Oracle9i Performance Tuning Chapter 1 Performance Tuning Overview

Oracle9Oracle9ii Performance TuningPerformance Tuning

Chapter 1Chapter 1

Performance TuningPerformance TuningOverviewOverview

Chapter 1: Performance Tuning Overview 2

Chapter ObjectivesChapter Objectives

• Learn general concepts of database tuning

• Review the System Development Life Cycle

• Identify tuning goals and measurements

• Describe and understand performance problems


Chapter Objectives Chapter Objectives (continued)(continued)

• Learn the steps of the tuning process

• Use a database tuning checklist

• Understand the roles and responsibilities of the database administrator (DBA)

• Learn about Oracle tuning tools


Database Tuning OverviewDatabase Tuning Overview• Database tuning is the ongoing process of optimizing

the operation of a database configuration based on attainable tuning goals• There are no quick formulas or specific methods for tuning a

database

• It depends on the “art” of developing good designs and creativity in troubleshooting and analyzing problems as well as the “science” of using technical tools to detect problems before they occur


System Development MethodologiesSystem Development Methodologies

• System Development Life Cycle

• Structured analysis and design

• Object-oriented analysis and design

• Rapid application development

• Prototyping development

• Joint application development


System Development Life CycleSystem Development Life Cycle

• Referred to as the SDLC

• Purpose of the SDLC:• Establishes a consistent framework for development• Provides a solution to solve a problem• Delivers the application design and code that has

been reviewed and signed off by technical leads


System Development Life Cycle System Development Life Cycle (continued)(continued)

• Short-cutting the SDLC leads to:• Inferior system design• Poor system architecture• Inefficient application code• Performance problems• Lower user productivity


System Development Life Cycle System Development Life Cycle (continued)(continued)


DBA Tasks DBA Tasks

• A DBA must be involved in all phases of the SDLC

• DBA tasks for each of the database phases:• Database analysis phase:

• Identify new resources and capacities that are required for the new system

• Analyze the business functions of the new system to determine database features and functions

• Identify database performance goals and objectives


DBA Tasks DBA Tasks (continued)(continued) • Logical design phase:

• Identify the type of database application

• Gather data from existing system and business requirements

• Analyze data and identify all entities

• Identify relationships between entities

• Create a conceptual data model

• Identify degrees of relationships and cardinalities


DBA Tasks DBA Tasks (continued)(continued) • Logical design phase:

• Identify all attributes for each entity

• Create a logical data model

• Identify domains for each attribute

• Create a data dictionary

• Identify data constraints and validation techniques

• Normalize data model


DBA Tasks DBA Tasks (continued)(continued) • Physical design phase:

• Decide which database management system will be employed

• Examine the features of the database management system to be used

• Create a storage capacity plan

• Analyze initial data and growth

• Design database procedures to implement business rules

• Identify data migration procedures

• Identify and create backup and recovery strategies


DBA Tasks DBA Tasks (continued)(continued) • Database implementation phase:

• Create the database by using a template configuration

• Create application users and roles and grant privileges

• Create application schema

• Create and code all database procedures and scripts

• Create data migration procedures and scripts

• Create necessary data feeds and/or loads

• Document database configuration

• Implement a backup strategy for testing


DBA Tasks DBA Tasks (continued)(continued) • Database testing phase:

• Test database connections

• Identify problematic queries

• Gather database statistics and analyze results to determine whether performance goals are met

• Test all database procedures and scripts

• Identify database configuration problems

• Document database maintenance procedures and administration tasks

• Test backup and recovery strategies


DBA Tasks DBA Tasks (continued)(continued) • Database maintenance phase:

• Create a production database

• Migrate data to the production database

• Use tools to monitor the database and install scripts

• Tune and improve database performance as required

• Verify backups and perform random recovery testing


Tuning GoalsTuning Goals

• Performance-tuning goals must be measured by the following criteria:• Database response time• Database availability• Database statistics and ratios• CPU utilization• Memory utilization• Disk thrashing or paging• Excessive I/O (caused by reads and writes)


Tuning Goals Tuning Goals (continued)(continued)


Performance ProblemsPerformance Problems• Performance problems are classified as follows:

• Contention problems• Resource consumption problems• Scalability problems• Architectural problems• Application problems• Network problems• Sorting problems


Performance Problems Performance Problems (continued)(continued)

• Performance problems are classified as follows:• Connection problems• Allocation problems• Full Table Scan (FTS) problems• Parsing problems• Index problems• Storage parameters problems


Tuning Processes and StepsTuning Processes and Steps


Degree of Tuning EffortDegree of Tuning Effort


Database Tuning ChecklistDatabase Tuning Checklist


DBA Roles and ResponsibilitiesDBA Roles and Responsibilities


DBA Roles and Responsibilities DBA Roles and Responsibilities (continued)(continued)

• The DBA should be focused on the following activities:• Be involved in all SDLC phases• Recommend best practices in data modeling and

database designs• Educate developers on how to optimize their code

(queries)• Work with designers and developers on transaction

controls



• The DBA should be focused on the following activities:• Recommend to developers SQL tuning tools• Monitor database performance• Collect and analyze database statistics• Educate users on best practices for working with

database applications










Oracle Tuning Tools and UtilitiesOracle Tuning Tools and Utilities

• Performance Views (V$ Views)

• Data dictionary views

• Oracle Optimizer

• Oracle Optimizer Hints

• Explain Plan Statement

• SQL Trace


Oracle Tuning Tools and Utilities Oracle Tuning Tools and Utilities (continued)(continued)

• Autotrace settings

• Tkprof

• Outlines

• UTLBSTAT.SQL and UTLESTAT.SQL

• Statspack package


Oracle Manager ToolsOracle Manager Tools• Oracle Enterprise Management Console• Diagnostic Pack:

• Lock Monitor• Performance Manager• Performance Overview• Top Sessions• Top SQL• Trace Data Viewer


Oracle Manager Tools Oracle Manager Tools (continued)(continued)

• Tuning Pack• Oracle Expert• Outline Management• SQL Analyze• Tablespace Map


SummarySummary• The System Development Life Cycle provides a

consistent methodology for solving business problems

• A DBA should be involved in most SDLC phases• Performance tuning is one of the most challenging

tasks of a DBA• DBAs should focus their efforts on database design

and code• Most performance problems stem from bad design

and inefficient code


Summary Summary (continued)(continued)

• DBAs should implement a mechanism to collect statistics and analyze these statistics to determine performance trends

• The Oracle9i product provides DBAs with a number of tools that assist with performance tuning

• Knowing who should perform tuning tasks and what should be tuned is essential for allocating resources to performance problems

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Oracle9i Performance Tuning Chapter 1 Performance Tuning Overview