The Integration Service uses cache memory to process Aggregator transformations with unsorted input. When you run the session, the Integration Service stores data in memory until it completes the aggregate calculations.
The Integration Service creates the following caches for the Aggregator transformation:
Stores group values as configured in the group by ports.
Stores calculations based on the group by ports.
By default, the Integration Service creates one memory cache and one disk cache for both the data and index in the transformation.
When you create multiple partitions in a session with an Aggregator transformation, the Integration Service uses cache partitioning. It creates one disk cache for all partitions and a separate memory cache for each partition.