Pythian Group

It’s that time of the year again — Oracle OpenWorld time — and it’s my pleasure to announce our regular Oracle bloggers meetup again this year. We all know that Oracle community has grown this year so we expect to see folks from all the different technologies including MySQL, Java, Sun hardware folks in addition to the core Oracle database and apps crowd.

So… all of you Oracle bloggers attending Oracle Open World 2010…
… you are invited to attend this Oracle Bloggers Meetup during OOW 2010 — a chance to meet your online buddies face-to-face in relaxed and informal atmosphere.

When: Wed, 22-Sep-2010, 5:30pm

Where: Lower Dining Room, Jillian’s Billiards @ Metreon, 101 Fourth Street, San Francisco, CA 94103.
Read the rest of this entry . . .

Michigan OakTable Symposium (MOTS) is a unique event taking place just before Oracle OpenWorld — 16-17 September. Why unique? This is the first conference (is it not?) where all presenters are members of OakTable Network, a group that gathers number of like-minded IT professionals with scientific approach to Oracle database technology and to the life in general.

It happens in Ann Arbor, Michigan — a place I wanted to visit for a very long time. For those of you who are cost conscious and don’t have much in their education budget, this conference is a great value priced at a third of the Oracle OpenWorld pass and I can assure you that quality of presentations is on par with or higher then the top Oracle OpenWorld sessions. The conference is organized by volunteers from OakTable Network and few good friends as a non-commercial event so you will hear no marketing crap whatsoever.

Unlike, huge OpenWorld crowd, which has always intimidated me a little bit, MOTS is going to be a cozy event with strictly limited cap of only 300 participants – ideal size to support peer networking and opportunity to mingle with some of the folks you’ve been dying to talk to.

I especially enjoyed this video promotion: Read the rest of this entry . . .

I hear lots of feedback on Exadata front asking for more and more technical information and I often refer them to some material online. I think I should reference couple credible resources for the readers of our blog in addition to our own Exadata content and Oracle’s own Exadata Technology section.

Kevin Closson — Oracle Exadata Performance Architect, fellow OakTable Network member and someone who knows loads about Oracle specifics on various hardware platforms and particularly storage — has a nice collection of Exadata blog posts. Some people say that Kevin is biased as he is working for Oracle on Exadata but I’d say that he’s rather passionate about this stuff and truly believes in what he writes.
Read the rest of this entry . . .

Updated: 29-Jun-2010, 30-Jun-2010.

For me, ODTUG Kaleidoscope 2010 started on Friday with the ACE Directors briefing. Best practices topic was touched there slightly and I twitted about it. I decided that the feedback deserves a blog post so I’m simply quoting the conversation here. If you have anything to add, you know where to find the comment box.

alexgorbachev:
best practices should be forbidden or rather renamed to blue-prints #ACED

Fri Jun 25 16:26:26 +0000 2010

GregRahn: @alexgorbachev IMHO “Best Practices” are often sought after as an alternative to thinking and understanding. Two key components there!

Fri Jun 25 16:33:07 +0000 2010

Read the rest of this entry . . .

It is time… Time for one more very special conference for me. Why special?

1. I have never been to ODTUG Kaleidoscope before. I always like new conferences — new experience.
2. Unlike Sheeri, I do not speak! This is one of those rare conferences where I come to slack off, meet old friends and make new ones, go to lots of sessions and actually learn stuff.
3. Coming from the DBA background, it’s not often that I come to development oriented conferences and I think I should do more of that.
4. It’s in Washington, DC. I lived there for some time and have number of good friends there. I’m really excited to see them again!

So what am I going to do there? I just arrived and right in time for the Oracle ACE Directors’ briefing that will run for the whole days of Friday. This is a super secret meeting where Oracle’s super secret plans are shared. Nobody can talk about that after this meeting or their tongues are cut off on the spot. For those of you who didn’t realize I’m joking, the ACE Director’s briefing is where Oracle shares the roadmap of its products — some of it is long term strategy and some is about the upcoming releases. There are few things that we are asked not to share in public but, frankly, there is nothing really sensitive. One of the most interesting parts of the briefing are the Q&A moments when all kind of questions get asked (sometimes tough ones) and, to the most parts, gets answered.
Read the rest of this entry . . .

The error message I received this morning trying to login at oracle.com was:

Your account has been locked for the next 3 hours due to too many invalid login attempts. Please try again later.

This was odd — I think I used the right password and I only did it once. Oh well, SSO on oracle.com has been behaving strangely these days (and I’m not even talking about availability of oracle.com itself).

Fortunately, there was a simple solution for this thanks to Simon Haslam who provided solution on Twitter. All you need to do is to use “Forgot password” functionality — this will do both, reset your password and unblock the account. The latter is a surprising side-effect for me and that’s why I didn’t even think about resetting my password in the first place.

Now, why would I blog about such a seemingly irrelevant issue? Since My Oracle Support (formerly Metalink) migrated to Single Sign-On integrated with oracle.com, you can’t access your Oracle support without a functioning oracle.com account. I don’t need to tell you what it means for a production DBA to loose access to Oracle support in critical times.

Update: You won’t be asked to reset your temporary password so you should change it yourself right away — remember that your new password is potentially compromised as it’s been sent using email which is not a secure media. To reset your account password go to your Account and click on “Change Password” in the top-right corner.

I found I never published this post as it was sitting in my drafts few months now — it was written in 13th February, 2010. I’m publishing it without any changes.

I learn therefore I am!

I’ve just wrote few bits about learning a new technology and after skimming through my Google Reader, I noticed a great post by Chen Shapira — Deliberate Practice. That’s reminded me about another aspect of learning that I didn’t mention — learning is a continuous process.

There are two aspects…

• No matter how good I am and how much I know, my knowledge and expertize become outdated relatively quickly these days unless I keep up with the new stuff. Unfortunately, there is so much new technologies these days that I have to be very selective on what I want to follow which is a big challenge in itself. On the other hand, I’d rather be challenged than bored. As DBA’s we are luckier than Developers — their world changes much faster than ours.
• I forget things I don’t use/do/read about/think about regularly. Refreshing my “old” memory is a must do. This is why I think Chen’s idea of deliberate practice is so great.

Read the rest of this entry . . .

For one of our customers, I’ve recently reviewed the strategy of migration from single-byte encoding to variable length multi-byte UTF8 (AL32UTF8 encoding in Oracle naming standards). These type of projects are coming up again and again so I think it must be common for many of you. Thus, this bit might be useful. I’m also interested in your experience – perhaps you can run this simple simulation on your platforms and provide the results in the comments?

Back to the project… One area was estimation of the string manipulation overhead. Based on Pythian experience as well as the feedback from my network, I could conclude that nobody has observed any measurable performance degradation or significant CPU usage growth clearly attributed to UTF8 migration.

Thus, I decided to simulate at least some operations and measure them. One of the concerns was sub-string extraction — fixed length encoding sub-string is super easy to implement as the offset and length in bytes are known. Variable length character set would require scanning the whole string from the very beginning because byte offset and byte length are not known until the string is traversed from the beginning character by character.

This is the PL/SQL block I came up with: Read the rest of this entry . . .

I was recently installing one APEX application and needed to upload a bunch of images. APEX was configured to use EGP (Embedded PL/SQL Gateway) so traditional options were to configure FTP or WebDAV but I’d rather not open these services on production environment.

After searching for the solution on the Internet, I surprisingly realized that there is none. At least, nothing I could find easily. Our resident APEX expert, Alex Fatkulin, pointed me to the installation process and suggested that there is a simple way to do that using a single PL/SQL call.

It turned out that it was more than a single PL/SQL call involved but nothing too difficult.

What you need is to create the hierarchy of files and directories that you want to upload (images or not – doesn’t matter). Then you create an XML file imagelist.xml listing required directories and files to upload.

Here is the example:

imagelist.xml
image1.png
logo/pythian.png

The content of imagelist.xml:

<upload>
    <directories>
        <directory>logo</directory>
    </directories>
    <files>
        <file>/image1.png</file>
        <file>/logo/pythian.png</file>
    </files>
</upload>

Read the rest of this entry . . .

This is just a short blog post to spread the word about the upcoming webinar organized by Embarcadero with fellow member of OakTable Network — Jonathan Lewis and Kyle Hailey — Ultimate SQL Tune-off.

Kyle and Jonathan are on my list of the most respected Oracle performance experts and I could only imagine what they can deliver joining the forces. I’ll allow myself to quote the opening of the webinar as it sounds really interesting:

According to Jonathan Lewis, there is a basic strategy to writing efficient SQL, but it requires knowledge of the data, the metadata, and the intent of the query.

Jonathan will start with the basic principles of efficient data access and then show different ways of analyzing the data. He’ll then describe a graphical approach to finding the most efficient access path for a query and then apply the method to a problem he recently saw with one of his clients.

But wait… is there more than one way to skin a cat? Kyle Hailey thinks so, and he’s not afraid to let Jonathan know it!

Kyle’s fancy footwork will include his own approach to Visual SQL Tuning (VST) with some ring side support from DB Optimizer XE. Hitting below the belt? You be the judge.

The webinar is on June 10, 2010 at 11AM Pacific / 2PM Eastern.