Re: Re: Future plans for raw devices ?

On Fri, 2 Jun 2000, Bruce Momjian wrote:

> > > Most think that raw devices are a pain and offer little performance
> > > improvement and lots of portability and coding problems.
> >
> > I don't know how much it is a performance improvement (someone say 10-20%),
> > but Bruce is probably right, it is a huge work and with dependence on
> > hardware & system implementation.
> >
> > We already discussed about it --- it is hacker's archive.
>
> One intresting issue is that commerical databases that recommended raw
> spaces are moving away from them, which helps us to know that the
> raw device benefit must be pretty small.

Yes. Before one year I thought that I/O raw is very good feature. Hmm, but
if I a little explore something about it, I in current time not sure.

Primaty must be good operating system. A raw is a jink only :-)

> > IMHO now is not in PG background for features like I/O raw or on-line
> > replication. It needs better storage layout and tablespace feature.
>
> Vadim is working on storage layout for 7.2, and replication should be
> done after WAL is implemented.

I know. Will possible create on-line replication via WAL? Probably not,
because it needs locking over more backend. Has this feature (on-line
replication) anywise SQL engine? Sybase?

Karel