by Przemysław Malkowski | Apr 15, 2024 | Insight for DBAs, MariaDB, MySQL
If you have enough experience with MySQL, it is very possible that you stumbled upon an unusually slow SELECT COUNT(*) FROM TABLE; query execution, at least occasionally.Recently, I had a chance to investigate some of these cases closer, and it stunned me what huge... by Przemysław Malkowski | Feb 9, 2024 | Insight for DBAs, MySQL
Historically, MySQL does not require explicit primary key defined on tables, and it’s like that by default till this day (MySQL version 8.3.0). Such a requirement is imposed through two replication methods, though: Group Replication and Percona XtraDB Cluster... by Przemysław Malkowski | Jan 31, 2024 | Insight for DBAs, Insight for Developers, MySQL
It is a known good practice to keep only necessary indexes to reduce the write performance and disk space overhead. This simple rule is mentioned briefly in the official MySQL Documentation:https://dev.mysql.com/doc/refman/8.0/en/optimization-indexes.htmlHowever, in... by Przemysław Malkowski | Dec 14, 2023 | Database Trends, Insight for DBAs, MongoDB, MySQL
Will 2023 be called the year of Generative Artificial Intelligence (AI)? I don’t know, but certainly, the launching of ChatGPT at the end of 2022 sparked a huge hype explosion around that technology throughout this year. Interesting time indeed, we’re... by Przemysław Malkowski | Nov 1, 2023 | Insight for DBAs, MariaDB, MySQL, Percona Software
Sometimes, there is a need to update the table and index statistics manually using the ANALYZE TABLE command. Without going further into the reasons for such a need, I wanted to refresh this subject in terms of overhead related to running the command on production... by Przemysław Malkowski | Oct 12, 2023 | Insight for DBAs, MongoDB
Have you ever encountered queries delayed by flow control but found no lagged secondaries? This article shows a possible scenario of why this happens.Replica Sets provide high availability and redundancy to MongoDB clusters. There is always one primary node that can... by Przemysław Malkowski | Jul 5, 2023 | Insight for DBAs, MySQL
Upgrading to MySQL version 8.0 is a hot topic since version 5.7 is approaching the official end of life very soon. MySQL 5.7 EOL is set for the end of October 2023.If you feel unprepared for the upgrade, consider post-EOL support from Percona. But it would be the... by Przemysław Malkowski | Feb 23, 2023 | Cloud, Insight for DBAs, MongoDB
If you ever had to make a quick ad-hoc backup of your MongoDB databases, but there was not enough disk space on the local disk to do so, this blog post may provide some handy tips to save you from headaches.It is a common practice that before a backup can be stored in... by Przemysław Malkowski | May 26, 2022 | Insight for DBAs, MySQL
The binary logging format in MySQL has been ROW by default since MySQL 5.7, yet there are still many users sticking with STATEMENT or MIXED formats for various reasons. In some cases, there is just simple hesitation from changing something that has worked for years on... by Przemysław Malkowski | Apr 5, 2022 | Insight for DBAs, Insight for Developers, MySQL
Do you wonder if MySQL tells you the truth about writes to tables that have foreign key constraints? The situation is complex, and getting visibility on what is really happening can be a problem.I found this issue intriguing and decided to share and highlight some... by Przemysław Malkowski | Feb 3, 2022 | Insight for DBAs, MySQL, Percona Software
Percona XtraDB Cluster (PXC) offers a great deal of flexibility when it comes to the state transfer (SST) options (used when a new node is automatically provisioned with data). For many environments, on-the-fly compression capability gives great benefits of saving... by Przemysław Malkowski | Nov 22, 2021 | Insight for DBAs, MySQL, Storage Engine
If you ever had to deal with performance and/or disk space issues related to temporary tables, I bet you eventually found yourself puzzled. There are many possible scenarios depending on the type of temporary table, settings, and MySQL version used. We have observed a... by Przemysław Malkowski | Jul 12, 2021 | Insight for DBAs, MySQL, Percona Software
The ProblemState Snapshot Transfer can be a very long and expensive process, depending on the size of your Percona XtraDB Cluster (PXC)/Galera cluster, as well as network and disk bandwidth. There are situations where it is needed though, like after long enough node... by Przemysław Malkowski | Apr 28, 2021 | Insight for DBAs, Insight for Developers, MySQL, Percona Software
Multi-writer replication has been a challenge in the MySQL ecosystem for years before truly dedicated solutions were introduced – first Galera (and so Percona XtradDB Cluster (PXC)) replication (around 2011), and then Group Replication (first GA in 2016).Now,... by Przemysław Malkowski | Jan 14, 2021 | Insight for DBAs, MongoDB, MySQL, Percona Software, Security
by Przemysław Malkowski | Oct 8, 2020 | Insight for DBAs, MySQL, Percona Software
Recently I was dealing with an unexpected issue raised by our Support customer, in which data became inconsistent after a schema change was applied.After some investigation, it turned out that affected tables had a special word in the comments of some columns, which... by Przemysław Malkowski | Jun 29, 2020 | Insight for DBAs, Insight for Developers, MySQL, Percona Software
Last year, I made the first post in a small series, which aimed to highlight unique features of Percona Server for MySQL, by discussing binlog_space_limit option.Today, I am going to discuss another important type of log available in MySQL that is enhanced in Percona... by Przemysław Malkowski | Jul 3, 2019 | Insight for DBAs, MySQL, Percona Software
I think it is often confusing to compare upstream MySQL and Percona Server for MySQL, and some helpful information can be found in the introductory notes. But what does that really mean for an ordinary DBA, especially if none of the known big extra features are... by Przemysław Malkowski | Mar 25, 2019 | Insight for DBAs, MySQL, Percona Software
If you are using Galera replication, you know that schema changes may be a serious problem. With its current implementation, there is no way even a simple ALTER will be unobtrusive for live production traffic. It is a fact that with the default TOI alter method,... by Przemysław Malkowski | Nov 5, 2018 | Insight for DBAs, MySQL
In this blog, we’ll look at how to quickly add a node to an InnoDB Cluster or Group Replication using Percona XtraBackup.Adding nodes to a Group Replication cluster can be easy (documented here), but it only works if the existing nodes have retained all the...