It is common practice to grant your application the privileges of “GRANT SELECT, INSERT, UPDATE, DELETE ON yourdb.* TO user@host”.

But what if you want to ensure you cannot DELETE data from just one table?

Ideally I want to be able to “REVOKE DELETE ON yourdb.important_table FROM user@host”. You cannot do currently this with the MySQL privilege system.

If your schema has 100 tables, and you want to remove DELETE from one, you have to define DELETE for the 99 others, and remember that for each new table, you need to remember to also modify user privileges.

The MariaDB CONNECT Storage Engine allows to access heterogeneous data sources. In my previous post I show you how to use the MariaDB CONNECT Storage Engine to access an Oracle database. This is quite easy through the CONNECT Storage Engine ODBC table type.

For most architectures where heterogeneous databases are involved an ETL (Extract-Transform-Load) is [...]

Whenever I have a problem query in MySQL, I say to myself, I know, I’ll use Explain Plan. Now I have two problems. I run the explain plan, but then I have to look up all the cryptic terms and read through the documentation to know what in the world is going on. Well, over the weekend, I decided to solve my own problem. I created a simple page that allows you to run an explain plan, and then each of those obscure, abbreviated terms is annotated with a tooltip that explains exactly what’s going on. I’m calling it MySQL Explain Explained.

I created a demo using the sample employees database (which you can download here). Here’s a sample query:

select gender, count(emp_no) as manager_cnt, sum(cnt) as sum, avg(cnt) as avg
from
(
    select m.emp_no, m.gender, count(de.emp_no) as cnt
    from …

When we are hired for a MySQL performance audit, we are expected to review the MySQL configuration and to suggest improvements. Many people are surprised because in most cases, we only suggest to change a few settings even though hundreds of options are available. The goal of this post is to give you a list of some of the most critical settings.

We already made such suggestions in the past here on this blog a few years ago, but things have changed a lot in the MySQL world since then!

Before we start…

Even experienced people can make mistakes that can cause a lot of trouble. So before blindly applying the recommendations of this post, please keep in mind the following items:

• Change one setting at a time! This is the only way to estimate if a change is beneficial.
• Most …

As announced last month, MySQL Connect will this year be aligned with Oracle OpenWorld and run from Monday September 29 to Thursday October 2, 2014, in San Francisco.

The MySQL Connect and Oracle OpenWorld Calls for Papers will also open at the same time, and you will most likely be able to submit your sessions between March 4 and April 8 (dates subject to change).

While you will have 5 weeks or so to actually submit your talk proposals, you can already prepare your submissions NOW in order to be ready to submit then, and here is the key information you need to do so. In order to submit a session, you will need to provide:

• Title
• Conference session type: This can be either a conference session (1 hour), a Birds-of-a-Feather session (1 hour), or a tutorial (2,5 hours). You are …

What is it about?

I used to do some benchmarkstuff and blogged about it on my blog written in German. Im going to do testings and benchmarkings again:)

We are going to have a look into ‘benchmarking’ a 3-node Galera Cluster. The application (sysbench) is on a separate node accessing one node of the cluster. This would be the case in a i.e. VIP setup.

Setup

3 Galera Nodes

• Virtual machines (OpenStack) provided by teuto.net
• VCPU: 4
• RAM: 4GB
• OS: Centos 6.4-x86_64
• MySQL-server-5.6.14wsrep25.1-1.rhel6.x86_64
• galera-25.3.2-1.rhel6.x86_64

Separate sysbench node

• Same specs as the Galera nodes
• sysbench 0.5
• oltp test on 5 tables 1000000 rows each (ca. 1.2GB)
• A run took 60 seconds

Last Wednesday, I spoke at the San Francisco MySQL Meetup on the topic of changes coming in MySQL 5.7 (and later).  We actually went through two different slide decks; the first on features being considered for deprecation in MySQL 5.7 (or later), and the second set providing a brief overview of the new features and benefits already introduced in MySQL 5.7 via the development milestone releases (DMRs) published to date.  A big thanks to the entire SF Meetup group, and in particular the organizers (Erin, Mike and Darren), for having me.  The event was streamed and recorded, and you can view the full presentation on YouTube.  The slide deck can be found here.

The discussion around proposed deprecation was good, and this blog serves to document my own notes about what …

In the previous article, we learned how you can design your database schema so that many customers can share one database and one set of tables. The examples I used were fairly simple: they consisted of single tables or simple hierarchies like the order and line item tables. In those examples, you had a single tenant id that segmented the tables. Now I’d like to introduce the idea of hierarchical segmentation. This is a pretty big term for the idea of allowing customers to see data based on where they are in a hierarchy, like an org chart.

Let’s say you have three sales teams each with its own manager for three regions in the US: East, Central, and West. A salesman in the East only gets to see his own prospects, while the East sales manager sees the prospects of the entire East sales team. At the very top, the VP of US Sales can access the …

We are nearing the one-year anniversary since MySQL 5.6 went GA – which is typically a good time even for the most conservative users to start thinking about upgrading. At this point there is a fair amount of practical use and experience; many bugs have also been fixed (1991 to be exact according to Morgan Tocker).

We also know that MySQL 5.6 has been used in some very demanding environments on a very large scale, such as at Facebook. We also know from the Facebook team, after kindly sharing their upgrade experiences, that it takes a lot of work to upgrade to MySQL 5.6. That’s where Percona can help!

In my webinar this Wednesday, “ …

Configuring MySQL Server, with the dozens of options available, has always been perceived as a bit of a black art. In MySQL Database 5.6, configuring your MySQL server for optimal performance is easier than ever before.

In the MySQL for Database Administrators course you can learn more.

MySQL 5.6 is configured to work faster out of the box in a wide range of installation scenarios and it is easier than ever to set up the server by adjusting only a small number of settings which cause others to be set. In addition, you get a new default my.cnf file with instructions guiding your through adjusting key settings. The …