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@inproceedings{DBLP:conf/vldb/Kleewein96,
author = {Jim Kleewein},
editor = {T. M. Vijayaraman and
Alejandro P. Buchmann and
C. Mohan and
Nandlal L. Sarda},
title = {Practical Issues with Commercial Use of Federated Databases},
booktitle = {VLDB'96, Proceedings of 22th International Conference on Very
Large Data Bases, September 3-6, 1996, Mumbai (Bombay), India},
publisher = {Morgan Kaufmann},
year = {1996},
isbn = {1-55860-382-4},
pages = {580},
ee = {db/conf/vldb/Kleewein96.html},
crossref = {DBLP:conf/vldb/96},
bibsource = {DBLP, http://dblp.uni-trier.de}
}
Uses of federation can be divided into intelligent gateways, replication, and on-line access.
Intelligent gateway users want a uniform query language and a high level of abstraction. They want to learn one query language and use that to access all their data via the federation.
Federation provides replication support by enabling transparent access to the replication source or target, thus making it easier to create replication tools. It also enables new replication capability by enabling replication to or from a multiple database view.
On-line access provides applications and queries with access to data stored in multiple databases without requiring knowledge of location, multiple, query dialects, and multiple APIs.
The impediments to federation fall into several areas: (1) non-technical, (2) Usability, (3) Performance, and (4) Data source support.
Some non-technical issues that impede federation are skepticism about the performance of the system or its capabilities.
chema integration is one aspect of usability that impedes federation. There are often thousands of tables or views involved in a federation making maintenance of a global schema difficult. Another aspect in installation and configuration; establishing a federation requires lots of set-up and expertise.
Performance, performance monitoring, turning, and problem determinate are areas of concern. Federations, and their associated communication systems, require considerable tuning.
The databases themselves are problematic. Differences in query dialects, functions supported, and data types are some factors that complicate federation. Other include support for multiple versions of databases, different behaviors based on configuration parameters, and concurrency control schemes.
Copyright © 1996 by the VLDB Endowment. Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the VLDB copyright notice and the title of the publication and its date appear, and notice is given that copying is by the permission of the Very Large Data Base Endowment. To copy otherwise, or to republish, requires a fee and/or special permission from the Endowment.
