The latest from the MySQL community

Today a customer gave me the idea of using a separate file as a volume for limiting the MySQL tmpdir size. On some not so well set-up Linux systems the MySQL tmpdir is located under /tmp which is the same mount point as / (root). This can lead to troubles in case the tmpdir is filled up with implicit temporary MyISAM tables which fills up the / (root) directory of the O/S as well.

MySQL itself has no possibility to limit explicitly the total size nor the number of implicit temporary tables. So this can happen easily if your application runs amok or you do not have your application under control.

An sometimes there is no possibility to have an extra mount point for tmpdir because the disk is completely used by volumes etc. But you have still some space in the file system.

In this case you can, similar to a swap file, use a file in the …

Release of RonDB 21.04.0

RonDB is based on MySQL NDB Cluster optimised for use in modern cloud settings. Today we launch RonDB 21.04.0. In RonDB 21.04.0 we have integrated benchmark scripts to execute various benchmarks towards RonDB.

There are three ways of using RonDB. The first is using the managed version provided by Logical Clocks. This is currently available in AWS and is currently being developed to also support Azure. This is still in limited access mode. To access it contact Logical Clocks at the rondb.com website.

The second way is to use a script provided by Logical Clocks that automates the creation of VMs and the installation of the software components required by RonDB. These scripts are available to create RonDB clusters on Azure and GCP (Google Cloud). This script can be downloaded from nexus.hops.works/rondb-cloud-installer.sh.

Introduction In this article, I’m going to explain how we can index JSON columns when using MySQL. While other relational database systems provide GIN (Generalized Inverted Index) indexes, MySQL allows you to index a virtual column that mirrors the JSON path expression you are interested in indexing. Database table Let’s assume we have the following database book table: The properties column type is json, so we can store JSON objects as book properties. Querying MySQL JSON columns without an index If we try to filter one record by its associated title attribute... Read More

The post How to index JSON columns using MySQL appeared first on Vlad Mihalcea.

Automation is in vogue these days. Technology evolves quickly, and more people are contributing to existing available third party automation software platforms. As the season of fast-paced deployments, automation is now necessary and considered as de facto; you cannot get rid of automating things deemed necessary. These necessities are important to get things done quickly and eliminate redundant tasks. Once this is present, organisations and companies can focus on the logical business things that make it more interesting for growth. This blog covers a short overview tools and consideration points for database automation followed by a a topic on how to use ClusterControl for database automation. 

Technologies for Database Deployment Automation

Sophisticated tools for Infrastructure as Code (IaC) such as Puppet, Chef, Ansible, SaltStack, and Terraform are usually the mainstream technologies to choose from. These tools help DBAs …

MySQL 8.0.24 introduces several new improvements and updates, many of which deserve their own blog post for a deep dive into the new features. The new version includes new features and bug fixes for Optimizer, GIS, InnoDB, Performance schema, Replication, Group Replication, Router, MTR Testsuite, an...

This blog post will show how to compile the Percona XtraBackup (PXB) tool for ARM. For this, we are going to use an AWS EC2 ARM instance with Ubuntu 20.04(Focal Fossa).

The motivation for this was born in my interest in the new generation of ARM processors and if this is a viable option for the future. Ideally, I do not recommend installing all the necessary packages to compile Xtrabackup in a production environment for security reasons. Still, you can have a “compiling” server for this purpose and then move the binaries around.

Machine Configuration

For this blog post, I picked a c6g.2xlarge instance. The machine has the following hardware configuration:

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, with both multi-writer technologies available, do we still need traditional asynchronous replication, set up in active-active topology? Apparently yes, there are still valid use cases. And you may need it not only when for some reason Galera/PXC or GR are not suitable, but also when you actually use them. Of course, the most typical case is to have a second cluster in a different …

Programming logic is foundational in any application or piece of software. Without it, software wouldn’t really do much of anything. Everything happens off of choice. In the end, some truthy or falsy value is what makes stuff work. For IF/THEN/ELSE logic in standard SQL, there is the CASE expression. There are 2 variations of the CASE Expression: Simple and Searched. In this post, I cover the Simple MySQL CASE expression with example queries…

Image by Nika Akin from …

The first tutorial supplementing the MySQL Connector/NET Developer Guide showed you how to connect and run static INSERT statement. It was a barebones PowerShell script with the MySQL Connector. This post shows you how to run a PowerShell script that uses a dynamic form to gather the MySQL credentials and then run a static query. Below is the MySQL Credentials form.

You enter the correct user name, password, hostname (or IP address), port, and database, like this:

Here’s the complete code for this staticQuery.ps1 PowerShell script:

# Add libraries for form components. …

It was interesting to note that the MySQL Connector/NET Developer Guide doesn’t have any instructions for connecting to the MySQL database from Microsoft Powershell. I thought it would be helpful to write a couple demonstrations scripts, especially when a quick search didn’t find a set of easy to follow samples.

The connection process to MySQL with Powershell is easiest with a non-query, so I created a db_connect table into which I could write a row of data:

CREATE TABLE db_connect
( db_connect_id  INT UNSIGNED PRIMARY KEY AUTO_INCREMENT
, version        VARCHAR(10)
, user           VARCHAR(24)
, db_name        VARCHAR(10));

The following insert.ps1 PowerShell script connects to the MySQL database, and inserts one row into the db_connect table:

# Connect to the libaray …