EvalFunc#outputSchema method not called in UDF

[Zhang Jianfeng]

Hello everyone,

   I am coding one pig UDF function, like MyUDF:

   public class MyUDF extends EvalFunc<Object>{

       public Object exec(Tuple input) throws IOException()
       public Schema outputSchema(Schema input){}
   }

But I found the outputSchema method never called in jobs.  I use the 0.7
pig. Does anyone know why this happens?

Any thoughts will be appreciated.

Thanks,
Jian Feng