Re: v$log_history

On May 22, 11:32 am, tim2bo..._at_gmail.com wrote:
> On May 22, 12:01 pm, "fitzjarr..._at_cox.net" <orat..._at_msn.com> wrote:
>
>
>
>
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> > On May 22, 10:56 am, tim2bo..._at_gmail.com wrote:
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> > > On May 22, 11:01 am, "Uwe Schmidt" <uwe.schm..._at_dataport.de> wrote:
>
> > > > Hy NG,
>
> > > > how long are the entries stored in the view v$log_history ?
> > > > I looked into 2 diffrent databases and saw diffrent entries; 1= 2weeks ***
> > > > 2=3month ??? Wher can i customize the time how long the entries are stored?
>
> > > > So long
> > > > Uwe
>
> > > I believe that these entries are based on the controlfile and the
> > > controlfile keep time is based on the initialization parameter
> > > CONTROL_FILE_RECORD_KEEP_TIME .
>
> > > Regards
> > > tim Boles
>
> > The redo log history is not controlled by that parameter, it is
> > governed by the MAXLOGHISTORY setting.  I've explained how to change
> > this in a prior response.
>
> > David Fitzjarrell- Hide quoted text -
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> > - Show quoted text -
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> I don't think so:
>
> Some references to view:http://www.mydatabasesupport.com/forums/oracle-server/8800-archive-lo...
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> http://download.oracle.com/docs/cd/B10501_01/server.920/a96536/ch3100...
> V$LOG_HISTORY -- This view contains log history information from the
> control file.
>
> http://download.oracle.com/docs/cd/B10501_01/server.920/a96536/ch126....
> CONTROL_FILE_RECORD_KEEP_TIME specifies the minimum number of days
> before a reusable record in the control file can be reused. In the
> event a new record needs to be added to a reusable section and the
> oldest record has not aged enough, the record section expands.  This
> parameter applies only to records in the control file that are
> circularly reusable (such as archive log records and various backup
> records).
>
> http://download.oracle.com/docs/cd/B10501_01/server.920/a96540/statem...
> MAXLOGHISTORY Clause
> This parameter is useful only if you are using Oracle in ARCHIVELOG
> mode with Real Application Clusters. Specify the maximum number of
> archived redo log file groups for automatic media recovery of Real
> Application Clusters. Oracle uses this value to determine how much
> space in the control file to allocate for the names of archived redo
> log files. The minimum value is 0. The default value is a multiple of
> the MAXINSTANCES value and depends on your operating system. The
> maximum value is limited only by the maximum size of the control file.
>
> So basically you are correct except when the number of log files you
> write exceeds the MAXLOGHISTORY and the CONTROL_FILE_RECORD_KEEP_TIME
> has not been meet.  But for example if your MAXLOGHISTORY is 20, your
> CONTROL_FILE_RECORD_KEEP_TIME is set for 3 days and you are producing
> about 10 logs day.  Then your CONTROL_FILE_RECORD_KEEP_TIME over rides
> your MAXLOGHISTORY and you wind up with 30 logs instead of just 20.
> If your CONTROL_FILE_RECORD_KEEP_TIME is set to 0 then the redo log
> history entries in teh control file can be reused as required rather
> than retained until time expired.  See METALINK note 101343.102
>
> Regards
> Tim- Hide quoted text -
>
> - Show quoted text -

And in the databases Uwe mentions the length of time the log history reports is far longer than the 7 day default for controlfile_record_keep_time, leading me to believe that MAXLOGHISTORY is set to a larger value, which will override the controlfile_record_keep_time setting. I have at least one 10.2.0.3 database which is not in ARCHIVELOG mode and the log history far exceeds the controlfile_record_keep_time setting of 7 because MAXLOGHISTORY is set to 1168.

There are times when Metalink notes are not the reference standard one would expect.

David Fitzjarrell Received on Thu May 22 2008 - 11:48:30 CDT