by Vadim Tkachenko | Aug 6, 2007 | Insight for Developers
Recently we were puzzled by question how query_cache works with column level privileges. The question was appeared as we discovered function query_cache_send_result_to_client is called before real parsing of query, so at the moment of execution the query_cache is not...
by Peter Zaitsev | Mar 23, 2007 | Insight for DBAs
During last couple of months I had number of consulting projects with MySQL Query Cache being source of serious problems. One would see queries both for MyISAM and Innodb tables mysteriously stalling for few seconds with “NULL” in State column. These could...
by Arunjith Aravindan | Aug 29, 2022 | Insight for DBAs, MySQL, Percona Software
by Francisco Bordenave | Jan 5, 2022 | Insight for DBAs, MySQL
Recently we were asked to check the performance of the new family of AMD EPYC processors when using MySQL in Google Cloud Virtual Machines. This was motivated by a user running MySQL in the N1 machines family and willing to upgrade to N2D generation considering the...
by Fernando Laudares Camargos | Jun 3, 2021 | Insight for DBAs, MySQL, Percona Software
In the previous post of this series, we looked at the hardware specifications and operating system settings of the host server through the lenses of a pt-summary report. Now that we know the foundation on which the database is running, we can turn our focus to MySQL...
by Brian Sumpter | Apr 1, 2021 | Insight for DBAs, MySQL
In past versions of MySQL, there was often an ‘upgrade dance’ that had to be performed in starting up a newly upgraded MySQL instance with the previous version configuration file. In some cases a few deprecated options might no longer be supported in the newer server...
by Francisco Bordenave | Sep 30, 2020 | Insight for DBAs, MySQL, Storage Engine
In this post, we will discuss what to do when you add more memory to your instance. Adding memory to a server where MySQL is running is common practice when scaling resources. First, Some Context Scaling resources is just adding more resources to your environment, and...
by Ivan Groenewold | Aug 26, 2020 | Cloud, Insight for DBAs, MySQL
Oftentimes, we need to replicate between Amazon Aurora and an external MySQL server. The idea is to start by taking a point-in-time copy of the dataset. Next, we can configure MySQL replication to roll it forward and keep the data up-to-date. This process is...
by Brian Sumpter | Jun 30, 2020 | Insight for DBAs, Monitoring, MySQL
While there is no magic bullet for MySQL tuning, there are a few areas that can be focused on upfront that can dramatically improve the performance of your MySQL installation. While much information has been published on this topic over the years, I wanted to break...
by Brian Sumpter | Apr 1, 2020 | Insight for DBAs, Monitoring, MySQL, Percona Software
While there is no magic bullet for MySQL 5.7 database tuning, there are a few areas that can be focused on upfront that can dramatically improve the performance of your MySQL installation. While much information has been published on this topic over the years, I...
by Tibor Korocz | Jul 15, 2019 | MySQL
Recently I had a customer where every single query was running in a transaction, as well as even the simplest selects. Unfortunately, this is not unique and many connectors like Java love to do that. In their case, the Java connector changed autocommit=off for the...
by Ananias Tsalouchidis | Jul 17, 2018 | Cloud, Insight for DBAs, MySQL, ProxySQL
Now that Database-as-a-service (DBaaS) is in high demand, there is one question regarding AWS services that cannot always be answered easily: When should I use Aurora and when RDS MySQL? DBaaS cloud services allow users to use databases without configuring physical...
by Marco Tusa | Apr 3, 2018 | Cloud, Insight for DBAs, MySQL
In this post, we’ll look at how to implement ProxySQL with AWS Aurora. Recently, there have been a few discussions and customer requests that focused on AWS Aurora and how to make the various architectures and solutions more flexible. Flexible how, you may ask?...
by Ananias Tsalouchidis | Feb 7, 2018 | Insight for DBAs, MySQL, ProxySQL
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...
by Vadim Tkachenko | Jan 18, 2018 | Insight for DBAs, Insight for Developers, MySQL, Security
In this blog post, we’ll look at does the Meltdown fix affect performance for MySQL on bare metal servers. Since the news about the Meltdown bug, there were a lot of reports on the performance hit from proposed fixes. We have looked at how the fix affects MySQL...
by Bradley Mickel | Oct 9, 2017 | Insight for DBAs, MariaDB, MySQL
In this blog post, I’ll discuss some of the MySQL and MariaDB default configuration differences, focusing on MySQL 5.7 and MariaDB 10.2. Percona Server for MySQL uses the same defaults as MySQL, so I will not list them separately. MariaDB Server is a general purpose...
by Alex Poritskiy | Jul 11, 2017 | MySQL, Open Source, Percona Software
In this blog post, we’ll look at how using thread_statistics can cause high memory usage. I was recently working on a high memory usage issue for one of our clients, and made some interesting discoveries: high memory usage with no bounds. It was really tricky to...
by Alexey Zhebel | Apr 3, 2017 | Insight for DBAs, MariaDB, MongoDB, Monitoring, MySQL, Percona Events, Percona Software, ProxySQL
Percona announces the release of Percona Monitoring and Management 1.1.2 on April 3, 2017. For installation instructions, see the Deployment Guide. This release includes several new dashboards in Metrics Monitor, updated versions of software components used in PMM...
by Federico Razzoli | Mar 2, 2017 | MariaDB, MySQL
The MariaDB subquery cache feature added in MariaDB 5.3 is not widely known. Let’s see what it is and how it works. What is a subquery cache? The MariaDB subquery cache optimizes the execution of correlated subqueries. Correlated subqueries refer to a value from...
