the creation date of a database

This is a question that originated from this question by Jamie.

I thought I'll check Dougman's answer. What's happening here? A restore?

select created from dba_users where username = 'SYS';

select min(created) FROM dba_objects;

select created from v$database;

CREATED                   
------------------------- 
10-SEP-08 11:24:44        

MIN(CREATED)              
------------------------- 
10-SEP-08 11:24:28        

CREATED                   
------------------------- 
18-DEC-09 15:49:00      

Crea开发者_运维知识库ted from v$database is more than one year later than creation date of user SYS and SYS' objects.

If you ask for slightly more detail in the first two queries you'll find that the schemas are Oracle's default ones:

SQL> select owner, min(created), max(created)
  2  from dba_objects
  3  where created < (select created from v$database)
  4  group by owner
  5  /

OWNER                          MIN(CREATED)         MAX(CREATED)
------------------------------ -------------------- --------------------
PUBLIC                         15-OCT-2007 10:09:10 15-OCT-2007 11:08:07
OUTLN                          15-OCT-2007 10:09:17 15-OCT-2007 10:11:32
CTXSYS                         15-OCT-2007 10:35:41 15-OCT-2007 10:36:12
SYSTEM                         15-OCT-2007 10:09:22 15-OCT-2007 10:48:40
SCOTT                          15-OCT-2007 11:36:01 15-OCT-2007 11:36:01
XDB                            15-OCT-2007 10:36:34 15-OCT-2007 10:53:50
SYS                            15-OCT-2007 10:09:07 15-OCT-2007 12:01:43
....

21 rows selected.

SQL>

On my database the value for CREATED is before I installed Oracle on my machine. So I think the dates represent when Oracle populated the data dictionary for that version of Oracle.

edit

Yep, it could be the dates in the DCBA templates; certainly my database was built using them.