We describe the results of developing the GemStone object-oriented database server, which supports a model of objects similar to that of Smalltalk-80. We begin with a summary of the goals and requirements for the system: an extensible data model that captures behavioral semantics, no artificial bounds on the number or size of database objects, database amenities (concurrency, transactions, recovery, associative access, authorization) and an interactive development environment. Object-oriented languages, Smalltalk in particular, answer some of these requirements. We discuss satisfying the remaining requirements in an object oriented context, and report briefly on the status of the development efforts. This paper is directed at an audience familiar with object-oriented languages and their implementation, but perhaps unacquainted with the difficulties and techniques of database system development. It updates the original report on the project [CM], and expands upon a more recent article [MDP].

Development of an object-oriented DBMS

VLSI CAD applications deal with design objects that have an interface description and an implementation description. Versions of design objects have a common interface but differ in their implementations. A molecular object is a modeling construct which enables a database entity to be represented by two sets of heterogeneous records, one set describes the object's interface and the other describes its implementation. Thus a reasonable starting point for modeling design objects is to begin with the concept of molecular objects.In this paper, we identify modeling concepts that are fundamental to capturing the semantics of VLSI CAD design objects and versions in terms of molecular objects. A provisional set of user operations on design objects, consistent with these modeling concepts, is also defined. The modeling framework that we present has been found useful for investigating physical storage techniques and change notification problems in version control.

Modeling concepts for VLSI CAD objects

We describe indexing in the GemStone object-oriented database server, which supports a model of objects similar to that of Smalltalk-80. We begin with a brief description of the system's architecture and the role of indexing in GemStone. We then discuss the properties of object-oriented systems, and GemStone in particular, that make indexing considerably different than in a more conventional data model. Various approaches to indexing in an object-oriented model are presented. We describe both the design and implementation of indexing in GemStone. Lastly, we describe related work and note performance results from the initial instrumentation of the system.

Indexing in an object-oriented DBMS

Bibliography on temporal databases

In engineering applications, multiple copies of object descriptions have to coexist in a single database. A scheme is proposed that enables users to explicitly deal with these object versions. After introducing a basic version model, the problem of rerouting interobject references on the creation of new versions is solved by providing generic references and user-specific environments. Logical version clusters are introduced that allow for the meaningful grouping of versions. Some remarks on implementation and a comparison with other approaches are also included. >

Version support for engineering database systems

Relational databases are of increasing interest for applications outside the traditional business data-processing environment We have introduced the notion of complex objects as one extension to a relational database system (System R) to better support these non-business applications, in particular, engineering design In this chapter, we discuss five aspects of complex objects: concepts and semantics, implementation, query optimization, efficient use within application programs, and user interface

Supporting Complex Objects in a Relational System for Engineering Databases

Advantages claimed for the relational model in the classical data processing domain include ease of use, data independence, increased productivity, and multi-file correlation. These advantages also hold for design applications. However, engineering applications impose several additional requirements.

A Database System for Engineering Design

A Database System for Engineering Design.

One primary difference between transactions in an engineering design environment and those in conventional business applications is that an engineering transaction typically lasts a much longer time. Existing proposals for supporting the long-lived engineering transactions are all based on the public/private database architecture, in which a transaction checks out design objects from the public database, modifies them, and checks them into the public database for use by other transactions. However, the design environment which these proposals model is a very rigid one which does not allow a team of designers to complete a complex design involving numerous design objects by passing incomplete objects back and forth among them in a controlled manner. In this paper we present a model of engineering transactions which attempts to resolve this shortcoming as well as satisfying the constraints imposed by the engineering design environment. The model augments existing models by refining the notion of checkout environment which a transaction sees and coupling it with the notion of nested transactions. The model is then extended to a practical mechanism for supporting a complex engineering design environment by imposing the view that a long-lived engineering transaction is really a sequence of conventional short-lived transactions.

/pdf/a-transaction-mechanism-for-engineering-design-databases-48kqgmzt14.pdf

A Transaction Mechanism for Engineering Design Databases

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Dan McNabb

Author Tools

Chat about Author

Papers

Supporting Complex Objects in a Relational System for Engineering Databases

A Database System for Engineering Design

A Database System for Engineering Design.

A Transaction Mechanism for Engineering Design Databases