How do we handle untyped executions? There are two ways:-
1. Stick dummy schema of ByteArrays in LOLoad. This way is a bit ugly but very simple to do. Bad things: 1) This enforces maximum tuple arity for untyped execution. 2) We also have to carry a number of schema fields to downstream operators. 2. Implement all LOs to support null schema. This is more clean but requires a bit more work. I still see some LOs like LOUnion that will die immediately in getSchema() if one of the inputs have a null schema. I am more tempted to do (2) just because I want it to be clean but we could do (1) first if we want to get the whole thing done quickly. What about other people's opinion? Pi
