A trap for those new to the MySQL Performance Schema is the expectation that thread_id in tables such as events_statements_current matches the id you find in the MySQL processlist. This is NOT TRUE.

If we look at the INFORMATION_SCHEMA.PROCESSLIST table we will find information like:

mysql> select id,db,command,state from information_schema.processlist order by id;
-----------+--------------------+---------+------------------------------------------------------------------+
| id        | db                 | command | state                                                            |
+-----------+--------------------+---------+------------------------------------------------------------------+
|         1 | NULL               | Connect | Slave has read all relay log; waiting for the slave I/O thread t |
|         2 | NULL               | …

because i have many more important things to be doing, i procrastinated by whipping up a little web-based command-line client for mysql. what does that mean? you load the webpage, start typing in sql commands, and it presents the results to you. it is just a weekend hack at this point, and has a lot of rough edges. it does have some cool features, though, like a persistent command-line history using Web Storage.

probably the biggest limitation is because it not maintaining a persistent connection on the backend, you can’t use variables, temporary tables or transactions.

it was really born because i was getting frustrated running queries using the command-line client and having the ASCII table look all wonky because it was too big for my terminal screen. html makes that …

A while ago, I wrote how to make MySQL perform durably in production. Today I want to do the opposite: configure MySQL (with the InnoDB storage engine) for when you really don’t care about your data.

Continuous integration/automated testing is a good example of when you want to do this, since you usually test for functionality and not performance characteristics. It also helps in situations when the data is very easy to rebuild.

Obligatory Disclaimer: These settings are not safe for production environments!

Configuration Settings

• Keep the binary log disabled (i.e. comment out any log-bin lines in configuration). For testing, you don’t need to be able to point-in-time restore, or seed replicas with changes. …

It took a little more than 10 years, but as of version 5.6 MySQL is finally using error code 1215! Since MySQL first introduced foreign key support more than 10 years ago in version 3.23.44, all the way through version 5.5, the server has always given a generic 1005 error when you try to add an invalid foreign key.

Here's an example in MySQL 5.5, where the parent key is unsigned and the child key is signed:

``` mysql> create table parent (

->   id int unsigned primary key
-> ) engine = innodb;

Query OK, 0 rows affected (0.01 sec) mysql> create table child (

->   id int primary key,
->   parent_id int,
->   foreign key …

Percona is glad to announce the release of Percona XtraDB Cluster 5.5.34-23.7.6 on November 4, 2013. Binaries are available from the downloads area or from our software repositories.

Bugs Fixed:

• Fixed the issues with upgrade on Debian caused by debian-start script. Bug fixed #1112363.
• Adding the AUTO_INCREMENT column to a table would result in data inconsistency because different nodes use different auto_increment_offset. Bug fixed …

If you are responsible for a MySQL Database, you make choices based on your priorities; cost, security and performance.

To learn more about improving performance, take the MySQL Performance Tuning course. 

In this 4-day instructor-led course you will learn practical, safe and highly efficient ways to optimize performance for the MySQL Server. It will help you develop the skills needed to use tools for monitoring, evaluating and tuning MySQL.

You can take this course via the following delivery methods:Training-on-Demand:

• Take this course at your own pace, starting training within 24 hours of registration.
• Live-Virtual Event: Follow a live-event from your own desk; no travel required. You can choose from a …

because i have many more important things to be doing, i procrastinated by whipping up a little web-based command-line client for mysql. what does that mean? you load the webpage, start typing in sql commands, and it presents the results to you. it is just a weekend hack at this point, and has a lot of rough edges. it does have some cool features, though, like a persistent command-line history using Web Storage.

probably the biggest limitation is because it not maintaining a persistent connection on the backend, you can’t use variables, temporary tables or transactions.

it was really born because i was getting frustrated running queries using the command-line client and having the ASCII table look all wonky because it was too big for my terminal screen. …

[…] Announcing new Yum repositories for MySQL. This is a big deal, for anyone running MySQL or a related product. It was MariaDB‘s yum repositories which made it easy for me to migrate to v5.5 from 5.1 in CentOS. […]

There’s a lot to love about the MySQL product documentation – a lot of hard work from a number of very talented Oracle staff goes into it (not to mention the helpful suggestions and feedback from the community).  There is, however, one page I find myself coming back to again and again, despite the fact that it’s somewhat hard to find.  This is the MySQL Server options/variable reference page.  It’s a helpful table that lists every MySQL Server option or variable, what version it was introduced or deprecated in, whether it’s dynamic or not, whether variables have session/global/both scope, and links to the version-specific documentation for that variable (useful to know when default values changed, for example).

It always takes me a while to find this page again when I’m looking for it, as it’s …

We are pleased to announce that MySQL Enterprise Monitor 3.0.3 is now available for download on the My Oracle Support (MOS) web site. It will also be available via the Oracle Software Delivery Cloud with the November update in about 1 week. This is a maintenance release that fixes a number of bugs. You can find more information on the contents of this release in the change log.

You will find binaries for the new release on My Oracle Support. Choose the "Patches & Updates" tab, and then use the "Product or Family (Advanced Search)" feature.

You will also find the binaries on the Oracle Software Delivery Cloud in approximately 1 week. Choose "MySQL Database" as the Product Pack and you will find the Enterprise Monitor along …