Re: Benchmarck PostgreSQL 8.1.4 MySQL 5.0.20 and Oracle

> > Could you give us some more infos about the box' performance while you
> > run the PG benchmark? A few minutes output of "vmstat 10" maybe? What
> > does "top" say?
>
> >
> Here, an extract from the vmstat 3 during the test, you can see that
> my problem is probably a very high disk usage (write and read).
>

> procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
> r b swpd free buff cache si so bi bo in cs us sy id wa
> 0 11 92 128344 9224 2428432 0 0 287 9691 2227 685 4 3 0 93
> [...]

Yes, as is the case most of the time, disk I/O is the bottleneck here...
I'd look into everything disk releated here...

> > How are you using the 3 disks? Did you split pg_xlog and the database
> > on different disks or not?
> >
>
> Data are on disk 1 et 2. Index on disk 3. Perhaps i'm wrong but fsync
> = off, pg_xlog are running with that ?

Yes, pg_xlog ist also used with fsync=off. you might gain quite some
performance if you can manage to put pg_xlog on its own disk (just
symlink the directory).

Anyway, as others have pointed out, consider that with fsync = off
you're loosing the "unbreakability" in case of power failures / os
crashes etc.

> > Can you say something about the clients? Do they run over network from
> > other hosts? What language/bindings do they use?
> >
>
> Client is another server from the same network. Clients are connected
> with JDBC connector.

ok, don't know about that one..

> > When they do inserts, are the inserts bundled or are there
> > single insert transactions? Are the statements prepared?

> I use prepared statements for all requests. Each transaction is about
> 5-45 requests.

sounds ok,
could be even more bundled together if the application is compatible
with that.

Bye, Chris.