Table of Contents

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  1. Preface
  2. Introduction to Data Validation Option
  3. New Features and Behavior Changes
  4. Repositories
  5. XML Data Source
  6. Tests for XML Data Sources
  7. Connections
  8. Expressions
  9. Table Pairs
  10. Tests for Table Pairs
  11. Single-Table Constraints
  12. Tests for Single-Table Constraints
  13. Examples of Tests from Spreadsheets
  14. SQL Views
  15. Lookup Views
  16. Join Views
  17. Aggregate Views
  18. Business Intelligence and Reporting Tools Reports
  19. Dashboards
  20. DVOCmd Command Line Program
  21. Troubleshooting
  22. Datatype Reference
  23. Reporting Views
  24. Metadata Import Syntax
  25. Jasper Reports
  26. Glossary

Data Validation Option User Guide

Data Validation Option User Guide

Rules and Guidelines for Aggregate Views

Rules and Guidelines for Aggregate Views

Certain rules and guidelines apply when you create an aggregate view.
Consider the following rules and guidelines when you create an aggregate view:
  • Use sorted input to decrease the use of aggregate caches. Sorted input reduces the amount of data cached during the session and improves session performance.
  • Limit the number of input/output columns to reduce the amount of data the aggregate view stores in the data cache.
  • Filter the data before aggregating it.
  • If you create a column in the aggregate view, verify that the datatype, precision, and scale match the PowerCenter datatype, precision, and scale shown in the
    Column Definitions
    area. By default, the scale is 0.
  • You can either include single level functions, for example,
    SUM(QUANTITY)
    , or nested functions, for example,
    MAX(COUNT(ITEM))
    , in the output columns of an aggregate view. However, you cannot include both single level and nested functions in an aggregate view.