Table of Contents

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  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

Dynamic Lookup Cache Overview

Dynamic Lookup Cache Overview

Use a dynamic lookup cache to keep the cache synchronized with the target.
You can use a dynamic cache with a relational lookup, flat file lookup, or a pipeline lookup.
The Integration Service builds the dynamic lookup cache when it processes the first lookup request. It queries the cache based on the lookup condition for each row that passes into the transformation. The Integration Service updates the lookup cache when it processes each row.
Based on the results of the lookup query, the row type, and the Lookup transformation properties, the Integration Service performs one of the following actions on the dynamic lookup cache when it reads a row from the source:
Inserts the row into the cache
The Integration Service inserts the row when the row is not in the cache and you configured the Lookup transformation to insert rows into the cache. You can configure the transformation to insert rows into the cache based on input ports or generated sequence IDs. The Integration Service flags the row as insert.
Updates the row in the cache
The Integration Service updates the row when the row exists in the cache and you configured the Lookup transformation to update rows in the cache. The Integration Service updates the row in the cache based on the input ports. The Integration Service flags the row as an update row.
Makes no change to the cache
The Integration Service makes no change when the row exists in the cache and you configured the Lookup transformation to insert new rows only. Or, the row is not in the cache and you specified to update existing rows only. Or, the row is in the cache, but based on the lookup condition, nothing changes. The Integration Service flags the row as unchanged.
Based on the value of the NewLookupRow, you can also configure a Router or Filter transformation with the dynamic Lookup transformation to route insert or update rows to the target table. You can route unchanged rows to another target table or flat file, or you can drop them.
The following figure shows a mapping with a Lookup transformation that uses a dynamic lookup cache:
The mapping contains a source, source qualifier, dynamic Lookup transformation, Router transformation, two Update Strategy transformations, and two instances of the same target. The Router transformation routes inserted rows from the Lookup transformation to an Update Strategy transformation, which inserts data to the target. The Router transformation also routes updated rows from the Lookup transformation to the other Update Strategy transformation, which updates data in the target.

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