query, the OID join algorithm may reduce the query evaluation cost significantly by taking full advantage of the path indexes. We present a cost analysis for the OID join algorithm and compare it with those of conventional ones.