Table of Contents

Search

  1. Preface
  2. Transformations
  3. Source transformation
  4. Target transformation
  5. Aggregator transformation
  6. Cleanse transformation
  7. Data Masking transformation
  8. Deduplicate transformation
  9. Expression transformation
  10. Filter transformation
  11. Hierarchy Builder transformation
  12. Hierarchy Parser transformation
  13. Hierarchy Processor transformation
  14. Input transformation
  15. Java transformation
  16. Java transformation API reference
  17. Joiner transformation
  18. Labeler transformation
  19. Lookup transformation
  20. Mapplet transformation
  21. Normalizer transformation
  22. Output transformation
  23. Parse transformation
  24. Python transformation
  25. Rank transformation
  26. Router transformation
  27. Rule Specification transformation
  28. Sequence Generator transformation
  29. Sorter transformation
  30. SQL transformation
  31. Structure Parser transformation
  32. Transaction Control transformation
  33. Union transformation
  34. Velocity transformation
  35. Verifier transformation
  36. Web Services transformation

Transformations

Transformations

Lookup source filter

Lookup source filter

You can configure a lookup source filter for a relational Lookup transformation that has caching enabled. Add the lookup source filter to limit the number of lookups that the
mapping
task performs on a lookup source table. When you configure a lookup source filter, the
mapping
task performs lookups based on the results of the filter statement.
To configure a lookup source filter, open the
Advanced
tab of the Lookup transformation, and enter the filter in the
Lookup Source Filter
field. Do not include the WHERE keyword in the filter condition.
For example, you might need to retrieve the last name of every employee whose ID is greater than 510.
You configure the following lookup source filter on the EmployeeID field in the Lookup transformation:
EmployeeID >= 510
When the
mapping
task reads the source row, it performs a lookup on the cache when the value of EmployeeID is greater than 510. When EmployeeID is less than or equal to 510, the Lookup transformation does not retrieve the last name.
When you add a lookup source filter to the Lookup query for a
mapping
task that uses pushdown optimization, the
mapping
task creates a view to represent the SQL override. The
mapping
task runs an SQL query against this view to push the transformation logic to the database.
If you configure a lookup source filter and a lookup SQL override in the same transformation, the
mapping
task ignores the filter.