Re: v$log_history

On May 22, 12:01 pm, "fitzjarr..._at_cox.net" <orat..._at_msn.com> wrote:
> 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:
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> > > 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?
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> > > So long
> > > Uwe
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> > 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 -

I don't think so:

Some references to view:
http://www.mydatabasesupport.com/forums/oracle-server/8800-archive-log-files-reaches-maxloghistory.html

http://download.oracle.com/docs/cd/B10501_01/server.920/a96536/ch3100.htm#1117380 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.htm#REFRN10020 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/statements_54a.htm#2078255 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 Received on Thu May 22 2008 - 11:32:41 CDT