Book Image

Oracle Database 11gR2 Performance Tuning Cookbook

By : Ciro Fiorillo
Book Image

Oracle Database 11gR2 Performance Tuning Cookbook

By: Ciro Fiorillo

Overview of this book

Oracle's Database offers great performance, scalability, and many features for DBAs and developers. Due to a wide choice of technologies, successful applications are good candidates to run into performance issues and when a problem arises it's very difficult to identify the cause and the right solution to the problem. The Oracle Database 11g R2 Performance Tuning Cookbook helps DBAs and developers to understand every aspect of Oracle Database that can affect performance. You will be guided through implementing the correct solution in a proactive way before problems arise, and how to diagnose issues on your Oracle database-based solutions. This fast-paced book offers solutions starting from application design and development, through the implementation of well-performing applications, to the details of deployment and delivering best-performance databases. With this book you will quickly learn to apply the right methodology to tune the performance of an Oracle Database, and to optimize application design and SQL and PL/SQL code. By following the real-world examples you will see how to store your data in correct structures and access and manipulate them at a lightning speed. You will learn to speed up sort operations, hack the optimizer and the data loading process, and diagnose and tune memory, I/O, and contention issues. The purpose of this cookbook is to provide concise recipes, which will help you to build and maintain a very high-speed Oracle Database environment.
Table of Contents (21 chapters)
Oracle Database 11gR2 Performance Tuning Cookbook
Credits
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Index

Avoiding dynamic SQL


The title of this recipe should be extended to say "… when you can do your stuff without using it". In this recipe, we will see when and how to use dynamic SQL.

Dynamic SQL is the only choice when:

  • We want to execute DDL statements in our application.

  • We have to code different queries depending on user input, for example, a search form with different search criteria that the user can choose from. This leads to different predicates in the WHERE clause.

  • We want to code generic procedures, which can act on any table, for example, a generic "print" procedure, which shows the content of a table in a certain format.

For each of these situations, there are drawbacks to be taken care of.

How to do it...

To execute DDL statements in our application, we cannot use static SQL inside PL/SQL code. So, if we want to grant the RESOURCE role to the user SH, we have to do something similar to the following:

BEGIN
  EXECUTE IMMEDIATE 'GRANT RESOURCE TO SH'
END;

To search the EMPLOYEES table...