Table of Contents

Search

  1. Preface
  2. Working with Transformations
  3. Aggregator Transformation
  4. Custom Transformation
  5. Custom Transformation Functions
  6. Data Masking Transformation
  7. Data Masking Examples
  8. Expression Transformation
  9. External Procedure Transformation
  10. Filter Transformation
  11. HTTP Transformation
  12. Identity Resolution Transformation
  13. Java Transformation
  14. Java Transformation API Reference
  15. Java Expressions
  16. Java Transformation Example
  17. Joiner Transformation
  18. Lookup Transformation
  19. Lookup Caches
  20. Dynamic Lookup Cache
  21. Normalizer Transformation
  22. Rank Transformation
  23. Router Transformation
  24. Sequence Generator Transformation
  25. Sorter Transformation
  26. Source Qualifier Transformation
  27. SQL Transformation
  28. Using the SQL Transformation in a Mapping
  29. Stored Procedure Transformation
  30. Transaction Control Transformation
  31. Union Transformation
  32. Unstructured Data Transformation
  33. Update Strategy Transformation
  34. XML Transformations

Transformation Guide

Transformation Guide

Indexes and a Lookup Table

Indexes and a Lookup Table

If you have privileges to modify the database containing a lookup table, you can improve lookup initialization time by adding an index to the lookup table. You can improve performance for very large lookup tables. Since the Integration Service queries, sorts, and compares values in lookup columns, the index needs to include every column in a lookup condition.
You can improve performance by indexing the following types of lookup:
  • Cached lookups.
    You can improve performance by indexing the columns in the lookup ORDER BY. The session log contains the ORDER BY clause.
  • Uncached lookups.
    Because the Integration Service issues a SELECT statement for each row passing into the Lookup transformation, you can improve performance by indexing the columns in the lookup condition.

0 COMMENTS

We’d like to hear from you!