Database Performance Tuning Guide - Oracle

1 Oracle DatabaseDatabase Performance Tuning Guide19cE96347-04 April 2020 Oracle Database Database Performance Tuning Guide , 19cE96347-04 Copyright 2007, 2020, Oracle and/or its Authors: Glenn MaxeyPrimary Authors: Rajesh Bhatiya, Immanuel Chan, Lance AshdownContributors: Hermann Baer, Deba Chatterjee, Maria Colgan, Mikael Fries, Prabhaker Gongloor, KevinJernigan, Sue K. Lee, William Lee, David McDermid, Uri Shaft, Oscar Suro, Trung Tran, Sriram Vrinda, YujunWangThis software and related documentation are provided under a license agreement containing restrictions onuse and disclosure and are protected by intellectual property laws.

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6 UNIX is a registeredtrademark of The Open software or hardware and documentation may provide access to or information about content, products,and services from third parties. Oracle Corporation and its affiliates are not responsible for and expresslydisclaim all warranties of any kind with respect to third-party content, products, and services unless otherwiseset forth in an applicable agreement between you and Oracle . Oracle Corporation and its affiliates will not beresponsible for any loss, costs, or damages incurred due to your access to or use of third-party content,products, or services, except as set forth in an applicable agreement between you and PrefaceAudiencexviiiDocumentation AccessibilityxviiiRelated DocumentsxixConventionsxix Changes in This Release for Oracle Database Performance TuningGuideChanges in Oracle Database Release 19c, Version in Oracle Database Release 18c, Version in Oracle Database 12c Release 2 ( )

7 XxiChanges in Oracle Database 12c Release 1 ( )xxiiChanges in Oracle Database 12c Release 1 ( )xxiiiPart I Database Performance Fundamentals1 Performance Tuning OverviewIntroduction to Performance Tuning1-1 Performance Planning1-1 Instance Tuning1-1 Performance Principles1-2 Baselines1-2 The Symptoms and the Problems1-2 When to Tune 1-3 SQL Tuning1-4 Query Optimizer and Execution Plans1-4 Introduction to Performance Tuning Features and Tools1-5 Automatic Performance Tuning Features1-5 Additional Oracle Database Tools1-6iiiV$ Performance Views1-62 Designing and Developing for PerformanceOracle Methodology2-1 Understanding

8 Investment Options2-1 Understanding Scalability2-2 What is Scalability?2-2 System Scalability2-3 Factors Preventing Scalability2-4 System Architecture2-5 Hardware and Software Components2-5 Hardware Components2-5 Software Components2-6 Configuring the Right System Architecture for Your Requirements2-7 Application Design Principles2-10 Simplicity In Application Design2-10 Data Modeling2-10 Table and Index Design2-11 Appending Columns to an Index or Using Index-Organized Tables2-11 Using a Different Index Type2-11 Finding the Cost of an Index2-12 Serializing within Indexes2-13 Ordering Columns in an

9 Index2-13 Using Views2-13 SQL Execution Efficiency2-14 Implementing the Application 2-15 Trends in Application Development2-17 Workload Testing, Modeling, and Implementation2-17 Sizing Data2-18 Estimating Workloads2-18 Application Modeling2-19 Testing, Debugging, and Validating a Design2-19 Deploying New Applications2-20 Rollout Strategies2-20 Performance Checklist2-213 Performance Improvement MethodsThe Oracle Performance Improvement Method3-1 Steps in the Oracle Performance Improvement Method3-2ivA Sample Decision Process for Performance Conceptual Modeling3-3 Top Ten Mistakes Found in Oracle Systems3-4 Emergency Performance Methods3-6 Steps in the Emergency Performance Method3-64 Configuring a Database for PerformancePerformance Considerations for Initial Instance Configuration4-1

10 Initialization Parameters4-2 Undo Space4-3 Redo Log Files4-4 Tablespaces4-4 Creating and Maintaining Tables for Optimal Performance4-6 Table Compression4-6 Reclaiming Unused Space4-8 Indexing Data4-8 Performance Considerations for Shared Servers4-9 Identifying and Reducing Contention Using the Dispatcher-Specific Views 4-10 Identifying Contention for Shared Servers4-11 Improved Client Connection Performance Due to Prespawned Processes4-12 Part II Diagnosing and Tuning Database Performance5 Measuring Database PerformanceAbout Database Statistics5-1 Time Model Statistics5-1 Active Session History Statistics5-2 Wait Events Statistics5-3 Session and System Statistics5-4 Interpreting Database Statistics5-5 Using Hit Ratios5-5 Using Wait Events with Timed Statistics5-5 Using Wait Events without Timed Statistics5-6 Using Idle Wait Events5-6 Comparing Database Statistics with Other Factors5-6 Using Computed Statistics5-76 Gathering Database StatisticsAbout Gathering Database Statistics6-1vAutomatic Workload Repository6-2 Snapshots6-2 Baselines6-3 Fixed