Seth J. White

Shoring up persistent applications

SHORE (Scalable Heterogeneous Object REpository) is a persistent object system under development at the University of Wisconsin. SHORE represents a merger of object-oriented database and file system technologies. In this paper we give the goals and motivation for SHORE, and describe how SHORE provides features of both technologies. We also describe some novel aspects of the SHORE architecture, including a symmetric peer-to-peer server architecture, server customization through an extensible value-added server facility, and support for scalability on multiprocessor systems. An initial version of SHORE is already operational, and we expect a release of Version 1 in mid-1994.

Implementing crash recovery in QuickStore: a performance study

Implementing crash recovery in an Object-Oriented Database System (OODBMS) raises several challenging issues for performance that are not present in traditional DBMSs. These performance concerns result both from significant architectural differences between OODBMSs and traditional database systems and differences in OODBMSs target applications. This paper compares the performance of several alternative approaches to implementing crash recovery in an OODBMS based on a client-server architecture. The four basic recovery techniques examined in the paper are termed page differencing, sub-page differencing, whole-page logging, and redo-at-server. All of the recovery techniques were implemented in the context of QuickStore, a memory-mapped store built using the EXODUS Storage Manager, and their performance is compared using the OO7 database benchmark. The results of the performance study show that the techniques based on differencing generally provide superior performance to whole-page logging.

QuickStore: a high performance mapped object store

QuickStore is a memory-mapped storage system for persistent C++, built on top of the EXODUS Storage Manager. QuickStore provides fast access to in-memory objects by allowing application programs to access objects via normal virtual memory pointers. This article presents the results of a detailed performance study using the OO7 benchmark. The study compares the performance of QuickStore with the latest implementation of the E programming language. The QuickStore and E systems exemplify the two basic approaches (hardware and soft-ware) that have been used to implement persistence in object-oriented database systems. In addition, both systems use the same underlying storage manager and compiler, allowing us to make a truly apples-to-apples comparison of the hardware and software techniques.

Enterprise Java platform data access

This paper describes alternative methods for data access that are available to developers using the Java#8482; platform and related technologies to create a new generation of enterprise applications. The paper highlights industry trends and describes Java technologies that are responsible for a new paradigm in data access. Java technology represents a new level of portability, scalability, and ease-of-use for applications that require data access.