SET allow_experimental_analyzer = 1; -- { echoOn } EXPLAIN header = 1, optimize = 0 SELECT avgWeighted(x, y) FROM (SELECT NULL, 255 AS x, 1 AS y UNION ALL SELECT y, NULL AS x, 1 AS y); SELECT avgWeighted(x, y) FROM (SELECT NULL, 255 AS x, 1 AS y UNION ALL SELECT y, NULL AS x, 1 AS y); -- { echoOff }