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

Guidelines for Sharing a Named Lookup Cache

Guidelines for Sharing a Named Lookup Cache

Use the following guidelines when you configure Lookup transformations to share a named cache:
  • Do not share a lookup cache between sessions if the cache is a dynamic lookup cache or the transformation is configured to recache from the source.
  • You can share a cache between dynamic and static Lookup transformations but you must follow the guidelines for the cache location.
  • You must configure some of the transformation properties to enable named cache sharing.
  • A dynamic lookup cannot share the cache if the named cache has duplicate rows.
  • A named cache created by a dynamic Lookup transformation with a lookup policy of error on multiple match can be shared by a static or dynamic Lookup transformation with any lookup policy.
  • A named cache created by a dynamic Lookup transformation with a lookup policy of use first, use last, or use all values can be shared by a Lookup transformation with the same lookup policy.
  • Shared transformations must use the same output ports in the mapping. The criteria and result columns for the cache must match the cache files.
  • A dynamic Lookup transformation cannot share the cache with another Lookup transformation within the same target load order group. In a target load order group, processing of caches takes place in parallel and completes after the target loads. The PowerCenter Integration Service does not allow cache sharing because the full cache is unavailable for subsequent Lookup transformations.
The Integration Service might use the memory cache, or it might build the memory cache from the file, depending on the type and location of the Lookup transformations.
The following table shows when you can share a named cache between a static Lookup transformation and a dynamic Lookup transformation:
Location for Sharing Named Cache
Shared Cache
Location of Transformations
Cache Shared
Static with Static
  • Same target load order group.
  • Separate target load order groups.
  • Separate mappings.
  • Integration Service uses memory cache.
  • Integration Service uses memory cache.
  • Integration Service builds memory cache from file.
Dynamic with Dynamic
  • Separate target load order groups.
  • Separate mappings.
  • Integration Service uses memory cache.
  • Integration Service builds memory cache from file.
Dynamic with Static
  • Separate target load order groups.
  • Separate mappings.
  • Integration Service builds memory cache from file.
  • Integration Service builds memory cache from file.
The following table describes the guidelines to follow when you configure Lookup transformations to share a named cache:
Properties for Sharing Named Cache
Properties
Configuration for Named Shared Cache
Lookup SQL Override
If you use the Lookup SQL Override property, you must use the same override in all shared transformations.
Lookup Table Name
Must match.
Lookup Caching Enabled
Must be enabled.
Lookup Policy on Multiple Match
  • A named cache created by a dynamic Lookup transformation with a lookup policy of error on multiple match can be shared by a static or dynamic Lookup transformation with any lookup policy.
  • A named cache created by a dynamic Lookup transformation with a lookup policy of use first or use last can be shared by a Lookup transformation with the same lookup policy.
  • A named cached can be shared by a dynamic Lookup transformation with a lookup policy of use all values if it shares the cache with another active lookup transformation with the same lookup policy.
Lookup Condition
Shared transformations must use the same ports in the lookup condition. The conditions can use different operators, but the ports must be the same.
Connection Information
The connection must be the same. When you configure the sessions, the database connection must match.
Source Type
Must match.
Tracing Level
-
Lookup Cache Directory Name
Must match.
Lookup Cache Persistent
Must be enabled.
Lookup Data Cache Size
When transformations within the same mapping share a cache, the Integration Service allocates memory for the first shared transformation in each pipeline stage. It does not allocate additional memory for subsequent shared transformations in the same pipeline stage.
Lookup Index Cache Size
When transformations within the same mapping share a cache, the Integration Service allocates memory for the first shared transformation in each pipeline stage. It does not allocate additional memory for subsequent shared transformations in the same pipeline stage.
Dynamic Lookup Cache
For more information about sharing static and dynamic caches, see Guidelines for Sharing a Named Lookup Cache.
Output Old Value on Update
Does not need to match.
Update Dynamic Cache
Does not need to match.
Cache File Name Prefix
Must match. Enter the prefix only. Do not enter .idx or .dat. You cannot share a named cache with an unnamed cache.
Recache from Source
If you configure a Lookup transformation to recache from source, subsequent Lookup transformations in the target load order group can share the existing cache whether or not you configure them to recache from source. If you configure subsequent Lookup transformations to recache from source, the Integration Service shares the cache instead of rebuilding the cache when it processes the subsequent Lookup transformation.
If you do not configure the first Lookup transformation in a target load order group to recache from source, and you do configure the subsequent Lookup transformation to recache from source, the Integration Service does not rebuild the cache.
Lookup/Output Ports
Lookup/output ports must be identical, but they do not need to be in the same order.
Insert Else Update
-
Update Else Insert
-
Thousand Separator
-
Decimal Separator
-
Case-Sensitive String Comparison
-
Null Ordering
-
Sorted Input
Must match.
You cannot share a lookup cache created on a different operating system. For example, only an Integration Service on UNIX can read a lookup cache created on a Integration Service on UNIX, and only an Integration Service on Windows can read a lookup cache created on an Integration Service on Windows.

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