Re: Which hardware ?

On Tue, Jun 17, 2008 at 7:38 AM, Lionel <lionel(at)art-informatique(dot)com> wrote:
> Hi,
>
> I need to install a 8.3 database and was wondering which hardware would be
> sufficient to have good performances (less than 30s for² slowest select).
>
> Database size: 25 Go /year, 5 years of history
> One main table containing 40 million lines per year.
> Batch inserts of 100000 lines. Very very few deletes, few updates.
>
> 30 other tables, 4 levels of hierarchy, containing from 10 lines up to 20000
> lines.
> 5 of them have forein keys on the main table.
>
> I will use table partitionning on the year column.
>
> Statements will mainly do sums on the main table, grouped by whatever column
> of the database (3-5 joined tables, or join on join), with some criterions
> that may vary, lots of "joined varchar in ('a','b',...,'z')".
> It's almost impossible to predict what users will do via the webapplication
> that queries this database: almost all select, join, group by, where...
> possibilities are available.
>
> Up to 4 simultaneous users.
>
> I'm planning to host it on a quad xeon 2.66Ghz with 8Go of DDR2, and a dual
> (RAID1) SATA2 750Go HD.
> Perharps with another HD for indexes.
>
> Do you think it will be enough ?
> Is another RAID for better performances a minimum requirement ?
> Will a secondary HD for indexes help ?

More drives, all in the same RAID-10 setup. For reporting like this
writing speed often isn't that critical, so you are often better off
with software RAID-10 than using a mediocre hardware RAID controller
(most adapatecs, low end LSI, etc...)

You'd be surprised what going from a 2 disk RAID1 to a 4 disk RAID10
can do in these circumstances. Going up to 6, 8, 10 or more disks
really makes a difference.

> Which OS would you use ? (knowing that there will be a JDK 1.6 installed
> too)

I'd use RHEL5 because it's what I'm familiar with. Any stable flavor
of linux or FreeBSD7 are good performance choices if you know how to
drive them.

> With 5 millions of lines, the same application runs quite fast on windows
> 2000 on a single P4 2.8 GHz (very few statements last more than 10s, mostly
> when concurrent statements are made). Each statement consumes 100% of the
> CPU.

That statement about concurrent statements REALLY sells me on the idea
of a many disk RAID10 here. I'd take that over quad cores for what
you're doing any day. Not that I'd turn down quad cores here either.
:)