Object-relational Database Management System Research Articles

Looking for the objects in object-relational DBMSs (panel)

The Relational Model first came into vogue in the early 1980's. It was based on the simplifying idea that all data could be modeled as mathematical relations (tables in "normal form"). Permissible operations on this table data structure were specified by the relation algebra and calculus. The Relational Model led to years of research in areas such as query languages, query optimization, transaction models, and database design methodologies. This research has dominated DBMS conferences for the last fifteen years and has also lead to major products offerings in wide-spread use in the computer industry today.While the Relational revolution was happening in the DBMS community there was a minority opinion emerging from the object community. This minority opinion surfaced in heated debates and panels at DBMS conferences where it was often pitted against "relational purists." The object proponents wanted to discuss storing and retrieving complex objects and relationships in databases while the relational purists insisted on maintaining "mathematical purity and simplicity". These panels were often some of the most acrimonious (and entertaining) at these conferences and many thought there was no way to bridge the chasm between the two schools of thought.However times changes and so do the realities of the commercial world. Object languages such as C++, Smalltalk, and Java have become de facto standards. The Internet and the PC have increased the demand for complex data types. And the relational model is evolving to accommodate these realities.All of the major RDBMS vendors have announced plans for, or are already shipping, Object-Relational DBMS (ORDBMS) products. A natural question for the object community is how well these new products will address the well-known "impedance mismatch" between a pure object model and the relational model. For example, how does one make Java, Smalltalk, or C++ objects persist using an ORDBMS? Can one search for these objects in the database using their methods?The vendors for ORDBMS are claiming well-known OO features in their implementations, such as extensible data types, inheritance, object identity, and object language bindings. This panel will allow the major vendors to explain how those features match up with the kinds of object models that OO developers are accustomed to. The panel will consist of representatives from three of the major ORDBMS vendors as well as a representative of "pure object think". The vendor representatives will each present a brief overview of the object-related features of their products and will explain why OO programmers are going to have an easier time with these ORDBMSs. This will be followed by counterpoint discussion from the pure object thinker.

Object persistence in object-oriented applications

Object-oriented models have rapidly become the model of choice for programming most new computer applications. Since most application programs need to deal with persistent data, adding persistence to objects is essential to making object-oriented applications useful in practice. There are three classes of solutions for implementing persistence in object-oriented applications: the gateway-based object persistence approach, which involves adding object-oriented programming access to persistent data stored using traditional non-object-oriented data stores, the object-relational database management system (DBMS) approach, which involves enhancing the extremely popular relational data model by adding object-oriented modeling features, and the object-oriented DBMS approach (also called the persistent programming language approach), which involves adding persistence support to objects in an object-oriented programming language. In this paper, we describe the major characteristics and requirements of object-oriented applications and how they may affect the choice of a system and method for making objects persistent in that application. We discuss the user and programming interfaces provided by various products and tools for object-oriented applications that create and manipulate persistent objects. In addition, we describe the pros and cons of choosing a particular mechanism for making objects persistent, including implementation requirements and limitations imposed by each of the three approaches to object persistence previously mentioned. Given that several object-oriented applications might need to share the same data, we describe how such applications can interoperate with each other. Finally, we describe the problems and solutions of how object-oriented applications can coexist with non-object-oriented (legacy) applications that access the same data.

Providing access to a multimedia archive using the World Wide Web and an object-relational database management system

Reformatting information currently held in databases into Web pages requires significant effort in both creating the pages initially and their subsequent maintenance. We avoid these costs by coupling a Web server indirectly to a multimedia database using additional software we have developed. This software layer translates Web requests for information into SQL queries, and generates Web pages dynamically to display the results to the user. The method we have developed allows users to query the database directly and browse for information.

UniSQL's next-generation object-relational database management system

Object-Relational DBMSs have been receiving a great deal of attention from industry analysts and press as the next generation of database management systems. The motivation for a next generation DBMS is driven by the reality of shortened business cycles. This dynamic environment demands fast, cost-effective, time-to-market of new or modified business processes, services, and products. To support this important business need, the next generation DBMS must: 1. leverage the large investments made in existing relational technology, both in data and skill set; 2. Take advantage of the flexibility, productivity, and performance benefits of OO modeling; and 3. Integrate robust DBMS services for production quality systems. The objective of this article is to provide a brief overview of UniSQL's commercial object-relational database management system.

Multimedia Databases and Servers

Database technology is evolving to accommodate complex multimedia objects — data types that present unique challenges in the storage and movement of large time-dependent objects. The manipulation and analysis of these large and semantically rich objects require techniques far different from those used for alphanumeric databases. This paper presents multimedia server-based architectures based on massively parallel processor systems and an object-relational database management system. The transition from client-centric multimedia applications to a client/server environment is examined, and several applications are discussed that illustrate the use of multimedia database servers based on the object-relational model. Finally, this paper reviews the architecture of two scaleable multimedia servers that can support these applications: MoonBase, a database server with full content analysis capability for multimedia objects, and the audio/video server, a system-based file server that can operate within the MoonBase architecture.

Development of OSIMS: an Oil Spill Information Management System

This paper presents the architectural design of OSIMS (Oil Spill Information Management System), which is an integrated information management tool consisting of an object-relational database management system, an intelligent decision support system, an advanced visualization system (AVS) and a geographic information system (GIS). OSIMS will handle large and diverse databases of environmental, ecological, geographical, engineering, and regulatory information and will be used for risk analysis and contingency planning.

The Miro DBMS

This short paper explains the key object-relational (OR) DBMS technology used by the Miro DBMS.

The hybrid emergency: multiple risk and hazard in marine transportation: The Greenwich forum, Royal United Services Institution, London, 7 June 1985

This paper presents the architectural design of OSIMS (Oil Spill Information Management System), which is an integrated information management tool consisting of an object-relational database management system, an intelligent decision support system, an advanced visualization system (AVS) and a geographic information system (GIS). OSIMS will handle large and diverse databases of environmental, ecological, geographical, engineering, and regulatory information and will be used for risk analysis and contingency planning.