In this blog post, I’ll look at how you can analyze raw MySQL query logs with ClickHouse.

For typical query performance analyses, we have an excellent tool in Percona Monitoring and Management. You may want to go deeper, though. You might be longing for the ability to query raw MySQL “slow” query logs with SQL.

There are a number of tools to load the MySQL slow query logs to a variety of data stores. For example, you can find posts showing how to do it with LogStash. While very flexible, these solutions always look too complicated and limited in functionality to me.   

By far the best solution to parse and load MySQL slow query logs (among multiple log types supported) is Charity …

The latest release of Percona Monitoring and Management (PMM) 1.8.0 is available as of February 27, 2018.

Percona Monitoring and Management is a free and open-source platform for managing and monitoring MySQL and MongoDB performance. You can run PMM in your own environment for maximum security and reliability. It provides thorough time-based analysis for MySQL and MongoDB servers to ensure that your data works as efficiently as possible.

This release introduces many improvements in the user interface and optimizations of performance.

New landing page

The home page has been removed in favor of the …

Recently we faced an issue where the config management software had automatically upgraded the mariadb-server-10.1 package to the latest 10.1.31 version. This upgrade broke the galera cluster setup for this installation.

I’ve started to recreate this issue in my local lab setup and I managed to reproduce this problem.

I have created a 3 node galera setup: galera1 (192.168.55.100), galera2 (192.168.55.101) and galera3 (192.168.55.102). All 3 servers run MariaDB-10.1.30. Galera replication is working fine.

This is the basic galera config:

# cat /etc/mysql/conf.d/cluster.cnf
#########################################################
# Galera config
#########################################################

[mysqld]
wsrep_on                                  = ON
wsrep_provider                            = /usr/lib/libgalera_smm.so
wsrep_provider_options                    =
wsrep_cluster_name                        = …

The conference session schedule for the seventh annual Percona Live 2018 Open Source Database Conference, taking place April 23-25 at the Santa Clara Convention Center in Santa Clara, CA is now live and available for review! Advance Registration Discounts can be purchased through March 4, 2018, 11:30 p.m. PST.

Percona Live Open Source Database Conference 2018 is the premier open source database event. With a theme of “Championing Open Source Databases,” the conference will feature multiple tracks, including MySQL, MongoDB, Cloud, PostgreSQL, Containers and Automation, Monitoring and Ops, and Database Security. Once again, Percona will be …

Whenever we do upgrades for our clients from one major version of MySQL to another we strongly recommend to test in two forms.

First, it would be a performance test between the old version and the new version to make sure there aren’t going to be any unexpected issues with the query processing rates. Secondly, do a functional test to ensure all queries that are running on the old version will not have syntactic errors or problems with reserved words in the new version that we’re upgrading to.

If a client doesn’t have an appropriate testing platform to perform these types of tests, we will leverage available tools to test to the best of our ability. More often than not this includes using pt-upgrade after capturing slow logs with …

Percona has revealed the line-up of in-depth tutorials for the Percona Live 2018 Open Source Database Conference, taking place April 23-25, 2018 at the Santa Clara Convention Center in Santa Clara, Calif. Secure your spot now with Advanced Registration prices (available until March 4, 2018). Sponsorship opportunities for the conference are still available.

Percona Live 2018 Open Source Database Conference is the premier open source database event. The theme for the upcoming conference is “Championing Open Source Databases,” with a range of topics on …

In this blog post, I’ll present the ProxySQL query cache functionality. This is a query caching mechanism on top of ProxySQL. As there are already many how-tos regarding the ProxySQL prerequisites and installation process, we are going to skip these steps. For those who are already familiar with ProxySQL query cache configuration, let’s go directly to the query rules and the performance results.

Before talking about the ProxySQL query cache, let’s take a look at other caching mechanisms available for MySQL environments.

MySQL query cache is a query caching mechanism – deprecated as of MySQL 5.7.20 and removed in MySQL 8.0 – on top of MySQL itself (based on the official MySQL documentation).

The MySQL query cache stores the text of a SELECT statement together with the corresponding result sent to the client. If an identical statement is …

In this blog post, we’ll introduce how you can look at some experimental Percona Monitoring and Management (PMM) features using Percona Labs builds on GitHub.

Note: PerconaLabs and Percona-QA are open source GitHub repositories for unofficial scripts and tools created by Percona staff. While not covered by Percona support or services agreements, these handy utilities can help you save time and effort.

Percona software builds located in the PerconaLabs and Percona-QA repositories are not officially released software, and also aren’t covered by Percona support or services agreements. 

Percona Monitoring and Management (PMM) is a free and open-source platform for managing and …

In this blog post, I’ll look into four ways MySQL executes GROUP BY. 

In my previous blog post, we learned that indexes or other means of finding data might not be the most expensive part of query execution. For example, MySQL GROUP BY could potentially be responsible for 90% or more of the query execution time. 

The main complexity when MySQL executes GROUP BY is computing aggregate functions in a GROUP BY statement. How this works is shown in the documentation for UDF Aggregate Functions. As we see, the requirement is that UDF functions get all values that constitute the single group one …

In this blog post, we’ll look at ways you can use MySQL 5.7 generated columns (or virtual columns) to improve query performance.

Introduction

About two years ago I published a blog post about Generated (Virtual) Columns in MySQL 5.7. Since then, it’s been one of my favorite features in the MySQL 5.7 release. The reason is simple: with the help of virtual columns, we can create fine-grained indexes that can significantly increase query performance. I’m going to show you some tricks that can potentially fix slow reporting queries with GROUP BY and ORDER BY.

The Problem

Recently I was working with a customer who was struggling with this query:

SELECT
CONCAT(verb, ' - …