Understanding UDF I/O
Tuesday, March 01, 2011
8:31 AM
Understanding UDF I/O
Every function input is a single Tuple
Tuples are variable-size.
Elements exhibit hidden polymorphism. 
Return value of a UDF depends upon its kind.
Return values can be builtin types, Tuple, or DataBag.
Builtin types are constructed normally.
Both tuples and bags are created via factories. 