scn number

[FredBear]

"Uwe Schmidt" <uwe.schmidt@dataport.de> a écrit dans le message de
news:newscache$hx7t8i$9om$1@www-neu.dzsh.de...
| Hy NG,
|
|
| is there
| 1) a view or a table where i can select the actuel scn-number from the db ?
| 2) if the db is down (offline), can i see the last scn-number ? in
| ctrl-file, data-file, logfile (in alert-file, i
| know)
|
|
| Thanks .....
|

1. select dbms_flashback.get_system_change_number from dual;
2. It is in the control file but you can't see it.
Maybe in the mount state there is a x$ table containing that?

Regards
Michel Cadot

[GQ]

You can also see it from the view v$database, and therefore, as Michel
suggested,
is available under x$kccdi.dicur_scn (from which v$database is based
on).

The funny thing is that this value is set to 0 when the database is in
a mount state.
The value is only set to the current SCN when the database is open.

[Denis Do]

v$datafile_header view is probably the best source

[FredBear]

"Michel Cadot" <micadot{at}altern{dot}org> a écrit dans le message de
news:41c16f14$0$7556$636a15ce@news.free.fr...
|
| "Uwe Schmidt" <uwe.schmidt@dataport.de> a écrit dans le message de
| news:newscache$hx7t8i$9om$1@www-neu.dzsh.de...
| | Hy NG,
| |
| |
| | is there
| | 1) a view or a table where i can select the actuel scn-number from the db ?
| | 2) if the db is down (offline), can i see the last scn-number ? in
| | ctrl-file, data-file, logfile (in alert-file, i
| | know)
| |
| |
| | Thanks .....
| |
|
| 1. select dbms_flashback.get_system_change_number from dual;
| 2. It is in the control file but you can't see it.
| Maybe in the mount state there is a x$ table containing that?
|
| Regards
| Michel Cadot
|
|

Assuming the last shutdown was not abort, in the mount state, you can get it with:

select checkpoint_change# from v$database; -- from control file
select checkpoint_change#, last_changes# from v$datafile; -- from control file
select checkpoint_change# from v$datafile_header; -- from datafile headers

Regards
Michel Cadot

[Denis Do]

Hi Michael!

I gave the same answer - and just couple seconds later realised it was not
exactly what has been asked:-)

Have a look here:
1 select current_scn, flashback_on, CONTROLFILE_CHANGE#, CHECKPOINT_CHANGE#
2* from v$database
SQL> /

CURRENT_SCN FLA CONTROLFILE_CHANGE# CHECKPOINT_CHANGE#
----------- --- ------------------- ------------------
386884 NO 386780 386617

SQL> /

CURRENT_SCN FLA CONTROLFILE_CHANGE# CHECKPOINT_CHANGE#
----------- --- ------------------- ------------------
386886 NO 386780 386617

SQL> commit;

Commit complete.

SQL> /

Commit complete.

SQL> select current_scn, flashback_on, CONTROLFILE_CHANGE#, CHECKPOINT_CHANGE#
2 from v$database;

CURRENT_SCN FLA CONTROLFILE_CHANGE# CHECKPOINT_CHANGE#
----------- --- ------------------- ------------------
386898 NO 386780 386617

SQL> select distinct CHECKPOINT_CHANGE# from v$datafile_header;

CHECKPOINT_CHANGE#
------------------
386617
So, I would say correct answer is :
- on open instance - v$database.CURRENT_SCN column
- on mounted instance - v$datafile_header

Cheers!

On 2004-12-19, Michel Cadot <micadot{at}altern{dot}org> wrote: "Michel Cadot" <micadot{at}altern{dot}org> a écrit dans le message de news:41c16f14$0$7556$636a15ce@news.free.fr...
select checkpoint_change# from v$database; -- from control file select checkpoint_change#, last_changes# from v$datafile; -- from control file select checkpoint_change# from v$datafile_header; -- from datafile headers