Re: Raw Disk Partition vs. Unix File System (Oracle 6)

In article <1993Aug18.155644.348_at_exlog.com>, Lee Parsons <lparsons_at_exlog.com> wrote:
>
>I'll acknowlege that these are cases where Managment does the wrong
>thing. But I'll also argue that cases like yours where the right thing
>is done are not as prevalent as we would like to think.
>
>And (to bring this thread back in line with the Subject line) a whole lot
>of people are hearing things like "GO RAW" and thinking to themselves
>"Gee a whole 15% increase in performance, for FREE"
>
>Stop and think about this guys or you are going to wake up in two years
>with 1) no more database 2) a stupid expression on you face and
>3) a whole bunch of realatively unused backup tapes.

I agree. As we've said before, do it right or don't do it.

>CASE-IN-POINT: Another response to the original posting that started
>this thread stated that backups should be unaffected after going raw.

What do you want to bet that the poster in question uses EXPORT to backup his database (so that it isn't affected by going raw?) :-)

>>3) If you tune Oracle buffers correctly, you will always win over
>> Oracle buffering overhead plus file system buffering overhead.
>> Admittedly, the difference may be small, but there is still a difference.
>
>Still not sure about this one, If you tune the SGA correctly your
>having to tune memory for average utilization/load. But what about
>peaks in the load? At 3:00 every day you do something really ugly
>that could use a ton of Block Buffers if they where there. You
>can't make the SGA Really big all the time because that would waste
>memory most of the day. You cant shutdown/startup with new SGA
>because people are used it. So instead you let SUN/OS buffer these
>I/Os in its extended cache a feature you wouldn't get from raw.
>
>An overly specific example I know, But still for the shop that has
>this need the FS may be a win.

I admit hadn't thought of this scenario, since it has never occurred in our environment. Our large database servers are just that; database servers. There is never a time when non-database activity is heavy enough to require restricting resources allocated to the database functions.

I'd be curious if anyone has chosen FS over RAW for that kind of reason, though.

Regards,

-Dave.

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