Beginning Microsoft SQL Server 2008 ... - S3 Tech Training

8
Being Normal:
Normalization and Other
Basic Design Issues
I can imagine you as being somewhat perplexed about the how and why of some of the tables
we’ve constructed thus far. With the exception of a chapter or two, this book has tended to have an
online transaction-processing, or OLTP, flair to the examples. Don’t get me wrong; I will point out,
from time to time, some of the differences between OLTP and its more analysis-oriented cousin
Online Analytical Processing (OLAP). My point is that you will, in most of the examples, be seeing a
table design that is optimized for the most common kind of database — OLTP. As such, the table
examples will typically have a database layout that is, for the most part, normalized to what is
called the third normal form.
So what is “normal form”? We’ll be taking a very solid look at that in this chapter, but, for the
moment, let’s just say that it means your data has been broken out into a logical, non-repetitive
format that can easily be reassembled into the whole. In addition to normalization (which is the
process of putting your database into normal form), we’ll also be examining the characteristics of
OLTP and OLAP databases. And, as if we didn’t have enough between those two topics, we’ll also
be looking at many examples of how the constraints we’ve already seen are implemented in the
overall solution.
This is probably going to be one of the toughest chapters in the book to grasp because of a paradox
in what to learn first. Some of the concepts used in this chapter refer to things we’ll be covering
later — such as triggers and stored procedures. On the other hand, it is difficult to relate those
topics without understanding their role in database design.
I strongly recommend reading this chapter through, and then coming back to it again after you’ve
read several of the subsequent chapters.