Re: log switch sequence

From: Alexey M. Reshetov <real_at_kpbank.ru>
Date: 31 Oct 1998 08:53:57 GMT
Message-ID: <71ej75$3hf$1@home.kpbank.ru>

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 - 02:53:57 CST