On Locking Protocols in Object-Oriented Database Systems

Shinichi TANIGUCHI  Budiarto  Shojiro NISHIO  

IEICE TRANSACTIONS on Information and Systems   Vol.E78-D    No.11    pp.1449-1457
Publication Date: 1995/11/25
Online ISSN: 
Print ISSN: 0916-8532
Type of Manuscript: Special Section PAPER (Special Issue on Advanced Database Technologies)
Category: Model
object-oriented database,  concurrency control,  performance evaluation,  simulation,  

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As Object-Oriented Database Systems (OODBS) play an increasingly important role in advanced database systems, OODBS performance becomes a significant issue. It is well known that there is a strong relationship between performance and the concurrency control algorithms employed by the Database Management System (DBMS). Class Granularity Locking (CGL) and Class Hierarchy Granularity Locking (CHGL) are proposed as the concurrency control algorithms for OODBS to minimize the locking overhead. However, their basic characteristics, including the licking overhead and concurrency, have not been extensively investigated and it is not known which one is most appropriate for the general case. In this paper, we construct a simulation model for OODBS and carry out several performance evaluation studies on these two Class-Hierarchy Locking protocols and the Non Class-Hierarchy Locking (NCL) protocol. The NCL protocal is a variation of the conventional two phase locking protocol being applied to OODBS data structures.