This dissertation explores the use of statically derived information to improve concurrency control and recovery in objectbase systems. It surveys the relevant background material including existing objectbase systems and conventional concurrency control and recovery. The problem of providing concurrency control and recovery in objectbases supporting nested transactions is analyzed and types of static information which are useful to concurrency control and recovery are determined. Algorithms are proposed to derive the needed static information. The problem of concurrency control in objectbases is decomposed into two simpler problems: intra-transaction concurency control and inter-transaction concurrency control and algorithms are developed for each. A novel concurrency control algorithm combining the algorithms for intra- and inter-transaction concurrency control which specifies serialization orders ` a priori is presented. The algorithm selects appropriate serialization orders based o...

Many researchers have demonstrated the importance of entity fragmentation in distributed relational database design. Database design will be essential in the "next-generation" engineering design environment that exploits object-oriented technologies. Fragmentation enhances application performance by reducing the amount of irrelevant data accessed and the amount of data transferred unnecessarily between distributed sites. Algorithms for effecting horizontal and vertical fragmentation of relations exist, but fragmentation techniques for class objects in a distributed object based system have not appeared in the literature. This paper first presents a taxonomy of the fragmentation problem in a distributed object based system capable of supporting systems engineering applications. Detailed horizontal fragmentation algorithms are then presented for one of these class models using a top--down approach where the entity of fragmentation is the class object. The algorithms described i...