Re: PostgreSQL

On Thu, 2 Feb 2006 09:43:50 +0900 (JST)
Curt Sampson <[email protected]> wrote:

> On Thu, 2 Feb 2006, Marcin Jessa wrote:
> 
> > I was wondering if any of you have experience with PostgreSQL's
> > performance on NetBSD 3.0 or CURRENT compared to other open source
> > O.S's.
> 
> I have been using PostgreSQL extensively on NetBSD since 7.3. I don't
> have much comparison data, but what I do have indicates that
> performance is roughly the same across NetBSD, FreeBSD and Linux,
> assuming similar hardware and configuration. This isn't surprising
> since PostgreSQL doesn't actually use much in the way of
> sophisticated services from the OS. The most important thing would be
> the filesystem code.

What CPU's are you referring to and how many of them when you say
performance is pretty much the same?
Would that include SMP on 64-bit AMD on NetBSD? 
How well does it work today and how well would PostgreSQL work on a
multi-processor NetBSD system? 
Do you know of any recent, reasonable benchmarks for
BSDs/Linux/OpenSolaris that could shed some light on the performance of
64-bits SMP systems of the respective OS's?
I am not that picky on what to use as I am pretty familiar with of the
above mentioned, although I obviously prefer NetBSD over the others.

> Unless your database is very small (i.e., only a few GB) database, by
> far the most important factor in performance will be the configuration
> of your disk storage system and how you design your schema and
> queries. The OS won't make anywhere near as much difference as either
> of those.

What more can be done to assure fast disk performance besides
implementing RAID on fast drives? I will propably be using SCSI HDs on
this server. Are there any additional kernel options to consider to
speed things up? 
This is pretty much a private, low budget project so I wonder if SATA
can be also considered as an alternative, since they are cheaper than 
SCSI drives of decent size.

> > What threading model will be used
> 
> PostgreSQL does not use threads; it uses a separate process for each
> connection. So how well or poorly the OS performs with threads is
> irrelevant.

Yes, I was attenting a lecture about PostgreSQL just two days ago when
this was mentioned and I realized that a minute after I sent this
email... 

> BTW, it's best, if you're looking at PostgreSQL, not even to consider
> data about MySQL's comparative performance on different OSes. MySQL is
> a completely different animal--it's not in fact a real DBMS at all,
> but more a dumb data storage system that can be queried with SQL. So
> the underlying techniques it uses can be quite different.
> 
> Note that this was a bit heavily cross-posted; I've redirected
> responses to tech-perform.

Yes you're right. I am sorry for that. As I said I was not sure which
audience to approach with my question since NetBSD does not have an ISP
nor database specific list.