SQL Tuning [Electronic resources] نسخه متنی

Chapter 1. Introduction

Well begun is half done.

Aristotle Politics, Bk. V, Ch. 4

This book is for readers who already know SQL and have an opportunity
to tune SQL or the database where the SQL executes. It includes
specific techniques for tuning on Oracle, Microsoft SQL Server, and
IBM DB2. However, the main problem of SQL tuning is finding the

optimum path to the data. (The path to the
data is known as the execution plan.) This
optimum path is virtually independent of the database vendor, and
most of this book covers a vendor-independent solution to that
problem.

The least interesting, easiest parts of
the SQL tuning problem are vendor-specific techniques for viewing and
controlling execution plans. For completeness, this book covers these
parts of SQL tuning as well, for Oracle, Microsoft SQL Server, and
IBM DB2. Even on other databases, though (and on the original
databases, as new releases bring change), the vendor-independent core
of this book will still apply. As such, this book is fairly universal
and timeless, as computer science texts go. I have used the method at
the core of this book for 10 years, on four different
vendors' databases, and I expect it to apply for at
least another 10 years. You can always use your own
vendor's current documentation (usually available
online) to review the comparatively simple, release-dependent,
vendor-specific techniques for viewing and controlling execution
plans.