I have been getting a lot of comments and errata from people who seem to be mistakenly buying the first edition and believing it’s the second edition. A lot of the blame for this probably rests with Amazon, who did not distinguish between the two editions at all until the editor and I (among others) leaned on them persistently for about 6 weeks. I think some people are buying the second edition and getting the first edition.

One of our developers ran into the strangest error a few days ago, which neither the MySQL manual nor Google searching could find any information on. When he called certain stored procedures in a certain order, he got "Error 153 returned from storage engine." It's been reduced to a very simple test case, and a bug report has been filed. Here's the test case:

DROP TABLE IF EXISTS foo;
CREATE TABLE `foo` (
`a` int(11) NOT NULL auto_increment,
PRIMARY KEY  (`a`)
) ENGINE=InnoDB;

begin;
insert into foo values();
savepoint a1;
insert into foo values();
savepoint a2;
insert into foo values();
savepoint a1;
insert into foo values();
savepoint a2;
show warnings;
rollback;

The very last "savepoint" generates the warning "Got error 153 from storage engine". Any other MySQL'ers use savepoints and …

Part of updating the MySQL Certifications is trying out all the new features that have appeared with 5.1 and 6.0. Currently I am working with 5.1.24-rc on a Mac and 6.0 on Ubuntu and looking for items to add to the exams. The Event Scheduler is sure to become one of those Swiss Army Knife tools that we will wonder how we ever accomplished anything without.

I usually experiment with very simple tasks.

CREATE EVENT x1_event ON SCHEDULE AT '2008-07-16 14:01:01' DO INSERT INTO x1 VALUES (9,'nine');

SHOW EVENTS did exactly that. And just after 14:01, I found the new row in my x1 table.

So now I am thinking of a dozen think I used to do with cron(1) or at(1) that I could do with the event scheduler.

Warning: There are ramifications with backups and the event scheduler that I will not go into details here. But for now do not try to run your backups with event scheduler. The …

This is a request to all MySQL users to help mysql developers, by providing information, so that we can help you, by providing a more stable MySQL server for your needs.

As you may know, MySQL 5.1 has been in state of release candidate (RC) for some time. The last RC was announced as the last RC and is supposed to be followed by a GA release. The GA release is planned to be the exact same code as the last GA, only with the label changed.

The question we, who are developing and supporting the MYSQL server have been asking ourselves is, "Are really now in shape to do a proper GA release?".

We would like you as a MySQL User to help us out with deciding this.

We don't want to repeat the mistake we did with MySQL 5.0 GA and then again with MySQL 5.1 RC, by releasing a MySQL 5.1 GA too early.

Our external criteria for General Availability (GA) or Production release can be found …

We've been busy! Now that we're past version 1.0, we had a chance to make some fundamental improvements to opentaps for a long-term. We have begun to develop a new domain driven architecture for future versions of opentaps. This object-oriented architecture will make it easier for you to customize and extend opentaps or to combine it with other applications. It will also make it easier for us to develop opentaps and help it continue to grow.

opentaps Analytics is also coming along nicely. You are now able to slice and dice customer, order, and return data by over a dozen different ways, including by country, by brand, by month of the year, and by category. You're also able to look at the lifetime value of your customers from all these different angles. …

In the Cleveland area? Tonight, 6pm, I'll be giving my "Join-Fu: The Art of SQL" talk at the inaugural MySQL meetup in Independence, Ohio. Come join me! Here is the address to the venue:

2 Summit Park Drive
Suite 530
Independence, OH 44131 
Get Google Directions

See you there!

There's been a lot of rumors floating around internally at Yahoo that it's best to turn off some of your CPU cores when using Innodb, especially if you have a machine with > 4 cores.  At this point there's no question in my mind that Innodb doesn't perform much better when you double your cores from 4 to 8, but I really wanted to know if 8 actually performed worse. 

To test, I used a Dell 2950 with 6 drives and a simple mysqlslap test script.  There's basically no I/O going on here, just a small table in memory being queried a lot.  To be fair, I actually got this test from Venu.  I used maxcpu=4 in my grub.conf to limit the cpus (I also tested with tasksel and it seemed to have the same effect as maxcpu).

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There's been a lot of rumors floating around internally at Yahoo that it's best to turn off some of your CPU cores when using Innodb, especially if you have a machine with > 4 cores.  At this point there's no question in my mind that Innodb doesn't perform much better when you double your cores from 4 to 8, but I really wanted to know if 8 actually performed worse. 

To test, I used a Dell 2950 with 6 drives and a simple mysqlslap test script.  There's basically no I/O going on here, just a small table in memory being queried a lot.  To be fair, I actually got this test from Venu.  I used maxcpu=4 in my grub.conf to limit the cpus (I also tested with tasksel and it seemed to have the same effect as maxcpu).

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How did two vulnerabilities in the widely used Spring Framework remain hidden for so long? And what are the security implications for single-vendor-driven open source projects? READ MORE