What can we do to improve the performance of Informatica Aggregator Transformation?

When records are sorted before being passed to the aggregator and the ‘sorted input’ option under Aggregator Properties is selected, aggregator performance increases substantially. The record set should be sorted according to the columns used in the Group By procedure. Unless there is a possibility that the previously sorted records from the source qualifier may become unsorted again before reaching the aggregator, it is typically a good idea to sort the record set at the database level, e.g., within a source qualifier transformation.