I understand that MySQL as a company wants to recruit paying customers. However, as a community user I have a hard time finding what I want on the MySQL website. Today’s frustration is brought to you by trying to find the documentation.

Go ahead, hit http://www.mysql.com. From there, where do you go to find the documentation?

It’s not Services, not even Services -> Support.

According to Products, the community server is not even a product. How is a potential new user, who wants to learn about MySQL, supposed to know a community version exists? Here are the products listed on the Products page:

MySQL Enterprise
MySQL Enterprise Monitor
MySQL Cluster
MySQL Embedded Database
MySQL Database Drivers
MySQL Database Tools

Where’s “MySQL Database” on that list? A website user basically has to know what they’re looking for, since that page does not help find “the mysql database”. You can guess it’s the “MySQL Enterprise” — but you’d be wrong. Imagine if you’re a person unfamiliar with MySQL who has been told “go to the MySQL website and get the free version of the database, it’s great!”

OK, OK, I know, you’re saying “click on Downloads”. Which takes me to the “choose which version you want to download.” OK, nice for newbies, but really annoying for the experienced. Why aren’t the links to download at the top, with the explanations just underneath? A newbie would be presented with the links, think “I don’t know which to choose!” but then see that the descriptions are just underneath. An experienced user can just click and go.

This of course is made even more silly when you realize that the community download link simply scrolls down. Yes, that’s right, the community downloads immediately follow that chart of explanations. Which means that in the current state, when the link is at the bottom of the chart, the link points you to the next line. If the link is at the top of the page, at least there’s a reason for it — to scroll down past the explanations.

Now recall that the exercise was to find documentation. There is no way to download the documentation here.

I am a non-paying user, not a developer. Going to the “Developer Zone” is not intuitive for me. However, that is exactly where I need to be:

* DevZone
* Downloads
* Documentation
* Articles
* Forums
* Bugs
* Forge
* Blogs

Given that list of topics, why on earth is this section called the “Developer Zone”? (it’s a rhetorical question!) Sure, if I’m a software developer I might think it’s useful to me. On any other website “developer zone” is relegated to advanced users, or folks using some different part of the product than what most people use (think Apple’s Developer Connection).

Take a look at that list. On any other website, it would be under “Support” or “Help” or “Learn”.

No wonder folks have no idea that the forums exist, much less the Forge or Planet MySQL. If I was a new user to MySQL and I wanted to find the documentation, I’d be very unhappy.

Heck, I’m very unhappy anyway — what kind of company has a huge community of people supporting each other and contributing back to the company, and does not give people an easy way to find the community?

One of the most frequently needed functionality in the MySQL Proxy is the need to know which server you are on. This is not given, on purpose, by the proxy, because the proxy is supposed to be transparent. It is not supposed to matter which back-end server you are on.

However, for testing purposes we often want to know which back-end server we’re on. Thus I developed functionality for SHOW PROXY BACKEND [INDEX ADDRESS OTHER].

SHOW PROXY BACKEND INDEX — gives the index of the server you’re on (backend_ndx, ie 1)

SHOW PROXY BACKEND ADDRESS — gives the address of the server you’re on (ie, foo.bar.com:3306)

SHOW PROXY BACKEND OTHER — gives the address of all the other servers except those you’re not on, in multiline format.

Note that I was pretty lazy and the commands are case-sensitive. But I figured that since this is supposed to be used mostly in testing circumstances, it did not really matter.

The code is on the MySQL Forge Wiki at http://forge.mysql.com/tools/tool.php?id=139

Interestingly enough, this script is actually being used in production — a site has a primary and failover server, and wants to check that when the primary server is in use, there are no connections on the failover. I wrote that check as well, but as the logic is somewhat particular, I am not sure it would be useful to many. The logic is:

1. Run SHOW PROXY BACKEND INDEX.
2. if it fails, I can’t connect to the proxy, log an error, exit.
3. if it !=1, I’m on the failover server, log a warning, exit.
4. if it =1, I’m on the primary server.
5. Run SHOW PROXY BACKEND OTHER.
6. if it is empty, either I can’t connect to the proxy or there are no failovers defined, log a warning, exit
7. For each OTHER address, connect to them and find what that connection’s host looks like (sometimes it looks like foo.bar.com:4325, other times it looks like 1.2.3.4:4573). Get the value of “my host” by stripping off the port.
8. Connect to the OTHER address again, killing off connections from “my host” except for the “system user” and a few other special accounts (replication slave being one of them). Log each kill with the thread number and a warning.
9. If there are no connections to be killed, log OK.

Let me know if you’d like to see that…it’s a shell script, and it requires the mysql client and bintools like grep and cut.

Recently, while answering a question, I came across what appeared to be a change to the rules for licensing Oracle Standard Edition — a change that appears to be subtle on the surface, but one that could have significant and surprising repercussions.

It was with considerable fanfare that Oracle announced, several years ago, the last major change to the licensing rules for Standard Edition — that multi-core processors would be counted as a single CPU for the purposes of licensing Standard Edition products. (For Enterprise Edition, Oracle continued to count each core as a separate “processor”, but then provided price discounts, presumably in recognition that a 2- 4- or 8-core CPU rarely provides equivalent performance to an equivalent number of single-core processors running at the same clock rate).

The revised licensing rule went like this (I have highlighted the relevant text in bold):

Processor: shall be defined as all processors where the Oracle programs are installed and/or running. Programs licensed on a processor basis may be accessed by your internal users (including agents and contractors) and by your third party users. For the purpose of counting the number of processors which require licensing for a Sun UltraSPARC T1 processor with 4, 6 or 8 cores at 1.0 gigahertz or 8 cores at 1.2 gigahertz for only those servers specified on the Sun Server Table which can be accessed at http://oracle.com/contracts , “n” cores shall be determined by multiplying the total number of cores by a factor of .25. For the purposes of counting the number of processors which require licensing for AMD and Intel multicore chips, “n” cores shall be determined by multiplying the total number of cores by a factor of .50. For the purposes of counting the number of processors which require licensing for all hardware platforms not otherwise specified in this section, a multicore chip with “n” cores shall be determined by multiplying “n” cores by a factor of .75. All cores on all multicore chips for each licensed program for each factor listed below are to be aggregated before multiplying by the appropriate factor and all fractions of a number are to be rounded up to the next whole number. When licensing Oracle programs with Standard Edition One or Standard Edition in the product name, a processor is counted equivalent to a socket.

This is exactly the definition you will find today today in Oracle’s online store, for example here.¹ In fact, being lazy and not having access to a two-year-old copy of the OLSA, that is exactly where I got the text above.

Now, that little bit of bold text was a pretty big deal. As I understood it, and everybody I could find seemed to agree, this affected both the licensing cost and the eligibility rules. These 23 simple words now meant that Oracle Standard Edition was limited to computers with a maximum capacity of four (4) CPU sockets, not four processor cores. Although multi-core processors were — at the time, several years ago — relatively new, at least in the “commodity hardware” space, we all new that Intel and AMD had near-term plans for 4-core and eventually event 6- and 8-core processors. Suddenly, we could build an Oracle database server with 16 processors (cores) and 16GB of RAM or more, for less than $200,000. (Prior to this change, you would pay $640,000 — list price — just for the Enterprise Edition database licenses.)

But now, it seems, all of this is changing again, only this time, not for the better.

So what exactly has changed? (more…)

Contemporary software engineering models include many loosely-defined layers. Database developers might help with other layers, but for the most part a database administrator’s domain is the persistence layer.

• Presentation


• Application


• Business Logic


• Persistence (also called Storage)

The Daily WTF has an article on The Mythical Business Layer makes the case for not separating the business layer and the application layer:

A good system (as in, one that’s maintainable by other people) has no choice but to duplicate, triplicate, or even-more-licate business logic. If Account_Number is a seven-digit required field, it should be declared as CHAR(7) NOT NULL in the database and have some client-side code to validate it was entered as seven digits. If the system allows data entry in other places by other means, that means more duplication of the Account_Number logic is required.

It almost goes without saying that business logic changes frequently and in unpredictable ways. The solution to this problem is not a cleverly coded business layer. Unfortunately, it’s much more boring than that. Accommodating change can only be accomplished through careful analysis and thorough testing.

I will call this merged business/application layer the “functional layer.”

The serious scaling requirements posed by most applications these days call for partitioning, clustering, sharding or some other term for “dividing up the data so it does not become the bottleneck”. Enter the “architecture layer”.

“Wait a minute,” I hear you asking. “Isn’t that just the persistence layer?”

Yes and no. To me, there’s a difference between the storage and the architecture of said storage. The database schema for storing a user profile is a persistence layer issue. Figuring out which database instance to go to is an architecture layer issue.

This is an important distinction for me. Many folks are coding the architecture layer directly into the functional layer. A “save_profile()” API function might call an ORM to deal with the persistence, or it will have MySQL (or other database) connection handling and queries. However, the database will grow, and at some point you will find yourself wanting to split the data [more].

This type of information, like the presentation layer, needs to be separate. Why should the application care whether save_profile(’Sheeri’,'hair color’,'blonde’) accesses database1 or database2? More importantly, why should there be major code changes to the functional layer if the architecture changes? Just like no functionality has changed when you change your website color from blue to red, there is no functionality change when you go from splitting data between 2 database servers to splitting among 3, or 10.

For me, the persistence layer is about how the data is stored. Which, explicitly and for the record, I also believe should be separate from the functional layer — if you store hair color and eye color in one table or 2, the functionality of the application has not changed; all that’s needed is a change in how that data is stored and retrieved.

The architecture layer is all about where the data is stored. Early forms of the architecture layer are configuration files, though most would not call that a “layer”. Database administrators should be able to change the architecture of the database system without requiring mucking about in the application’s functional code.

Thoughts?

You might have already seen the blog update on Steven Chan’s site. TXK AutoConfig and Templates Rollup Patch S (6372396) was released on May 5th.

This patch differs from traditional TXK autoconfig template patch releases in that the ATG team decided to include some other important TXK patches also with this release. One of these is TXK Advanced Utilities Rollup Patch C (5011249).

This Advanced Utilities patch brings some import scripts that can be used to implement advanced topologies. The important benefit here is that these scripts can be run from command line. For complete details, refer to Metalink note 277574.1, Running Configuration Wizards from the Command Line in Oracle Applications 11i.

As a side effect of this generous inclusion of import updates, the patch size has increased from 16mb (RUP R) to 65mb (RUP S).

This Rollup Patch has also brought in some new Context variables. These new XML tags in Rollup Patch S are:

1. s_jdbc_connect_descriptor_generation: The value of this variable determines whether the jdbc connect descriptor is regenerated and whether the value of the context variable s_apps_jdbc_connect_descriptor is updated. Acceptable values for this context variable are true (the default) or false. Set this value to false when using a custom apps jdbc connect descriptor
2. s_apcprestart: This variable is used to specify the complete path of the script to be executed before the Apache service is started.
3. s_ccmmaxsyspathlen: (Windows-specific) This context variable is used for setting the maximum length of the Windows System Path.

(more…)

It is with great pride that I am able to announce that Pythian is making a large investment in Europe. As of this month, Pythian Europe s.r.o. is fully operational and we have headquartered the company in beautiful Prague. Additional offices are planned in Paris and Malta by the end of the summer.

Pythian Europe is launching with an elite, full-fledged team and I would like to introduce the founders:

On the left is Lukas Vysusil, who joins us from Oracle where he served for 6 years in a variety of roles, including Oracle Applications DBA, DBA Team Lead, Manager of the Configuration Queue for Oracle OnDemand outsourcing services, and also Senior Technology Consultant. He brings a wealth of experience in team leadership, troubleshooting, Oracle Apps, the pressure cooker of consulting in the enterprise database and applications technology space and formal configuration and change management processes to Pythian and will serve as Service Delivery Manager.

On the right is Jan Polnicky, who joins us from Oracle where he served for 6 years in a wide variety of roles. You’ll have to check his linkedin profile for the entire list, but suffice it to say he started out as a developer for Online Services, quickly took on a leadership role in that team, moved to OnDemand where he became a services team lead, then got promoted to EMEA queue manager for configurations, and then got promoted to OnDemand Services EMEA Manager - Release Management where he led a team of up to 15 engineers across geographies (UK, ES, CZ, EG + USA & APAC indirects) doing general Oracle Database & Apps management, tons of preventative maintenance and supervised a number of Oracle Applications upgrade projects. In his spare time, Jan is working on his Ph.D., I kid you not. Jan will serve as a peer to Lukas as Service Delivery Manager.

You may think that’s enough.

You may be thinking, OK, with these guys and the teams they will soon be leading now Pythian has added so much expertise and horsepower in Europe they’ll stand pat for a while.

But oh no. Not me. That was not enough!

To lead these guys, on the centre, we have also added Peter Simecka as Vice President, Pythian Europe. Peter joins us from, you might have guessed it, Oracle Corporation where he started out in 1994. Even before joining Oracle, he had substantial expertise on Oracle/UNIX, dating back to Oracle 4 (I first worked on Oracle 5, but 6 was already out by then). Over his career at Oracle, Peter has led teams as large as 60 engineers, served as Product Support Manager for five years, served as Customer Support Manager for four years, and then built and led the Oracle OnDemand Outsourcing centre in Prague for four years. To say that he brings a wealth of leadership experience, customer support and liaison experience, and outsourced services design, development and delivery experience is a woeful understatement. I am hoping and planning to learn a lot from him.

It’s funny because the way I presented these guys, it makes it seem like I selected each of them individually, but that’s not how it happened at all. I’ll leave that story for another day, or maybe Peter will want to tell it.

So, what are we planning to do with this ambitious operation in Europe? Stay tuned.

According to the wikipedia page,

“The rack is a medieval torture . . . which induces excruciating pain as the victim’s joints slowly dislocate.”

Per the Oracle website,

“Oracle RAC is a cluster database with a shared cache architecture that overcomes the limitations of traditional shared-nothing and shared-disk approaches to provide highly scalable and available database solutions for all your business applications.”

Which is more painful, you might ask? I cannot say for certain, as I have never been subjected to the torture of a medieval rack, but I have experienced some pain at the hands of the Oracle RAC. My first encounter was about five months ago when I first became an “official” DBA. Being eager to jump into solving problems in my new job (as that’s what most DBAs do, solve problems), I relished the chance to get my hands dirty and work on a “real” DBA task — a database lock.

Even though I had never been officially titled a DBA before, I was somewhat familiar with the concepts as I have been working around them for years (and still chose to join their ranks, if that tells you anything). Theoretically, I knew exactly what a database lock was, but I had no clue how to practically diagnose or kill one off.

Checking with a few knowledgeable co-workers, I was directed to a set of common database diagnostic scripts affectionately known as the “Pythian Kit”. (more…)

Next Thursday, May 8, the New England SQL Server Users Group will have a special meeting, featuring Craig Freedman from the SQL Server development team. Craig is The Man when it comes to query optimizer internals, and wrote an incredibly detailed chapter on the topic for “Inside SQL Server 2005: Query Tuning and Optimization”.

At the meeting next week, Craig will discuss some of what he talked about in the chapter, including the basics of how the query processor works and what iterators are. He’ll cover the various operators you’ll commonly see in query plans, and describe how they actually work internally.

This should be a great meeting, and we expect it to be very well attended. In order to help us figure out food and drink, in addition to securing enough chairs for the meeting room, we need you to RSVP if you’re planning to attend. In order to RSVP, sign up for our mailing list. I will send out an e-mail next Tuesday, and you can RSVP by replying to it. Only attendees who RSVP will be eligible for our prize draw at the end of the night, so make sure to sign up for our list by Monday in order to guarantee that you don’t get left out.

We would like to thank Red Gate Software, who made a very generous donation to the group that allowed us to have this special meeting. Red Gate makes some of my favorite SQL Server tools and provides a huge amount of community support in the SQL Server and .NET space, and we hope that you will give their products a try.

I have already blogged about this keynote at http://www.pythian.com/blogs/948/liveblogging-who-is-the-dick-on-my-site.

If you are interested in actually seeing the video, the 286 Mb .wmv file can be downloaded at http://technocation.org/videos/original/mysqlconf2008/2008_04_17_panelDick.wmv and played through your browser by clicking the “play” link at http://tinyurl.com/55c5ps. This is not to be missed!

Here is the question that was posted on OTN Forum Grid Control Extensibility (not the topic of the forum!) yesterday:

I recently moved south to Bangalore and I am working for a large software integrator. My project team is working on a JEE application project that uses test driven development methodologies. We are planning to use a host of new breed technologies such as Enterprise 2.0, Ajax, Drools, JDO, Hibernate,and mashups. Are you able to point me to online and offline resources/trainings that can help our team get up to speed with these latest technologies.

All the help that group members can provide in this regard is much appreciated.

My first reaction was — how stupid one should be to post such absolutely irrelevant question in that forum? I do see from time to time some questions that are about Grid Control but not about Extensibility and, assuming I have a minute, I might suggest to ask it in the neighboring forum instead. However, this time it seemed absurd to choose this place.

I was even more surprised that someone actually tried to provide a sensible response, I was thinking to blog about it to re-iterate the point that Tom Kyte expressed recently but I couldn’t find the thread anymore. I thought it was moved by a wise admin to a more appropriate place. I did a quick search on OTN forums and found it in… well, many other OTN forums. So it seems that it was simply deleted from Extensibility forum.

Google showed that OTN forums are not the only one appearance of this request. Is this an absolute stupidity or an example of plain scam?

Well, I just needed that rant.