presto-main/src/main/java/io/prestosql/sql/planner/optimizations/StreamPropertyDerivations.java/StreamPropertyDerivations/visitDelete
class StreamPropertyDerivations:        @Override
        public StreamProperties visitDelete(DeleteNode node, List<StreamProperties> inputProperties)
        {
            StreamProperties properties = Iterables.getOnlyElement(inputProperties);
            // delete only outputs the row count
            return properties.withUnspecifiedPartitioning();
        }