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  1. Preface
  2. Understanding Pipeline Partitioning
  3. Partition Points
  4. Partition Types
  5. Pushdown Optimization
  6. Pushdown Optimization and Transformations
  7. Real-time Processing
  8. Commit Points
  9. Row Error Logging
  10. Workflow Recovery
  11. Stopping and Aborting
  12. Concurrent Workflows
  13. Grid Processing
  14. Load Balancer
  15. Workflow Variables
  16. Parameters and Variables in Sessions
  17. Parameter Files
  18. FastExport
  19. External Loading
  20. FTP
  21. Session Caches
  22. Incremental Aggregation
  23. Session Log Interface
  24. Understanding Buffer Memory
  25. High Precision Data

Advanced Workflow Guide

Advanced Workflow Guide

Example of Pushdown Optimization for Session with Multiple Partitions

Example of Pushdown Optimization for Session with Multiple Partitions

The following figure shows a mapping that contains a Sorter transformation with hash auto-keys partitioning:
The mapping includes a source, Source Qualifier, Sorter transformation, and target.
The first key range is 1313 - 3340, and the second key range is 3340 - 9354. The SQL statement merges all the data into the first partition:
SELECT ITEMS.ITEM_ID, ITEMS.ITEM_NAME, ITEMS.ITEM_DESC FROM ITEMS1 ITEMS WHERE (ITEMS.ITEM_ID >= 1313) AND (ITEMS.ITEM_ID < 9354) ORDER BY ITEMS.ITEM_ID
The SQL statement selects items 1313 through 9354, which includes all values in the key range, and merges the data from both partitions into the first partition.
The SQL statement for the second partition passes empty data:
SELECT ITEMS.ITEM_ID, ITEMS.ITEM_NAME, ITEMS.ITEM_DESC FROM ITEMS1 ITEMS WHERE (1 = 0) ORDER BY ITEMS.ITEM_ID


Updated August 27, 2020