Oracle recently published the MySQL 5.7.5 Development Milestone release, a pre-production release providing numerous improvements to the MySQL server. You can download the release here: http://dev.mysql.com/downloads/mysql/5.7.html

This release carries some incompatible changes, as explained in the release notes and in the blog post describing the release. During my work in the Server QA team I have experienced some of these changes first hand already, and we have had to modify some tests and tools to adapt to some of it.

One very big change (well, some may not notice at all, while others may need to adjust their tools and applications) is the new default value …

September 26, 2014 By Severalnines

Paytrail is a leading e-payment method provider from Finland, and is expanding globally. Established in 2007, Paytrail currently has over 4,000 business customers, works with over 350 partners and its solution is available in all SEPA (Single Euro Payments Area) countries.

Paytrail offers a new online shopping solution that allows consumers to use one login for all of their online purchases. And it provides everything that is needed for online shopping in addition to traditional payment methods (bank e-payments, credit and debit card payments, invoicing and installments). 

This new case study describes how Paytrail came to work with Severalnines to achieve a fault-tolerant database cluster across two data centers.

Of course, this is just a catchy title. As far as I know not all system tables can be converted to InnoDB yet (e.g. grant tables), which makes the header technically false. MyISAM is a very simple engine, and that has some inherent advantages (no transactional overhead, easier to “edit” manually, usually less space footprint on disk), but also some very ugly disadvantages: not crash safe, no foreign keys, only full-table locks, consistency problems, bugs in for large tables,… The 5.7.5 “Milestone 15” release, presented today at the Oracle Open World has an impressive list of changes, which I will need some time to digest, like an in-development ( …

MySQL 5.5.40 was recently released (it is the latest MySQL 5.5, is GA), and is available for download here:

http://dev.mysql.com/downloads/mysql/5.5.html

This release, similar to the last 5.5 release, is mostly uneventful.

There were 0 “Functionality Added or Changed” bugs this time, and 18 bugs overall fixed.

Out of the 18 bugs, most seemed rather minor or obscure, but there are 3 I think are worth noting (all 3 are InnoDB-related, regressions, and serious if you encounter them, so best to be aware of them):

• InnoDB: An ALTER TABLE … ADD FOREIGN KEY operation could cause a serious error. (Bug #19471516, Bug #73650)
• InnoDB: With a transaction isolation level less than or equal to READ COMMITTED, gap locks …

I’ve been setting up a simplified lab environment to let my students learn use in class. This added content will show them how to do reverse engineering with MySQL Workbench.

It’s a complete Fedora image with MySQL and Oracle Database 11g for the course. The uncompressed image is 14GB and the compressed image is 5.3GB. I chose Fedora because it’s the smallest open source image that supports both environments, and Fedora is the closest to Red Hat and Oracle Unbreakable Linux. I’m inclined to make the instance available generally but haven’t figured out the best way to do that.

Here are the new instructions I’m adding and if you have any input leave it as a comment.

You connect as the student user, which puts you in the /home/student directory. Once connected to the Fedora OS, you open a Terminal session by clicking on Activities in the upper right hand corner, and then you …

Today new version of JSON UDF functions: 0.3.2 was released. This is development release which contains new functionality. You can download functions from the MySQL Labs website.

What is new?

New function `JSON_COUNT` added. This function returns number of children of the key path specified. If no key path specified, number of children of the root element is returned. Bug #70580/17584692 ADD FUNCTION `JSON_COUNT` TO COUNT SIZE OF JSON DOCUMENT

mysql> select json_count('{"MySQL Central": ["conference", 2014]}') as 'root count',
    ­> json_count('{"MySQL Central": ["conference", 2014]}', 'MySQL Central') as 'first element count'\G     
                                                   
************************ 1. row ************************
         root count: 1
first element count: 2
1 row in set …

In this blog post we are going to talk about one of the features included since MySQL for Excel 1.3.0. 

Importing MySQL data into Excel is a common and important operation in MySQL for Excel. There may be times when you need to analyze the data stored in several MySQL tables or views, (possibly in an ExcelPivotTable which will be the subject of a future blog post), and to do it you need to dump the data into Excel as the first step. Starting with MySQL for Excel 1.3.0 we introduced a feature that allows you to import the data from multiple MySQL tables or views in a single operation.

Remember you can install the latest GA or maintenance version using the MySQL Installer or optionally you can download directly any GA or non-GA version from the  …

The biggest innovation in TokuDB v7.5 is Read Free Replication (RFR). I blogged a few days ago posting a benchmark showing how much additional throughput can be achieved on a replication slave, while at the same time lowering the read IO operations to almost zero. The official documentation on the feature is available here.

In this second blog I want to cover the requirements for RFR, as well as some interesting use-cases for the technology.

Recently I encountered a specific situation in which a customer was forced to stay with the MyISAM engine due to a legacy application using tables with over 1000 columns. Unfortunately InnoDB has a limit at this point. I did not expect to hear this argument for MyISAM. It is usually about full text search or spatial indexes functionality that were missing in InnoDB, and which were introduced in MySQL 5.6 and 5.7, respectively, to let people forget about MyISAM. In this case though, InnoDB still could not be used, so I gave the TokuDB a try.

I’ve created a simple bash script to generate a SQL file with …

September 25, 2014 By Severalnines

Coming up with a backup strategy that does not affect database performance or lock your tables can be tricky. How do you backup your production database cluster without affecting your applications? Should you use mysqldump or Percona Xtrabackup? When should you use incremental backups? Where do you store the backups? In this blog post, we will cover some of the common backup methods for Galera Cluster for MySQL/MariaDB, and how you can get the most out of these. 

Backup Method

There are various ways to backup your Galera Cluster data:

• xtrabackup (full physical backup)
• xtrabackup (incremental physical backup)
• mysqldump (logical backup)
• binary logging 
• replication slave

Xtrabackup (full backup)

Xtrabackup is an open-source MySQL hot …