This tutorial describes how to declare a variable (like user-defined, local, and system vars) in MySQL. We’ll tell you the complete syntax and provide simple examples for clarity. MySQL puts up the below three ways: 1. Declare a user-defined variable 2. Declare a local variable 3. Declare a system variable Let’s start with looking at all of them one by one. Declare Variable in MySQL There are primarily three types of variables in MySQL. And each has its specific way to provide a declaration. 1. Declare a User-defined Variable In MySQL, we can use the SET statement to declare a

The post How to Declare Variables in MySQL appeared first on Learn Programming and Software Testing.

The Question Recently, a customer asked us:

Where are the logs for a Tungsten Cluster and which are the proper log files to monitor if I do a master role switch to another node?

The Answer: Part I Both basic and advanced logs are available!

The basic logs are symbolic links into the log subdirectory for each layer of the cluster.

For example, this is the listing of the default log directory, /opt/continuent/service_logs:

connector-user.log -> /opt/continuent/tungsten/tungsten-connector/log/connector-user.log
manager-user.log -> /opt/continuent/tungsten/tungsten-manager/log/manager-user.log
mysqldump.log -> /opt/continuent/tungsten/tungsten-replicator/log/mysqldump.log
replicator-user.log -> /opt/continuent/tungsten/tungsten-replicator/log/replicator-user.log
xtrabackup.log -> /opt/continuent/tungsten/tungsten-replicator/log/xtrabackup.log

As you can see, each log file is a …

When having only several databases to manage, regular backup operations can be done quite easily and seamlessly either with the help of a few simple scripts or by configuring an SQL Server agent that will perform the backup automatically. But sometimes the situation is more complicated. When, for instance, there are hundreds of databases, backing […]

In the first part of the series, we showed you how to deploy a MySQL Replication setup with ProxySQL with WHM and cPanel. In this part, we are going to show some post-deployment operations for maintenance, management, failover as well as advantages over the standalone setup.

MySQL User Management

With this integration enabled, MySQL user management will have to be done from WHM or cPanel. Otherwise, ProxySQL mysql_users table would not sync with what is configured for our replication master. Suppose we already created a user called severaln_user1 (the MySQL username is automatically prefixed by cPanel to comply to MySQL limitation), and we would like to assign to database severaln_db1 like below:

The above will result to the following mysql_users table output in ProxySQL:

If you would like to create …

During this week you can find MySQL at following shows:

• Oracle Global Partnership Summit, Munich, Germany, July 9-11, 2019

  • Do not miss this event organized by Oracle University with Rich Mason, the Senior VP and General Manager for MySQL having a keynote & Carsten Thalheimer, the MySQL Master Principal Sales Consultant running the technical session. 
  • Registration here
• MySQL User Group Munich - Meetup, Germany, July 11, 2019 @7:30pm
  • Carsten Thalheimer, the MySQL Master Principal Sales Consultant is a speaking guest of this meetup. He will be …

As the administrator of a cluster, among other tasks, you should be able to restore failed nodes and grow (or shrink) your cluster by adding (or removing) new nodes.
In MySQL, as a backup tool (and if your amount of data is not too big), you can use mysqldump a client utility that performs logical backups.
The results are SQL statements that reproduce the original schema objects and data.
For substantial amounts of data however, a physical backup solution such as MySQL Enterprise Backup is faster, particularly for the restore operation.
But this is the topic of my next blog post :)

The post MySQL InnoDB Cluster - Recovering and provisioning with mysqldump first appeared on dasini.net - Diary of a MySQL expert.

This is a follow-up post in the MySQL Master Replication Crash Safety series.  In the three previous posts, we explored the consequence of reducing durability on masters (including setting sync_binlog to a value different from 1).  But so far, I only quickly presented why a DBA would run MySQL with such configuration.  In this post, I present actual benchmark results.  I also present a

This post is a sister post to MySQL Master Replication Crash Safety Part #4: benchmarks of high and low durability.  There are no introduction or conclusion to this post, only landing sections: reading this post without its context is not recommended. You should start with the main post and come back here for more details.

Environment

My benchmark environment is composed of three vms in

Next in our Benefits of SQL Diagnostic Manager for MySQL (formerly Monyog) blog series, we discuss monitoring and understanding performance trends using visual analytics and the display dashboard of SQL Diagnostic Manager for MySQL. If you missed it, you can read last week’s blog on identifying and analyzing problematic SQL queries.

View and Understand Trends By Analyzing Historical Data

Configure the time duration for storing the data collected by SQL Diagnostic Manager for MySQL. It stores the data in a high-performance database (that is, the embedded relational database management system SQLite). By analyzing historical data, quickly obtain answers to questions like:

• How many times and when did database servers go down during the last six months? Which …

Fairly recently, we’ve upgraded to MySQL 8; it’s been a relatively smooth transition, however, some minor differences needed to be handled. One of them is the behavior of trailing spaces.

Trailing spaces are a (not in a good way) surprising, but also widely covered argument. This article gives a short overview, and relates it to how this affects people upgrading to MySQL 8.0.

Contents:

• Premises/Requirements
• Behavior in different contexts
  • …