Skip to main content
SpringerLink
Log in

The Problem of Incomplete Information in Relational Databases

  • Book
  • © 1991

Overview

Editors:
  1. Gösta Grahne
    View editor publications

    You can also search for this editor in PubMed   Google Scholar

Part of the book series: Lecture Notes in Computer Science (LNCS, volume 554)

This is a preview of subscription content, log in via an institution to check access.

Access this book

Log in via an institution
Softcover Book USD 54.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Other ways to access

Licence this eBook for your library

Institutional subscriptions

Table of contents (6 chapters)

  1. Front Matter

    Download chapter PDF

  2. Introduction

    Pages 1-5

  3. Relational databases

    Pages 6-32

  4. Semantic aspects of incomplete information

    Pages 33-54

  5. Syntactic and algorithmic aspects of incomplete information

    Pages 55-103

  6. Computational complexity aspects of incomplete information

    Pages 104-131

  7. Some conclusive aspects

    Pages 132-142

  8. Back Matter

    Download chapter PDF
Back to top

Keywords

About this book

In a relational database the information is recorded as rows in tables. However, in many practical situations the available information is incomplete and the values for some columns are missing. Yet few existing database management systems allow the user to enter null values in the database. This monograph analyses the problems raised by allowing null values in relational databases. The analysis covers semantical, syntactical, and computational aspects. Algorithms for query evaluation, dependency enforcement and updates in the presence of null values are also given. The analysis of the computational complexity of the algorithms suggests that from a practical point of view the database should be stored as Horn tables, which are generalizations of ordinary relations, allowing null values and Horn clause-like restrictions on these null values. Horn tables efficiently support a large class of queries, dependencies and updates.

Bibliographic Information

Publish with us

Policies and ethics

Back to top

Search

Navigation