As part of my using JMeter for the purpose of testing a new Transactional storage engine PBXT for MySQL, I’ve been investigating the best approach for handling transactions. Read more about earlier decisions at my earlier post Testing a new MySQL Transactional Storage Engine.

I found that the JMeter JDBC Sampler only supports SELECT and UPDATE Statements, and not calls to stored procedures. This is just one approach I’m considering taking.

Well, I guess it’s time to contribute code to an Apache Project. I’ve modified code and logged bugs before for Tomcat, but this will be my first attempt …

Temporary tables behave very differently across various database servers. If you’re not familiar with MySQL, some things might catch you off guard. In this article I explain some subtleties of temporary tables in MySQL and explain when you might encounter problems with them. I also show you how the platform-specific features can sometimes be very useful indeed. Creating temporary tables In MySQL, creating a temporary table has exactly the same syntax as creating a regular table, with a few restrictions (no foreign keys, for example).

In my earlier post I asked about how to create a trigger that can access the auto incremented value.

One solution is:

CREATE TRIGGER article_filename BEFORE INSERT ON adoppt.articles2 FOR EACH ROW SET NEW.permalink = CONCAT(NEW.permalink, "-" , ( SELECT MAX(id) FROM articles2 ) + 1 )

This however doesn't works properly if the lastest record, or the record with the highest value has been deleted after insertion.

Is there a reliable way to access the auto increment value for the next record? LAST_INSERT_ID() doesn't work if there was no insert in the current session.

--Frank

In an interview with Forbes, Microsoft’s CEO Steve Ballmer stops short of announcing patent litigation against “Linux”:

Well, I think there are experts who claim Linux violates our intellectual property. I’m not going to comment. But to the degree that that’s the case, of course we owe it to our shareholders to have a strategy. And when there is something interesting to say, you’ll be the first to hear it.

This is almost like announcing that there will sooner or later be an announcement of Microsoft starting patent litigation against “Linux” vendors and/or users.

By “intellectual property” he must mean patents. IP is a broad term and includes diverse rights, but it’s hard to see how Linux would infringe any trade mark rights or copyrights held by Microsoft. …

Frappr is an interesting way of showing the geographic locations of people that share a common interest. It's based on Google Maps and of course there is MySQL Users Group, too!

I will be speaking at the MySQL Users Conference 2006 in Santa Clara on Wednesday the 26th of April.The topic of the session is Web Application Clustering with MySQL. Zak Greant will be co-presenting with me.

I would like to set a trigger where upon inserting a new record with permalink set to "myfilename" would become "myfilename-id" where id represents the auto-incremented value of the id field. So I tried:

drop trigger article_filename;
CREATE TRIGGER article_filename BEFORE INSERT ON adoppt.articles2 FOR EACH ROW SET NEW.permalink = CONCAT(NEW.permalink, "-" , NEW.id );

However this creates a permalink of myfilename-0 as the id value was obviously not available.

So I tried changing the above to AFTER INSERT:

CREATE TRIGGER article_filename AFTER INSERT ON adoppt.articles2 FOR EACH ROW SET NEW.permalink = CONCAT(NEW.permalink, "-" , NEW.id );

and got:

#1362 - Updating of NEW row is not allowed in after trigger

So I tried

CREATE TRIGGER article_filename …

Warning: Rough Notes Follow

Any user-focused social networking community should aim to keep its members informed about what?s happening in the community.

At the very least, the community should inform members of important events that relate to them.

By default all communication should be turned on to avoid confusing members with various signups. In each e-mail that is sent out, a member should be given the option to conveniently unsubscribe from receiving all future notifications of that type.

These are the notes for what we are doing at Adoppt.com. The "cleaner version" of these notes and how I actually did all this with Ruby on Rails and MySQL will be in my upcoming book, Pro Rails (the first few chapters of which are almost ready to be mailed out to beta readers who have kindly notified me about beta reading the book. Thanks).

On …

Every so often, somebody asks me a question about MySQL replication. Usually that question is phrased something like "I think I've run into a bug in MySQL replication", or "does mysql replication always work" or something along those lines. These are almost always related to errors resulting from data inconsistency between the master and the slave. I've never personally seen a case where a bug resulted in inconsistent data between a master and a slave.

So, if your slave encounters an error because you have a duplicate key, then you have a data consistency problem. The data on your slaves doesn't match the data on your masters. In most cases this is because statements were skipped on one or more slaves. If that isn't the case, then something is writing to one or more slaves, which leaves the master inconsistent. You could also have a replication rules problem if you are restricting replication only to certain tables or databases.
…

Updated 28-mar-2006
There really is no way to do a comparision by numbers in features and functionality when it comes to Oracle and MySQL in the area of Stored Procedures and Triggers. Oracle does provide a far greater and extensive features list, however having more only means it has more.

We all know this, MySQL is a growing evolving database product, having just celebrated it’s tenth anniversary, Oracle on the other hand, will next year be 30, and has had significant funding in R&D being up until recently the second largest software company world wide. However, being open source, MySQL has the advantages of being lean and mean, providing only …