Running Stored Procedures on MySQL 4.x

This blog post has moved. Please find it at:

http://www.mpopp.net/2006/11/running-stored-procedures-on-mysql-4-x/.

www.howtoforge.org

Many of you might know HowToForge, but for those who don't - there's a bunch of excellent and interesting tutorials relating to Linux and OpenSource.

There are also many about MySQL or using MySQL - here are some examples:

• How To Set Up Database Replication In MySQL


• MySQL Master Master Replication


• How To Set Up A Load-Balanced MySQL Cluster


• Running A MySQL-Based DNS Server: MyDNS


• Virtual Users And Domains With Postfix, Courier And MySQL (Fedora Core 5)


• Virtual Users And Domains With Postfix, Courier And MySQL (+ SMTP-AUTH, Quota, SpamAssassin, ClamAV)

... and more.

There's definitely a lot of stuff to play with.

Official German MySQL 5.1 Reference Manual to be released this month

All German speaking folks will have a chance to get a printed German MySQL 5.1 Reference Manual which covering 1,312 pages for a price of EUR 59.95 (hey, most books with that amount of pages cost much more than that).

It is about to be released this month and can be pre-ordered at amazon.de.

I pre-ordered my copy today. Sometimes it's nice to leave the PC for a while and dig into a good book, but still use the time to improve skills. There are still some topics about MySQL that I'm not as familiar with as I wished and this will be good opportunity to remove some gaps in my knowledge.

New Lists of Certified Candidates online

The Lists of MySQL Certified Candidates now also include the new Certifications for MySQL 5.0 - Certified MySQL 5.0 Developer and Certified MySQL 5.0 DBA:

http://www.mysql.com/training/certification/candidates.php

Also new is that you can now find some statistic figures. You can see how many have passed each individual Certification and on the detail page you also find how many people have passed this particular Certification in each specified country. So you can for example easily say: I'm one of eight Certified MySQL 5.0 DBAs in Germany.

db4free.net now exclusively runs MySQL 5.1

It's past 7 o'clock in the morning, but this night has been a productive one (hey - no bad thinking please ;-)).

I have updated db4free.net to the latest MySQL 5.1 development source version (5.1.12-beta) and discontinued the 5.0 server. The "former" 5.1 server which ran on port 3307 is still alive, but no new accounts are being created there anymore. During the next days I plan to make the databases that run on the port 3307 server accessible on the main 5.1 server (with standard port 3306) to have everything together on one server - and let the port 3307 server die.

Before the update, most users have only used the 5.0 server, but only a little number of users did anything on the 5.1 server. My intention is to test 5.1 more intensively under a higher load and I hope that this also helps to contribute to the development of MySQL 5.1 by finding bugs or other flaws on a production system. I'm also thinking of setting up a replication slave server (instead of the second production server) to do regular backups from there - and of course for testing and finding bugs.

Running MySQL 5.1 offers new possibilities for the users and for me as administrator. The users can now create events and triggers (it was not possible for users to create triggers on the 5.0 server since this would have required SUPER privileges). I want to make use of new logging capabilities, events and new information_schema views to set up a monitoring system - all done by the server. The new MySQL 5.1 features make it much more comfortable for me to keep track of what's happening on the server. This will also be used to clean up unused accounts and to find misused accounts more easily and more quickly.

So this is a great improvement for the users as well as for me - and hopefully also for the MySQL company and products.

New information_schema views

As you might have recognized already, I love to take a look into the Change logs from time to time and hope to find some goodies there. Here's an especially nice one in the Change log of 5.1.12:

INFORMATION_SCHEMA contains new tables, GLOBAL_STATUS, SESSION_STATUS, GLOBAL_VARIABLES, and SESSION_VARIABLES, that correspond to the output from the SHOW {GLOBAL|SESSION} STATUS and SHOW {GLOBAL|SESSION} VARIABLES statements.

This was reason enough for me to compile MySQL 5.1 from source and take a look:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3 to server version: 5.1.12-beta-log

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> use information_schema
Database changed
mysql> show tables;
+---------------------------------------+
| Tables_in_information_schema          |
+---------------------------------------+
| CHARACTER_SETS                        |
| COLLATIONS                            |
| COLLATION_CHARACTER_SET_APPLICABILITY |
| COLUMNS                               |
| COLUMN_PRIVILEGES                     |
| ENGINES                               |
| EVENTS                                |
| FILES                                 |
| GLOBAL_STATUS                         |
| GLOBAL_VARIABLES                      |
| KEY_COLUMN_USAGE                      |
| PARTITIONS                            |
| PLUGINS                               |
| PROCESSLIST                           |
| REFERENTIAL_CONSTRAINTS               |
| ROUTINES                              |
| SCHEMATA                              |
| SCHEMA_PRIVILEGES                     |
| SESSION_STATUS                        |
| SESSION_VARIABLES                     |
| STATISTICS                            |
| TABLES                                |
| TABLE_CONSTRAINTS                     |
| TABLE_PRIVILEGES                      |
| TRIGGERS                              |
| USER_PRIVILEGES                       |
| VIEWS                                 |
+---------------------------------------+
27 rows in set (0.00 sec)

So what can you do with it? Certainly a lot. You want to know when your server has been restarted the last time? Here's what to do:

mysql> SELECT (NOW() - INTERVAL VARIABLE_VALUE SECOND) 
   AS server_start_time
    -> FROM information_schema.GLOBAL_STATUS
    -> WHERE VARIABLE_NAME = 'UPTIME';
+---------------------+
| server_start_time   |
+---------------------+
| 2006-09-23 20:38:05 |
+---------------------+
1 row in set (0.00 sec)

There are other nice things you can do. You can create a monitoring table and an event to copy the values of all Com% status variables into the monitoring table regularily, like so:

SELECT NOW() AS ts, 
   VARIABLE_NAME, VARIABLE_VALUE
FROM information_schema.GLOBAL_STATUS
WHERE VARIABLE_NAME LIKE 'Com%'

And that's certainly not everything you can do ;-).

db4free.net runs dev source version again (5.1.12)

It's three months ago since MySQL 5.1.11 was released and many things have changed since then. Just watch the Change Log for 5.1.12 - I believe it's one of the longest ever:

http://dev.mysql.com/doc/refman/5.1/en/news-5-1-12.html

But I've found another nice and interesting thing: watch this bug report. This says that it's now allowed to do many more things in Prepared Statements inside Stored Procedures:

SHOW BINLOG EVENTS
SHOW (MASTER | SLAVE) STATUS
SHOW (MASTER | BINARY) LOGS
SHOW (PROCEDURE | FUNCTION) CODE (parsable only in debug builds)
SHOW CREATE (PROCEDURE | FUNCTION | EVENT | TABLE | VIEW)
SHOW (AUTHORS | CONTRIBUTORS | WARNINGS | ERRORS)
CHANGE MASTER
RESET (MASTER | SLAVE | QUERY CACHE)
SLAVE (START | STOP)
CHECKSUM (TABLE | TABLES)
INSTALL PLUGIN
UNINSTALL PLUGIN
CACHE INDEX
LOAD INDEX INTO CACHE
GRANT
REVOKE
KILL
(CREATE | RENAME | DROP) DATABASE
(CREATE | RENAME | DROP) USER
FLUSH (TABLE | TABLES | TABLES WITH READ LOCK | HOSTS | PRIVILEGES |
LOGS | STATUS | MASTER | SLAVE | DES_KEY_FILE | USER_RESOURCES)

Ain't that nice? This gives a lot more flexibility to dynamic SQL! (I know some guys who will have a lot of fun with that ;-))

This was reason enough for me to update the MySQL 5.1 server (on Port 3307) on db4free.net to this latest Development Source version. So you can try out all the nice enhancements that have been introduced in the last three months.

Enjoy!

MySQL Playground for Download

I have now uploaded my MySQL Playground and you can get it from

http://www.db4free.org/mysql-playground.tar.gz

The size of the file is 1 GB, so please take into account that it might take some time to download the file.

After download, just extract it to your "Virtual machines" directory:

tar xvfz mysql-playground.tar.gz

... and load it into your VMWare Server (should work for VMWare Workstation, VMWare Player too, I guess). I have assigned 768 MB RAM to this machine, so depending on your total amount of memory available you might have to change this.

The virtual machine runs SuSE Linux 10.1 (32-bit). The root password is simply "root" and there's a normal user named "user" with password "user". The same for the three MySQL instances (MySQL 5.1.11 each): user "root" - password "root", user "user" - password "user". There's also a replication slave user names "slave" with password "slave". The MySQL servers are installed into directory /MySQL_51/server-x, x being 1, 2 and 3. They use port 3306 for the first server, 3307 for the second server and 3308 for the third server. The database "replication_db" is set up multi-master replication, so whatever you do inside this database on one of the servers should also happen on the other two servers.

Please tell me if I have forgotten some important piece of information.

Feel free to play around with it and if you create other nice setups out of it, feel free to publish your versions.

MySQL GUI tools bundle replaces individual GUI tools

You may have noticed that you don't find any links for MySQL Administrator, MySQL QueryBrowser, MySQL MigrationToolkit and MySQL Workbench on dev.mysql.com anymore.

All these tools are now available in the new MySQL GUI Tools bundle and you can download versions for Windows, Linux and MacOS.

My new MySQL playground

The VMWare Server allows to do great things that you usually wouldn't like to do on your working machines, mostly because of the danger to damage something that can take a lot of time to recover. And it's also a great thing to play with advanced MySQL issues.

So I installed myself a "MySQL playground" - a VMWare machine running SuSE Linux 10.1 - and installed three MySQL 5.1.11 servers (placed in different directories and assigned the ports 3306, 3307 and 3308). The first thing that I played with was to set up a multimaster replication example, based on Giuseppe Maxia's article: Advanced MySQL Replication Techniques (I planned to do this for quite a while and now I finally did it!).

Giuseppe's article is great and makes this a very straight-forward task. The only thing I'd like to mention (because I overlooked it and lost a bit of time) is that if you run more than two servers, you absolutely need to add the log-slave-updates option to the [mysqld] section of your my.cnf files. Otherwise your actions will be replicated only to the next slave, but since this one wouldn't write these actions to the binlog, it would not be replicated to the other servers as well.

Just try it out - get yourself a virtual machine, install a few MySQL instances and play around with them. This can be a lot of fun and of course very instructive!

I'm not sure whether there are any legal issues distributing VMWare machines (I don't think so, but the VMWare server is proprietary software so I'm not completely sure)? If there aren't any I would be happy to offer my playground for download.

A new idea?

Since we are currently speaking a lot about new ideas, maybe there is one.

MySQL provides a lot of Live Web Seminars being offered as On-Demand Webinars a few days later. This is a great offer - it provides presentations from experts that everybody can join in and watch or download as soon as they are provided on the On-Demand Webinar pages - all for free.

During the Users Conference, there were some "HackFests" where developers showed how to extend functionality in code right in front of the attendees.

Maybe this could be combined with Webinars? There are many topics that can be presented perfectly from code, from the command line or from the desktop, better than from conventional presentations. Some examples?

* How to set up a replication environment
* How to set up MySQL cluster
* How to use the MySQL Test tools
* How to create backups, showing different options
* Performance tuning
* How to get debugging information for bug reports
* How to enable plugins
* and so on, and so forth, ...

Personally, I need easy ways to get into a feature or a technique. Once I jumped over the first barriers, it's not that difficult anymore to hook in and get involved more deeply. But the most difficult part is the beginning and the lower the barriers to get started are, the easier it gets to enhance the skills.

This includes many benefits for MySQL, too. When people get an easy way to learn how to use such things, they will use it which will in return provide better feedback for MySQL.

Maybe there are technical issues that make it difficult to present Webinars like this at the moment - but hey ... this should not be a reason not to think about it ;-).

Supporting ideas and being productive

Hey, that's a great topic and I very much like Zack's article and the responses (thanks Roland, Mats ... did I forget someone?).

Some time before I joined MySQL I worked for a local company (which is the biggest company in the region where I live) and I could perfectly see how it should not be. There were (and still are) very strong hierachies and if you are in the low areas of the hierachy structure, the management only wanted you to "work on something". The last thing they wanted was that employees speak up and shake on the structures of the company. No criticism was appreciated, employees should just do their daily work and even if they do it in a very inefficient way - that's perfectly fine.

The worst thing you could do was to make your work more efficient to get yourself a little time for breaks or for other (even educational) activities. So for example - if you stupidly entered numbers into an Excel spreadsheet for 4 hours, it was perfectly OK. If you found a way to automatically import the same data in half an hour and you allowed yourself a little coffee break so that everything together summed up to let's say 45 minutes - you were labeled lazy (speaking of coffee, cigarette or whatever breaks - I even consider them important to get your head free again and keep a distanced look at your work, so many of the best ideas arise during breaks!). The management just wanted to see you sit in front of your PC and do something that's somehow related to your work, but never do anything else. Needless to say that everyone was frustrated, everybody was working just to get paid and hardly anyone had ambitions to make things better (and those who did soon ended up as candidates to be fired).

Such conservative views are the worst idea killers. Work is done most efficiently if you like what you do and if you can identify with your work and your company. That doesn't even mean that you have to be the best skilled expert on your job. If you like what you do and if you like what your company does, you will look for good solutions and try to give the best you can. By looking for the best solutions, this individual will learn and become better skilled anyway. But if somebody isn't motivated to look for good solutions, there's no chance to learn from finding new ideas.

Being productive doesn't work without a certain amount of freedom and it definitely requires a pleasant atmosphere in your daily working life.

MySQL tries to find new employees who are already dedicated to MySQL's products and databasing in general, providing the best chances that new employees are motivated to create improvement. Most employees work from their home office which gives an employee the possibility to set up the working environment according to personal needs. Working times are more flexible - people work best at different hours, so everyone can find the working times that suit him/her best (e.g., I'm a completely night person, I could not find a company that allows me to work during night somewhere around my place). And being an Open Source company which represents open mindedness by definition makes pretty much sure that ideologies that I found in my former company don't have a chance.

Just see this - no manager from my former company would never have written or said something like Zack in his article.

I have seen two very different ways and it's easy to see which one works much better ;-).

PHP 5 Certification exam available soon

A new and updated version of the Zend PHP Certification is on the way and will be available starting August, 31st:

Zend PHP 5 Certification Page

It's a complete rewrite, but the exam will still (as with the PHP 4 exam) cover 70 questions in 90 minutes. A new Study Guide will be available starting September and current PHP 4 certified people will get a discount for the PHP 5 exam.

To get detailed information, you can also listen to the Webcast Recordings at the phparch.com website.

And for those who prefer taking a MySQL 5 certification, there's also information available for you :-).

Too many connections

Here's another good rule about using MySQL in your application:

Never let your application access the MySQL server with a user that has SUPER privileges (at least unless there's a VERY good reason to do it).

There may be more reasons for that but one is that it might stop your root user from accessing the server if all allowed connections are being used (the "Too many connections" error).

Here's what the manual says:

"mysqld actually allows max_connections+1 clients to connect. The extra connection is reserved for use by accounts that have the SUPER privilege. By granting the SUPER privilege to administrators and not to normal users (who should not need it), an administrator can connect to the server and use SHOW PROCESSLIST to diagnose problems even if the maximum number of unprivileged clients are connected."

But if your application user also has SUPER privileges, this might have used that one extra connection that should be reserved for that purpose.

A good application starts with good database design

... and most important - good use of SQL!

That doesn't sound surprising, I guess.

Recently, Giuseppe Maxia provided a good hint (An ugly query should be a warning bell) how to get an indicator that something is wrong with your query. I would like to add a hint to help you find out that something is wrong with the way you use your database inside your application. Just ask yourself the following question:

How much of my client side code is there just to get the data that I got from the database into the form that I need in my application?

Your answer should be: very little.

In most cases, SQL provides the capabilities to get out of the database exactly what you need. Needless to say that it's most important to normalize your data. It's not a bad sign if you end up with complex queries and joins that bind together several tables (just take care that your queries don't look like Giuseppe's negative example ;-)). Place the correct indexes to make sure that these queries still perform well when there are thousands and millions of records in the tables. There are many rules about good database design and they exist for a good reason.

But the message of my words shall be: don't waste hundreds of client side code lines to do what one SQL query can do!

Current activities and plans

It's very important for me to keep closely in touch with MySQL's products and all the fun stuff that comes with working with databases which is also a good way to keep in memory what the background of my job and our company is. A job is much more fun if you know and use the products that the company you work for produces instead of only doing it to get paid (that's something I also know well from local companies I worked for earlier - that makes a huge difference). Because of this, I never want to lose the fun side that comes with Community activities which involves to sometimes simply play and experiment with various things that come to my mind and write about that.

Unfortunately I found a little less time recently for Community related activities than the months before, but there are plans which I hope will bring that back to what it used to be. During the next months I plan to reorganize my working environment and my PC infrastructure which involves setting up a new office. My current office is quite a mess and now during the summer heat it gets unpleasantly hot here, so I'll move downstairs where a nice, quite large room is free and where it doesn't heat up as much as upstairs, so I can setup my new working place exactly according to my needs which will certainly raise my productivity for both my job as well as my Community work.

The reorganization of my PCs includes to start using MySQL 5.1 as my production system (besides moving many things that still run under Windows to Linux) - which will certainly bring up new topics to blog about. The same is planned for db4free.net - until autumn I'd like to move everything to one single MySQL 5.1 server (probably set up a second server as replication slave to provide better security) - so there will be a large amount of new 5.1 users who will contribute in testing 5.1 in production and hopefully provide valuable feedback to us.

So there's definitely a lot to come ;-).

Forum navigation now available!

Many people have complained that the new MySQL Forum misses an appropriate navigation. Now it's back:



Stay tuned - more enhancements are to come!

mysqldump improvements

Since the last few versions and especially since 5.0.23, the mysqldump command includes new and very important bug fixes.

I'd like to mention three of them that I was affected by:

Bug 16878 (fixed in 5.0.19, 5.1.8): Dump of triggers
Bug 17201 (fixed in 5.0.23, 5.1.12): mysqldump sometimes creates database twice
Bug 18462 (fixed in 5.0.23): mysqldump does not dump view structures correctly

New GUI Tool bundle available

You may have noticed the new link on dev.mysql.com to the MySQL GUI Tool Download.

This bundle includes new beta versions for MySQL Administrator, MySQL QueryBrowser, the MySQL MigrationToolkit and a new alpha version of MySQL Workbench. All these GUI products are supposed to be offered in one single package in the future.

To get all details, read Mike Zinner's Announcements in the forum:

http://forums.mysql.com/read.php?108,100559,100559#msg-100559
http://forums.mysql.com/read.php?108,100561,100561#msg-100561

Needless to say, Feedback and Bug Reports are very much appreciated ;-)!

Installed MySQL 5.2 today

You think I'm kidding? No way!

There is this web page (I blogged about it a few months ago) where you get an interface to BitKeeper to watch the development activities: http://mysql.bkbits.net:8080/mysql-5.1/index.html.

Just for fun I replaced 5.1 with 5.2 and - it worked. So I followed the instructions from the manual and only replaced 5.1 with 5.2 again. This way, I ended up with a MySQL 5.2.0-alpha installation:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3 to server version: 5.2.0-alpha

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>

I doubt that there are many (if any at all) differences to the current 5.1 development source - but it's nice to see that MySQL 5.2 is on the way.

And I'm really excited to hear about the new features that are planned for 5.2!

Welcome on board, Roland and all the best to Frank!

I have been knowing that Roland Bouman is about to join 
Carsten Pedersen's MySQL Certification team for quite a while, 
but now - as of 1st July - it's official and time to wish him all the best 
and much fun in his new job!

Also Frank Mash has recently moved to New York and started
a new job as MySQL DBA (I hope, I remember everything
correctly). Also my best wishes for him!

MySQL not only rocks as a database server, but also for great job
opportunities! And the best thing is - MySQL is currently hireing ...
so check out MySQL's job page - there might be the right job for you!

Sorting of numeric values mixed with alphanumeric values

This blog post has moved. Please find it at:

http://www.mpopp.net/2006/06/sorting-of-numeric-values-mixed-with-alphanumeric-values/.

Driving to FrOSCon

I am ready to leave for the FrOSCon Conference, taking place on Saturday and Sunday in St. Augustin/Germany.

Here's the program that contains many MySQL related sessions.

I hope to meet many MySQL people there ;-).

Information_schema query taking more than 7 minutes

The biggest current problem that I know in the MySQL servers is the performence of information_schema. This is reported as bug 19588:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1829 to server version: 5.0.22-max-log

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> SELECT TABLE_SCHEMA,
    ->   sum((DATA_LENGTH + INDEX_LENGTH) / (1024 * 1024)) as size_mb
    -> FROM information_schema.TABLES
    -> GROUP BY TABLE_SCHEMA
    -> HAVING size_mb > 10
    -> ORDER BY size_mb DESC;

...

xxx rows in set (7 min 34.71 sec)

Even though this server hosts a lot of data - more than 7 minutes for this query is tough.

www.mysql.com higher PageRank than Google

Google offers a little Toolbar that provides additional information about the displayed website, including the PageRank value that indicates how "important" the website is in Google's eyes (and that's said to be used to calculate the relevance in Google searches).

Here are some values that I looked up:

www.mysql.com: 9/10
www.planetmysql.org: 8/10
www.google.com: 8/10
www.microsoft.com: 9/10
www.yahoo.com: 9/10
www.oracle.com: 9/10
www.postgresql.org: 8/10
www.amazon.com: no value
www.phpmyadmin.net: 8/10
www.php.net: 9/10
www.wikipedia.org: no value
www.novell.com: 8/10
www.redhat.com: 8/10
www.orf.at (Austria's national TV broadcast station): 7/10
www.db4free.net: 6/10
www.freesql.org: 5/10 (but currently no content)
www.freemysql.net: 4/10
www.mpopp.net: 4/10

There's only one website that I've found with a value of 10/10: www.apple.com.

However, it's great to see that the relevance of MySQL's website is among the highest of all websites of the world.

Knoppix 5.0.1 available

Today I have downloaded the brand new Knoppix 5.0.1 DVD and played a bit around with it.

It looks quite nice, although some of the packages are very up to date and others are quite old. MySQL comes with 5.0.21, so there's probably no distribution with a more recent MySQL version at the moment.

PostgreSQL is included with version 8.0.4, while the current version is 8.1.4 (and the latest version of the 8.0 tree is 8.0.8). Apache comes with versions 1.3.34 and 2.0.55, but only Apache 1.3.34 is configured to start with PHP and that only with PHP 4.4.2, which is the most disappointing aspect that I found.

Multiple SP call crash to be fixed in MySQL 5.0.23

There was this bug that I wrote about earlier which caused certain Stored Procedures to crash when they were executed more often than once.

I noticed in the bug report and in the change log that this bug will be fixed in MySQL 5.0.23.

Goodbye anger, hello fun

I just saw a Microsoft commercial video clip using the slogan

"Better and more simple Visual Basic - goodbye anger, hello fun"

What do they want to tell us? Does that mean, the former version of Visual Studio/Visual Basic caused anger? Do they worsen their old product to make advertising for the new one?

My next thought would be - how will they advertise when the next version comes out? Will they again say, that the now current release causes anger or something similar?

I don't think that's good advertising.

How I work

I think it was Brian Aker who got this "How I work" series started and it's a pleasure for me to join in and tell you something about how I work.

Actually, it's only half a month since I've been working for the web development team of MySQL, so some things might still be subject to change. But most things are very likely fixed, so here they are ...

My working PC is an Athlon AMD64 3200+ with 2 GBs RAM and two 250 GB hard drives. Currently it's running SuSE Linux 10.0, preferably with KDE and I'm using the ext3 file system. However, I consider switching over to Fedora not too far from now (maybe in early October, when Fedora Core 6 is released).

Formerly I worked most of the time with Windows, but delegated some server tasks (file server, print server, web server, database server, ...) to Linux - which always used to be SuSE, so I'm still most familiar with this distribution. I used to do a lot with YaST (SuSE's configuration tool), but since I started my job with MySQL and with it started to extensively use Linux, I'm doing much more on the command line and therefore become more independant of GUI tools. More about that later.

My email client is currently "Kontakt", one of KDE's standard email, contact and scheduling applications. I'm not yet sure if I hold on to this, since there are some issues that don't work like I'd like it to (however, I didn't spend much time with this application - so maybe it's because of me ;-)).

For development, I currently use kvim, but though I often used the vi editor to make modifications on files, I'm not very sure if I'll like it for more complicated development tasks. Maybe I'll look around if I find a good PHP plugin for Eclipse (which I preferably used for Java development so far - one of the best IDEs, I guess). If you can recommand something like this, please let me know!

My preferred web browser is Opera. The big advantage compared to Firefox is (in my opinion) that I don't need to install plugins to get everything I need. It's very comfortable to work with!

But of course, I also need different browsers, and some browsers require different operating systems - therefore I use VMWare Server. Unfortunately, I don't have a Mac available yet, but this might also change ;-).

As I already mentioned - I do a lot at the command line now. One of my favourites is

find -name '*' -exec -q [regexp] {} \; -print

which allows me to find all files in the current directory (including subdirectories) where a certain regex pattern occurs. This is extremely helpful mostly now at the beginning of my web developer job to find the code sections that I'm looking for.

Another useful thing I've learned recently is to use the tar compression command not only for decompressing (I actually used that for a while), but also for compressing files and whole directory structures.

And finally, I learned a lot about Subversion. Actually, I have used CVS (and for a short time also Subversion) before, but on quite a low level - so this is also an important improvement.

And of course - I'm learning more and more every day, which is one of the most pleasant aspects of my job.

My working hours are mostly in the evening and during the night, which provides several advantages. First of all, my colleagues live in different parts of the world, so it's easiest to catch them at these times and second, I'm a night person. I used to sleep in the morning (so, right now is an exception - it's currently 10:20 a.m., that's when I'm usually deeply asleep) and can do some other things during the afternoon (and do little job tasks in-between) - to dedicate myself to the job starting from the late afternoon or early evening, mostly until 3 or 4 o'clock in the morning. Another big advantage is that during the evening and night, it's very calm and there's no danger of being disturbed by anyone ;-).

Did I forget something important?

FrOSCon Conference in St. Augustin/Germany from 24th to 25th June

I'm looking forward to visiting the FrOSCon Conference in St. Augustin/Germany from 24th to 25th June and to meeting some fellow MySQL Community members and colleagues.

The MySQL related events are:

* MySQL Administration - Backup and Security Strategies on Linux by Lenz Grimmer

* MySQL Cluster: an introduction - A journey into High Availability by Geert Vanderkelen

* Pivot tables in MySQL 5 - creating cross tabulations with MySQL 5 stored routines by Giuseppe Maxia

* The MySQL Business Model - Where and How we Thrive by Lenz Grimmer

... and of course there are many more events that are related to MySQL indirectly (like PHP, Java, Typo3, ...).

Filling table with prime numbers

First of all many thanks to Dean Swift, Carsten Pedersen, Kai Voigt and Kristian Köhntopp for providing me with this example and allowing me to blog about it.

This origins from a stored procedure exercise that a group of students did which ended up in an optimization competition. It's about a table that should be filled with prime numbers - up to a pre-defined bound - by a stored procedure.

So here's the basic solution:

mysql> DELIMITER //
mysql> CREATE DATABASE sieve //
Query OK, 1 row affected (0.00 sec)

mysql> USE sieve //
Database changed
mysql> CREATE TABLE sieve (
     ->   id INT PRIMARY KEY
     -> ) //
Query OK, 0 rows affected (0.06 sec)

mysql> CREATE PROCEDURE sieve (max INT)
     -> BEGIN
     ->   DECLARE l0 INT;
     ->   DECLARE l1 INT;
     ->   TRUNCATE sieve;
     ->   SET l0=2;
     ->   WHILE l0
     ->     INSERT INTO sieve (id) VALUES (l0);
     ->     SET l0=l0+1;
     ->   END WHILE;
     ->   SET l0=2;
     ->   WHILE l0
     ->     SET l1=l0*2; # delete from first multiple
     ->     WHILE l1
     ->       DELETE FROM sieve WHERE id=l1;
     ->       SET l1=l1+l0;
     ->     END WHILE;
     ->     SET l0=l0+1;
     ->   END WHILE;
     -> END //
Query OK, 0 rows affected (0.00 sec)

Here's some further information, if you want to play with optimizing this stored procedure:

Our colleague, Philippe Campos, suggested removing the inner loop and replacing it with a modulo operator. (DELETE FROM sieve WHERE (id%l0)=0 AND id>l0) This increased speed. He then suggested batch inserts. This made it much faster. A student suggested batch insert of odd numbers to the memory storage engine. The former is cunning and the latter opens much scope for optimization beyond the algorithm of the stored procedure.

By what ratio can you improve the basic implementation? Do indexes help or hinder?


So what's your best solution?

Enjoy!

From Oracle via MS SQL Server up to PostgreSQL or MySQL

This morning I browsed through a training course book (from one of the largest Austrian training providers) and found the description for a SQL course which I think sounds really nice. Translated to English, it says about this:

"You will learn to know dialect independant SQL, which can be used in almost all database systems without major changes - from Oracle via MS SQL Server up to PostgreSQL or MySQL."

I really like the way how they've set the priorities :-).

Started to use replication

It's been a long time that I've been using MySQL, but it has just happened now that I made use of replication in production.

What's the reason for this? Well, I have a working machine (currently with SuSE Linux 10.0) and a private machine (with Windows), both running the latest production release of MySQL 5.0. On my working machine, I've set up a Wiki. I used to make regular backups on my private machine and wanted to backup my Wiki database, too.

There are certainly serveral solutions for this, but the solution that I preferred was to replicate the Wiki database to my private machine to simply backup it together with my other databases there.

Here's how I did it (not very difficult - and not at all with the help of Jay's and Mike's Pro MySQL 5 book ;-)):

First I added the following lines to the my.cnf file of the master (which is the working machine):

log-bin
binlog-do-db=wikidb (wikidb is the name of the database)

and there should also be a line

server-id=1 (which might already be there). Then restart the MySQL server.

Then I accessed MySQL using my root user to add a slave_user:

CREATE USER slave_user@'%' IDENTIFIED BY 'xxxxxx';
GRANT REPLICATION SLAVE ON *.* TO slave_user@'%';

(xxxxxx is of course your password and you can limit the host information of the user more strictly than just %.)

Then flush the tables, apply a read lock and output the replication master information:

mysql> flush tables with read lock;
Query OK, 0 rows affected (0.00 sec)

mysql> show master status\G
*************************** 1. row ***************************
            File: master-bin.000002
        Position: 98
    Binlog_Do_DB: wikidb,wikidb
Binlog_Ignore_DB:
1 row in set (0.00 sec)

Note the position number (here 98), since you will need it to configure the slave.

Keep the lock and open another client to make a dump of the database (make sure you add --lock-tables=false, because otherwise mysqldump might try to apply another lock and you end up waiting forever):

mysqldump --databases wikidb --lock-tables=false > wikidb.sql

... and import the database to the slave:

mysql -h [slave host] < wikidb.sql

This makes sure that you have exactly the same data on your slave and nobody can modify any data on the master in the meantime.

Then change to your slave and enter the following lines to your my.cnf there:

server-id=2
master-host=[your master ip address]
master-user=slave_user
master-password=xxxxxx
master-port=3306

Then access your slave host and enter the following lines (according to the SHOW MASTER STATUS output on your master):

mysql> CHANGE MASTER TO
MASTER_HOST='[your master ip address]',
MASTER_USER='[slave_user]',
MASTER_PASSWORD='[your slave_user password]',
MASTER_LOG_FILE='master-bin.000002',
MASTER_LOG_POS=98;

START SLAVE;

... and that's it - now your replication system should be running. Try to modify data on your master server and the change should immediately be visable on your slave as well.

You can also try this:

on your master:

mysql> show master status\G
*************************** 1. row ***************************
            File: suse-bin.000005
        Position: 196
    Binlog_Do_DB: wikidb,wikidb
Binlog_Ignore_DB:
1 row in set (0.00 sec)

on your slave:

mysql> show slave status\G
*************************** 1. row ***************************
...
            Master_Log_File: suse-bin.000005
        Read_Master_Log_Pos: 196
...
1 row in set (0.00 sec)

File on master and Master_Log_File on slave as well as Position on master and Read_Master_Log_Pos on slave should always match.

You can find more information about replication as already mentioned in Jay Pipes' and Mike Kruckenberg's Pro MySQL 5 book, in the MySQL manual and if you want to do extremely fancy stuff, refer to Giuseppe Maxia's Advanced MySQL Replication Techniques, where you can learn how to set up a master/master-replication system with MySQL.

Check out this Podcast Episode

Pro MySQL 5 from Jay Pipes and Mike Kruckenberg is definitely one of the best advanced MySQL books around.

dbazine.com has published a Podcast Episode with an interview with Jay and Mike where they talk about themselves and - of course - MySQL:

http://www.dbazine.com/podcasts/podcast-kruckenberg

MySQL Upgrade Certification exams available

I just checked out my account at www.pearsonvue.com and found out that the MySQL Upgrade Certification exams from 4.x to 5.0 are available.

Guess, I'll have to start learning again.

Congratulation to the Finns and the Swedes

MySQL is a Finnish/Swedish founded company, so it's nice to congratulate both countries to this successful weekend!

On Saturday, Finland won the Eurovision Song Contest. That's fantastic - finally, Europe woke up and let a Hard Rock song ("Hard Rock Halleluja" from Lordi) win!

To explain the Eurovision Song Contest to Non-European readers, I'd like to quote Kaj Arnö: "that’s a yearly classic event going on since tens of years, which everybody watches but nobody admits watching.". That's usually true - but this years winning song literally ROCKS!

Today, Sweden won the Ice Hockey World Championships. It's the first time that the Olympic Champion wins the World Championships in the same year.

Happy celebrations!

A good example of what is not freedom

I love the spirit of freedom that comes with Open Source - that's one important thing that I like about MySQL. This is about an extreme example of the opposite.

I like the US band called Live (for those who don't know, that's really the name of the band - very disadvantageous if you try to google for that band) - they make great Rock music. I had the opportunity to see this band live in 1999 and I have several CDs from the band.

Recently they have issued a new CD called "Songs From Black Mountain" which comes in a normal CD edition and a DualDisc Edition, which is double sided - on one side a CD and on the other side a DVD with videos from the songs. I pre-listened the songs in iTunes, liked them and decided to buy the DualDisc from Amazon.

Fine - you probably might already guess what's the issue. The CD is copy protected and not only that - if I play the CD on my PC, there are several short interruptions in the songs and the sound quality is extremely bad. Also the DVD is copy protected, but at least it's possible to play the songs in good quality from the DVD. I didn't find any indication on Amazon's product page about the copy protection, which should actually enable me to return the disk.

Why does the copy protection bother me? Very simple - I used to make MP3 files out of my CDs to play them on my PC without the need to insert the disk, copy them to my iPod, create CDs for my car - all reasonable things that I think I should be allowed to do with a CD that I bought for good money.

I'm not really sure about what I will do with the disk. Should I return it? If I return it, should I buy the songs from iTunes, burn them on CD and rip the CD to get MP3 files out of it? That's another barrier, because files from iTunes are not compatible with many devices and applications. Should I return the disk and protest against all this stupidity by not buying the disk (although I like the music)? Should I keep the CD and try to crack the songs (and waste precious time that I could spend doing useful things like writing blog articles ;-))? Is it at all legal? Nobody's sure about that, because on one hand there's the right to create backup copies, on the other hand it's illegal to skip copy protection ... that's absolutely ambiguous. Will I end up in jail for just wanting to listen to a few songs? Can you really be sure that this is as ridiculous as it sounds?

It's extremely annoying that the music industry punishes honest customers - and makes people who would legally buy stuff (if it came without the limitations) get the songs from illegal sources. I don't mind to pay money for good music - that's just fair. I also think that there's nothing bad about sharing songs with friends (even though I don't think that's legal). But I think that most people would spend a reasonable amount of money for good music - and private sharing certainly helps to learn about new music and if those people who like the songs go out and buy the CD and visit concerts, it will be no harm to anybody (my personal opinion, obviously not the opinion of the music industry). How about those who share this material in a commercial and criminal way? They won't be stopped by copy protection anyway.

This all really looks to me like the maximum amount of possible stupidity!

Let's get one stop further ... can I be sued for using the word stupidity in the same context as "music industry" in a public article?

Will the click on the Submit button mean the end of my life in freedom?

Am I a criminal for having thoughts like that?

Is that Freedom?

How do you think about certain product name extensions?

As you probably know, the MySQL server comes in two variations - a Community version and MySQL Network. I thought about how names like "Community" and "Network" and other descriptive name extensions from other products feel to me.

I never felt that the Community version is a less complete product than MySQL Network. It feels - and that's basically what it is - that MySQL Network provides additional features - mainly support. But MySQL - Community Edition is nevertheless still a complete product.

How's that with other products? Lets take a few examples.

SuSE Linux also offered two variations up to version 9.3 - there was a Personal Edition and a Professional Edition. The Personal Edition was never an option for me. It always felt like an incomplete product and it really missed many applications that I need. So it feels like: Personal: incomplete, Professional: the "real" SuSE Linux.

Let's take Fedora/RedHat Enterprise Linux. Do you feel like Fedora is an incomplete product? I don't. The term "Enterprise" does not give me the sense that the Non-Enterprise equivalent (the Community product Fedora) is less complete and not something "real".

The most extreme example I can think of is Microsoft Windows. And it's getting worse with Windows Vista. There will be

* Windows Vista Starter
* Windows Vista Home Basic
* Windows Vista Home Premium
* Windows Vista Business
* Windows Vista Enterprise
* Windows Vista Ultimate

Needless to say that the price raises with each edition and the "higher level" editions will probably be unaffordable to most private people.

I hate distinctions like that! I don't bother about Business/Enterprise/Ultimate, although I don't think that it makes sense to separate Enterprise targeted editions into three pieces. But how about Starter/Home Basic/Home Premium? That feels to me like "X for idiots" (Starter), "X for poor people" (Home Basic) and "X for wealthy people" (Home Premium). It's like making judgements about the customer. I looks like a bad marketing strategy to me (regardless of Microsoft's business success).

People usually associate product edition names with something and I personally think that some of them create bad feelings about the product (or even imply an insult of the customer) and some are neutral or positively associated.

What are your feelings about such extensions?

How db4free.net helps to improve MySQL

Today I had a perfect example to show you how db4free.net helps to find bugs - which are of course reported and consequently fixed. And sometimes, like this one, the bugs even result from a (although in this case not serious) bug in db4free.

A few days ago, a db4free.net user contacted me and told me that he could not connect to his database. He only saw information_schema and on the MySQL 5.1 server, he could see the show_log database, in which I provide access to a view where every user can see his individual slow queries (thanks to the new table logging feature).

I looked up his user and found out that he has entered an empty string for the host information (that's the db4free.net bug, because this should be prevented). I fixed the host info manually in the mysql schema and changed it to a % sign, but I forgot to update the tables_priv table where access to the show_log database was granted.

So he contacted me again and reported that he couldn't connect to the show_log database anymore. I issued a GRANT USER for his_username@'%' command - and the server crashed. I soon found out that this was because the host information was inconsistant between the user, db and tables_priv tables.

Here's how to repeat this bug:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2 to server version: 5.0.21-max

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> CREATE USER testuser@'%';
Query OK, 0 rows affected (0.00 sec)

mysql> CREATE DATABASE test1;
Query OK, 1 row affected (0.02 sec)

mysql> CREATE DATABASE test2;
Query OK, 1 row affected (0.00 sec)

mysql> CREATE TABLE test2.tt (
    ->   id INT NOT NULL PRIMARY KEY);
Query OK, 0 rows affected (0.06 sec)

mysql> GRANT ALL ON test1.* TO testuser@'%';
Query OK, 0 rows affected (0.00 sec)

mysql> GRANT ALL ON test2.tt TO testuser@'%';
Query OK, 0 rows affected (0.00 sec)

mysql> UPDATE mysql.tables_priv
    ->   SET host=''
    ->   WHERE user='testuser';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)

mysql> SHOW GRANTS FOR testuser@'%';
ERROR 2013 (HY000): Lost connection to MySQL server during query

You can also look up for this in the bug report.

This story is very typical for two reasons. One is that db4free.net hosts a huge variety of different users. They do things in different ways and sometimes (and this should not be considered bad) in unexpected ways. And you find most of the bugs, if you do unexpected things.

The second reason is that the bug itself was typical. Most of the bugs that I found so far can be split into two categories. The first category are of course bugs in new features (mainly in development releases) - that's just natural. Then I found quite a few bugs that result from complex privilege settings, including database or even table specific privileges (and probably even more if you define privileges on the column level, which I - to be honest - never did except for educational purposes when I learnt for my MySQL exams).

There would even be a third reason, why this bug is typical - but you can easily avoid this. I manually modified the mysql schema tables and flushed the privileges. If you do this and make a mistake so that you create inconsistant values (like I did), it's not unlikely that you stumble across a bug. However, if you can avoid to edit the mysql schema tables manually (and in almost all cases you can avoid it using the GRANT and REVOKE commands as well as CREATE USER and DROP USER), I'd highly recommand you to avoid it. It's a bad habit from me that I often do it anyway ;-).

I haven't counted the number of bugs that I found through db4free.net, but it were quite a few. Most of them of course in the development releases - in MySQL 5.1 and in MySQL 5.0 before it became GA and most of the bugs that I reported recently refer to the Event Scheduler - but that's probably because it's one of my favourite new MySQL 5.1 features that I played with more than with the other nice new things.

Podcast with Brian Aker, Dana Gardner & Michael Baum

Here's an interesting Podcast about Troubleshooting with Brian Aker, Dana Gardner and Michael Baum:

http://www.splunk.com/index.php/articles/news/311?ac=MySQL06

Check it out ;-)!

Joined the MySQL web development team

Yesterday I have officially joined the MySQL web development team. During the Users Conference three weeks ago I have talked with Eric Braswell about joining the team and just after the Conference finished, he promised me the job offer. This was the perfect ending of a Users Conference that has also started incredibly perfect when I was awarded with the MySQL Community Award "Writer of the Year 2006". The last month was just absolutely fantastic!

It's such a great feeling to work for a company that I can fully identify with. I love the MySQL database server and I want MySQL to be the best database server of the world. I love the spirit of freedom that comes with Open Source and to work with people from all over the world who have the same goal in mind: providing the best, but still free database server of the world. I love to use English (which is not my native language) as working language and I love to learn new things. Even though I live in quite a remote area with no big city in a radius of more than 100 km, I can be part of a "huge world wide thing". Many other people of my age in this area have moved to Vienna or other urban areas to find good jobs. I got a great job that I can do at home - what more can I want? I will get the opportunity to travel and see new parts of the world. And I can arrange my working hours to work very much at night, which is the most convenient working time for me (which gives me the chance to do other things while most people work). There are many great things about working for MySQL!

However, the job will definitely not be easy and will include many big challenges. It's a high responsibility to provide a good service and there will be many technical issues that will be new for me. But of course it's also a perfect opportunity to learn a lot - and I'll do my best to get a good job done!

MySQL 5.1.10 is on the way

I found out that the MySQL 5.1 development source version has changed to 5.1.11, so MySQL 5.1.10 will probably be released very soon.

This is especially interesting for two reasons. First, MySQL 5.1.9 had a major bug in the Event scheduler, which will be fixed in 5.1.10:

"Executing a CREATE EVENT statement could cause 100% CPU usage. (Bug#19170)"

Second, MySQL 5.1.10 looks like the first full featured MySQL 5.1 version for Windows. It will include the CSV storage engine which will make it possible to write the general_log and slow_log into database tables:

"Logging to the mysql.general_log and mysql.slow_log tables did not work for Windows builds because the CSV storage engine was unavailable. The CSV engine now is enabled in Windows builds. (Bug#17368))"

Also the mysql_upgrade command will be available for Non-Unix-OS, too:

"The mysql_upgrade command has been converted from a shell script to a C program, so it is available on non-Unix systems such as Windows. This program should be run for each MySQL upgrade."

To see all the changes, take a look into the Change history. 5.1.10 really looks like a very interesting release.

How reliable are checksums?

Or should I ask, how reliable are copy commands?

Okay, this doesn't relate to MySQL directly, but one should know that also MySQL provides md5 checksums for all downloads where you can easily verify if your downloaded file is really identical to the file on MySQL's server. Just type in "md5sum [filename]" and compare the displayed code to the code shown on the website - if they are identical, the file is also identical to its very last bit.

Last night I have downloaded the new SuSE Linux 10.1. I compared the md5 sums and they were absolutely identical to the codes provided at the download source:

sputnik:~/SuSE # md5sum SUSE-Linux-10.1-GM-x86_64-CD*
60cf3e9b090326c39334a72c66145ad2 SUSE-Linux-10.1-GM-x86_64-CD1.iso
15ea8db1b388fadce8e8ca853bb05901 SUSE-Linux-10.1-GM-x86_64-CD2.iso
0bdc464910785936a322f2519ca49da3 SUSE-Linux-10.1-GM-x86_64-CD3.iso
20884a4c45d406ae0c38fb0bc3ee7de8 SUSE-Linux-10.1-GM-x86_64-CD4.iso
5538cba168f0b32b9562f73a40977405 SUSE-Linux-10.1-GM-x86_64-CD5.iso

(compare with http://download.opensuse.org/distribution/SL-10.1/iso/MD5SUMS)

Then I used the scp command to transfer the iso files to another PC (from which I want to burn the CDs). After copying, I checked the md5 sums again and got following output:

mpopp@suse:~/SuSE_10_1> md5sum *
449c04a969166e49aa20efbe7be0a6a2 SUSE-Linux-10.1-GM-x86_64-CD1.iso
15ea8db1b388fadce8e8ca853bb05901 SUSE-Linux-10.1-GM-x86_64-CD2.iso
a828021a47c6af08c699469234ba4587 SUSE-Linux-10.1-GM-x86_64-CD3.iso
20884a4c45d406ae0c38fb0bc3ee7de8 SUSE-Linux-10.1-GM-x86_64-CD4.iso
59e3ebb1c397b923216dcca55acf7127 SUSE-Linux-10.1-GM-x86_64-CD5.iso

So, the checksums for CDs 2 and 4 are still identical, but all the others have changed. It took me two more attempts to get identical codes for CDs 3 and 5 and I'm still trying to get a correct checksum for CD 1 (after copying the file for at least 4 times, I got different checksums after each attempt). So this looks very strange to me.

However, I also have a downloaded Fedora Core 5 DVD where the md5 checksum did not match the code that was provided on the download source (which was of course the official Fedora download page). But the DVD works without problems and I have found no errors at all.

db4free.net's MySQL 5.0 server is not able to execute SELECT * FROM INFORMATION_SCHEMA.TABLES anymore

I wrote about a similar issue recently when I tried to update db4free.net's phpMyAdmin to 2.8.0.3 and couldn't do so because the latest phpMyAdmin versions refer to information_schema instead of SHOW commands. Now there's another problem that shows that queries on information_schema perform much too slow on large servers - I can't execute a simple SELECT * FROM INFORMATION_SCHEMA.TABLES query on db4free.net's MySQL 5.0 server anymore. After running for quite a long time, it fails in a "ERROR 2013 (HY000): Lost connection to MySQL server during query".

I guess that many MySQL DBAs must have similar problems. Now I've filed an official bug report with Severity S1.

Patch of bug 17204 still pending

There has been that nasty issue when the MySQL server (both 5.0 and 5.1) crashed when certain Stored Procedures were executed several times. Giuseppe Maxia, Beat Vontobel, Roland Bouman and I experimented with a Stored Procedure that should retrieve foreign key dependencies out of information_schema - that's when we found this issue and reported it as bug 17204 - that was in February.

Now there's a patch pending for this bug since March, 29th, but it still hasn't found its way into the source and the bug still exists in MySQL versions 5.0.21 and 5.1.9.

I'm afraid that this issue has somehow been forgotten (I also asked in the bug report recently and got no answer) - does anybody know more about it?

Unable to build MySQL 5.1 dev version from source

For a few weeks now I haven't been able to compile the most current MySQL 5.1 dev versions from the source anymore. My system is an AMD64 with SuSE 10.0 - and I tried it in two ways.

The first way is to get the current source code from BitKeeper. BitKeeper is installed on my system, so I get the current version with the "sfioball -r+ bk://mysql.bkbits.net/mysql-5.1-new mysql-5.1" command (which works fine). I change into the directory mysql-5.1 and enter "BUILD/compile-amd64-max" - that's the way I used to do it and before the problems started to occur, it always worked fine.

But now, after quite a while I end up with the following errors:

ccache gcc -DDBUG_OFF -Wimplicit -Wreturn-type -Wswitch -Wtrigraphs -Wcomment -W -Wchar-subscripts -Wformat -Wparentheses -Wsign-compare -Wwrite-strings -Wctor-dtor-privacy -Wnon-virtual-dtor -felide-constructors -fno-exceptions -fno-rtti -mtune=athlon64 -O3 -fno-omit-frame-pointer -g -fno-implicit-templates -fno-exceptions -fno-rtti -rdynamic -o ndb_mgmd MgmtSrvr.o MgmtSrvrGeneralSignalHandling.o main.o Services.o convertStrToInt.o SignalQueue.o MgmtSrvrConfig.o ConfigInfo.o InitConfigFileParser.o Config.o ../../../../storage/ndb/src/mgmclient/CommandInterpreter.o ../../../../storage/ndb/src/.libs/libndbclient.a -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread -lpthread ../../../../dbug/libdbug.a ../../../../mysys/libmysys.a ../../../../strings/libmystrings.a ../../../../cmd-line-utils/readline/libreadline.a -lncurses -lpthread -lcrypt -lnsl -lm -lpthread
../../../../storage/ndb/src/.libs/libndbclient.a(NdbDictionaryImpl.o):(.debug_loc+0x921): undefined reference to `.LVL119'
../../../../storage/ndb/src/.libs/libndbclient.a(NdbDictionaryImpl.o):(.debug_loc+0x92c): undefined reference to `.LVL119'
collect2: ld returned 1 exit status
gmake[5]: *** [ndb_mgmd] Error 1
gmake[5]: Leaving directory `/MySQL_51/mysql-5.1/storage/ndb/src/mgmsrv'
gmake[4]: *** [all-recursive] Error 1
gmake[4]: Leaving directory `/MySQL_51/mysql-5.1/storage/ndb/src'
gmake[3]: *** [all-recursive] Error 1
gmake[3]: Leaving directory `/MySQL_51/mysql-5.1/storage/ndb'
gmake[2]: *** [all-recursive] Error 1
gmake[2]: Leaving directory `/MySQL_51/mysql-5.1/storage'
gmake[1]: *** [all-recursive] Error 1
gmake[1]: Leaving directory `/MySQL_51/mysql-5.1'
gmake: *** [all] Error 2
suse:/MySQL_51/mysql-5.1 #

The second way is to download the nightly snapshot (the tar.gz file) and extract it to a new directory - and then again execute "BUILD/compile-amd64-max". This time, it doesn't take long until compilation fails:

suse:/MySQL_51/mysql-5.1.10-beta-nightly-20060505 # BUILD/compile-amd64-max
testing athlon64 ... ok
+++ gmake -k distclean
gmake: *** No rule to make target `distclean'.
+++ true
+++ /bin/rm -rf '*/.deps/*.P' config.cache storage/innobase/config.cache storage/bdb/build_unix/config.cache bdb/dist/autom4te.cache autom4te.cache innobase/autom4te.cache
+++ path=BUILD
+++ . BUILD/autorun.sh
++++ aclocal
/usr/share/aclocal/progsreiserfs.m4:13: warning: underquoted definition of AC_CHECK_LIBREISERFS
run info '(automake)Extending aclocal'
or see http://sources.redhat.com/automake/automake.html#Extending-aclocal
/usr/share/aclocal/pilot-link.m4:1: warning: underquoted definition of AC_PILOT_LINK_HOOK
/usr/share/aclocal/lib3ds.m4:4: warning: underquoted definition of AM_PATH_LIB3DS
++++ autoheader
++++ test -f /usr/bin/glibtoolize
++++ libtoolize --automake --force
++++ automake --add-missing --force
configure.in:813: required file `zlib/Makefile.in' not found
++++ die 'Can'\''t execute automake'
++++ echo 'Can'\''t execute automake'
Can't execute automake
++++ exit 1
suse:/MySQL_51/mysql-5.1.10-beta-nightly-20060505 #

My simple question is - does anyone have a clue what's wrong here?

New information_schema view

I often take a look into the Changelogs to see if I can find something interesting new - and often I do. Today I found this entry in the changelog for MySQL 5.1.10:

"Added the REFERENTIAL_CONSTRAINTS table to INFORMATION_SCHEMA. It provides information about foreign keys."

It seems (or lets say, I hope) that information_schema will now also provide information like "ON UPDATE CASCADE" or "ON DELETE CASCADE". I think (and I heard of other people who also think this way) that every CREATE statement (be it a table, a view, a stored procedure, an event or whatever) should be re-creatable from the content that's provided by information_schema. So this would be one step further to achieve this goal.

Unfortunately, the queries against information_schema are often very slow (mainly, if there's a lot of data in the databases), but this issue has also been discussed during the MySQL Users Conference and as far as I know, the developers are currently working to provide better performance. I wish them luck and success!

mysql_upgrade to run on all systems from 5.0.22 & 5.1.10

Just found an interesting note in the Changelog. The mysql_upgrade command has been converted from a shell script to an executable binary and therefore be available not only on Unix systems, but also on other operating systems like Windows. This will be starting from MySQL 5.0.22 and 5.1.10.

Event scheduler out of control?

I tried to test (once more) the event scheduler of MySQL 5.1.9 on Windows and experienced a very strange behaviour:

CREATE TABLE  `tt` (
   `id` int(10) unsigned NOT NULL auto_increment,
   `d` int(10) unsigned NOT NULL,
   `ts` timestamp NOT NULL,
   PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

DELIMITER //

DROP EVENT insertIntoTT //

CREATE EVENT insertIntoTT
ON SCHEDULE EVERY 5 SECOND
STARTS current_timestamp + INTERVAL 5 SECOND
DO
BEGIN
  insert into tt (d) values (floor(rand() * 100));
END //

DELIMITER ;

After a while, I found this content in table tt:

mysql> select * from tt;
+-----+----+---------------------+
| id  | d  | ts                  |
+-----+----+---------------------+
| 1   | 83 | 2006-05-02 07:40:20 |
| 2   | 35 | 2006-05-02 07:40:25 |
| 3   | 66 | 2006-05-02 07:40:25 |
| 4   | 68 | 2006-05-02 07:40:25 |
| 5   | 82 | 2006-05-02 07:40:25 |
| 6   | 50 | 2006-05-02 07:40:25 |
| 7   | 44 | 2006-05-02 07:40:30 |
| 8   | 14 | 2006-05-02 07:40:30 |
| 9   | 79 | 2006-05-02 07:40:30 |
| 10  | 94 | 2006-05-02 07:40:30 |
| 11  | 75 | 2006-05-02 07:40:30 |
| 12  | 35 | 2006-05-02 07:40:30 |
| 13  | 90 | 2006-05-02 07:40:30 |
| 14  | 88 | 2006-05-02 07:40:30 |
| 15  | 13 | 2006-05-02 07:40:30 |
| 16  | 44 | 2006-05-02 07:40:30 |
| 17  | 21 | 2006-05-02 07:40:30 |
| 18  | 16 | 2006-05-02 07:40:30 |
| 19  | 56 | 2006-05-02 07:40:30 |
| 20  | 76 | 2006-05-02 07:40:30 |
| 21  | 54 | 2006-05-02 07:40:30 |
| 22  | 81 | 2006-05-02 07:40:30 |
| 23  | 88 | 2006-05-02 07:40:30 |
| 24  | 38 | 2006-05-02 07:40:30 |
| 25  | 66 | 2006-05-02 07:40:30 |
| 26  | 59 | 2006-05-02 07:40:30 |
| 27  | 39 | 2006-05-02 07:40:30 |
| 28  | 60 | 2006-05-02 07:40:30 |
| 29  | 25 | 2006-05-02 07:40:30 |
| 30  | 89 | 2006-05-02 07:40:30 |
| 31  | 9  | 2006-05-02 07:40:30 |
| 32  | 19 | 2006-05-02 07:40:30 |
| 33  | 10 | 2006-05-02 07:40:30 |
| 34  | 36 | 2006-05-02 07:40:30 |
| 35  | 90 | 2006-05-02 07:40:30 |
| 36  | 84 | 2006-05-02 07:40:30 |
| 37  | 93 | 2006-05-02 07:40:30 |
| 38  | 55 | 2006-05-02 07:40:30 |
| 39  | 36 | 2006-05-02 07:40:30 |
| 40  | 58 | 2006-05-02 07:40:31 |
| 41  | 23 | 2006-05-02 07:40:35 |
| 42  | 81 | 2006-05-02 07:40:35 |
| 43  | 80 | 2006-05-02 07:40:35 |
| 44  | 97 | 2006-05-02 07:40:35 |
| 45  | 88 | 2006-05-02 07:40:35 |
| 46  | 90 | 2006-05-02 07:40:35 |
| 47  | 26 | 2006-05-02 07:40:35 |
| 48  | 5  | 2006-05-02 07:40:35 |
| 49  | 88 | 2006-05-02 07:40:35 |
| 50  | 66 | 2006-05-02 07:40:35 |
| 51  | 8  | 2006-05-02 07:40:35 |
| 52  | 83 | 2006-05-02 07:40:35 |
| 53  | 33 | 2006-05-02 07:40:35 |
| 54  | 59 | 2006-05-02 07:40:35 |
| 55  | 38 | 2006-05-02 07:40:35 |
| 56  | 54 | 2006-05-02 07:40:35 |
| 57  | 99 | 2006-05-02 07:40:35 |
| 58  | 76 | 2006-05-02 07:40:35 |
| 59  | 22 | 2006-05-02 07:40:35 |
| 60  | 27 | 2006-05-02 07:40:35 |
| 61  | 8  | 2006-05-02 07:40:35 |
| 62  | 1  | 2006-05-02 07:40:35 |
| 63  | 25 | 2006-05-02 07:40:35 |
| 64  | 62 | 2006-05-02 07:40:35 |
| 65  | 78 | 2006-05-02 07:40:35 |
| 66  | 45 | 2006-05-02 07:40:35 |
| 67  | 35 | 2006-05-02 07:40:35 |
| 68  | 80 | 2006-05-02 07:40:35 |
| 69  | 36 | 2006-05-02 07:40:35 |
| 70  | 80 | 2006-05-02 07:40:35 |
| 71  | 38 | 2006-05-02 07:40:35 |
| 72  | 89 | 2006-05-02 07:40:35 |
| 73  | 73 | 2006-05-02 07:40:35 |
| 74  | 39 | 2006-05-02 07:40:35 |
| 75  | 19 | 2006-05-02 07:40:35 |
| 76  | 19 | 2006-05-02 07:40:36 |
| 77  | 81 | 2006-05-02 07:40:36 |
| 78  | 88 | 2006-05-02 07:40:40 |
| 79  | 42 | 2006-05-02 07:40:40 |
| 80  | 84 | 2006-05-02 07:40:40 |
| 81  | 38 | 2006-05-02 07:40:40 |
| 82  | 81 | 2006-05-02 07:40:40 |
| 83  | 30 | 2006-05-02 07:40:40 |
| 84  | 50 | 2006-05-02 07:40:40 |
| 85  | 2  | 2006-05-02 07:40:40 |
| 86  | 1  | 2006-05-02 07:40:40 |
| 87  | 42 | 2006-05-02 07:40:40 |
| 88  | 48 | 2006-05-02 07:40:40 |
| 89  | 57 | 2006-05-02 07:40:40 |
| 90  | 81 | 2006-05-02 07:40:40 |
| 91  | 78 | 2006-05-02 07:40:40 |
| 92  | 87 | 2006-05-02 07:40:40 |
| 93  | 42 | 2006-05-02 07:40:40 |
| 94  | 91 | 2006-05-02 07:40:40 |
| 95  | 70 | 2006-05-02 07:40:40 |
| 96  | 22 | 2006-05-02 07:40:40 |
| 97  | 38 | 2006-05-02 07:40:40 |
| 98  | 69 | 2006-05-02 07:40:40 |
| 99  | 70 | 2006-05-02 07:40:40 |
| 100 | 88 | 2006-05-02 07:40:40 |
| 101 | 71 | 2006-05-02 07:40:40 |
| 102 | 31 | 2006-05-02 07:40:40 |
| 103 | 85 | 2006-05-02 07:40:40 |
| 104 | 76 | 2006-05-02 07:40:40 |
| 105 | 63 | 2006-05-02 07:40:40 |
| 106 | 30 | 2006-05-02 07:40:40 |
| 107 | 3  | 2006-05-02 07:40:40 |
| 108 | 68 | 2006-05-02 07:40:40 |
| 109 | 72 | 2006-05-02 07:40:40 |
| 110 | 97 | 2006-05-02 07:40:40 |
| 111 | 13 | 2006-05-02 07:40:40 |
| 112 | 15 | 2006-05-02 07:40:40 |
| 113 | 78 | 2006-05-02 07:40:40 |
| 114 | 86 | 2006-05-02 07:40:40 |
| 115 | 36 | 2006-05-02 07:40:41 |
| 116 | 66 | 2006-05-02 07:40:45 |
| 117 | 61 | 2006-05-02 07:40:45 |
| 118 | 51 | 2006-05-02 07:40:45 |
| 119 | 15 | 2006-05-02 07:40:45 |
| 120 | 61 | 2006-05-02 07:40:45 |
| 121 | 2  | 2006-05-02 07:40:45 |
| 122 | 68 | 2006-05-02 07:40:45 |
| 123 | 78 | 2006-05-02 07:40:45 |
| 124 | 25 | 2006-05-02 07:40:45 |
| 125 | 35 | 2006-05-02 07:40:45 |
| 126 | 42 | 2006-05-02 07:40:45 |
| 127 | 47 | 2006-05-02 07:40:45 |
| 128 | 51 | 2006-05-02 07:40:45 |
| 129 | 56 | 2006-05-02 07:40:45 |
| 130 | 70 | 2006-05-02 07:40:45 |
| 131 | 21 | 2006-05-02 07:40:45 |
| 132 | 39 | 2006-05-02 07:40:45 |
| 133 | 75 | 2006-05-02 07:40:45 |
| 134 | 99 | 2006-05-02 07:40:45 |
| 135 | 12 | 2006-05-02 07:40:45 |
| 136 | 5  | 2006-05-02 07:40:45 |
| 137 | 31 | 2006-05-02 07:40:45 |
| 138 | 82 | 2006-05-02 07:40:45 |
| 139 | 58 | 2006-05-02 07:40:45 |
| 140 | 85 | 2006-05-02 07:40:45 |
| 141 | 93 | 2006-05-02 07:40:45 |
| 142 | 53 | 2006-05-02 07:40:45 |
| 143 | 25 | 2006-05-02 07:40:45 |
| 144 | 11 | 2006-05-02 07:40:45 |
| 145 | 19 | 2006-05-02 07:40:45 |
| 146 | 6  | 2006-05-02 07:40:45 |
| 147 | 14 | 2006-05-02 07:40:45 |
| 148 | 93 | 2006-05-02 07:40:45 |
| 149 | 64 | 2006-05-02 07:40:45 |
| 150 | 83 | 2006-05-02 07:40:45 |
| 151 | 65 | 2006-05-02 07:40:45 |
| 152 | 17 | 2006-05-02 07:40:45 |
| 153 | 35 | 2006-05-02 07:40:46 |
| 154 | 63 | 2006-05-02 07:40:50 |
| 155 | 51 | 2006-05-02 07:40:50 |
+-----+----+---------------------+
155 rows in set (0.00 sec)

Instead of inserting one row every 5 seconds, MySQL inserted 155 rows in 30 seconds. Can anybody else experience something like this?

More from the MySQL UC

So here are a few photos from me that I've taken at the Conference and around. So let's start with my hotel.

      

It was quite a cheap hotel and to be honest - not the very cleanest one. But I didn't spend much time there anyway, so why bother. But what's that against the litter that I could find on the streets and sidewalks (to not be misunderstood I'd like to add that none of the litter is from me ;-)).

      

Since I'm quite a heavy smoker, I was quite concerned about the smoking opportunities in California. But it was by far not that tough. Only during the flight I had to help myself with an inhalor, but finding places to smoke was not really hard in CA.

So here's my car that I rented for my 6 day stay in CA - it was an even bigger one than the one I've ordered (which wasn't available at the time when I picked it up, so I got a car one class higher). It had masses of buttons that I even didn't find out what they are good for, but most of them are not needed for driving anyway - so I even got quite used to it and felt quite comfortable (although
I usually don't drive cars with automatic transmission - another thing to get used
to).

      

   

It's a bit off-topic, but here's my own car - so you can compare a little bit ;-).

         



One of the bad things is that I hardly have any photos from the Conference and many are quite hazy. But there are many photos from other attendees of the Conference around - check out here:

http://sheeri.com/archives/48
http://www.flickr.com/photos/x180/tags/mysqluc06/
http://www.flickr.com/photos/x180/sets/72057594112748158
http://www.flickr.com/photos/byte/sets/72057594120596064/
http://jcole.us/gallery/uc2006

If you know more links, please let me know!

But here are two from me - one showing Sheeri during her MySQL Meetup BOF session and the second one shows Giuseppe Maxia receiving his Community Award - seconds before Roland Bouman and me had to face a huge surprise.

   

I like road and highway photos because they show a lot of the country and what people really see when they visit a specific place. Most photos were taken out of my car.

         

         

         

         

      

And last but (by far) not least there was the San Francisco sightseeing tour on April, 23rd together with Roland Bouman and Mike Kruckenberg.