To give some context, the null semantics in Pig follow SQL's. In SQL, null is
viral, so any operation with null results in null. The idea is that null means
unknown, not empty. So concat('x', unknown) = unknown.Alan. On Nov 2, 2012, at 3:09 PM, Yang wrote: > looks a more intuitive result should be "something" , right? > > but on my system it gave null
