Pointer-Based Join Techniques for Object-Oriented Databases

Abstract

In this paper, we describe and analyze four parallel pointer-based joins for set-valued attributes. These joins will be common in next-generation object-oriented database systems, so efficiently supporting them is crucial to the performance of such systems. Pointer-based join algorithms based on Hybrid-hash provide good performance, but algorithms that require less replication will often produce as good or better performance, especially if each set-valued attribute references a small number of nodes. 1. Introduction Set-valued attributes are an important feature of next-generation database systems, both for Database Programming Languages (DBPLs) and Object-Oriented Database Systems (OODBSs). Examples of systems with datamodeling facilities for set-valued attributes include Bubba [BORA90], E [RICH92], GemStone [BUTT91], Iris [FISH87], LDL [CHIM90], O++ [AGRA89], ObjectStore [LAMB91], ORION [KIM90], and O 2 [DEUX91]. Setvalued attributes often contain the object identifiers (oids) of o..