In this blog post we’ll look at how to move a MySQL partition from one table to another, for MySQL versions before 5.7.

Up to version 5.7, MySQL had a limitation that made it impossible to directly exchange partitions between partitioned tables. Now and then, we get questions about how to import an .ibd for use as a partition in a table, as well as how to exchange partitions with another partitioned table. Below is step-by-step instructions on how to move a partition from one table to another.

In this example, one of our customers had two tables with the following structures:

CREATE TABLE live_tbl (
some_id bigint(20) NOT NULL DEFAULT '0',
summary_date date NOT NULL,
PRIMARY KEY (some_id,summary_date)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci
/*!50500 PARTITION BY RANGE …

This post discusses the next MySQL development milestone: MySQL 8.0.1.

From the outset, MySQL 8.0 has received plenty of attention. Both this blog (see the MySQL 8.0 search) and other sites around the Internet have covered it. Early reviews seem positive (including my own MySQL 8.0 early bugs review). There is plenty of excitement about the new features.

As for early feedback on MySQL 8.0, Peter Zaitsev (Percona CEO) listed a set of recommendations for benchmarking MySQL 8.0. I hope these get reviewed and implemented. …

This post discusses archiving MySQL and MongoDB data, and determining what, when and how to archive data.

Many people store infrequently used data. This data is taking up storage space and might make your database slower than it could be. Archiving data can be a huge benefit, both regarding the performance impact and storage savings.

Why archive?

One of the reasons for archiving data is freeing up space on your database volumes. You can store archived data on slower, less expensive storage devices, and current data on the faster database drives. Archiving old data makes backups and restores run faster since they need to process less data. Last, but by no means least, archiving data has the benefit of making your queries perform more efficiently since they do not need to process through old …

This post discusses enabling and disabling jemalloc on Percona Server for MySQL.

The benefits of jemalloc versus glibc for use with MySQL have been widely discussed. With jemalloc (along with Transparent Huge Pages disabled) you have less memory fragmentation, and thus more efficient resource management of the available server memory.

For standard installations of Percona Server 5.6+ (releases starting with 5.6.19-67.0), the only thing needed to …

Welcome to another post in the series of Percona Live featured tutorial speakers blogs! In these blogs, we’ll highlight some of the tutorial speakers that will be at this year’s Percona Live conference. We’ll also discuss how these tutorials can help you improve your database environment. Make sure to read to the end to get a special Percona Live 2017 registration bonus!

In this Percona Live featured tutorial, we’ll meet Øystein Grøvlen, Senior Principal Software Engineer at Oracle. His tutorial is on How to Analyze and Tune MySQL Queries for Better Performance. SQL query …

In this blog post, we’ll find out how to use Percona XtraBackup on a MySQL instance with a large number of tables.

As of Percona Xtrabackup 2.4.5, you are required to have enough open files to open every single InnoDB tablespace in the instance you’re trying to back up. So if you’re running innodb_file_per_table=1, and have a large number of tables, you’re very likely to see Percona XtraBackup fail with the following error message:

InnoDB: Operating system error number 24 in a file operation.
InnoDB: Error number 24 means 'Too many open files'
InnoDB: Some operating system error numbers are described at http://dev.mysql.com/doc/refman/5.7/en/operating-system-error-codes.html
InnoDB: File ./sbtest/sbtest132841.ibd: 'open' returned OS error 124. Cannot continue operation
InnoDB: Cannot …

This blog discusses how to prepare your database for the new leap second coming in the new year.

At the end of this year, on December 31, 2016, a new leap second gets added. Many of us remember the huge problems this caused back in 2012. Some of our customers asked how they should prepare for this year’s event to avoid any unexpected problems.

It’s a little late, but I thought discussing the issue might still be useful.

The first thing is to make sure your systems avoid the issue with abnormally high CPU usage. This was an problem in 2012 due to a Linux kernel bug. After the leap second was added, CPU utilization sky-rocketed on many systems, taking down …

In this blog post, we’ll discuss the differences between row store and column store databases.

Clients often ask us if they should or could be using columnar databases. For some applications, a columnar database is a great choice; for others, you should stick with the tried and true row-based option.

At a basic level, row stores are great for transaction processing. Column stores are great for highly analytical query models. Row stores have the ability to write data very quickly, whereas a column store is awesome at aggregating large volumes of data for a subset of columns.

One of the benefits of a columnar database is its crazy fast query speeds. In some cases, queries that took minutes or hours are completed in seconds. This makes columnar databases a good choice in a query-heavy …

Using Vault with MySQL

In my previous post I discussed using GPG to secure your database credentials. This relies on a local copy of your MySQL client config, but what if you want to keep the credentials stored safely along with other super secret information? Sure, GPG could still be used, but there must be an easier way to do this.

This post will look at a way to use Vault to store your credentials in a central location and use them to access your database. For those of you that have not yet come across Vault, it is a great way to manage your secrets – securing, storing and tightly controlling access. It has the added benefits of being able to handle leasing, key revocation, key rolling and auditing.

During this blog post we’ll accomplish the following …

Encrypt your credentials using GPG

This blog post will look how to use encryption to secure your database credentials.

In the recent blog post Use MySQL Shell Securely from Bash, there are some good examples of how you might avoid using a ~/.my.cnf – but you still need to put that password down on disk in the script. MySQL 5.6.6 and later introduced the  –login-path option, which is a handy way to store per-connection entries and keep the credentials in an encrypted format. This is a great improvement, but as shown in Get MySQL Passwords in Plain Text from .mylogin.cnf, …