Continuent is pleased to announce that the following new software releases are now available:

• Tungsten Clustering version 6.1.0
• Tungsten Replicator version 6.1.0

Release 6.1.0 is significant in that it introduces MySQL 8 support, along with many new features, stability improvements and bug fixes.

Highlights common to both products:

Improvements, new features and functionality

• Two new utility scripts have been added to the release to help with setting the Replicator position:
  • tungsten_find_position, which assists with locating information in the THL based on the provided MySQL binary log event position and outputs a dsctl set command …

In MySQL 8.0, when using invalid values for date data types, an error is returned. This was not the case in 5.x versions.

Let’s have a look using the table definition of bug 96361:

CREATE TABLE `new_table` (
  `id_table` int(11) NOT NULL AUTO_INCREMENT,
  `text_table` varchar(45) DEFAULT NULL,
  `date_table` date DEFAULT NULL,
  PRIMARY KEY (`id_table`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci

Now we can try the following statement in MySQL 5.7 and MySQL 8.0:

MySQL 5.7.26> SELECT id_table, text_table 
              FROM new_table WHERE date_table = '' OR date_table IS NULL;
Empty set, 1 warning (0.01 sec)

MySQL 5.7.26> show warnings;
+---------+------+-----------------------------------------------------------+
| Level   | Code | Message                                                   | …

Our database tools team is pleased to announce the release of our dbForge MySQL products with a CHECK constraint support. We are looking forward to seeing our customers benefit from it in their everyday work. The fact that MySQL doesn’t support CHECK Constraints syntax caused lots of inconveniences to the developers and DBAs. That deviation […]

WordPress is the largest website builder platform in the world, supporting over 34% of all websites on the internet today. MySQL is a free open source relational database management system that is leveraged across a majority of WordPress sites, and allows you to query your data such as posts, pages, images, user profiles, and more. As any WordPress developer knows, each installation requires a database in the backend, and MySQL is the database of choice for storing and retrieving your WordPress data.

In order for your WordPress website to be able to access, store and retrieve the data in your MySQL database, it needs to be hosted online through a cloud computing service. ScaleGrid offers a convenient way to setup and configure MySQL hosting for your …

Dear MySQL users,

MySQL Connector/NET 6.10.9 is the fifth GA release with .NET Core
now supporting various connection-string options and MySQL 8.0 server
features.

MySQL Connector/NET 6.10.9 is the final release in the 6.10 series.

To download MySQL Connector/NET 6.10.9 GA, see the “Generally Available
(GA) Releases” tab at
http://dev.mysql.com/downloads/connector/net/

Changes in MySQL Connector/NET 6.10.9 (2019-07-29, General Availability)


     * Functionality Added or Changed

     * Bugs Fixed

Functionality Added or Changed


     * Connector/NET now supports IPV6 connections made using
       the classic …

Overview The Skinny

Database Proxies provide a single entry point into MySQL for the calling client applications.

Proxies are wonderful tools to handle various situations like a master role switch to another node for maintenance, or for transparency with read and write connections.

However, when the time comes to perform the switch action, all of the calling clients have been funneled through the proxy, so identification of the calling host from the database itself becomes difficult.

The Problem What is going on?

Let’s illustrate how not knowing the source of a client connection can be an issue for the database administrator…

In the following diagram, three client applications connect to a Tungsten Cluster via the Connector proxy:

…

When we explore strategies to scale our MySQL-based database layer, we realize that there are many different options. As opposed to proprietary solutions, open-source products nourish themselves from their communities and novel architectures or enhanced versions are generated, often incorporating other open source technologies. MySQL is not an exception.

Other players build completely different engines aiming to mitigate some of MySQL well-known weaknesses, but still support its wire protocol, with the challenge of sacrificing as little compatibility as possible.

In this white paper, we briefly discuss the scale-up vs scale-out dilemma, to then review the different scale-out strategies. We are also going to go over some of the most common MySQL architectures and products with horizontal scaling in mind.

Finally, we will share some guidelines to …

Sometimes, the MySQL Optimizer chooses a wrong plan, and a query that should execute in less than 0.1 second ends-up running for 12 minutes !  This is not a new problem: bugs about this can be traced back to 2014, and a blog post on this subject was published in 2015.  But even if this is old news, because this problem recently came yet again to my attention, and because this is still not fixed in MySQL 5.7 and 8.0, this is a subject worth writing about.

The MySQL Optimizer

Before looking at the problematic query, we have to say a few words about the optimizer.  The Query Optimizer is the part of query execution that chooses the query plan.  A Query Execution Plan is the way MySQL chooses to execute a specific query.  It …

MariaDB 10.4 has being declared GA, and few presentations on Galera4 in the last conferences were hold.

So, I thought, it is time to give it a try and see what is going on.

It is not a secret that I consider the Codership guys my heroes, and that I have push for Galera as solid and very flexible HA solution, for many years.

Given that my first comment is that it was a shame to have Galera4 available only in MariaDB, I would have preferred to test the MySQL vanilla version for many reasons, but mainly because the MySQL/Oracle is and remain the official and main line of the MySQL software, you like it or not, and as such I want to see how the Galera4 behave with that. Anyhow Codership state that the other versions will be out AFTER the summer, and I hope this will be true.

To test the new version given I do not have the vanilla MySQL, I decide to use the other distribution coming from Percona. At the end the test …

Optimal Indexing for Performance – How to plan Index Ops. ? 

An index or database index is a data structure which is used to quickly locate and access the data in a database table. Indexes are created on columns which will be the Search key that contains a copy of the primary key or candidate key of the table. These values are stored in sorted order so that the corresponding data can be accessed quickly (Note that the data may or may not be stored in sorted order). They are also Data Reference Pointers holding the address of the disk block where that particular key value can be found. Indexing in database systems is similar to what we see in books. There are complex design trade-offs involving lookup performance, index size, and index-update performance. Many index designs exhibit logarithmic (O(log(N))) lookup performance and in some applications it is possible to achieve flat (O(1)) performance. Indices can …