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

Dynamic cache and lookup source synchronization

Dynamic cache and lookup source synchronization

The Lookup transformation maintains a dynamic lookup cache to track the rows that it passes to the target. When multiple tasks update the same target, you can configure the Lookup transformation in each task to synchronize the dynamic lookup cache to the same lookup source instead of a target.
To synchronize the cache with the lookup source, enable the
Synchronize Dynamic Cache
property for the Lookup transformation.
When you configure a Lookup transformation to synchronize the cache with the Lookup source, the Lookup transformation performs a lookup on the lookup source. If the data does not exist in the Lookup source, the Lookup transformation inserts the row into the lookup source before it updates the dynamic lookup cache.
The data might exist in the lookup source if another task inserted the row. To synchronize the lookup cache to the lookup source, the task retrieves the latest values from the lookup source. The Lookup transformation inserts the values from the Lookup source in the dynamic lookup cache.
For example, you have multiple tasks running simultaneously. Each task generates product numbers for new product names. When a task generates a product number, the other tasks must use the same product number to identify the product. The product number is generated once and inserted in the lookup source. If another task processes a row containing the product, it must use the product number that is in the lookup source. Each task performs a lookup on the lookup source to determine which product numbers have already been generated.
When you configure the Lookup transformation to synchronize the cache with the lookup source, the task performs a lookup on the dynamic lookup cache for insert rows. If data does not exist in the dynamic lookup cache, the task performs a lookup on the lookup source. It then completes one of the following tasks:
  • If data exists in the lookup source, the task inserts a row in the dynamic lookup cache with the columns from the lookup source. It does not update the cache with the source row.
  • If data does not exist in the lookup source, the task inserts the data into the lookup source and inserts the row into the cache.
The lookup source contains the same fields as the lookup cache. The task does not insert a row in the lookup cache unless the column is projected from the Lookup transformation or the field is part of a lookup condition.

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