HiRDB database supports CURRENT_TIMESTAMP function. SQLWays leaves CURRENT_TIMESTAMP without precision as is.

CURRENT_TIMESTAMP(precision) converted according rules:

-if precision >= 6 , converted to CURRENT_TIMESTAMP(6)

-if precision is odd number, converted to CURRENT_TIMESTAMP(precision + 1)

Oracle:

select CURRENT_TIMESTAMP, CURRENT_TIMESTAMP(3), CURRENT_TIMESTAMP(12) from t;

HiRDB:

select CURRENT_TIMESTAMP, CURRENT_TIMESTAMP(4), CURRENT_TIMESTAMP(6) from t; 

References in Wiki