The Data Integration Service determines whether it needs to add an additional partition point at the transformation, and then determines the optimal number of threads for that transformation pipeline stage. The Data Integration Service also determines whether it needs to redistribute data at the partition point. For example, the Data Integration Service might redistribute data at an Aggregator transformation to group rows for an aggregate expression.

Some transformations do not support partitioning. When a mapping enabled for partitioning contains a transformation that does not support partitioning, the Data Integration Service uses one thread to run the transformation. The Data Integration Service can use multiple threads to run the remaining mapping pipeline stages.

The following transformations do not support partitioning: