Percona announces the release of Percona XtraDB Cluster 5.7.17-27.20 on March 16, 2017. Binaries are available from the downloads section or our software repositories.

NOTE: You can also run Docker containers from the images in the Docker Hub repository.

Percona XtraDB Cluster 5.7.17-27.20 is now the current release, based on the following:

• …

This blog shares some column store database benchmark results, and compares the query performance of MariaDB ColumnStore v. 1.0.7 (based on InfiniDB), Clickhouse and Apache Spark.

I’ve already written about ClickHouse (Column Store database).

The purpose of the benchmark is to see how these three solutions work on a single big server, with many CPU cores and large amounts of RAM. Both systems are massively parallel (MPP) database systems, so they should use many cores for SELECT queries.

For the benchmarks, I chose …

This tutorial shows how you can install an Apache webserver on a CentOS 7 server with PHP (mod_php with PHP 5.4, PHP 7.0, or PHP 7.1) and MySQL support. This setup is often referred to as LAMP which stands for Linux - Apache - MySQL - PHP.

One of the major challenges of query optimizers is to correctly estimate how many rows qualify from each table of a join. If the estimates are wrong, the optimizer may choose a non-optimal join order.

Before MySQL 5.7, the estimated number of rows from a table only took into account the conditions from the WHERE clause that were used to set up the access method (e.g., the size of an index range scan). This often led to row estimates that were far too high, resulting in very wrong cost estimates for join plans. To improve this issue, MySQL 5.7 introduced a cost model that considered the entire WHERE condition when estimating the number of qualifying rows from each table. This model estimates the filtering effect of the table’s conditions.

As shown in the above …

Yesterday I was invited to speak at the “Jeudis du Libre” in Mons.

The location was very special as it was in one auditorium of Polytech, the oldest university in the city of Mons.

I presented in French two very hot topics in the MySQL ecosystem:

• MySQL InnoDB Cluster
• MySQL as Document Store with JSON datatype & X plugin

Those are very new technologies illustrating MySQL’s innovation. And of course there is much more to come with MySQL 8 !

Here are the slides if you are interested:

Jeudis du Libre – MySQL InnoDB Cluster from Frederic Descamps

…

In this blog post, I will discuss the solutions for monitoring databases (which includes alerting) I have worked with and recommended in the past to my clients. This survey will mostly focus on MySQL solutions. 

One of the most common issues I come across when working with clients is monitoring and alerting. Many times, companies will fall into one of these categories:

• No monitoring or alerting. This means they have no idea what’s going on in their environment whatsoever.
• Inadequate monitoring. Maybe people in this camp are using a platform that just tells them the database is up or connections are happening, but there is no insight into what the database is doing.
• Too much monitoring and alerting. Companies in this camp have tons of dashboards filled with graphs, and their inbox is full of alerts that get promptly ignored. This type of monitoring is just as useful as the first option. Alert …

Since MySQL 5.5, MySQL has supported the utf8mb4 character set.  With the character-set defining the repertoire of characters that can be stored (utf8mb4 can present Unicode characters from U+0000 to U+10FFFF), a collation defines how sorting order and comparisons should behave.…

Ever wondered how to write tests for the front-end of your web application? You may already have functional back-end tests, for example to ensure that your models and views are working. However, you may be unsure how to simulate a user of your app for testing. How can you test front-end functions like registration and logging in, which are done in a browser?

In this two-part tutorial, I will show you how to write front-end tests for an existing Python/Flask web application. You should therefore already have a functional application, along with a virtual environment with the necessary software dependencies installed. We will use Project Dream Team, a CRUD web app I built in a three-part tutorial (here is Part One, Part Two and …

Somebody asked on Freenode. I don't know why they wanted it. How would you drop all MySQL users who do not have "GRANT ALL ON *.* ... WITH GRANT OPTION"? That is, drop any users who have 'N' in any of the privilege columns in `mysql`.`user`.

My solution shown below. Did you think of a different approach?

My solution ▼

I used SQL to build SQL which built more SQL. Get the list of 'priv' columns from information_schema.columns. Build a query that looks for 'N' in any of those columns (it feels funny to search for a constant in a list of fields instead of a field in a list of constants, but it's perfectly legal). Use the results to build the DROP USER statement.

mysql -BNe "SELECT CONCAT('SELECT CONCAT(''DROP USER '', QUOTE(user), ''@'', QUOTE(Host), '';'') FROM mysql.user WHERE ''N'' IN (', GROUP_CONCAT(column_name), ')') FROM information_schema.columns WHERE table_schema = 'mysql' AND table_name = 'user' AND …

MySQL Connector/Net 7.0.7 is the fourth development release that expands cross-platform support to Linux and OS X when using Microsoft’s .NET Core framework. Now,
.NET developers can use the X DevAPI with .NET Core and Entity Framework Core
(EF Core) 1.0 to create server applications that run on Windows, Linux and OS X.
We are very excited about this change and really look forward to your feedback on it!

MySQL Connector/Net 7.0.7 is also the sixth development release of MySQL Connector/Net to add support for the new X DevAPI. The X DevAPI enables
application developers to write code that combines the strengths of the
relational and document models using a modern, NoSQL-like syntax that
does not assume previous experience writing traditional SQL.

To learn more about how to write applications using the X DevAPI, see
…