Re: Oracle on ram drive with no redo log or other archiving

HansF wrote:

HansF,

Thank you for your answers. I'm putting them to use. I do realize that Oracle has very sophisticated caching and thus a lot of operations are as fast as if they were in memory especially if the READ/WRITE ratio of the application is high.

In my case, though, there is almost as many updates as selects and it takes a lot longer to durably store data on harddisk compared to storing it on a ram drive. Tests run about 20-25 times faster when Oracle storage is in ram already and I'm just looking to get that to go even faster by minimizing unneccessary I/O.

• robert

> Why bother with RAM drive under a traditional Oracle database when Oracle
> already provides a full-fledged optimized (and supported) in-memory
> database. (Unless you are trying to buffalo some sucker?)

> On Wed, 28 Sep 2005 17:32:42 -0700, robertbrown1971 interested us by
> writing:
>
> > Question:
>
> Yee-haw, ride 'em cowboy. Can anyone say 'skunk works'?
>
> >
> > 1) How can I start oracle to minimize or disable redo log? I know there
> > is a NOARCHIVE mode. Is that it? How do I enable it for the whole
> > instance?
>
> Nope. NOARCHIVE is related to how the log files are safely tucked away by
> the archiver.
>
> Basically the redo log is so fundamental to Oracle's philosophy of
> protecting the database that I doubt there is a way of telling it to not
> generate any redo. There are ways of minimizing it, yes, but not
> eliminating. Then again, is anything wrong with having 2 redo log
> groups at, say 1M (or less). They are used in a circular buffer basis,
> wasted pretty quickly, and eliminate any risk of hitting some undocumented
> log file check/read that might exist (although logically probably doesn't).
>
> Perhaps a few days in the Concepts manual will help.
>
> > 2) What other logs are there and how can I turn them off (or minimize
> > output)
>
> look for the background_dump_dest (and other *dump_dest) parameters. The
> alert.log comes to mind. And you may want to point those directories to
> oblivion.
>
> >
> > 3) What other files besides that data files for the tablespaces used by
> > tests need to be in RAM drive for fastest performance. In other words,
> > if I have a regular oracle account and just execute vanilla updates
> > where does Oracle write to besides the redo log and the data files.
>
> Control file, orapwd, spfile/pfile are required to run, or at least start.
> First one is a writeable file and MUST be visible. This would also be
> identified in the Concepts manual. (Ya, I know - that takes time, and
> things are moving real fast here!)
>
> >
> > Note that not all are in RAM. Since ram is expensive it would be
> > preferrable to keep the files that are changing rarely in durable
> > location and then only put the files that actually affect performance on
> > the ram drive.
>
> Check out Oracle's Times Ten as well.
>

> --
> Hans Forbrich
> Canada-wide Oracle training and consulting
> mailto: Fuzzy.GreyBeard_at_gmail.com
> *** I no longer assist with top-posted newsgroup queries ***
Received on Thu Sep 29 2005 - 09:40:50 CDT