How to "enable" microseconds in SYSTIMESTAMP on Windows platform / extend fractional seconds ?

Hi all,

in context with  an     ORA-00001: Unique Constraint (SYS.I_WRI$_OPTSTAT_HH_OBJ_ICOL_ST)  violation - which occures during   DBMS_STATS.GATHER_TABLE_STATS() on a table having a lot of empty partitions -  we realized   that  SYSTIMESTAMP returns only  milliseconds  -  the last 3 digits of the default-precision of 6 fractional seconds    are always 000:

for example:

select systimestamp from dual;

07/11/2019 19:46:42,093000 +01:00

We checked our Logging-table-entries  and  could find the same problem:  values of all  timestamp(6) -columns  contain  millisecond-resolution only ..

Also in Oracle's internal tables - as  SYS.WRI$_OPTSTAT_HISTHEAD_HISTORY -    we could find the same / limited resolution: