If you can capture changes from the source that affect less than half the target, you can use incremental aggregation to optimize the performance of Aggregator transformations.

When you use incremental aggregation, you apply captured changes in the source to aggregate calculations in a session. The Integration Service updates the target incrementally, rather than processing the entire source and recalculating the same calculations every time you run the session.

You can increase the index and data cache sizes to hold all data in memory without paging to disk.