Aggregator, Joiner, Lookup, and Rank transformations require an index cache and a data cache. The Data Integration Service stores key values in the index cache and output values in the data cache. Sorter transformations require a single cache. The Data Integration Service stores sort keys and the data to be sorted in the Sorter cache.
The following table describes the type of information that the Data Integration Service stores in each cache:
Mapping Object
Cache Types and Descriptions
Aggregator
Index. Stores group values as configured in the group by ports.
Data. Stores calculations based on the group by ports.
Joiner
Index. Stores all master rows in the join condition that have unique keys.
Data. Stores master source rows.
Lookup
Index. Stores lookup condition information.
Data. Stores lookup data that is not stored in the index cache.
Rank
Index. Stores group values as configured in the group by ports.
Data. Stores ranking information based on the group by ports.