Back in November 2009 I was working on a project to port Scribd.com code base to Rails 2.2 and noticed that some old plugins we were using in 2.1 were abandoned by their authors. Some of them were just removed from the code base, but one needed a replacement – that was an old plugin called acts_as_readonlyable that helped us to distribute our queries among a cluster of MySQL slaves. There were some alternatives but we didn’t like them for one or another reasons so we’ve decided to go with creating our own ActiveRecord plugin, that would help us scale our databases out. That’s the story behind the first release of DbCharmer.

Today, six months after the first release of …

Saw this interesting paper about highly concurrent programming methods and figured the word should be spread! It’s not new material but it’s a good read. See the full article here: http://www.usenix.org/events/hotos03/tech/full_papers/vonbehren/vonbehren_html/

“Highly concurrent applications such as Internet servers and transaction processing databases present a number of challenges to application designers. First, handling large numbers of concurrent tasks requires the use of scalable data structures. Second, these systems typically operate near maximum capacity, which creates resource contention and high sensitivity to scheduling decisions; overload must be handled with care to avoid thrashing. Finally, race conditions and subtle corner cases are common, which makes debugging and code maintenance difficult.

…

I hinted last week of my acceptance with Oracle before the formal announcement this week at the MySQL Users Conference, not for a job but as Oracle ACE Director. In today’s State of the MySQL Community keynote by Kaj Arnö I was one of the first three MySQL nominees that are now part of this program.

What exactly is an ACE Director? Using the description from the Oracle website.

Oracle ACEs and Oracle ACE Directors are known for their strong credentials as Oracle community enthusiasts and advocates, with candidates nominated by anyone in the Oracle …

Edward Screven – Chief Corporate Architect of Oracle provided the opening keynote at the 2010 MySQL Users Conference.

Overall I was disappointed. The first half was more an Oracle Sales pitch, we had some product announcements, we had some 5.5 performance buzz. While a few numbers and features were indeed great to hear, there was a clear lack of information to the MySQL ecosystem including employees, alumni and various support services. I hope more is unveiled this week.

Some notes of the session.

• Oracle’s Strategy covers storage, servers, virtual machines, operating system, database, middleware, applications
• We build a complete technology stack that is “open” and “integrated” based on “open standards”
• products talk via open standards with the intention for customers to not feel locked in to any technology
…

Brian Aker parted ways with the mainstream MySQL release, and with Sun Microsystems, when Sun was acquired by Oracle. These days, Aker is working on Drizzle, one of several MySQL offshoot projects. In time for next week's MySQL Conference & Expo, Aker discussed a number of topics with us, including Oracle's motivations for buying Sun and the rise of NoSQL.

The key to the Sun acquisition? Hardware:

Brian Aker: I have my opinions, and they're based on what I see happening in the market. IBM has been moving their P Series …

There have been a number of April fools jokes today so I thought I’d add my own to the list. While this sounds unexpected it’s actually no joke.

I just accepted a position with Oracle yesterday but I can’t say any more about the details until the MySQL users conference in a few weeks.

A special thanks to Lenz, Kaj & Giuseppe that championed everything to make it all happen, I really didn’t have to do anything other then accept.

Using ROLLBACK with MyISAM is useless. A ROLLBACK command is used to undo any DML that occurs during a transaction (i.e. START TRANSACTION and COMMIT). The MySQL default storage engine MyISAM does not support transactions.

It is easy with the SHOW GLOBAL STATUS command to see if your application code uses ROLLBACK. By performing two samples you can look at the delta over time. The statpack utility is one product that provides a human friendly display of this delta. As seen below, the use of ROLLBACK in combination with the read/write ratio and the my.cnf –skip-innodb indicate unnecessary database work.

====================================================================================================
                    Variable    Delta/Percentage         Per Second              Total …

A colleague pointed me at More fun with the MySQL Audit Plugin API which looks very interesting.  Analysis of the queries going on inside a msyqld has been something that has been wanted for some time.  Until now it’s only been possible with external addons such as MySQL Enterprise Monitor which do a good job. However, really the place for this functionality is inside the db server itself. If 5.5 m3 provides the hooks to do this that’s great news and while Anders’ first implementation may be simple, this can surely be extended in many ways.

The things I would like to see added to this plugin are the following many of which are safeguards to ensure you can use functionality on a system like this in production without …

As I already wrote, I will be speaking at the MySQL Conference & Expo in Santa Clara in two weeks and I am excited to be there again. This year's conference is going to be interesting for a number of reasons, but most importantly I think that the schedule looks great! This is going to be a "drinking from the firehose of MySQL knowledge" event. Afterwards, I'll be on parental leave in May and June, so I likely will miss a lot of great conferences – these months are usually quite packed, as our Open Source Events Calendar can confirm. I just received a notice that my talk …

Berkeley DB (BDB) is undoubtedly the workhorse among the opensource embedded database engines. It started as a university project in the mid-eighties and was further developed by Sleepycat Software, until it got acquired by Oracle in February 2006.

I had the impression that BDB had lost a lot of its popularity among opensource developers to SQLite in recent times, which has evolved into becoming the default choice for developers looking for an embedded data store. I'd assume primarily because the code is not released under any particular license, but put in the public domain …