Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Oracle Database 11gR2 Performance Tuning Cookbook

You're reading from   Oracle Database 11gR2 Performance Tuning Cookbook Shifting your Oracle Database into top gear takes a lot of know-how and fine-tuning ability. The 80+ recipes in this Cookbook will give you those skills along with the ability to troubleshoot if things starts running slowly.

Arrow left icon
Product type Paperback
Published in Jan 2012
Publisher Packt
ISBN-13 9781849682602
Length 542 pages
Edition 1st Edition
Languages
Arrow right icon
Author (1):
Arrow left icon
Ciro Fiorillo Ciro Fiorillo
Author Profile Icon Ciro Fiorillo
Ciro Fiorillo
Arrow right icon
View More author details
Toc

Table of Contents (21) Chapters Close

Oracle Database 11gR2 Performance Tuning Cookbook
Credits
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
1. Starting with Performance Tuning FREE CHAPTER 2. Optimizing Application Design 3. Optimizing Storage Structures 4. Optimizing SQL Code 5. Optimizing Sort Operations 6. Optimizing PL/SQL Code 7. Improving the Oracle Optimizer 8. Other Optimizations 9. Tuning Memory 10. Tuning I/O 11. Tuning Contention Dynamic Performance Views A Summary of Oracle Packages Used for Performance Tuning Index

Tuning the Library Cache


The Library Cache is part of the Shared Pool, inside the System Global Area. In this recipe, we will see how to inspect the use of the Library Cache, and how to tune it to obtain the best performance from our database.

How to do it...

The following steps will demonstrate how to tune the Library Cache:

  1. Connect to the database as SYSDBA using SQL*Plus:

    CONNECT / AS SYSDBA
    
  2. Query the V$LIBRARYCACHE dynamic performance view:

    COL NAMESPACE FOR A20
    SELECT NAMESPACE, GETS, GETHITRATIO, PINS, PINHITRATIO,
      RELOADS, INVALIDATIONS
    FROM V$LIBRARYCACHE;
    CLEAR COL
    
  3. Calculate the library cache hit ratio:

    SELECT SUM(PINS - RELOADS)*100/SUM(PINS) AS "Hit Ratio"
    FROM V$LIBRARYCACHE;
    
  4. Execute a sample query:

    SELECT /* TEST */ COUNT(*)
    FROM SH.CUSTOMERS
    WHERE CUST_YEAR_OF_BIRTH = 1975;
    
  5. Inspect the execution details of a query:

    SELECT SUBSTR(SQL_TEXT,1,30), USERS_EXECUTING,
      EXECUTIONS, LOADS, HASH_VALUE
    FROM V$SQLAREA
    WHERE SQL_TEXT like 'SELECT /* TEST */ %';
    
  6. Inspect cached execution...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $19.99/month. Cancel anytime
Banner background image