I’ve been working on MySQL since 2008 but I didn’t write any technical blogs until I joined FromDual GmbH and my first blog was published in October 24th 2013! (You can find all my blogs at FromDual here).
I liked writing blogs for many reasons but mainly for the following two:

1. Sharing knowledge and contributing with MySQL community to make the information easier and available for all.
2. Very good reference for myself to do my daily work more efficiently.

Now, I’m eager to blog again so I decided to create my own blog, MySQL Step-by-Step Blog.
The idea of choosing the name “Step-by-Step” is I like to explain all steps needed for doing a task – you may have discovered that …

So, its been a long time since I contributed anything to my blog. That will end very soon. Things coming up is writing about the architecture of Shots, Shard optimizations, Data Organization and Grouping, Java, Golang and some cool other stuff. Also how to handle Justin Biebers traffic, which is INSANE.


In the meantime if you live in the San Francisco California Bay Area, you want to work with the coolest founders on the planet, make a big difference in peoples lives, know mySQL / redis / memcache / Some C style language or want to learn contact me. I have a great job for you!

The MariaDB CONNECT storage engine now offers access to JSON file and allows you to see a external JSON file as a MariaDB table. JSON (JavaScript Object Notation) is a lightweight data-interchange format widely used on the Internet. JSON like XML represents data hierarchically. The mapping from hierarchical data to tabular data needs to be specified.

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MySQL is fairly relaxed about prefixing column names with a table name or alias in a query involving multiple tables. As long as the column name you use only exists in one of the tables in your query, MySQL does not require you to prefix it, regardless of SQL mode.

My policy has always been to prefix all column names with the table name/alias in a multiple table query. This is not simply a syle choice. If I reference a column name without prefixing it the query may work today, but it is not future-proof. If the schema changes in the future and I add a column with the same name to one of the other tables involved in that query, then the query will fail with ERROR 1052:

ERROR 1052 (23000): Column 'used_to_be_unique' in field list is ambiguous

Therefore I recommend always prefixing all column names in a multi table query to protect your queries against future additive schema changes.

Here's some code …

In the MySQL team, we have always had a requirement to support upgrades from one major version. For example:

• Upgrading from MySQL 5.5 to 5.6 is supported.
• Upgrading from MySQL 5.1 to 5.6 is not supported.

Downgrades are also supported for one major version. For example, if a user upgrades to 5.6 but discovers that it is not working as expected, they have the safety knowing that there is a way to step back to MySQL 5.5. This may come with some limits; for example when new features (such as new row formats or page checksums) are enabled, this may no longer be possible.

Today I wanted to discuss a current non-requirement. We do not support skipping major versions, such as upgrading from MySQL 5.1 to 5.6. Justin however makes the …

The Severalnines team is pleased to announce the release of ClusterControl 1.2.9. This release contains key new features along with performance improvements and bug fixes. We have outlined some of the key new features below. 

Join us for our Release Webinar on March 24th, which includes a live demo of the new ClusterControl 1.2.9.

Highlights of ClusterControl 1.2.9 include:

• Support for PostgreSQL Servers
• Advanced HAProxy Configurations and Built-in Stats
• Hybrid Replication with Galera Clusters
• Galera Replication Traffic Encryption
• Encrypted Communication between ClusterControl and …

I am leaving Oracle. My last day will be tomorrow. Since Oracle blogs are for Oracle employees only I would not be able to post here. I will write new posts to my personal just created blog http://troubleshootingfreak.blogspot.com/

This blog will stay, so you should be able to access older entries. Therefore I would not migrate them. Just don't expect somebody will manage comments. If you have questions about old entries in this blog use this page.

Last years I worked on JSON UDF project. I will stop working on it after I leave to avoid conflict of interest with Oracle, but project will live. I don't know if it will be passive or Oracle will find new developer for it, but versions 0.3.3 and …

Tomorrow will be my last day at Oracle. Next day I would not have access to my working blog at https://blogs.oracle.com/svetasmirnova/ But content will stay.

However Oracle blogs require manual managing of comments and I simply don't expect my colleagues will have time to do it in timely manner. Therefore if you have questions about my old blog posts just write them here together with the URL of the post.

We are getting closer to the next major version of MySQL, and yesterday we announced another development milestone release of what will become MySQL Server 5.7. In addition to the announcement blog post itself, more in-depth posts on specific changes and improvements in the 5.7.6 milestone release will appear on the MySQL Server Team blog over the next […]

Introduction

The MySQL Optimizer sometimes needs a temporary data-store during query processing, for storing intermediate results. Before MySQL 5.7, this need was serviced exclusively using a combination of the HEAP/MEMORY storage engine (for smaller tables) and the MyISAM storage engine (for larger tables). You can find more information on when disk based temporary tables (MyISAM or InnoDB) are used instead of MEMORY tables here.

The …