If you have to do the aggregation using Informatica aggregator, then ensure that all the columns used in the group by are sorted in the same order of group by and “Sorted Input” option is checked in the aggregator properties. Ensuring the input data is sorted is absolutely must in order to achieve better performance and we will soon know why.
Other things that need to be checked to increase aggregator performance are –
- Check if “Case-Sensitive String Comparison” option is really required. Keeping this option checked (default) slows down the aggregator performance
- Enough memory (RAM) is available to do the in memory aggregation.
- Aggregator cache is partitioned