As part of uncovering a new security improvement in MySQL 5.6 with the default installation being secured with a unique root MySQL password, the MySQL provided rpm’s installed the MySQL configuration file in /usr.

I feel this maybe a bug, however this is just as an explanation for others to comment on.
The following steps reproduces this.

1. Launch a CentOS 6.4 AWS EC2 Instance

LOG=/tmp/create-instance.tmp.$$
INSTANCE_TYPE=m1.medium
ec2-run-instances ami-eb6b0182 --instance-type ${INSTANCE_TYPE} --region us-east-1 --availability-zone us-east-1b --key db --group db | tee ${LOG}
INSTANCE=`grep ^INSTANCE ${LOG} | awk '{print $2}'`
ec2-describe-instances ${INSTANCE} | tee ${LOG}
while [ `grep ^INSTANCE ${LOG} | awk '{print $6}'` != 'running' ] ;  do cat ${LOG}; sleep 5; ec2-describe-instances ${INSTANCE} | tee ${LOG}; done …

What if the data you retrieved from the database did not match the data the application claimed to had successfully stored? How comfortable would your organization feel about your skills and the products that are being used to store important information if data integrity was not guaranteed?

MySQL employs a terrible default technique known as silent truncation where the product determines that it knows about your data better than you. Never has the saying “do not assume” because it makes an “ass” out of “u” and “me” been more applicable.

Customer Example

A HTML form for new customers provide input fields for the customer first and last name. Good design was considered with the HTML form client validation to ensure that each field could not exceed 20 characters in length. However, the database design is different, where the first name is only defined as 10 characters. In most cases this is sufficient, …

And what would you do if you have setup mysql with a replica slave? Would you still use RAID 10 or RAID 0? If something goes wrong with the RAID0 on the master database, you can switch to the slave database, and then take some time to recreate/fix the RAID0 for the master database to finally switch back to the master database.

MySQL 5.6.13 was released earlier this week, and in that release (as well as 5.5.33) the ability to use unique option prefixes was deprecated.  This is fully removed from MySQL 5.7, and I thought it might be useful to amplify the change log notes on why this was done:

Previously, program options could be specified in full or as any unambiguous prefix. For example, the --compress option could be given to mysqldump as --compr, but not as --comp because the latter is ambiguous. Option prefixes now are deprecated. They can cause problems when new options are implemented for programs. A prefix that is …

MySQL Connector/J 5.1.26, a maintenance release of the production 5.1 branch has been released. Connector/J is the Type-IV pure-Java JDBC driver for MySQL. Version 5.1.26 is suitable for use with many MySQL server versions, including 4.1, 5.0, 5.1, 5.4, 5.5 and 5.6. It is already available for download on the My Oracle Support (MOS) website. The eDelivery download will be available on it's own regular schedule. As always, we recommend that you check the "CHANGES" file in the download archive to be aware of changes in behavior that might affect your application.

MySQL Connector/J 5.1.26 includes the following general bug fixes and improvements, also available in more detail here

Functionality Added or Changed:

• Added a toString() method to the PreparedStatementWrapper class to help debug prepared …

As a developer of an application there really isn't a problem better than finding that you have to scale up the application and the database that supports it to handle the increased load. The main bottleneck to most expansion is the database server and in many modern environments that replication is based around MySQL. 

Application servers are easy to add on to the front-end of your environment.

The -N or –skip-column-names is a convenient option with the mysql client to skip the header line of output.
However I found when viewing the output via the terminal, some interesting and unexplained output.

$ mysql -h*** -u*** -p -e "SELECT VARIABLE_NAME,VARIABLE_VALUE FROM INFORMATION_SCHEMA.GLOBAL_STATUS"
+--------------------------------+----------------+
| VARIABLE_NAME                  | VARIABLE_VALUE |
+--------------------------------+----------------+
| ABORTED_CLIENTS                | 710001         |
| ABORTED_CONNECTS               | 31             |
| BINLOG_CACHE_DISK_USE          | 0              |
| BINLOG_CACHE_USE               | 0              |
| BYTES_RECEIVED                 | 2522301004     |
| BYTES_SENT                     | 317785976      |
| COM_ADMIN_COMMANDS             | 2890667        |
| COM_ASSIGN_TO_KEYCACHE         | 0              |
| COM_ALTER_DB                   | 0              |
| COM_ALTER_DB_UPGRADE           | …

On Wednesday night, the Boston MongoDB User group was kind enough to have me speak about TokuMX Internals. I spoke about Fractal Tree® indexes and the technical reasons behind the benefits they provide to MongoDB applications. Although the talk mostly references TokuMX and MongoDB, all the theory applies to TokuDB and MySQL as well.

My slides are on our technology overview page, along with other great content.

Opportunities to present technical material to an engaged audience asking tough questions is rare, and much appreciated. So thank you to the Boston MongoDB User group for having …

” One of the biggest challenges with any project of such a long duration is coping with change. There are many aspects to coping with change, including changes in requirements, changes in technology, vendor stability, changes in staffing and so on”–Jon Brumfitt. On May 14, 2009, the European Space Agency launched an Arianne 5 rocket [...]

Thanks to all who attended my “MySQL Query Tuning” webinar on July 24.  If you missed it, you can you can download the slides and also watch the recorded video. Thank you for the excellent questions after the webinar as well. Query tuning is a big topic and, due to the limited time, I had to skip some material, especially some of the monitoring. I would like, however, to answer all the questions I did not get into during the webinar session.

Q: Did you reset the query cache before doing your benchmark on your query? 0.00 seconds sounds too good 

A: (This is in response to a …