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

Rules and Guidelines for Dynamic Lookup Caches

Rules and Guidelines for Dynamic Lookup Caches

Certain rules and guidelines apply when you use a dynamic lookup cache.
Consider the following guidelines when you use a dynamic lookup cache:
  • You cannot share the cache between a dynamic Lookup transformation and static Lookup transformation in the same target load order group.
  • You can enable a dynamic lookup cache for a relational, flat file, or Source Qualifier transformation lookup.
  • The Lookup transformation must be a connected transformation.
  • You can use a persistent or a non-persistent cache.
  • If the dynamic cache is not persistent, the Integration Service always rebuilds the cache from the database, even if you do not enable
    Recache from Lookup Source
    .
  • When you synchronize dynamic cache files with a lookup source table, the Lookup transformation inserts rows into the lookup source table and the dynamic lookup cache. If the source row is an update row, the Lookup transformation updates the dynamic lookup cache only.
  • You can only create an equality lookup condition. You cannot look up a range of data in a dynamic cache.
  • You must associate each lookup port that is not in the lookup condition with an input port, sequence ID, or associated expression.
  • Use a Router transformation to pass rows to the cached target when the NewLookupRow value equals one or two.
  • Use the Router transformation to drop rows when the NewLookupRow value equals zero. Or, you can output the rows to a different target.
  • Verify that the Integration Service outputs the same values to the target that it writes to the lookup cache. When you choose to output new values on update, only connect lookup/output ports to the target table instead of the input/output ports. When you choose to output old values on update, add an Expression transformation after the Lookup transformation and before the Router transformation. Add output ports in the Expression transformation for each port in the target table and create expressions to ensure you do not output null input values to the target.
  • When you use a lookup SQL override, map the correct columns to the appropriate targets for lookup.
  • When you add a WHERE clause to the lookup SQL override, use a Filter transformation before the Lookup transformation. This ensures that the Integration Service inserts rows in the dynamic cache and target table that match the WHERE clause.
  • When you configure a reusable Lookup transformation to use a dynamic cache, you cannot edit the condition or disable the
    Dynamic Lookup Cache
    property in a mapping.
  • Use Update Strategy transformations after the Lookup transformation to flag the rows for insert or update for the target.
  • Use an Update Strategy transformation before the Lookup transformation to define some or all rows as update if you want to use the Update Else Insert property in the Lookup transformation.
  • Set the row type to Data Driven in the session properties.
  • Select Insert and Update as Update for the target table options in the session properties.

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