Table of Contents

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  1. Preface
  2. Understanding Pipeline Partitioning
  3. Partition Points
  4. Partition Types
  5. Pushdown Optimization
  6. Pushdown Optimization 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
  26. POWERCENTERHELP

Advanced Workflow Guide

Advanced Workflow Guide

Cache Files

Cache Files

When you run a session, the Integration Service creates at least one cache file for each transformation. If the Integration Service cannot process a transformation in memory, it writes the overflow values to the cache files.
The following table describes the types of cache files that the Integration Service creates for different mapping objects:
Mapping Object
Cache File
Aggregator, Joiner, Lookup, and Rank transformations
The Integration Service creates the following types of cache files:
  • One header file for each index cache and data cache
  • One data file for each index cache and data cache
Sorter transformation
The Integration Service creates one sorter cache file.
XML target
The Integration Service creates the following types of cache files:
  • One data cache file for each XML target group
  • One primary key index cache file for each XML target group
  • One foreign key index cache file for each XML target group
The Integration Service creates cache files based on the Integration Service code page.
When you run a session, the Integration Service writes a message in the session log indicating the cache file name and the transformation name. When a session completes, the Integration Service releases cache memory and usually deletes the cache files. You may find index and data cache files in the cache directory under the following circumstances:
  • The session performs incremental aggregation.
  • You configure the Lookup transformation to use a persistent cache.
  • The session does not complete successfully. The next time you run the session, the Integration Service deletes the existing cache files and creates new ones.
Since writing to cache files can slow session performance, configure the cache sizes to process the transformation in memory.


Updated July 04, 2018