Sometimes I give parts of a solution to increase the play time to solve a problem. I didn’t anticipate a problem when showing how to perform a sort operation with a CASE statement. It’s a sweet solution when you need to sort something differently than a traditional ascending or descending sort.

I gave my students this ORDER BY clause as an example:

  CASE
    WHEN filter = 'Debit' THEN 1
    WHEN filter = 'Credit' THEN 2
    WHEN filter = 'Total' THEN 3
  END;

It raises the following error in MySQL for students:

      ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ORDER BY
  CASE
    WHEN filter = 'Debit' THEN 1
    WHEN filter = 'Credit' THEN' at line 6

It raises the …

The schedule is out for Percona Live Europe: Amsterdam (September 21-23 2015), and you can see it at: https://www.percona.com/live/europe-amsterdam-2015/program.

From MariaDB Corporation/Foundation, we have 1 tutorial: Best Practices for MySQL High Availability – Colin Charles (MariaDB)

And 5 talks:

1. Using Docker for Fast and Easy Testing of MariaDB and MaxScale – Andrea Tosatto (Colt Engine s.r.l.) (I expect Maria Luisa is giving this talk together – …

The MySQL Enterprise Audit plug-in is part of the MySQL Enterprise Edition (available through a paid license). Basically, Enterprise Audit tracks everything that is happening on your MySQL server, and can be used to protect/detect the misuse of information, and to meet popular compliance regulations including HIPAA, Sarbanes-Oxley, and the PCI Data Security Standard.

MySQL Enterprise Audit uses the open MySQL Audit API to enable standard, policy-based monitoring and logging of connection and query activity executed on specific MySQL servers. Designed to meet the …

Thanks to everyone who joined us last week for this live session on backup strategies for MySQL and Galera clusters led by Krzysztof Książek, Senior Support Engineer at Severalnines. The replay and slides to the webinar are now available to watch and read online via the links below.

Watch the replay

Become a MySQL DBA - webinar series: Deciding on a relevant backup solution from Severalnines AB   Read the slides

Become a MySQL DBA - slides: Deciding on a relevant backup solution from …

Addition of support for Apache Cassandra and DataStax Enterprise extends Pythian’s leadership in extreme-scale database deployments and big data services

OTTAWA, Canada – July 8, 2015 – Pythian, a global IT services company specializing in helping companies leverage disruptive technologies to optimize revenue-generating systems, today announced the general availability of its consulting and follow-the-sun managed services support for both Apache™ Cassandra™ and DataStax®, the company that delivers Apache Cassandra to the enterprise. Cassandra is an open-source, distributed database management system designed to handle large amounts of data across many commodity servers, providing high availability with no single point of failure.

Pythian leverages an extensive suite of managed services, tools, and database experience to get organizations up and running in their Cassandra and …

There is nothing more to be said:

SELECT
gen.TABLE_SCHEMA
, gen.TABLE_NAME
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
) as COLUMN_NUM
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY != ""
) as INDEX_NUM_ALL
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY = "PRI"
) as INDEX_NUM_PRI
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY = "UNI"
) as INDEX_NUM_UNI
, (select
count(TABLE_NAME) from information_schema.columns idx
where
idx.TABLE_SCHEMA = gen.TABLE_SCHEMA
and idx.TABLE_NAME=gen.TABLE_NAME
and COLUMN_KEY = "MUL"
) as INDEX_NUM_MUL

from …

MySQL replication has been available for years, and even though a number of new clustering technologies showed up recently, replication is still very common among MySQL users. It is understandable as replication is a reliable way of moving your data between MySQL instances. Even if you use Galera or NDB cluster, you still may have to rely on MySQL replication to distribute your databases across WAN.

In this blog post we’d like to discuss one of the most common operations DBA has to handle - replication topology changes and planned failover. 

This is the fifth installment in the ‘Become a MySQL DBA’ blog series, and discusses one of the most common operations a DBA has to handle - replication topology changes and planned failover. Our previous posts in the DBA series include Schema Changes, …

Welcome to MySQL QA Episode 3: “Debugging: GDB, Backtraces, Frames and Library Dependencies”

In this episode you’ll learn how to use debugging tool GDB. The following debugging topics are covered:

1. GDB Introduction
2. Backtrace, Stack trace
3. Frames
4. Commands & Logging
5. Variables
6. Library dependencies
7. c++filt
8. Handy references
– GDB Cheat sheet (page #2): https://goo.gl/rrmB9i
– From Crash to testcase: https://goo.gl/3aSvVW

Also expands on live debugging & more. In HD quality (set your player to 720p!)

The post MySQL QA Episode 3: How to use the debugging tool GDB appeared first on …

As the old management adage goes, “You can’t manage what you don’t measure.” In the fast-paced world of IT, this more accurately translates to, “You can’t improve what you don’t measure.”

When it comes to your database, a continuous monitoring system provides the foundation for progress: metrics. Without a monitoring system, it’s impossible to determine whether changes actually impact the system’s performance, availability, and functionality.

Think of it like a science experiment: You wouldn’t trust research that didn’t measure the results. So why would you settle for faulty database metrics? Read the full article here.

Object-relational mapping is common in most modern web frameworks such as Ruby on Rails. For the developer APIs, the ORM provides simplified interaction with the database and a productivity boost. However, the layer of abstraction the ORM provides can hide how the database is being queried. If you’re not paying attention, these generated queries can have a negative effect on your database’s health and performance.

Join Owen August 4th at 2 PM EST (6 PM GMT), as he discusses ways common Rails ORMs can abuse various databases and how VividCortex can be used to discover them. He will show the before and after effects on database performance, using VividCortex to measure results.

This webinar is useful for any developer or sysadmin working with Ruby On Rails. While we use our product to detect problems, it will be helpful even if you do not currently use VividCortex.

About the Presenter

Owen Zanzal is a developer …