Observation: Merge Scan Join for Large Tables

Contents
Search

Application Audit Online Help
Compuware Enterprise Services
Fault Analytics
ISPW Web Interface
ThruPut Manager Web
Topaz For Java Performance
Topaz for Total Test Web Client User Guide
- Welcome to Topaz for Total Test
- Topaz for Total Test Non-virtualized Test Overview
- Getting Started
  - Getting Started Tutorial
  - Using the Web Client
  - Create a Test Suite from Browser
- Test Virtualization
  - Test Virtualization
  - Stubs in the Web Client
  - Recording Input Data to Sub Modules
- Extending Non-virtualized Test with Custom Data Definitions
- Code Coverage
- Configuring the Topaz for Total Test Repository Server
- Working with the Repository
  - Working with the Repository
  - General Information for All Artifacts
  - Defining and Using Components
  - Components in the Web Client
  - Connections
  - Environments
  - Systems
  - Categories
  - User Groups
  - Skins/Data and Execute
  - Stubs
  - Job Definitions
  - Dataset Skins
  - Test Scenarios
  - Suites
  - Reports
- Sample Programs
- Appendix A Tutorial Add a Component to the Repository with the Web Client
- Welcome to Topaz for Total Test
- Get a License
- Topaz for Total Test Functional Test Overview
- Getting Started
  - Getting Started Tutorial
  - Using the Web Client
  - Create a Test Suite from Browser
- Test Virtualization
  - Test Virtualization
  - Stubs in the Web Client
  - Recording Input Data to Sub Modules
- Extending Functional Test with Custom Data Definitions
  - Extending Functional Test with Custom Data Definitions
  - Extending a Test Scenario
  - Extending the Execution Context
- Code Coverage and IDz Integration
  - Code Coverage and IDz Integration
  - Browser Client
  - Eclipse Client
- Utility Tools
  - Utility Tools
  - Environment Specific Host UserIDs
  - Management Of Saved Host Credentials
  - Browse Datasets
  - Get Job Info and Spool Files
  - Copy And Delete Datasets
- Configuring the Topaz for Total Test Repository Server
  - Configuring the Topaz for Total Test Repository Server
- Working with the Repository
  - Working with the Repository
  - General Information for All Artifacts
  - Defining and Using Components
  - Components in the Web Client
  - Connections
  - Environments
  - Systems
  - Categories
  - User Groups
  - Skins/Data and Execute
  - Stubs
  - Job Definitions
  - Dataset Skins
  - Test Scenarios
  - Suites
  - Reports
  - Schedules
- Sample Programs
  - Sample Programs
  - Program XAPGMTST
  - Program XADB2TST
  - Program XAMOCTST
  - Program XAPGMCAL
  - Program XAPGMBT1
  - Program XARISCAL
  - Program XADTSTMP
  - Program XADGTIME
  - Program XADUTF8
iStrobe Online Help

Observation: Merge Scan Join for Large Tables

The DB2 optimizer invoked a merge scan join against at least one large table. Hybrid joins generally provide more consistent performance than merge scan joins for large tables. To influence the Db2 optimizer to use a hybrid join, use an indexed column to join on the inner table.