Hi,

I don't get out here too often. If you have a question, or comment, please feel free to post it here, but also send it directly to me @ jmiller@mysql.com. You will get a faster response.

Best wishes,
/Jeb

Recently I helped someone who accidentally ran ALTER TABLE my_table AUTO_INCREMENT=1234; on an InnoDB table, not realizing that this causes the *entire* table to be rebuilt[1]!

They were concerned that if they killed the ALTER process, InnoDB might have to ROLLBACK internally.. and it's possible that a ROLLBACK in InnoDB take up to about 30 times longer than applying the statement took.

So what's the answer? Killing SELECT and ALTER TABLE commands seem to be free of cost. Killing UPDATE, INSERT and DELETE statements is about as much fun as being stabbed in the eye:

mysql> show processlist;
+----+------+-----------+------+---------+------+-------+-------------------------------------------+
| Id | User | Host      | db   | Command | Time | State | Info                                      | …

I recently received a review copy of the book "Xen Virtualization" by Prabhakar Chaganti (Packt Publishing) and finished reading it a few days ago.

The subtitle "A fast and practical guide" is a matching description - I managed to read the ~130 pages over the course of a week. The book is by no means an exhaustive reference manual, but it gives the reader a good overview about Xen and assists with performing the first steps and getting started.

Continue reading "Book review: "Xen Virtualization" by Prabhakar Chaganti (Packt Publishing)"

This thing is catching on … today’s question comes courtesy of Lasse Christiansen who is apparently residing in Japan (Lasse, correct me if I’m wrong).

Suppose you issue the following list of commands:

CREATE TABLE test (
  id varchar(1) NOT NULL,
  PRIMARY KEY  (id)
);
INSERT INTO test VALUES ('0'), ('1'), ('2'), ('a'), ('b');

The INSERT succeeds — nothing surprising here, the table now contains the values ‘0′, ‘1′, ‘2′, ‘a’ and ‘b’

Now you do:

DELETE FROM test WHERE id=0;

…and your client informs you that 3 rows were deleted.

Explain why.

(more…)

As a rule I always execute the following commands on a fresh database installation. Then for each user that is granted privileges, of course they are given a password and the host permissions are locked down as much as possible for their needs, alternately table and column privs as well. I’m not going to get into the parts the manual covers, but rather mention a couple of things on my mind.

First the initial commands:


mysql> use mysql
mysql> delete from user where User='';
mysql> delete from db where User='';
mysql> update user set Password=password('password_here') where User=’root’;
mysql> flush privileges;


However, one thing I’ve noticed is that when you hand over a server to someone that doesn’t necessarily follow your same understanding or regard to user privilege security, bad things can happen. Such as users created without a password. …

A

• Falcon from the beginning by Jim Starkey and Ann Harrison;
• Falcon for InnoDB Users By Kevin Lewis and Ann Harrison;
• MySQL Sandbox - Easily using multiple database servers in isolation by yours truly
  
…

I have noticed some posts today on Hyper Table passing by Planet MySQL.

Here are a couple of more links you should look at:

Article by Don Marti:
http://www.linuxworld.com/news/2008/020608-hypertable.html

Podcast on it:
http://www.linuxworld.com/podcasts/linux/2008/013008-linuxcast.html

Don introduced it to me a little while ago. Personally I am pretty excited to see this work being done.

Now will someone please deliver a Map/Reduce system written in either C or Python? I have a big preference for it to be C.

(My other option for a Map/Reduce system is to cobble together some Danga technology and see what …

I suppose most readers get the contents of this blog through planetmysql — if you do, you can stop reading here.

If you do not subscribe to planetmysql, you may have missed out on Dave Stoke’s excellent writings on the subject of MySQL certification. Dave has been busy analyzing the results of previous certification exams, and he has authored several articles on the subject in the past few weeks.

Go read’em.

I think last time I attended FOSDEM it was not yet called like that.. was it 2001? Yeah, think so. Well, now 7 years later, I'm working for MySQL and I'm going back. Together with couple of other colleagues (Suzanne, Hartmut, Lenz, Jan, Roland, ..), we're going to be hanging around, and hopefully meet new colleagues from Sun. I'm even invited for a dinner-meeting with some PostgreSQL dude!

The session I'm most interested in is from Kris Buytaert, talking about MySQL Cluster and Drupal. I'm specializing in Cluster within MySQL and communicating with the big Telco's. Amazing where Cluster is running, I tell you! And now, Kris talks on how to …