SQLite

Since SQLite version 3.20.0 (2017-08-01), date/time functions have been allowed in contexts that require deterministic functions as long as they did not make use of 'now', 'localtime', or 'utc' keywords since it was assumed that the date-time functions would be deterministic without those keywords. However, as forum thread 28ab8d7150?t=h demonstrates, a date/time function with no arguments can also be non-deterministic. This results in illegal schemas like:

CREATE TABLE t1(a, b AS (datetime()));
CREATE TABLE t2(x CHECK( x<julianday() ));