Re: log switch sequence

I think I have this figured out.. whenever you add a new log group, it becomes

the next in the sequence no matter where you were at to begin with. It has nothing
to do with the number. This seems odd to me, like you should be able to create
a group no matter which log your on, and for safety, probably on the opposite end of
the sequence, but if you have 3 log groups, and your number one is current, and you
create number four, your sequence will be 1,4,2,3...1,4,2,3... Anyone have any
thoughts? Also, I am away from my system this weekend, so I can't query the v$log etc.
but I tried this on Personal Oracle and got the result I just explained.

• Dc.

Alexey M. Reshetov wrote:

> satar_at_my-dejanews.com wrote:
> : Do the following and re-post so we can better understand your situation:
>
> : SELECT * FROM V$LOG;
> : SELECT * FROM V$LOGFILE;
>
> : In article <363A3C92.7300E3C9_at_bigfoot.com>,
> : Doug Cowles <dcowles_at_bigfoot.com> wrote:
> : > I've got 4 redo logs, but they don't switch
> : > 1,2,3,4 - they go 1,2,4,3..1,2,4,3...etc.,
> : > What gives? How can I fix this?
> : >
> : > - Dc.
> : >
> : >
>
> Indeed, in my case it's takes place when I creating new logfile in the
> my test database with the next conditions:
>
> Before creating logfile:
> SELECT group#, thread#, sequence#, members, archived, status FROM v$log;
> GROUP# THREAD# SEQUENCE# MEMBERS ARC STATUS
> ------ ------- --------- ------- --- --------
> 1 1 238 1 NO INACTIVE
> 2 1 239 1 NO CURRENT
> 3 1 237 1 NO INACTIVE
>
> ALTER DATABASE ADD LOGFILE 'filename' SIZE 256K;
>
> SELECT group#, thread#, sequence#, members, archived, status FROM v$log;
> GROUP# THREAD# SEQUENCE# MEMBERS ARC STATUS
> ------ ------- --------- ------- --- --------
> 1 1 238 1 NO INACTIVE
> 2 1 239 1 NO CURRENT
> 3 1 237 1 NO INACTIVE
> 4 1 0 1 YES UNUSED
>
> ALTER SYSTEM SWITCH LOGFILE;
>
> SELECT group#, thread#, sequence#, members, archived, status FROM v$log;
> GROUP# THREAD# SEQUENCE# MEMBERS ARC STATUS
> ------ ------- --------- ------- --- --------
> 1 1 238 1 NO INACTIVE
> 2 1 239 1 NO INACTIVE
> 3 1 237 1 NO INACTIVE
> 4 1 240 1 NO CURRENT
>
> And later, when ALTER SYSTEM SWITCH LOGFILE occurs, switching of logfiles
> will: 1,2,4,3.
>
> I don't know about any negative consequences of it. It's only test system,
> and I never look for such database with archivelog mode and recovering.
>
> Regards,
> ____________________________________________________
> Alexey Reshetov
> real_at_kpbank.ru
Received on Sat Oct 31 1998 - 21:59:34 CST