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 bind variables and parsing


We have already discussed bind variables and parsing in the Using bind variables recipe in Chapter 4, Optimizing SQL Code. In this recipe, we will see another example, using the same principles applied to a PL/SQL procedure.

How to do it...

The following steps will demonstrate the bind variables using PL/SQL:

  1. Connect to the database as user SH:

    CONNECT sh@TESTDB/sh
    
  2. Create a function to calculate the maximum length of data stored in an arbitrary field with a variable condition on another field:

    CREATE FUNCTION CONDITIONAL_COLUMN_LEN(TABLE_NAME IN VARCHAR2,
     COLUMN_NAME IN VARCHAR2, COND_FIELD IN VARCHAR2,
     COND_VALUE IN VARCHAR2) RETURN NUMBER
    IS
      L_RESULT NUMBER := 0;
      L_STMT VARCHAR2(2000);
    BEGIN
      L_STMT := 'SELECT MAX(LENGTH(' || COLUMN_NAME ||
       ')) FROM ' || TABLE_NAME ||
       ' WHERE ' || COND_FIELD || ' = ' || COND_VALUE;
      EXECUTE IMMEDIATE L_STMT INTO L_RESULT;
      RETURN L_RESULT;
    END;
    /
    
  3. Calculate using the function created in the previous step for...