Re: CHECKPOINTS

Steve,

The log files are 50 MB each (10 groups, see previous post).

log_checkpoint_interval = 100000
log_checkpoint_timeout = 0

Let me know if you get any ideas.

Mario

Steve Adams <steve.adams_at_ixora.com.au> wrote in message news:38be56e7.66513170_at_news.eagles.bbs.net.au...
> Hi Mario,
>
> I should also have asked for the size of the log files, and the values of
> log_checkpoint_interval and log_checkpoint_timeout, just in case you are
> checkpointing too intensively for a checkpoint to finish before the next
 one
> starts.
>
> Regards,
> Steve Adams
> http://www.ixora.com.au/
> http://www.oreilly.com/catalog/orinternals/
> http://www.christianity.net.au/
>
>
> On Thu, 02 Mar 2000 04:05:48 GMT, steve.adams_at_ixora.com.au (Steve Adams)
 wrote:
>
> >Hi Mario,
> >
> >This is a DBWn bottleneck.
> >Some questions ...
> >
> >What version of AIX?
> >Is aio available (it should be)?
> > To find out, do the following as root
> > # smit aio
> > select "Change/Show Characteristics of Asynchronous I/O"
> >How many datafiles do you have?
> >How many physical disks (spindles) underlying the data files (not
> >counting log files)?
> >What are the values of the following parameters?
> > use_async_io
> > db_writers
> > db_files
> > db_file_simultaneous_writes
> > _db_block_write_batch (if set)
> > db_block_checkpoint_batch
> > db_block_buffers
> > db_block_size
> >
> >Regards,
> >Steve Adams
> >http://www.ixora.com.au/
> >http://www.oreilly.com/catalog/orinternals/
> >http://www.christianity.net.au/
> >
> >
> >On Wed, 1 Mar 2000 23:12:32 +0100, "Mario" <mtechera_at_yahoo.com> wrote:
> >
> >>
> >>We have a problem with redo log switching
> >>when running large jobs. All groups fill up
> >>and remain active even though they
> >>are archived - presumably this is because
> >>checkpointing is going on.
> >>
> >>Finally when the
> >>last log group fills and wants to switch back to
> >>the first group it cannot do so, because
> >>the first group is still active. At this point the system
> >>slows to a crawl and even trivial queries require minutes
> >>for a response.
> >>
> >>We have
> >>increased the number of redo log groups
> >>(almost doubling the space available),
> >>and have also increased the initialization
> >>parameter db_block_checkpoint_batch
> >>so as to allow for faster checkpointing.
> >>Yet the problem persists.
> >>
> >>Does anyone have any pointers for us?
> >>
> >>Is there any good documentation on how the checkpoint
> >>process works and why it takes so long?
> >>
> >>Our System
> >>Oracle V7.3.4, RS/6000, 2CPUs, 1.3 GB Memory, AIX
> >>
> >>Thanks in advance,
> >>Mario
> >>
> >>
> >>
> >>
> >
>
Received on Thu Mar 02 2000 - 00:00:00 CST