A Performance Evaluation of OID Mapping Techniques

Authors:

André Eickler

Carsten A. Gerlhof

Donald Kossmann

Conference:

Proc. of the 21st Intl. Conf. on Very Large Data Bases (VLDB), pages 18-29,

Zürich, Switzerland, September 1995,

(also available as Universität Passau Technical Report MIP-9507, March 1995).

Abstract:

In this paper, three techniques to implement logical OIDs are thoroughly evaluated: hashing, B-trees and a technique called direct mapping. Among these three techniques, direct mapping is the most robust; it induces at most one page fault to map an OID, and it scales very well to large, rapidly growing databases. Furthermore, the clustering of handles that are used to map logical OIDs is studied. In particular, the performance of B-trees and direct mapping can improve significantly if the handles of objects that are frequently accessed by the same methods are clustered. For direct mapping, two placement policies are compared: linear and matrix clustering.