Given Jonathan Schwartz’s proclamation that Sun will make further open source acquisitions, I’ve been putting some thought into likely targets and/or new directions opened up by the MySQL acquisitions. One likely target sector is the ecosystem of vendors that surround the MySQL database - such as clustering and HA software providers - as well as complementary technologies.

With that is mind it is interesting to see that the company has hired two key Python developers, Frank Wierzbicki and Ted Leung. As the Infoworld report states, this is similar to the way Sun …

I saw a post by Baron mentioning that his tool maatkit is best for handling situations where a master-master replication setup has got out of sync.

If you think Baron was blowing his own trumpet he has good reason to. I have used his mk-archiver tool as part of the Maatkit to make the problem of archiving and purging data much easier. This was much easier than rolling my own solution.

Anyhow. I

This is absolutely the most awesome release of memcached ever, and it has absolutely nothing to do with me being a patchmonkey for it.

Trees are stabilizing and people are getting to work. Fun and exciting things to come :)

Kudos to MySQL and Sun (like krow) for jumping in on the fun.

Next up: 1.3.0-rc. Time to start hammering down the binary protocol before it wanders off even more.

I'm up way too late :) Praise insomnia!

This is absolutely the most awesome release of memcached ever, and it has absolutely nothing to do with me being a patchmonkey for it.

Trees are stabilizing and people are getting to work. Fun and exciting things to come :)

Kudos to MySQL and Sun (like krow) for jumping in on the fun.

Next up: 1.3.0-rc. Time to start hammering down the binary protocol before it wanders off even more.

I'm up way too late :) Praise insomnia!

Today’s quiz comes out of an e-mail conversation with fenixshadow, aka

On my system (5.0.45-Debian_1ubuntu3.1-log) , I run these commands:

CREATE TABLE t (
  ID INT NOT NULL PRIMARY KEY,
  PID INT,
  FOREIGN KEY (PID) REFERENCES t(ID)
) ENGINE=INNODB;

INSERT INTO t VALUES (1, NULL);
INSERT INTO t VALUES (2, NULL);

SELECT * FROM t yields the expected result:

+----+------+
| ID | PID  |
+----+------+
|  1 | NULL |
|  2 | NULL |
+----+------+

I now do

UPDATE t SET PID  = 2 WHERE ID = 1

and observe the result of SELECT * FROM t again:

+----+------+
| ID | PID  |
+----+------+
|  2 | NULL |
|  1 |    2 |
+----+------+

Question 1: Can you easily explain why the rows are now in reverse order?

(more…)

Yesterday I passed the CMCDEV exam.

I only used the study guide (previous entry) and the official manual to prepare for the exam.

The study guide is a good preparation for the exam.(Thanks to Roland Bouman and all other people involved with the book. The only minor issue with the book is that it didn't feel finished. Images which should've been printed in high quality and some phrases about a CD which is absent (All listed/fixed in the errata)

I filed a few bug reports while studying. (patched included :) )

So now let's wait for MySQL 5.1 to become GA.

I have not been at CeBit for quite a while, but this year I will be there as a regular visitor this Thursday (6th of March). If you would like to meet with me, please send me an email or ping me via IM/Skype! I look forward to walking around the hallways, visiting my new employer's booth and finding out what other Open Source presences and activities there will be.

Here is some of my thoughts on migrating MySQL to Sql Server. It came out of an email discussion. I’d love to hear your thoughts on migrating to a different database platform, not just MySQL to Sql Server.

I actually thought about writing a white paper or even a course on migrating from MySQL to Sql Server, but never got the time to do it. Sometimes a project doing similar things can serve as a launchpad for this endeavour, but that never came along, at least not yet. I am very interested in database interoperability field though. I’ve done MySQL and Oracle admin in the past and have published some MySQL and Oracle stuff in blogs. I have much better technical skills on Sql Server than any other RDBMS platforms, primarily because I’ve worked on it longer.

Here are some of my thoughts. I think most of it applies equally on migration from Oracle, DB2, Sybase, Postgresql, etc., to Sql Server, or the other way around. It …

Ran into an interesting issue with a client today who was using innodb_file_per_table. This client had a lot of tables ( 300K+), they were using innodb_file_per_table. Today they had a problem that caused their db to crash. After fixing their issue, the database restart seemed to hang. The only thing in the error log was the mysql was started, their was no crash recovery messages. An strace revealed that the mysqld process was stating all the datafiles. It seems that during a recovery the first step is to just check to see if all the individual files are really their. The entire process to simply stat each datafile took over 45 minutes to complete after which the actual crash recovery started. Just a quick note to remind myself in the future if I see this again.

Here is a sample table you can create to test following problem/solution on: CREATE TABLE `t1` ( `a` char(1) default NULL, `b` smallint(6) default NULL ); insert into t1 values ('y','1'); I have a table t1 which has column a and b, I want column a to be updated to ‘n’ when column b = 0. Here is the first version [...]