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

Tips for Lookup Transformations

Tips for Lookup Transformations

Add an index to the columns used in a lookup condition.
If you have privileges to modify the database containing a lookup table, you can improve performance for both cached and uncached lookups. This is important for very large lookup tables. Since the Integration Service needs to query, sort, and compare values in these columns, the index needs to include every column used in a lookup condition.
Place conditions with an equality operator (=) first.
If you include more than one lookup condition, place the conditions in the following order to optimize lookup performance:
  • Equal to (=)
  • Less than (<), greater than (>), less than or equal to (<=), greater than or equal to (>=)
  • Not equal to (!=)
Cache small lookup tables.
Improve session performance by caching small lookup tables. The result of the lookup query and processing is the same, whether or not you cache the lookup table.
Join tables in the database.
If the lookup table is on the same database as the source table in the mapping and caching is not feasible, join the tables in the source database rather than using a Lookup transformation.
Use a persistent lookup cache for static lookups.
If the lookup source does not change between sessions, configure the Lookup transformation to use a persistent lookup cache. The Integration Service then saves and reuses cache files from session to session, eliminating the time required to read the lookup source.
Call unconnected Lookup transformations with the :LKP reference qualifier.
When you write an expression using the :LKP reference qualifier, you call unconnected Lookup transformations only. If you try to call a connected Lookup transformation, the Designer displays an error and marks the mapping invalid.
Configure a pipeline Lookup transformation to improve performance when processing a relational or flat file lookup source.
You can create partitions to process a relational or flat file lookup source when you define the lookup source as a source qualifier. Configure a non-reusable pipeline Lookup transformation and create partitions in the partial pipeline that processes the lookup source.

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