Hi Karen On 5/11/05, Karen Morton <Karen.Morton@xxxxxxxxxx> wrote: > Different OS use different epoch values. Our Linux box uses 1/1/70 00:00 = G=3D > MT (the Unix Epoch). Windows apparently uses instance restart time as it= =3D > s epoch. It's "just" a matter of studying it long enough to figure out w= =3D > hat epoch value AIX uses.=3D20 I'm pretty sure that Oracle on Windows uses host restart time as the 'epoch' (world's shortest epochs or something), rather than *instance* start time. The following sqlplus session=20 =3D=3D=3D=3D=3D=3D=3D=3D SQL> conn / as sysdba Connected. SQL> alter session set sql_trace=3Dtrue; Session altered. SQL> select sysdate from dual; SYSDATE --------- 11-MAY-05 SQL> shutdown abort; ORACLE instance shut down. SQL> startup ORACLE instance started. Total System Global Area 197132288 bytes Fixed Size 788108 bytes Variable Size 145750388 bytes Database Buffers 50331648 bytes Redo Buffers 262144 bytes Database mounted. Database opened. SQL> alter session set sql_trace=3Dtrue; Session altered. SQL> select sysdate from dual; SYSDATE --------- 11-MAY-05 SQL> alter session set sql_trace=3Dfalse; Session altered. SQL> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D results in (edited just to show single tim lines) PARSING IN CURSOR #1 len=3D24 dep=3D0 uid=3D0 oct=3D3 lid=3D0 tim=3D2715445= 84730 hv=3D2343063137 ad=3D'6b221304' select sysdate from dual END OF STMT and then after the instance restart (in a separate file naturally) PARSING IN CURSOR #12 len=3D24 dep=3D0 uid=3D0 oct=3D3 lid=3D0 tim=3D271573= 747478 hv=3D2343063137 ad=3D'6b88b8cc' select sysdate from dual END OF STMT so the tim value doesnt restart The system has been up for 3 days and a bit=20 C:\downloads>uptime \\HOST has been up for: 3 day(s), 3 hour(s), 29 minute(s), 28 second(s) which translates into a small amount more than 271573747478 microseconds (10g), I attribute the difference to typing time. HTH=20 --=20 Niall Litchfield Oracle DBA http://www.niall.litchfield.dial.pipex.com -- //www.freelists.org/webpage/oracle-l