use default; -- Test map_keys() UDF DESCRIBE FUNCTION map_keys; DESCRIBE FUNCTION EXTENDED map_keys; -- Evaluate function against INT valued keys SELECT map_keys(map(1, "a", 2, "b", 3, "c")) FROM src LIMIT 1; -- Evaluate function against STRING valued keys SELECT map_keys(map("a", 1, "b", 2, "c", 3)) FROM src LIMIT 1;