Table of Contents

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  1. Preface
  2. Transformations
  3. Source transformation
  4. Target transformation
  5. Access Policy transformation
  6. Aggregator transformation
  7. B2B transformation
  8. Cleanse transformation
  9. Data Masking transformation
  10. Data Services transformation
  11. Deduplicate transformation
  12. Expression transformation
  13. Filter transformation
  14. Hierarchy Builder transformation
  15. Hierarchy Parser transformation
  16. Hierarchy Processor transformation
  17. Input transformation
  18. Java transformation
  19. Java transformation API reference
  20. Joiner transformation
  21. Labeler transformation
  22. Lookup transformation
  23. Machine Learning transformation
  24. Mapplet transformation
  25. Normalizer transformation
  26. Output transformation
  27. Parse transformation
  28. Python transformation
  29. Rank transformation
  30. Router transformation
  31. Rule Specification transformation
  32. Sequence transformation
  33. Sorter transformation
  34. SQL transformation
  35. Structure Parser transformation
  36. Transaction Control transformation
  37. Union transformation
  38. Velocity transformation
  39. Verifier transformation
  40. 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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