Re: Oracle Exadata Machine

From: Greg Rahn <>
Date: Wed, 13 May 2009 11:25:42 -0700
Message-ID: <>

On Wed, May 13, 2009 at 6:44 AM, Goulet, Richard <> 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 launch.

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
Received on Wed May 13 2009 - 13:25:42 CDT

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