Preface

This book describes ways to improve Oracle performance by starting with good application design and using statistics to monitor application performance. It explains the Oracle Performance Improvement Method, as welll as emergency performance techniques for dealing with performance problems.

This preface contains these topics:

Audience

Oracle9i Database Performance Planning is a high-level aid for people responsible for the operation, maintenance, and performance of Oracle. To use this book, you could be a database administrator, application designer, programmer, or manager. You should be familiar with Oracle9i, the operating system, and application design before reading this manual.

Organization

This document contains:

Chapter 1, "Designing and Developing for Performance"

This chapter describes performance issues to consider when designing Oracle applications.

Chapter 2, "Monitoring and Improving Application Performance"

This chapter describes the Oracle Performance Improvement Method and the importance of statistics for application performance improvements.

Chapter 3, "Emergency Performance Techniques"

This chapter describes techniques for dealing with performance emergencies.

Conventions

This section describes the conventions used in the text and code examples of the this documentation set. It describes:

Conventions in Text

We use various conventions in text to help you more quickly identify special terms. The following table describes those conventions and provides examples of their use.

Convention	Meaning	Example
Bold	Bold typeface indicates terms that are defined in the text or terms that appear in a glossary, or both.	When you specify this clause, you create an index-organized table.
Italics	Italic typeface indicates book titles, emphasis, syntax clauses, or placeholders.	Oracle9i Database Concepts You can specify the parallel_clause. Run `U``old_release``.SQL` where old_release refers to the release you installed prior to upgrading.
UPPERCASE monospace (fixed-width font)	Uppercase monospace typeface indicates elements supplied by the system. Such elements include parameters, privileges, datatypes, RMAN keywords, SQL keywords, SQL*Plus or utility commands, packages and methods, as well as system-supplied column names, database objects and structures, user names, and roles.	You can specify this clause only for a `NUMBER` column. You can back up the database using the `BACKUP` command. Query the `TABLE_NAME` column in the `USER_TABLES` data dictionary view. Specify the `ROLLBACK_SEGMENTS` parameter. Use the `DBMS_STATS`.`GENERATE_STATS` procedure.
lowercase monospace (fixed-width font)	Lowercase monospace typeface indicates executables and sample user-supplied elements. Such elements include computer and database names, net service names, and connect identifiers, as well as user-supplied database objects and structures, column names, packages and classes, user names and roles, program units, and parameter values.	Enter `sqlplus` to open SQL*Plus. The `department_id`, `department_name`, and `location_id` columns are in the `hr.departments` table. Set the `QUERY_REWRITE_ENABLED` initialization parameter to `true.` Connect as `oe` user.

Conventions in Code Examples

Code examples illustrate SQL, PL/SQL, SQL*Plus, or other command-line statements. They are displayed in a monospace (fixed-width) font and separated from normal text as shown in this example:

SELECT username FROM dba_users WHERE username = 'MIGRATE';

The following table describes typographic conventions used in code examples and provides examples of their use.

Convention	Meaning	Example
[ ]	Brackets enclose one or more optional items. Do not enter the brackets.	`DECIMAL (digits [ , precision ])`
{ }	Braces enclose two or more items, one of which is required. Do not enter the braces.	`{ENABLE \| DISABLE}`
\|	A vertical bar represents a choice of two or more options within brackets or braces. Enter one of the options. Do not enter the vertical bar.	`{ENABLE \| DISABLE}` `[COMPRESS \| NOCOMPRESS]`
`...`	Horizontal ellipsis points indicate either: That we have omitted parts of the code that are not directly related to the example That you can repeat a portion of the code	`CREATE TABLE ... AS subquery;` `SELECT col1, col2, ... , col``n` `FROM employees;`
. . .	Vertical ellipsis points indicate that we have omitted several lines of code not directly related to the example.	SQL> SELECT NAME FROM V$DATAFILE; NAME ------------------------------------ /fsl/dbs/tbs_01.dbf /fs1/dbs/tbs_02.dbf . . . /fsl/dbs/tbs_09.dbf 9 rows selected.
Other notation	You must enter symbols other than brackets, braces, vertical bars, and ellipsis points as it is shown.	`acctbal NUMBER(11,2);` `acct CONSTANT NUMBER(4) := 3;`
`Italics`	Italicized text indicates variables for which you must supply particular values.	`CONNECT SYSTEM/``system_password`
`UPPERCASE`	Uppercase typeface indicates elements supplied by the system. We show these terms in uppercase in order to distinguish them from terms you define. Unless terms appear in brackets, enter them in the order and with the spelling shown. However, because these terms are not case sensitive, you can enter them in lowercase.	`SELECT last_name, employee_id FROM employees;` `SELECT * FROM USER_TABLES;` `DROP TABLE hr.employees;`
`lowercase`	Lowercase typeface indicates programmatic elements that you supply. For example, lowercase indicates names of tables, columns, or files.	`SELECT last_name, employee_id FROM employees;` `sqlplus hr/hr`

Documentation Accessibility

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http://www.oracle.com/accessibility/

Accessibility of Code Examples in Documentation

JAWS, a Windows screen reader, may not always correctly read the code examples in this document. The conventions for writing code require that closing braces should appear on an otherwise empty line; however, JAWS may not always read a line of text that consists solely of a bracket or brace.

Accessibility of Links to External Web Sites in Documentation

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