Re: [HACKERS] RAW I/O device

On Mon, 6 Dec 1999, Bruce Momjian wrote:

> > I raise the question, because the linux kernel opening with raw-device
> > new way for a faster and better database engine. I know (and agree)
> > that it not is priority for next year(s?). But it is interesting, and
> > is prabably good remember it during development, and not write (in future)
> > features which close this good way.
>
> I would be very surprised to see any significant change in raw vs.
> filesystem i/o on modern file systems, and I am sorry, but Linux ext2
> does not count as modern.

Yes. The ext2's limitation and unavailable is public secret and use it for
raw is crazy idea. On a raw device can be implement specific data organization
(specific for DB demand). Raw's advantage is non-universal organization.

A raw is not only about filesystem, this feature remove full control from
OS kernel to DB (example data caching - kernel not has information
how/why/what remove to cache but DB has this information... etc).

Karel