// check whether stream operator is present
// after MultiQueryOptimizer because it can shift streams from
// map to reduce, etc.
EndOfAllInputSetter checker = new EndOfAllInputSetter(plan);
checker.visit();
boolean isAccum =
"true".equalsIgnoreCase(pc.getProperties().getProperty("opt.accumulator","true"));
if (isAccum) {
AccumulatorOptimizer accum = new AccumulatorOptimizer(plan);