Design, Implementation, and Management of Distributed Databases— An Overview - High-Performance Web Databases: Design, Development, and Deployment - page 349

Chapter 22

Design,
Implementation,
and Management of
Distributed Databases
— An Overview

Elizabeth N. Fong, Charles L. Sheppard, and

Kathryn A. Harvill

A

DISTRIBUTED DATABASE ENVIRONMENT ENABLES A USER TO ACCESS

' , DATA RESIDING ANYWHERE IN A CORPORATION S COMPUTER NETWORK

,

WITHOUT REGARD TO DIFFERENCES AMONG COMPUTERS OPERATING SYS-

, D M L , .

TEMS Data that

is actually distributed across multiple remote computers will appear to the
user as if it resided on the user's own computer. This scenario is function-
ally limited with today's distributed database technology; true distributed
database technology is still a research consideration. The functional limi-
tations are generally in the following areas:

ATA ANIPULATION ANGUAGE OR FILE STRUCTURES

• transaction management
• standard protocols for establishing a remote connection
• independence of network topology

Transaction management capabilities are essential to maintaining reli-
able and accurate databases. In some cases, today's distributed database
software places and responsibility of managing transactions on the appli-
cation program. In other cases, transactions are committed or rolled back
at each location independently, which means that it is not possible to cre-
ate a single distributed transaction. For example, multiple site updates
require multiple transactions.