When it comes to the query tuning, EXPLAIN is one the most important tools in the DBA’s arsenal. Why is a given query slow, what does the execution plan look like, how will JOINs be processed, is the query using the correct indexes, or is it creating a temporary table?

You can now sign up for the webinar, which takes place at the end of this month on September 27th. We’ll look at the EXPLAIN command and see how it can help us answer these questions.

We will also look into how to use database indexes to speed up queries. More specifically, we’ll cover the different index types such as B-Tree, Fulltext and Hash, deepdive into B-Tree indexes, and discuss the indexes for MyISAM vs. InnoDB tables as well as some gotchas.

MySQL Query Tuning Trilogy: Indexing and …

Invisible indexes are a new feature in MySQL 8.0 that provide the ability to mark an index as unavailable for use by the Optimizer. This means that the index will still be maintained and kept up-to-date as data is modified, but no queries will be permitted to make use of the index (even if the query uses a FORCE INDEX hint).…

In this blog post, I will discuss the CVE-2016-6662 vulnerability, how to tell if it affects you, and how to prevent the vulnerability from affecting you if you have an older version of MySQL.

I’ll also list which MySQL versions include the vulnerability fixes.

As we announced in a previous post, there are certain scenarios in Percona Server (and MySQL) that can allow a remote root code execution (CVE-2016-6662).

Vulnerability approach

The website legalhackers.com contains the full, current explanation of the …

Many of you have probably already heard about the new vulnerability affecting most existing MySQL forks and versions. The bug has been patched in some of the most recent MySQL and Percona Server releases and so, at least in theory, all it takes to apply a fix is to update the MySQL or Percona Server packages to their latest versions. However, it would likely require a database restart and restarts are never particularly convenient, especially when done in a rush. But this time it is actually possible to fix the vulnerability without having to upgrade and restart your MySQL instances immediately.

The attack relies on the ability to load a forged memory allocator library through --malloc-lib option in one of the MySQL start-up scripts. This can only happen if such library is first uploaded to server …

MySQL has just released MySQL 8.0 DR (and yes, DR stands for Don’t Run-it-in-production-yet) so let’s jump right in and take a look at the hottest new features coming in this new release:

1. Persistent runtime configuration changes. Love it. From now on we’ll be able to use SET PERSIST innodb_buffer_pool_size = X; instead of SET GLOBAL innodb_buffer_pool_size = X; for the runtime changes to persist during a restart. It may not make much sense if you’re using a modern database that doesn’t even have a configuration file, but for us who lived with MySQL for over 20 years, this is huge!

How does it work? In a nutshell, these changes are saved in mysqld-auto.cnf file in MySQL data directory.

2. MySQL privilege tables are now InnoDB. I think this was …

MySQL 8.0.0 was released today. It has been some time in the making, shrouded in a veil of secrecy for over one year. We knew, from listening to the gossip and looking at the few available previews, some of what was going to bring. So, for the observant users, its main features may not come as a surprise. For the rest of you, here's a quick roundup:

Notable features

• No MyISAM tables anymore! The grant tables are now InnoDB, meaning that grant operations are now atomic.
• A real data dictionary. This change is less visible than the previous one. The data dictionary tables are hidden and only a subset of the data is available through information_schema views. The reason for the hidden tables is to allow a stable interface through several versions. I am …

The MySQL Development team is happy to announce our 8.0.0 development milestone release (DMR), now available for download at dev.mysql.com.  The source code is available at GitHub. You can find the full list of changes and bug fixes in the 8.0.0 Release Notes. …

This blog is an announcement for a Percona Server update with regards to CVE-2016-6662.

We have added a fix for CVE-2016-6662 in the following releases:

• Percona Server 5.5.51-38.1
• Percona Server 5.6.32-78.0
• Percona Server 5.7.14-7

From seclist.org:

A few events, but mostly circling around London:

• Open collaboration – an O’Reilly Online Conference, at 10am PT, Tuesday September 13 2016 – I’m going to be giving a new talk titled Forking Successfully. I’ve seen how the platform works, and I’m looking forward to trying this method out (its like a webminar but not quite!)
• September MySQL London Meetup – I’m going to focus on MySQL, a branch, Percona Server and the fork MariaDB Server. This will be interesting because one of the reasons you don’t see a huge Emacs/XEmacs push after about 20 years? Feature parity. And the work that’s going into MySQL 8.0 is mighty interesting.
• …

ProxySQL is design to do not perform any specialized operation in relation to the servers it communicate with.

Instead it has scheduled events that can be used to extend functionalities and cover any special need.

Given that specialized product like PXC, are not managed by ProxySQL and require the design and implementation of good/efficient extensions.

In this article I will illustrate how PXC/Galera can be integrated with ProxySQL to get the best from both.

Brief digression

Before discussing the PXC integration, we need to review a couple of very important concept in ProxySQL.ProxySQL has a very important logical component, the Hostgroup(s) (HG).
An hostgroup as a relation of :

+-----------+       +------------------------+
|Host group +------>|Server (1:N)            |
+-----------+       +------------------------+

Not only, …