Table of Contents

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  1. Preface
  2. Analyst Service
  3. Content Management Service
  4. Data Integration Service
  5. Data Integration Service Architecture
  6. Data Integration Service Management
  7. Data Integration Service Grid
  8. Data Integration Service Applications
  9. Metadata Manager Service
  10. Model Repository Service
  11. PowerCenter Integration Service
  12. PowerCenter Integration Service Architecture
  13. High Availability for the PowerCenter Integration Service
  14. PowerCenter Repository Service
  15. PowerCenter Repository Management
  16. PowerExchange Listener Service
  17. PowerExchange Logger Service
  18. SAP BW Service
  19. Search Service
  20. System Services
  21. Test Data Manager Service
  22. Web Services Hub
  23. Application Service Upgrade
  24. Application Service Databases
  25. Connecting to Databases from Windows
  26. Connecting to Databases from UNIX
  27. Updating the DynamicSections Parameter of a DB2 Database

Repository Statistics

Repository Statistics

Almost all PowerCenter repository tables use at least one index to speed up queries. Most databases keep and use column distribution statistics to determine which index to use to execute SQL queries optimally. Database servers do not update these statistics continuously.
In frequently used repositories, these statistics can quickly become outdated, and SQL query optimizers might not choose the best query plan. In large repositories, choosing a sub-optimal query plan can have a negative impact on performance. Over time, repository operations gradually become slower.
Informatica identifies and updates the statistics of all repository tables and indexes when you copy, upgrade, and restore repositories. You can also update statistics using the
pmrep UpdateStatistics
command.