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  1. Preface
  2. Mappings
  3. Mapplets
  4. Mapping Parameters
  5. Where to Assign Parameters
  6. Mapping Outputs
  7. Generate a Mapping from an SQL Query
  8. Dynamic Mappings
  9. How to Develop and Run a Dynamic Mapping
  10. Dynamic Mapping Use Cases
  11. Mapping Administration
  12. Import From PowerCenter
  13. Performance Tuning
  14. Pushdown Optimization
  15. Partitioned Mappings
  16. Developer Tool Naming Conventions

Developer Mapping Guide

Developer Mapping Guide

Dataship-Join Optimization Method

Dataship-Join Optimization Method

The dataship-join optimization method attempts to locate smaller data sets next to larger data sets to reduce join processing time. The Data Integration Service attempts to apply the dataship-join optimization method when there is a significant size difference between two tables.
For example, the Data Integration Service can apply the dataship-join optimization method to join a master table that contains 10,000 rows with a detail table that contains 1,000,000 rows. To perform the dataship-join, the Data Integration Service creates a temporary staging table in the database that contains the larger detail table. Then, the Data Integration Service copies the smaller master table to a temporary table and joins the data in the temporary table with the data in the larger detail table. After the Data Integration Service performs the join operation, the Joiner transformation logic is processed in the database.
Before applying the dataship-join optimization method, the Data Integration Service performs analyses to determine whether dataship-join optimization is possible and likely to be worthwhile. If the analyses determine that this method is likely to improve performance, the Data Integration Service applies it to the mapping. The Data Integration Service then reanalyzes the mapping to determine whether there are additional opportunities for dataship-join optimization. It performs additional optimizations if appropriate.
The Developer tool does not enable this method by default.

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