Expression Transformation in the Hadoop Environment
The Expression transformation processing in the Hadoop environment depends on the engine that runs the transformation.
Expression Transformation Support on the Blaze Engine
Mapping validation fails in the following situations:
- •The transformation contains stateful variable ports.
- •The transformation contains unsupported functions in an expression.
An Expression transformation with a user-defined function returns a null value for rows that have an exception error in the function.
Expression Transformation Support on the Spark Engine
Mapping validation fails in the following situations:
- •The transformation contains stateful variable ports.
- •The transformation contains unsupported functions in an expression.
If an expression results in numerical errors, such as division by zero or SQRT of a negative number, it returns an infinite or an NaN value. In the native environment, the expression returns null values and the rows do not appear in the output.
Expression Transformation Support on the Hive Engine
Mapping validation fails in the following situations:
- •The transformation contains stateful variable ports.
- •The transformation contains unsupported functions in an expression.
An Expression transformation with a user-defined function returns a null value for rows that have an exception error in the function.