UniqueID generates a unique id for each records in the job. This unique id is
stable in task retry. Any arguments to the function are ignored.
A = load 'mydata' as (name);
B = foreach A generate name, UniqueID();
UniqueID takes the form "index-sequence"
Nested Class Summary
Nested classes/interfaces inherited from class org.apache.pig.EvalFunc
This callback method must be implemented by all subclasses. This
is the method that will be invoked on every Tuple of a given dataset.
Since the dataset may be divided up in a variety of ways the programmer
should not make assumptions about state that is maintained between
invocations of this method.