Table of Contents

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  1. Preface
  2. Transformations
  3. Source transformation
  4. Target transformation
  5. Aggregator transformation
  6. Cleanse transformation
  7. Data Masking transformation
  8. Data Services transformation
  9. Deduplicate transformation
  10. Expression transformation
  11. Filter transformation
  12. Hierarchy Builder transformation
  13. Hierarchy Parser transformation
  14. Hierarchy Processor transformation
  15. Input transformation
  16. Java transformation
  17. Java transformation API reference
  18. Joiner transformation
  19. Labeler transformation
  20. Lookup transformation
  21. Machine Learning transformation
  22. Mapplet transformation
  23. Normalizer transformation
  24. Output transformation
  25. Parse transformation
  26. Python transformation
  27. Rank transformation
  28. Router transformation
  29. Rule Specification transformation
  30. Sequence Generator transformation
  31. Sorter transformation
  32. SQL transformation
  33. Structure Parser transformation
  34. Transaction Control transformation
  35. Union transformation
  36. Velocity transformation
  37. Verifier transformation
  38. 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.

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