April 11, 2011

Entertaining Exadata FUD from HP

Filed under: DWH, Exadata, HP, oracle — rmoff @ 09:06

Chris Mellor at The Register posted an interesting article a couple of days ago, entitled HP and Violin build Oracle Exadata killer. The slidedeck has been removed from HP’s FTP site, but a bit of Google magic throws up a couple of mirror copies.

It’s an entertaining read (“Do a Proof of Concept! 94% win rate!! We can and do win against Exadata!!”), and a nice illustration of the FUD techniques that companies use in marketing their products against others. Greg Rahn has taken Netezza to task in the past for this, and to be fair at least Netezza had a serious white paper to back up their arguments. HP’s deck (including choice sections such as “How to sell against Exadata”) is IMHO nothing more than a biased set of arguments for salespeople to use to attempt to bullshit customers.

The deck is entirely aimed at OLTP workloads, and lays all its weight on the IOPS you’ll get from lots of Flash memory (the Violin bit). As any ful kno, building a Data Warehouse on a system based on IOPS with no reference to throughput (GB/s), it doomed to painful failure. My understanding of Exadata is that it’s in part all about a properly balanced configuration. Unbalance this configuration at your peril, as you’ll start pushing unidentified bottlenecks around your system.

Kevin Closson (ex-Oracle performance architect on Exadata, now at EMC), commented on The Register article:

By my assessment the HPDBS (DL980 + Violin solution) is likely not positioned as an Exadata killer for bandwidth-sensitive DW/BI workloads. It simply doesn’t have enough high-bandwidth storage plumbing.

Ironically for HP, they actually quote Kevin in their slide deck with a selective quotation from his blog article about a TPC-H benchmark result here. The quote is used to imply that Exadata isn’t anything other than just disks thrown together. If you’re going to selectively quote, how about this one in the next paragraph of the same article – “I’m just comparing one Oracle Database 11g result to another Oracle Database 11g resul[…]The benchmark result was outstanding and it was Oracle technology in both the Database and Storage grid[…]” …

Kevin goes on to comment on HPDBS:

On the other hand, a single-rack Exadata only supports a scalable read:write ratio of 40:1 (their data sheet 1,000,000 RIOP : 50,000 WIOPS). Actually, that 50,000 WIOPS is a gross number accounting neither for redundant writes (ASM redundancy) nor the larger sequential writes that a transaction processing system also must concurrently sustain. In other words, mileage varies (downward trend)

Maybe HPDBS is a good solution, maybe it’s not. The deck certainly wasn’t published for public consumption so maybe it’s unfair to judge it on that. But it’s an interesting peek into the murky workings of technical sales. I’d be naïve to think that there isn’t a whole bunch of Oracle decks with similar “how to sell against xxxx” sections.

At the end of the day, solutions need to be judged on hard facts and whole pictures alone. For that reason, I’d take the technical blogs of respected writers any day above a sales pitch. Kevin Closson is a good example of this – working for a competitor he could easily have taken the opportunity to stick the knife in to Exadata, but as a respected technical writer he lets the facts speak for themselves.

April 7, 2011

Oracle documentation – available on Kindle and iPad

Filed under: documentation, kindle, oracle — rmoff @ 13:48

Whilst perusing the Oracle database documentation, I noticed something which caught my eye:

Mobi and ePub downloads for Oracle documentation

As well as reading the documentation online as HTML or downloading as PDF for viewing on your computer etc, you can also download it in formats (Mobi and ePub) designed for eReaders such as the Kindle and iPad (the latter obviously isn’t “just” an eReader). For information on format support, there’s a handy table on Wikipedia.

It looks like the availability of mobi/epub files isn’t universal. For example, the OBI 11g documentation appears still to be HTML & ZIP only. And whilst the Database documentation doesn’t link to the mobi files on the contents page, only each document’s TOC, the Essbase documentation does:

Why not link to the mobi and epub downloads here too?

But then, when’s the Oracle website ever been consistent 😉

I’m looking forward to having access to the documentation on my Kindle. It’s nicer to read from than a computer screen. It’s also got an awful lot of very good information that’s worth reading when not just looking something up. I’m not talking about reading the column definition of DBA_TABLES at bedtime, but for background education and learning. Never mind swanky OOW presentations, simply reading chapters such as Managing Optimizer Statistics would benefit a lot of people. RTFM, as they say, because they’re not just reference, they’re also the how and the why of what to do.

Oracle documentation on the Kindle

April 4, 2011

Oracle XE 11gR2 installation – “OracleXEService should not be installed already”

Filed under: oracle, windows, XE, XE 11gR2 — rmoff @ 09:09

Oracle XE 11gR2 beta has just been released, some details here and download here. It’s not a great deal of use for sandboxing DWH-specific stuff, given this list of excluded functionality (and this is by no means everything that’s not included):

  • Bitmapped index, bitmapped join index, and bitmap plan conversions
  • Oracle Partitioning
  • Parallel Data Pump Export/Import
  • Parallel query/DML
  • Parallel Statement Queuing


However, it’s always interesting to have to hand for trying out other things. And I like playing with new toys 🙂

On running the installer, I hit this problem:

"OracleXEService should not be installed already"


Checking for Oracle XE Service instance…:
Expected result : OracleXEService should not be installed already.
Actual result: OracleServiceXE found on system.
Check complete: The overall result of this check is failed.

The previous owner of the machine had installed Oracle XE 10, but I’d removed this:

No Oracle XE 10g listed in add/remove programs

Or so I thought:

OracleServiceXE still listed in Services

To remove the service entry, use the sc command:

sc delete OracleServiceXE

For good measure I did the same for OracleJobSchedulerXE.

Delete service entries using sc

After this, installation proceeded as normal.

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