Mapping validation fails in the following situations:

The target is configured to maintain row order and the Sorter transformation is not connected directly to a flat file target.

The Blaze engine can perform global sorts when the following conditions are true:

The Sorter transformation is connected directly to flat file targets.
The target is configured to maintain row order.
The sort key is not a binary data type.

If any of the conditions are not true, the Blaze engine performs a local sort.

If a Sorter transformation is inserted before an Aggregator or Rank transformation to optimize the Aggregator or Rank data cache, the size of the sorter cache is the same size as the data cache for the Aggregator or Rank transformation. To configure the sorter cache, you must configure the size of the data cache for the Aggregator or Rank transformation.