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

Using asynchronous I/O


In this recipe we will see how to use asynchronous I/O to obtain better performance from our I/O subsystem.

How to do it...

The following steps will describe the use of asynchronous I/O:

  1. Connect to the database as SYSDBA:

    CONNECT / AS SYSDBA
    
  2. Verify whether asynchronous I/O is enabled:

    SHOW PARAMETER FILESYSTEMIO_OPTIONS
    
  3. Enable asynchronous I/O, if it is not enabled:

    ALTER SYSTEM SET FILESYSTEMIO_OPTIONS=SETALL SCOPE=SPFILE;
    
  4. Shut down the database instance:

    SHUTDOWN IMMEDIATE
    
  5. Start and open the database:

    STARTUP OPEN
    
  6. Verify the change in system configuration:

    SHOW PARAMETER FILESYSTEMIO_OPTIONS
    

How it works...

The Oracle database may use synchronous or asynchronous I/O calls. With synchronous I/O, when an I/O request is submitted to the Operating System, the write process will block until the operation is completed.

Using asynchronous I/O, while the I/O request is still executing, the calling process continues its work without blocking. This is the reason why asynchronous...