Nothing is easy with oracle for a starter. What doesn’t work:
SELECT TO_CHAR(sysdate, 'HH24:MI:SS.FF4') from dual;
It gives the “ORA-01821 - date format is not recognized”. Explanation is that sysdate in oracle is given with precision of a second.
What does work:
SELECT TO_CHAR(SYSTIMESTAMP, 'HH24:MI:SS.FF4') from dual;
See if oracle docs say anything about it (guess…): http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/functions172.htm