The Data Integration Service considers the suggested parallelism value for the number of threads for that transformation pipeline stage as long as the transformation can be partitioned. For example, if you configure the mapping to maintain row order, the Data Integration Service might need to use one thread for the transformation.

If the

Maximum Parallelism

run-time property for the mapping is set to Auto, you cannot define a suggested parallelism value for any transformations in the mapping. If you set the maximum parallelism value for the mapping to Auto after defining a suggested parallelism value for a transformation, the Data Integration Service ignores the suggested parallelism value.

You might want to define a suggested parallelism value to optimize performance for a transformation that contains many ports or performs complicated calculations.

For example, if a mapping enabled for partitioning processes a small data set, the Data Integration Service might determine that one thread is sufficient to process an Expression transformation pipeline stage. However, if the Expression transformation contains many complicated calculations, the transformation pipeline stage can still take a long time to process. You can enter a suggested parallelism value greater than 1 but less than the maximum parallelism value defined for the mapping or the Data Integration Service. The Data Integration Service uses the suggested parallelism value for the number of threads for the Expression transformation.

You can configure the following values for the

Suggested Parallelism

property for a transformation when you override the maximum parallelism for the mapping:

You can define the

Suggested Parallelism

property in the mapping run-time properties for the following transformations: