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Book:   SQL Tuning
Subject:   SQL Tuning Review
Date:   2004-02-27 05:38:32
From:   Brian Blades
Rating:  StarStarStarStarStar

For many years the process of SQL Tuning has been considered an "art". SQL tuning books written to date have presented guidelines and "things to try" but "SQL Tuning" by Dan Tow is different. This is the first book I have seen that presents a clear methodology to attack the problem in a scientific/mathematical way and includes a diagramming technique to visualize the components of a query that affect performance. Dan's book has gone a long way in helping to transform SQL tuning from an art to a science.


The first four chapters of the book cover some of the subjects that are found in other SQL tuning books, and focus on the important points without delving too deeply into database internals. The really "good stuff" is covered in chapters 5 through 10, which includes how to "draw" a query diagram, and the procedures to follow to derive an optimal join order. The problems/examples presented and resolved in these chapters help the reader get a start on understanding the methodology, which can then be applied to actual tuning problems as they are encountered.


So far I have applied this technique to about 20 tuning problems I have encountered on the job using the Oracle RDBMS. I still consider myself a relative novice in using the methodology, but for each of the 20 problems I have been able to significantly reduce elapsed time and resource consumption (gets/reads). Also, these results were achieved in a matter or hours, rather than days. The query diagram has even facilitated finding "missing joins" in some of the queries without having a knowledge of the particular application.


This book is a "must have" for DBA's and developers and I highly recommend it.