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

Tuning the Program Global Area and the User Global Area


In this recipe, we will see the Program Global Area (PGA) and the User Global Area (UGA) and how to tune them for maximum performance.

The PGA is used to store real values of bind variables, sort areas, and cursor state information. In a dedicated server environment this area is in private user memory. Only in a shared-server environment the session stack space remains in the PGA, while session data and cursor state are moved into the shared pool.

How to do it...

The following steps will demonstrate tuning the PGA and UGA:

  1. Connect to Oracle Enterprise Manager as SYSDBA.

  2. Go to Advisor Central.

  3. Choose Memory Advisors.

  4. Choose the PGA palette to show or change the size of PGA.

  5. Connect to SQL*Plus as SYSDBA:

    CONNECT / AS SYSDBA
    
  6. Show the parameters related to cursors:

    SHOW PARAMETER CURSOR
    
  7. Query for the total session memory:

    SELECT SUM(VALUE) AS "session uga memory"
    FROM V$MYSTAT, V$STATNAME
    WHERE V$STATNAME.NAME = 'session uga memory'
    AND V$MYSTAT...