Distributed Data-base Management Systems by Olin H Bray

By Olin H Bray

Show description

Read Online or Download Distributed Data-base Management Systems PDF

Similar data modeling & design books

Modular Ontologies: Concepts, Theories and Techniques for Knowledge Modularization

This booklet constitutes a suite of analysis achievements mature adequate to supply a company and trustworthy foundation on modular ontologies. It supplies the reader a close research of the cutting-edge of the learn region and discusses the new ideas, theories and strategies for wisdom modularization.

Advances in Object-Oriented Data Modeling

Till lately, details structures were designed round assorted company capabilities, akin to debts payable and stock keep an eye on. Object-oriented modeling, against this, buildings platforms round the data--the objects--that make up a number of the enterprise services. simply because information regarding a specific functionality is proscribed to at least one place--to the object--the process is protected against the consequences of swap.

Introduction To Database Management System

Designed in particular for a unmarried semester, first path on database structures, there are four facets that differentiate our ebook from the remaining. simplicity - usually, the know-how of database structures could be very obscure. There are

Extra resources for Distributed Data-base Management Systems

Sample text

An attribute will be one of three types (see Figure 2-5): Unique identifier (UID), which uniquely identifies an entity instance. UIDs are implemented as primary keys. Mandatory attributes, which cannot be NULL. 5 Figure 2-5. Entity attributes According to the conventions supported by Barker’s notation: A column name is preceded by a special symbol: # denotes a key attribute * denotes a mandatory attribute o denotes an optional (nonmandatory) attribute Column Name is written with the first letter of each word in uppercase.

This type of recursion is called a hierarchy. Figure 2-9. Example of a one-to-many recursive relationship The recursive relationship in Figure 2-9 may be read as: Each employee may manage one or more employees Each employee may be managed by one and only one employee Implementing one-to-many recursive relationships in DBMS is relatively straightforward. Table 2-1 diagrams a solution by having a foreign key referencing the primary key of the same entity. Table 2-1. Implementing a One-to-Many Recursive Relationship Employee id Name Manager id 1 Joe 2 Tony 1 3 Robert 1 4 Richard 2 5 Jane 2 6 Lisa 3 7 Alex 3 8 Ben 5 9 Mark 5 10 Lan 6 Recursive Many-to-Many Relationships Another type of recursive relationship that is very important in data modeling is the recursive many-to-many (M:N) relationship.

Rather than use a trademark symbol with every occurrence of a trademarked name, logo, or image we use the names, logos, and images only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made.

Download PDF sample

Rated 4.93 of 5 – based on 6 votes