Thanks Jonathan.
What do I check for as the input type, because DataType.TUPLE does not seem
to work. I would like to use "getArgToFuncMapping()" to be able to invoke
different functions based on input type, and I am not sure how to check for
Case 2.
In my implementation, Case 1 could be checked for (DataType.TUPLE,
DataType.CHARARRAY) but for Case 2 I would assume it should be
(DataType.TUPLE) but that does not work. PIg UDF cannot infer a matching
function.
@Override
public List<FuncSpec> getArgToFuncMapping() throws FrontendException {
List<FuncSpec> funcList = new ArrayList<FuncSpec>();
Schema s = new Schema();
s.add(new Schema.FieldSchema(null, DataType.TUPLE));
s.add(new Schema.FieldSchema(null, DataType.CHARARRAY));
funcList.add(new FuncSpec(this.getClass().getName(), s));
s = new Schema();
s.add(new Schema.FieldSchema(null, DataType.TUPLE));
funcList.add(new FuncSpec(CustomUDF.class.getName(), s));
return funcList;
}
On Fri, Nov 25, 2011 at 12:52 AM, Jonathan Coveney <[email protected]>wrote:
> The first case will give you a tuple which contains, as it first element, a
> tuple of all of the stuff in *, and as its second element, 'input'.
>
> The second will give youa tuple which contains all of the elements of *,
> and then as its last element, 'input'.
>
> This is what I thought, but to be sure I ran this UDF:
>
> import org.apache.pig.EvalFunc;
> import java.io.IOException;
> import org.apache.pig.data.Tuple;
>
> public class ATHING extends EvalFunc<String> {
> public String exec(Tuple input) throws IOException {
> System.out.println(input.toString());
> return null;
> }
> }
>
> 2011/11/24 Prashant Kommireddi <[email protected]>
>
> > I have a question regarding the pig data types.
> >
> > If I have a UDF, say 'CustomUDF' and I do something like this:
> >
> > REGISTER 'foo.jar';
> >
> > A = LOAD '/shared/a.dat';
> >
> > What would be the difference in the data types for UDF arguments between
> > -->
> >
> > Case 1 : B = FOREACH A GENERATE CustomUDF(TOTUPLE(*), 'input'); AND
> > Case 2 : B = FOREACH A GENERATE CustomUDF(*, 'input');
> >
> > I am sure Case 1 is (tuple, chararray). Can anyone let me know the data
> > type for Case 2 arguments?
> >
> > Thanks,
> > Prashant
> >
>
