Re: Raw Partitions and Oracle

I'm curious to see how many folks are actually running raw vs. file. In the DBA class I went to I was given a doc stating that running raw is more of a hassle for backups (i.e. using dd instead of tar, cp...) and the the raw idea (unless you are using a third party backup tool because of limitations with dd) really is not worth it.

In other words the doc pretty much stated that the peformance gains really do NOT merit the limitations associated with raw.

Seems to me they stated that you should spend more time tuning the appl. or looking at SQL rather than messing around with raw.

Any feedback?

JB
Pei L. Ku wrote:

> In the case where unix files are used, Oracle uses 'sync write' to ensure
> that the writes are written from FS buffer cache to the disk before
> returning. Not doing so would be real bad the health the database
> (imagine your redo entries are not written all the way out to online redo
> logs)
>
> Pei
>
> Declan O'Reilly <declan_at_mcs.com> wrote in article
> <3501D76A.D129C1FE_at_mcs.com>...
> > In the oracle manuals they say that raw partitions are quicker than
> > using files system for tablespaces etc. because it bypass's the overhead
> > of the file system. But I thought that because unix file systems (we
> > are using HP 9000 - 570 using 10.20) buffer data before it writes it to
> > disk, that using a file system would be quicker since the database
> > server would not have to wait for disk access.
> > I thought that the reason for using raw partitions was more for data
> > integrity i.e. the database server would not loose data if the machine
> > crashes and the data is still in the buffer and not yet written to disk.
> > I am missing something
> >
> > Declan O'Reilly
> >
> >
Received on Mon Mar 09 1998 - 00:00:00 CST