Chapter 1. Laying Plans


Designing Databases for Performance

C'est le premier pas qui, dans toutes les guerres, décèle le génie.

It is the first step that reveals genius in all wars.

Joseph de Maistre (1754-1821)
Lettre du 27 Juillet 1812
à Monsieur le Comte de Front

The great nineteenth century German strategist, Clausewitz, famously remarked that war is the continuation of politics by other means. Likewise, any computer program is, in one way or another, the continuation of the general activity within an organization, allowing it to do more, faster, better, or cheaper. The main purpose of a computer program is not simply to extract data from a database and then to process it, but to extract and process data for some particular goal. The means are not the end.

A reminder that the goal of a given computer program is first of all to meet some business requirement[*] may come across as a platitude. In practice, the excitement of technological challenges often slowly causes attention to drift from the end to the means, from upholding the quality of the data that records business activity to writing programs that perform as intended and in an acceptable amount of time. Like a general in command of his army at the beginning of a campaign, we must know clearly what our objectives areand we must stick to them, even if unexpected difficulties or opportunities make us alter the original plan. Whenever the SQL language is involved, we are fighting to keep a faithful and consistent record of business activity over time. Both faithfulness and consistency are primarily associated with the quality of the database model. The database model that SQL was initially designed to support is the relational model . One cannot overemphasize the importance of having a good model and a proper database design, because this is the very foundation of any information system.

[*] The expression business requirement is meant to encompass non-commercial as well as commercial activities.




The Art of SQL
The Art of SQL
ISBN: 0596008945
EAN: 2147483647
Year: N/A
Pages: 143

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