The Object Behavior of Java Object-Oriented Database Management Systems

Due to its portability and popularity for Internet applications, Java has become one of the major programming languages. The similar syntax inherited from the C language and the pure object orientated features, compared to the non-pure object-oriented C++ language, have caused Java to be a good candidate as a tool in designing object oriented systems, especially in database servers. However, the performance of the Java Virtual Machine (JVM) would be the reason that several database designers, such as Oracle, IBM, Sybase and Informix, have not fully transferred their database management system (DBMS) into Java. One of the performance indices is the responsiveness for on-line transaction processing (OLTP) which may be dominated by the garbage collection system inside the JVM. In this paper eight Java programs, jess, javac, mtrt, compress, db, db4o, smallDB and ozone, are used to study the dynamic memory behavior. The latter four programs are Java object-oriented database management systems and their object behaviors are compared to those of the former four regular Java programs. Simulation results, such as object size distribution, average object size, object live distribution and total garbage collection cycle are reported.