Exadata

If you are not familiar with R, this is the description from the R site: R is a language and environment for statistical computing and graphics. I encountered R at the Erasmus university, where I am working on a project with DNA data which is put in an Oracle database (see: http://huvariome.erasmusmc.nl/ (It’s down at the moment)).

I am on my way back from the best UKOUG conference I ever attended, unfortunately a lot earlier than planned. Before I start forgetting all these great moments it is time to write them up. To make use of James Morle’s words: if you weren’t there, you lose. I couldn’t agree more!

The Oak Table Network organised “Oak Table Sunday”, a hugely successful event on Sunday afternoon. This event featured some of the brightest Oracle minds, and thanks to a very relaxed atmosphere made it all a truly exceptional experience. I have to say that the audience was quite illustrious too-I didn’t recognise Paul Vallee from Pythian with his Movember moustache at first and to my great joy I finally met Piet de Visser again. After exchanging a few words with them I ran into so many people it was just great!

On 30 November, 2011 Oracle published the second result in a recent series of TPC-H benchmarks. The prior result was a 1000GB scale result with a single SPARC T4-4 connected to 4 Sun Storage F5100 Flash Arrays configured as direct attached storage (DAS).  We can ascertain the DAS aspect by reading the disclosure report where we see there were 16 SAS host bus adaptors in the T4-4. As an aside, I’d like to point out that the F5100 is “headless” which means in order to provision Real Application Clusters storage one must “front” the device with a protocol head (e.g., COMSTAR) such as Oracle does when running TPC-C with the SPARC SuperCluster.

I had an interesting little project this morning. Of course it takes longer to write it down than to do actually do it, but it was kind of interesting and since I haven’t done a post in quite some time (and it’s the day before Thanksgiving, so it’s pretty quite at the office anyway) I decided to share. One of the Enkitec guys (Tim Fox) was doing a performance comparison between various platforms (Exadata using it’s IB Storage Network, Oracle Database Appliance (ODA) using it’s direct attached storage, and a standard database on a Dell box using EMC fiber channel attached storage). The general test idea was simple – see how the platforms stacked up for a query that required a full scan of a large table. More specifically, what Tim wanted to see was the relative speed at which the various storage platforms could return data.

An Oracle Exadata database machine consists of several parts: Intel based servers, infiniband switches, a cisco ethernet switch, a KVM switch and the hardware surrounding it like cables, 19″ rack, power distribution units. The Intel based servers are what “Exadata administrators” are administering the most. The intention of this article is to let the reader gain a little more insight into Exadata specific administration on those.

Two server layers: computing and storage
The two layers have quite different properties: the Exadata computing layer is Linux with Oracle grid infrastructure and the Oracle database software installed, very much as you would do yourself (if you install it in a strict OFA way), and the storage layer is Linux too, but with specific Exadata storage software.

I’ve seen some posts on the blogosphere where people attempt to explain (or should I say guess) how Exadata Smart Flash Logging works and most of them are wrong. Hopefully this post will help clear up some the misconceptions out there.

The following is an excerpt from the paper entitled “Exadata Smart Flash Cache Features and the Oracle Exadata Database Machine” that goes into technical detail on the Exadata Smart Flash Logging feature.

Just a little follow-up to my previous note on hybrid columnar compression. The following is the critical selection of code I extracted from the trace file after tracing a run of the advisor code against a table with 1,000,000 rows in it:

Hybrid Columnar Compression is one of the big features of Exadata that can make fairly dramatic differences to the amount of space it takes to store your data. But how do you find out what’s going on under the covers if you haven’t got an Exadata machine in your garage ?

Here’s a simple starting point that occurred to me a couple of days ago after the product manager (or some such) pointed out that there was no need to make an Exadata emulator available to anyone because all you needed was the compression advisor which you could trust because it actually compressed a sample of your data to see how well it could compress.

Oracle Big Data Appliance (BDA) is being announced at the Oracle OpenWorld keynote as I’m posting this. It will take some time for it to be actually available for shipment and some details will likely change but here is what we have so far about Oracle Big Data Appliance. A rack with InfiniBand, full of [...]

Many analysts are suggesting that a big data appliance will be announced at this OOW. Based on published Oracle OpenWorld focus sessions on oracle.com (PDF documents), the following technologies will most likely be the key — Hadoop, NoSQL, Hadoop data loader for Oracle, R Language. Want more details — you have to wait for them. [...]