My webinar “Multi-threaded Replication in MySQL 5.6 and 5.7″ on February 25 generated several excellent questions following the presentation (available here for playback along with the slides). I didn’t have time to answer many of the questions during the session and so in this post I answer all of them. Thanks to everyone who attended!

Q: What do you expect from MTS with logical clock? Do you think performance would be good as with per database?
A: MTS with 5.6 is not usable if you have a single database. I do not have numbers, but this is quite frequent. With 5.7 everyone should be able to benefit from multi-threaded replication.

Q: When MySQL 5.6 was released, performance of MTS was lower, than in 5.5, for example. Is this addressed now?
A: I am not sure which …

The MySQL developer tools team is pleased to announce 6.3.2 RC - the first release candidate for MySQL Workbench 6.3

For the full list of changes in this revision, visit

http://dev.mysql.com/doc/relnotes/workbench/en/changes-6-3.html

For detailed information about the new features, see What’s
New in MySQL Workbench 6.3
http://dev.mysql.com/doc/workbench/en/wb-what-is-new-63.html

For discussion, join the MySQL Workbench Forums:
http://forums.mysql.com/index.php?151

Download MySQL Workbench 6.3.2 RC now, for Windows, Mac OS X 10.7+,
Oracle Linux 6 and 7, Fedora 20 and Fedora 21, Ubuntu 14.04 and …

Today I read a nice article , which give a new design for mysql database . In this article , Author (Mr.lou) uses OneSQL (a branch of MySQL) for the whole test.

you can read from : http://www.onexsoft.com/?page_id=378

This article explain how to use mysql in seckilling scenario (especially for E-Commerce commany )

If you want to use transaction in RDBMS database, you must manual start transaction and commit in the end of your operation.
So,commit will be cost of the total process, round-trip cost will be the most important cost as author said

(For simple update operations, without regard to conflict of IO and locks, a statement execution time is about 0.1ms, network delay under normal conditions is 0.4-0.8ms, that the waiting time is longer than the transaction commit time to really notice the SQL execution several times, showing that the …

MySQL 5.7.6 brings in a simplification that solves the very first problem that I encountered back in the days when I first started using MySQL 5.0. Namely…

How do I create a new database instance?

I know it sounds like a very basic question. But as it turned out, the answer was not that simple. I tried mysqld --help. Nothing there. And then, after reading the manual and trying out the complex command line (including redirection) based steps a couple of times, I just resorted to employing the mysql-test-run.pl test suite driver to create the initial system tables and data for me.

Obviously this has …

Dear MySQL users,

The MySQL developer tools team announces 6.3.2 RC – the first release
candidate for MySQL Workbench 6.3.

For the full list of changes in this revision, visit
http://dev.mysql.com/doc/relnotes/workbench/en/changes-6-3.html

For detailed information about the new features, see What’s
New in MySQL Workbench 6.3
http://dev.mysql.com/doc/workbench/en/wb-what-is-new-63.html

For discussion, join the MySQL Workbench Forums:
http://forums.mysql.com/index.php?151

Download MySQL Workbench 6.3.2 RC now, for Windows, Mac OS X 10.7+,
Oracle Linux 6 and 7, Fedora 20 and Fedora 21, Ubuntu 14.04 and …

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.

[...]

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 …