Re: Oracle Exadata Machine

  • From: Greg Rahn <greg@xxxxxxxxxxxxxxxxxx>
  • To: "oracle-l@xxxxxxxxxxxxx" <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 13 May 2009 11:25:42 -0700

On Wed, May 13, 2009 at 6:44 AM, Goulet, Richard
<Richard.Goulet@xxxxxxxxxxx> wrote:
> A couple of weeks ago I asked the list if anyone was using HP/Oracle's
> Exadata machine..  The response was thunderous in it's silence and I can now
> see why;

Perhaps none of the current customers participate on this list.
Who pays list price these days?  Especially for Oracle?  Considering
that Oracle licenses are perpetual (both database and Exadata
software), look past the initial purchase as well.  And if your
company has a site license for database, then it looks even more
appealing.  Compare this to say, Netezza, where you have to purchase
hardware and licensing (its a package deal) every time you want to
upgrade.  If you are familiar with Teradata's model: discount up
front, full price for additional nodes, then it really looks good.

When comparing it, think of how much hardware it would take (and how
much it would cost!) to achieve the scan rates that Exadata achieves.
A half rack config (21 Rack Units) has a peak scan rate of 7GB/s for
the SAS configuration using 84 drives.  To get something close it
would take 3 EMC CX4-960 array heads (each can do a max of 3GB/s) and
over 200 drives (or similar).  Then you have to consider the 18+ 4Gbps
Fibre paths  that you would need to transport all that data back to
the db grid.  Next you have to consider how many CPUs would you need
to ingest 7GB/s of unfiltered blocks (vs the on-the-fly blocks created
with Exadata Smart Scans).  Let's just say that this little guy (half
rack DB Machine) can usually out perform a big SMP with expensive
enterprise storage by a significant margin.

All that being said, those numbers are from the current Intel
"Harpertown" based hardware.  If any of you have been following
Intel's x64 chip architecture road map, then you probably know where
this is going and what it means.

As I've been typing this, I've seen a few emails come in about
Netezza.  Today, Exadata has a scan rate of around 80MB/s per SAS
drive.  Netezza has a scan rate of around 60MB/s per SATA drive.   A
one rack DB Machine has 168 drives.  A one rack Netezza NPS 10100 has
108 active drives (112 total).  The max scan rate for a one rack SAS
DB Machine is 14GB/s.  The max scan rate for a NPS 10100 is 6.48GB/s.
When it comes to table scan rates, the DB Machine has a larger number
on a rack to rack comparison.  All that being said (and based on other
numbers I am aware of) I think the HP Oracle Database Machine has a
bit up on the competition when it comes to scan rates, no to mention
all the features that Oracle has that Netezza does not (like
partitioning and indexes, not to mention MAA stuff like Dataguard).

In full disclosure, I work in database development at Oracle
Corporation in the Real-World Performance Group doing customer
benchmarks and POCs using the HP Oracle Database Machine since its

Both Kevin Closson and I have blog posts about most of this, however,
Kevin has had more time to blog recently than me =)

Greg Rahn

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