Databases

MySQL/NoSQL/Cloud Conference Latin America

Last week I was a guest speaker at the second annual MySQL/NoSQL/Cloud Conference held in Buenos Aires, Argentina. Thanks to Santiago Lertora from Binlogic who has taken on the responsibility of organizing a event for the MySQL community in South America.

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An unexplained connection experience

The “Too many connections” problem is a common issue with applications using excessive permissions (and those that grant said global permissions). MySQL will always grant a user with SUPER privileges access to a DB to investigate the problem with a SHOW PROCESSLIST and where you can check the limits.

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A friday MongoDB funny

I had to laugh (just a bit) at this on the exhibitor floor at Oracle Open World 2013. There was a large MongoDB presence at the Slot 301 . There are a few reasons.

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Additional DB objects in AWS RDS

To expand on Jervin’s Default RDS Account Privileges , RDS for MySQL provides a number of routines and triggers defined the the ‘mysql’ meta schema. These help in various tasks because the SUPER privilege is not provided.

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MySQL MHA and Perl pathing

I am certainly not a knowledgeable Perl person, however I recently ran into the error Can’t locate MHA/MasterMonitor.pm on Red Hat 6.x. I have installed MySQL MHA on various systems before without any issues.

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Cloning MySQL 5.6 instances

A tip for all those cloud users that like cloning database servers (as reported in my book Effective MySQL – Replication Techniques in Depth ). Starting with MySQL 5.6, MySQL instances have a UUID .

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Unnecessary 3am (emergency) call

Help, the database is on fire. Well, it probably is but the solution may also be easy. Here are a few steps for the part-time MySQL DBA/sysadmin/developer. Total time to address this solution was 2 minutes, the inability to not go back to sleep, not priceless.

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Identifying empty tables in MySQL

The following simple INFORMATION_SCHEMA statement will identify and also verify tables that have no rows. These may be candidate tables to remove from your data model. mysql --defaults-file=.my.cnf -N -e "

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A simple FAILED SQL statement breaks MySQL 5.6 replication

I setup 6 shiny new MySQL 5.6.13 MySQL servers, ready for testing and production deployment tomorrow. I found that the New Relic MySQL Monitoring was throwing the following error. [2013-08-08 03:53:33 +0000] com.

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DP#8 The disadvantages of row at a time processing

It can be hard for software engineers to understand the following principle, however it is very important for improving performance and obtaining immediate scalability options. The principle is “Do Less Work”.

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MySQL configuration file created in /usr/my.cnf

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.

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DP#4 The importance of using sql_mode

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?

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Unexplained (trivial) MySQL behavior

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.

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Improved Security with MySQL 5.6

Installed on a clean CentOS 6.4 AWS instance. sudo su - cd /tmp wget http://cdn.mysql.com/Downloads/MySQL-5.6/MySQL-5.6.13-1.el6.x86_64.rpm-bundle.tar tar xvf MySQL-5.6.13-1.el6.x86_64.rpm-bundle.tar yum install -y libaio perl rpm -i MySQL*.rpm The following output is the sign that security is being considered with new MySQL versions.

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