Precision In TIMESTAMP

Question

Hi all;
I know timestamp data types has up to 9 precison after seconds.(Ref: http://download-uk.oracle.com/docs/cd/B19306_01/server.102/b14200/sql_elements001.htm)
SQL> SELECT systimestamp FROM dual;
SYSTIMESTAMP
02-FEB-07 02.26.51.207000 PM +02:00
SQL> BUt above query has 6(default for timestamp precision) digits and after 3 digits they become zero.(207000).
What i need is to display timestamp exactly 9 digits:
SQL> SELECT systimestamp FROM dual;
SYSTIMESTAMP
02-FEB-07 02.26.51.207569782 PM +02:00
SQL> Are there any ALTER SESSION command or any others to achieve this situation?
Thanks, Regards...

Answer 1

First insert..select is atomic so it will use one timestamp for all insert statements.
For second insert, if timestamp has 9 digits of precision(now it has 6) it may pass constraint(Am i right?)
Thanks..
SQL> SELECT * from v$version;
BANNER
Oracle Database 10g Enterprise Edition Release 10.1.0.5.0 - Prod
PL/SQL Release 10.1.0.5.0 - Production
CORE     10.1.0.5.0     Production
TNS for Compaq Tru64 UNIX: Version 10.1.0.5.0 - Production
NLSRTL Version 10.1.0.5.0 - Production
SQL>
SQL> drop table t;
drop table t
ORA-00942: table or view does not exist
SQL> create table t( d1 timestamp);
Table created
SQL> alter table t add constraint uq_d1 unique(d1);
Table altered
SQL> insert into t select systimestamp from all_objects where rownum < 1000;
insert into t select systimestamp from all_objects where rownum < 1000
ORA-00001: unique constraint (SYSADM.UQ_D1) violated
SQL> DECLARE
  2  BEGIN
  3    FOR i IN 1 .. 1000 LOOP
  4      INSERT INTO t VALUES (systimestamp);
  5      COMMIT;
  6    END LOOP;
  7  END;
  8  /
DECLARE
BEGIN
  FOR i IN 1 .. 1000 LOOP
    INSERT INTO t VALUES (systimestamp);
    COMMIT;
  END LOOP;
END;
ORA-00001: unique constraint (SYSADM.UQ_D1) violated
ORA-06512: at line 4
SQL> SELECT * FROM t;
D1
02-FEB-07 03.24.54.877353 PM
02-FEB-07 03.24.54.879306 PM
02-FEB-07 03.24.54.880282 PM
SQL>