In this blog post, we’ll provide an overview of the new MySQL 8.0 RESOURCE_GROUP feature.

One great new feature introduced in MySQL 8.0 that – from my point of view – requires attention is RESOURCE_GROUP.

Short disclaimer: I want to point out that MySQL 8.0 is not GA yet, so it is possible for the MySQL 8.0 RESOURCE_GROUP implementation to change in features and/or behavior.

I’ve used MySQL Community Server 8.0 RC, and everything mentioned below applies to this MySQL version.

In this post, I will quickly look at this feature and summarize what it’s for, how it makes the DBA’s life a little bit easier and highlight some known limitations.

The MySQL documentation describes it as follows:

“MySQL supports creation and …

The news that the latest MySQL 8.0.4 RC (release candidate) is available is indeed exciting. Unfortunately for users of the auth_socket plugin, dangers lie in wait!

Back in November 2015, I reported Failure of auth_socket authentication with sha256_password as default. This prevents users that identify with the

auth_socket

 plugin from logging in after SHA256 authentication has been made the default authentication method. With the …

Please join Percona’s Principal Support Engineer, Sveta Smirnova, as she presents Troubleshooting MySQL Crashes on January 25, 2018, at 10:00 am PST (UTC -8) / 1:00 pm EST (UTC -5).

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This webinar is for every MySQL user! In this talk, I won’t focus on how to analyze core files, read the source code or set breakpoints. Instead, I will focus on techniques that are available to anyone, even a novice.

Many tutorials, including my own, written based on Roel Van de Paar’s video, suggest how to create and analyze core files created at the time of a crash. While this …

In this blog post, we’ll look at the performance hit from the Spectre bug fix on Ubuntu.

Recently we measured the performance penalty from the Meltdown fix on Ubuntu servers. It turned out to be negligible.

Today, Ubuntu made a Spectre bug fix on Ubuntu available, shipped in kernel 4.4.0-112. As with the Meltdown fix, we measured the effect of this update. Unfortunately, we observed a major performance penalty on MySQL workloads with this new kernel.

Our benchmark used the following:

System:

• CPU:
  • 2 x Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (Codename Haswell)
  • /proc/cpuinfo has 48 …

Join Percona’s Chief Evangelist, Colin Charles as he presents Differences Between MariaDB and MySQL on Wednesday, January 24, 2018, at 7:00 am PST (UTC -8) / 10:00 am EST (UTC -5).

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Tags: MariaDB, MySQL, Percona Server for MySQL, DBA, SysAdmin, DevOps
Experience Level: Novice

MariaDB and MySQL. Are they syntactically similar? Where do these two query languages differ? Why would I use one over the other?

MariaDB is on the path of gradually diverging from MySQL. One obvious example is the internal data …

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 (Percona Server for MySQL) under a sysbench workload.

In this case, we used bare metal boxes with the following specifications:

• Two-socket Intel(R) Xeon(R) CPU E5-2683 v3 @ 2.00GHz (in total 56 entries in /proc/cpuinfo)
• Ubuntu 16.04
• Memory: 256GB
• Storage: Samsung SM863 1.9TB SATA SSD
• Percona Server for MySQL 5.7.20
• Kernel (vulnerable) 4.13.0-21
• Kernel (with Meltdown fix) 4.13.0-25

Please note, the current kernel for Ubuntu 16.04 contains only a Meltdown fix, …

In this post, we’ll look at updating and deleting rows with ClickHouse. It’s the second of two parts.

In the first part of this post, we described the high-level overview of implementing incremental refresh on a ClickHouse table as an alternative support for UPDATE/DELETE. In this part, we will show you the actual steps and sample code.

Prepare Changelog Table

First, we create the changelog table below. This can be stored on any other MySQL instance separate from the source of our analytics table. When we run the change capture script, it will record the data on this table that we can consume later with the incremental refresh script:

CREATE TABLE `clickhouse_changelog` (
  `db` varchar(255) NOT NULL …

Join Percona’s Product Manager Michael Coburn as he presents MySQL Troubleshooting and Performance Optimization with Percona Monitoring and Management (PMM) Part 2 on Thursday, January 18, 2018, at 11:00 am PST / 2:00 pm EST (UTC-8).

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Tags: Percona Monitoring and Management, PMM, Monitoring, MySQL, Performance, Optimization, DBA, SysAdmin, DevOps
Experience Level: Expert

Optimizing MySQL performance and troubleshooting MySQL problems are two of the most critical and challenging tasks for …

In this short blogpost, we’ll show you how to use the mysql_random_data_load tool to insert random data into tables. This is a great aide in testing when you have empty tables and need them to be populated with data. We’ve all done it manually (the INSERT INTO … VALUES … way), but that is surely a waste of time. It can add up to a lot if you need to test tables with many columns, or even worse, with foreign keys.

Before saying anything else, we would like to mention that this tool is still under development, and that it will insert random data into tables. Be aware if running it in a production environment!

mysql_random_data_load is a tool created by …

In this blog post, I’ll provide an explanation why you should avoid using the CREATE TABLE AS SELECT statement.

The SQL statement “create table <table_name> as select …” is used to create a normal or temporary table and materialize the result of the select. Some applications use this construct to create a copy of the table. This is one statement that will do all the work, so you do not need to create a table structure or use another statement to copy the structure.

At the same time there are a number of problems with this statement:

1. You don’t create indexes for the new table
2. You are mixing transactional and non-transactional statements in one transaction. As with any DDL, it will commit current and unfinished transactions
3. CREATE TABLE … SELECT …