Recently on a client site I had to fight the pain of having no way to confirm loss of data integrity when optimizing data types. Due to MySQL’s ability to perform silent conversion of data, when converting a number of columns we enabled sql_mode to catch any truncations as errors.

sql_mode=STRICT_ALL_TABLES

This ensured that should any data truncations occur, an error is thrown not a warning. The following shows an example case study for converting an INT to TINYINT UNSIGNED and shows that without sql_mode silent conversions occur.

mysql> drop schema if exists tmp;
Query OK, 25 rows affected (0.40 sec)

mysql> create schema tmp;
Query OK, 1 row affected (0.01 sec)

mysql> use tmp
Database changed
mysql> create table t1(i1 INT NULL);
Query OK, 0 rows affected (0.15 sec)

mysql> insert into t1 values(1),(2),(3),(256),(65536),(NULL);
Query OK, 6 rows affected (0.06 sec)
Records: 6  Duplicates: 0  Warnings: 0 …

Tomorrow (Wednesday, May 20, 2009), Ulf Wendel and Andrey Hristov, engineers working in the Connector team of Sun|MySQL database group, will be presenting a webinar about the new MySQL Connector/C++. This connector, which uses much the JDBC API patterns, was recently made available as a GA release during the MySQL Conference and Expo.

Register from anywhere in the world and listen to Ulf and Andrey as they talk to you about Connector/C++ from somewhere in Germany!

Addendum: At this very moment, I'm attending this free Webinar. It is truly amazing how well-coordinated this is. So, if you couldn't get to this, try to make it to some other upcoming MySQL Webinar.

Tomorrow (Wednesday, May 20, 2009), Ulf Wendel and Andrey Hristov, engineers working in the Connector team of Sun|MySQL database group, will be presenting a webinar about the new MySQL Connector/C++. This connector, which uses much the JDBC API patterns, was recently made available as a GA release during the MySQL Conference and Expo.

Register from anywhere in the world and listen to Ulf and Andrey as they talk to you about Connector/C++ from somewhere in Germany!

Addendum: At this very moment, I'm attending this free Webinar. It is truly amazing how well-coordinated this is. So, if you couldn't get to this, try to make it to some other upcoming MySQL Webinar.

As the recipient of the 2009 MySQL Community Member of the Year award I received a MySQL crystal ball. While it looks good in my bookcase, unfortunately the best advice I can offer during this time of uncertainty is “watch this space”.

A number of topics where information is still very much unknown and I’m either asked about, or am following includes:

• The Oracle acquisition of Sun, owner of MySQL.
• MySQL 5.4 Alpha release and schedule for production release
• The end of MySQL 5.0 Community/Enterprise split
• The future of Falcon in MySQL 6.0?

Thanks to Julian Cash of the Human Creativity Project of his photograph at the 2009 MySQL Conference.

…

The announcement last month of Oracle to acquire Sun continues to warrant a lot of discussion over exactly what Oracle will do with MySQL. Only time will tell what will happen with the official product, however it is important to remember that MySQL is GPL, there will always be a free version of MySQL available for popular LAMP stack products such as WordPress and Drupal and new and existing startup’s will continue to use MySQL.

This announcement will see Oracle resources begin to better understand and evaluate MySQL. As a resident MySQL Expert, I also have a strong background in Oracle having also worked for Oracle Corporation. I have also delivered several successful one day and half day workshops on MySQL/Oracle related content including:

• 2009 - Best Practices …

Sorry for the (relatively) short notice, but I will be talking at Sun’s CommunityOne conference in San Francisco on June 1st.

I’ll be talking about, and demonstrating, the DTrace probes we have put into MySQL in a joint presentation with Robert Lor who will be doing the same for Postgres.

CommunityOne West Badge

Our presentation is on the Monday afternoon.

Check out the CommunityOne West Conference Site for more details and registration.

Introduction

A question I recently saw on Stack Overflow titled Faster way to delete matching [database] rows? prompted me to organize my thoughts and observations on the subject and quickly jot them down here.

Here is the brief description of the task: say, you have 2 MySQL tables a and b. The tables contain the same type of data, for example log entries. Now you want to delete all or a subset of the entries in table a that exist in table b.

Solutions Suggested By Others

DELETE FROM a WHERE EXISTS (SELECT b.id FROM b WHERE b.id = a.id);

DELETE a FROM a INNER JOIN b on a.id=b.id;

DELETE FROM a WHERE id IN (SELECT id FROM b)

The Problem With Suggested Solutions

Solutions above are all fine if the tables are quite small and the …

On my last count, there are now 20+ Sun Contributor Agreement (SCA) signatories whose names appear on the master list and who are interested in contributing to MySQL. Only this week, three new members signed the SCA.

These 22+ signatories have all been added since mid-February when we launched the new, Sun-compliant SCA signing process. Before the end of 2009, if we proceed at this same rate, MySQL SCA signatories list should grow to about 70 to 90 contributors.

In the meantime, contributions from many of these contributors have already been accepted and integrated. (I had earlier pointed to Armin Schöffmann's contribution as a simple example of how all this works.)

Some people continue to …

On my last count, there are now 20+ Sun Contributor Agreement (SCA) signatories whose names appear on the master list and who are interested in contributing to MySQL. Only this week, three new members signed the SCA.

These 22+ signatories have all been added since mid-February when we launched the new, Sun-compliant SCA signing process. Before the end of 2009, if we proceed at this same rate, MySQL SCA signatories list should grow to about 70 to 90 contributors.

In the meantime, contributions from many of these contributors have already been accepted and integrated. (I had earlier pointed to Armin Schöffmann's contribution as a simple example of how all this works.)

Some people continue to …

On my last count, there are now 20+ Sun Contributor Agreement (SCA) signatories whose names appear on the master list and who are interested in contributing to MySQL. Only this week, three new members signed the SCA.

These 22+ signatories have all been added since mid-February when we launched the new, Sun-compliant SCA signing process. Before the end of 2009, if we proceed at this same rate, MySQL SCA signatories list should grow to about 70 to 90 contributors.

In the meantime, contributions from many of these contributors have already been accepted and integrated. (I had earlier pointed to Armin Schöffmann's contribution as a simple example of how all this works.)

Some people continue to …