-- -- MULTI_WORKING_COLUMNS -- -- Columns that are used in sorting and grouping but that do not appear in the -- projection order are called working (resjunk) columns. We check in here that -- these columns are pulled to the master, and are correctly used in sorting and -- grouping. SELECT l_quantity FROM lineitem ORDER BY l_shipdate, l_quantity LIMIT 20; SELECT l_quantity, count(*) as count FROM lineitem GROUP BY l_quantity, l_shipdate ORDER BY l_quantity, count LIMIT 20; SELECT l_quantity, l_shipdate, count(*) as count FROM lineitem GROUP BY l_quantity, l_shipdate ORDER BY l_quantity, count, l_shipdate LIMIT 20;