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

Sorting—in-memory and on-disk


In this recipe, we will see how to diagnose in-memory and on-disk sort, and the differences between optimal, one-pass, and multi-pass sort.

Getting ready

We will use a SQL script from SQL*Plus environment to test in-memory and on-disk sort (without displaying tons of data on the screen).

Open a text editor (for example, vi on UNIX systems or notepad for Windows) and save the following script as 2602_05_TestSort.sql in a directory of your choice (the home directory, for example):

CONNECT sh@TESTDB/sh
SET LINESIZE 120
SELECT * FROM v$sysstat WHERE name like '%sorts%';
-- Setting small sort area
ALTER SESSION SET WORKAREA_SIZE_POLICY = 'MANUAL';
ALTER SESSION SET SORT_AREA_SIZE = 1000;
ALTER SESSION SET SORT_AREA_RETAINED_SIZE = 1000;
SET TERMOUT OFF
SPOOL /dev/null
SELECT prod_id, cust_id, time_id FROM sales ORDER BY amount_sold desc;
SPOOL OFF
SET TERMOUT ON
SELECT * FROM v$sysstat WHERE name like '%sorts%';
-- Automatic sort area
ALTER SESSION SET WORKAREA_SIZE_POLICY...