now() – Returns the current timestamp at the start of query evaluation. Platforms: WhereOS, Spark,

next_day(start_date, day_of_week) – Returns the first date which is later than `start_date` and named as

normalize_unicode(string str [, string form]) – Transforms `str` with the specified normalization form. The `form`

nan() – Returns the constant representing not-a-number. SELECT nan(), is_nan(nan()); NaN true Platforms: WhereOS, Spark,

nanvl(expr1, expr2) – Returns `expr1` if it’s not NaN, or `expr2` otherwise. Platforms: WhereOS, Spark,

ndcg(array rankItems, array correctItems [, const int recommendSize = rankItems.size]) – Returns nDCG Platforms: WhereOS,