Table of Contents

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  1. Preface
  2. Analyst Service
  3. Content Management Service
  4. Data Integration Service
  5. Data Integration Service Architecture
  6. Data Integration Service Management
  7. Data Integration Service Grid
  8. Data Integration Service Applications
  9. Metadata Manager Service
  10. Model Repository Service
  11. PowerCenter Integration Service
  12. PowerCenter Integration Service Architecture
  13. High Availability for the PowerCenter Integration Service
  14. PowerCenter Repository Service
  15. PowerCenter Repository Management
  16. PowerExchange Listener Service
  17. PowerExchange Logger Service
  18. SAP BW Service
  19. Search Service
  20. System Services
  21. Test Data Manager Service
  22. Web Services Hub
  23. Application Service Upgrade
  24. Application Service Databases
  25. Connecting to Databases from Windows
  26. Connecting to Databases from UNIX
  27. Updating the DynamicSections Parameter of a DB2 Database

Processing Threads

Processing Threads

The DTM allocates process memory for the session and divides it into buffers. This is also known as buffer memory. The DTM uses multiple threads to process data in a session. The main DTM thread is called the master thread.
The master thread creates and manages other threads. The master thread for a session can create mapping, pre-session, post-session, reader, transformation, and writer threads.
For each target load order group in a mapping, the master thread can create several threads. The types of threads depend on the session properties and the transformations in the mapping. The number of threads depends on the partitioning information for each target load order group in the mapping.
The following figure shows the threads the master thread creates for a simple mapping that contains one target load order group:
The sample mapping contains the following objects: source, Source Qualifier transformation, Expression transformation, and target. The mapping also contains three threads.
  1. One reader thread.
  2. One transformation thread.
  3. One writer thread.
The mapping contains a single partition. In this case, the master thread creates one reader, one transformation, and one writer thread to process the data. The reader thread controls how the PowerCenter Integration Service process extracts source data and passes it to the source qualifier, the transformation thread controls how the PowerCenter Integration Service process handles the data, and the writer thread controls how the PowerCenter Integration Service process loads data to the target.
When the pipeline contains
only
a source definition, source qualifier, and a target definition, the data bypasses the transformation threads, proceeding directly from the reader buffers to the writer. This type of pipeline is a pass-through pipeline.
The following figure shows the threads for a pass-through pipeline with one partition:
The sample mapping contains the following objects: source, Source Qualifier transformation, and target. The mapping also contains three threads.
  1. One reader thread.
  2. Bypassed transformation thread.
  3. One writer thread.