// check that both reduce and combiner have the same strategy
assertEquals(DriverStrategy.SORTED_REDUCE, reduceNode.getDriverStrategy());
assertEquals(DriverStrategy.SORTED_PARTIAL_REDUCE, combineNode.getDriverStrategy());
// check the keys
assertEquals(new FieldList(1), reduceNode.getKeys());
assertEquals(new FieldList(1), combineNode.getKeys());
assertEquals(new FieldList(1), reduceNode.getInput().getLocalStrategyKeys());
// check DOP
assertEquals(6, sourceNode.getDegreeOfParallelism());
assertEquals(6, combineNode.getDegreeOfParallelism());
assertEquals(8, reduceNode.getDegreeOfParallelism());