Aggregator Transformation Support on the Hive Engine
Aggregator Transformation Support on the Hive Engine
Some processing rules for the Hive engine differ from the processing rules for the Data Integration Service.
Mapping Validation
Mapping validation fails in the following situations:
The transformation contains stateful variable ports.
The transformation contains unsupported functions in an expression.
Aggregate Functions
If you use a port in an expression in the Aggregator transformation but you do not use the port within an aggregate function, the Hive engine might use any row in the port to process the expression.
The row that the Hive engine uses might not be the last row in the port. Hadoop execution is distributed, and thus the Hive engine might not be able to determine the last row in the port.
Data Cache Optimization
You cannot optimize the data cache for the transformation to store data using variable length.