Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.

Still on Meltdown/Spectre, this time MariaDB Corporation has published Meltdown Vulnerability Impact On MariaDB Server – interesting the comparison between glibc/tcmalloc. Worthy Facebook thread about this too, with a bit of chat about MongoDB performance. Officially MongoDB says a degradation of 10-15%. ScaleGrid has a good post, in which they test MongoDB against …

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 …

Changing configuration settings in MySQL wasn’t always easy. Of course it’s possible to change things (hopefully), but keeping track of everything is not always obvious. This is where configuration management systems like puppet, chef, ansible, … excels in making our life easier.

/etc/my.cnf

With MySQL 8.0, we worked in making your life easier (and the life of configuration management systems easier too).

Let’s first illustrate the problematic very naively:

As you can see, we can modify this configuration variable, but after a restart of MySQL, this change is lost, this behavior, of course is something known by all MySQL DBAs. The usual solution is then to also modify the configuration file (/etc/my.cnf in most cases).

SET PERSIST …

This is the third post in the series on Write Set in MySQL.  In the first post, we explore how Write Set allows to get better parallel replication in MySQL 8.0.  In the second post, we saw how the MySQL 8.0 improvement is an extension of the work done in MySQL 5.7 to avoid replication delay/lag in Group Replication.  In this post, we will see how Write Set is used in Group Replication to detect

Join Percona’s, CEO and Co-Founder, Peter Zaitsev as he presents Why We’re Excited About MySQL 8.0 on Wednesday, January 10, 2018, at 11:00 am PST / 2:00 pm EST (UTC-8).

Experience: Basic

Tags: Developer, DBAs, Operations, Executive, MySQL

There are many great new features in MySQL 8.0, but how exactly can they help your applications? This session takes a practical look at MySQL 8.0 features and improvements. It looks at the bugs, issues and limitations of previous MySQL versions and how MySQL 8.0 addresses them. It will also cover what you can do with MySQL 8.0 that you couldn’t before.

…

In my MySQL Parallel Replication session at Percona Live Santa Clara 2017, I talked about a bug in Write Set tracking for parallel replication (Bug#86078).  At the time, I did not fully understand what was going wrong but since then, we (Engineers at Oracle and me) understood what happened and the bug is supposed to be fixed in MySQL 8.0.4.  This journey thought me interesting MySQL behavior and

Percona’s Technical Director of Quality Assurance Roel Van de Paar shares his findings on the quality of MySQL 8.0.3 RC.

On 21 September 2017, our upstream friends at Oracle released MySQL 8.0.3 RC as the first MySQL 8.0 Release Candidate.

I tested the MySQL 8.0.3 Release Candidate branch with selected Percona bugfixes applied and built it as debug using the pquery QA framework (freely available here). Percona releases Percona Server for MySQL – an improved fork of the MySQL server – with additional features and bug patches.

Any QA engineer would enjoy seeing the many bugs discovered:

================ [Run: 079328] Sorted unique issue strings (11258 trials executed, …

In this post, we’ll briefly look at window functions in MySQL 8.0.

One of the major features coming to MySQL 8.0 is the support of Window functions. The detailed documentation is already available here Window functions. I wanted to take a quick look at the cases where window functions help.

Probably one the most frequent limitations in MySQL SQL syntax was analyzing a dataset. I tried to find the answer to the following question: “Find the Top N entries for each group in a grouped result.”

To give an example, I will refer to this request on Stackoverflow. While there is a solution, it …

In this blog post, we’ll look at a solving Sudoku using MySQL 8.0 recursive common table expression.

Vadim was recently having a little Saturday morning fun solving Sudoku using MySQL 8. The whole idea comes from SQLite, where Richard Hipp has come up with some outlandish recursive query examples — WITH clause.

The SQLite query:

WITH RECURSIVE
 input(sud) AS (
   VALUES('53..7....6..195....98....6.8...6...34..8.3..17...2...6.6....28....419..5....8..79')
 ),
 digits(z, lp) AS (
   VALUES('1', 1)
   UNION ALL SELECT
   CAST(lp+1 AS TEXT), lp+1 FROM digits WHERE lp<9
 ),
 x(s, ind) AS (
   SELECT sud, instr(sud, '.') FROM input
   UNION ALL
   SELECT …