Thanks for the explanation. It's clearer to me now.
JW
"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message
news:cohat1$7lh$1_at_titan.btinternet.com...
>
> I think you mean the log_checkpoint_interval.
>
> However, there is a parameter in 9.2 which is
> called the archive_lag_target. This may be the
> one you want to set if you don't like the 2 hour
> delay between log file switches - specific it
> in seconds, and a log switch will occur that
> many seconds (at worst) after the previous
> log switch.
>
> The log_checkpoint_interval (and log_checkpoint_timeout)
> no longer have the meaning they did prior to 8.1 - they
> specify how long a data block can stay on the dirty queue
> before dbwr will have to write it out - the 'interval' measures
> in terms of redo blocks, the 'timeout' measures in seconds.
>
> You may find that you have a default of 1800 seconds on the
> timeout. Modifying this will change the general background rate
> at which dbwr trickles blocks to disc, hence the impact of clearing
> the data buffer at checkpoints.
>
> If you have "archiver not complete" warnings in the alert log, then
> it is perfectly reasonable to increase the number of redo log groups
> until they stop happening. You may also want to increase the size of
> the log files to reduce the frequency of log switches during the intense
> periods anyway.
>
>
>
>
> --
> Regards
>
> Jonathan Lewis
>
> http://www.jlcomp.demon.co.uk/faq/ind_faq.html
> The Co-operative Oracle Users' FAQ
>
> http://www.jlcomp.demon.co.uk/seminar.html
> Optimising Oracle Seminar - schedule updated Sept 19th
>
>
>
>
>
> "John Wood" <jwood_at_hotmail.com> wrote in message
> news:VEUqd.247110$9b.75520_at_edtnps84...
> > Hi there,
> >
> > We are running Oracle 9.2 on Window 200 environment. I found that the
> > log_archive_interval for our database is set to 0. Somehow, I read some
> > book, saying that we should never set that parameter to 0.
> >
> > In the normal hour of the day, I can see the redo log files get switched
> > at
> > around every 2 hours. When the daily script to purge some tables is
run,
> > the log files switch within a minute for two or three times. The
purging
> > deletes about 20K rows of data. I have 3 log groups; each log file is
> > 100M
> > in size.
> >
> > The question is: do I need to specify a value for the
log_archive_interval
> > ?
> > The Two hour log switching seems to be too long.
> >
> > Also are 3 log groups good enough to prevent the situation that the LGWR
> > has
> > to wait for ARC process to finish ? I plan to map a drive through
network
> > as an optional destination for the Archive Log destination. I noticed
in
> > this news group that some user use 4 log group for their system, I
wonder
> > under what situation the system need to configure so.
> >
> > Thanks for the advise in advance.
> >
> > JW
> >
> >
> >
>
>
Received on Tue Nov 30 2004 - 23:49:18 CST
