Replication is one of the well-known features that allows us to build an identical copy of a database. It is supported in almost every RDBMS. The advantages of replication may be huge, especially HA (High Availability) and load balancing. But what if we need to build replication between 2 heterogeneous databases like MySQL and PostgreSQL? Can we continuously replicate changes from a MySQL database to a PostgreSQL database? The answer to this question is pg_chameleon.

For replicating continuous changes, pg_chameleon uses the mysql-replication library to pull the row images from MySQL, which are transformed into a jsonb object. A pl/pgsql function in postgres decodes the jsonb and replays the changes into the postgres database. In order to setup this type of replication, your mysql binlog_format must be “ROW”.

A few points you should know before setting up this …

Second chapter of "MySQL Cluster 7.5 inside and out".

When I started developing the ideas for NDB Cluster in my Ph.D studies
about 25 years ago, the first thing I did was to perform a very thorough
study of the requirements.

At that time I participated in a European Research for UMTS. UMTS was
later marketed as 3G. My part of this big study group of more than 100
researchers was to simulate the network behaviour. We used the
protocols developed by other groups to see what the load would be on
the various nodes in the telecom network.

I was mostly interested in the load it contributed to the network databases.
Through these studies and also by studying the AXE system developed
in Ericsson I got a very good picture of the …

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

Beyond the MongoDB content that will be at Percona Live Europe 2018, there is also a bit of an agenda for MongoDB Europe 2018, happening on November 8 in London—a day after Percona Live in Frankfurt. I expect you’ll see a diverse set of MongoDB content at Percona Live.

The Percona Live Europe Call for Papers closes TODAY! (Friday August 17, 2018)

From Amazon, there have been some good MySQL changes. You now have access to …

The first chapter from the book "MySQL Cluster 7.5 inside and out".
This chapter presents a number of key features that makes NDB
unique.

Monitoring is a concern for containers, as the infrastructure is dynamic. Containers can be routinely created and destroyed, and are ephemeral. So how do you keep track of your MySQL instances running on Docker?

As with any software component, there are many options out there that can be used. We’ll look at Prometheus as a solution built for distributed infrastructure, and works very well with Docker.

This is a two-part blog. In this part 1 blog, we are going to cover the deployment aspect of our MySQL containers with Prometheus and its components, running as standalone Docker containers and Docker Swarm services. In part 2, we will look at the important metrics to monitor from our MySQL containers, as well as integration with the paging and notification systems.

Introduction to Prometheus

Prometheus is a full monitoring and trending system that includes built-in and active scraping, storing, querying, graphing, …

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MySQL Shell is a great tool for working with MySQL. One of the features that make it stand out compared to the traditional mysql command-line client is the support for JavaScript and Python in addition to SQL statements. This allows you to write code you otherwise would have had to write outside the client. I showed a simple example of this in my post about the instant ALTER TABLE feature in MySQL 8.0.12 where a Python loop was used to populate a table with 1 million rows This blog will look further into the use of Python and more specifically external modules.

…

Introduction As I explained in this article, multitenancy is an architectural pattern which allows you to isolate customers even if they are using the same hardware or software components. There are multiple ways you can achieve multitenancy, and in this article, we are going to see how you can implement a multitenancy architecture using the … Continue reading Hibernate database catalog multitenancy →

The post Hibernate database catalog multitenancy appeared first on Vlad Mihalcea.

You don’t need this tutorial if you have access to the root user or another one with SUPER and GRANT privileges.

The following instructions works for MySQL 5.7. You will need to stop the MySQL server and start it with mysqld_safe with the option skip-grant-tables:

sudo service mysql stop
sudo mysqld_safe --skip-grant-tables &
mysql -u root mysql

If you get an error on start, chances are there is no folder created for the mysqld_safe executable to run, on my tests I was able to solve by doing:

sudo mkdir /var/run/mysqld
sudo chown -R mysql:mysql /var/run/mysqld

And then trying to start the mysqld_safe process again.

After this, the MySQL console will pop up, and you need to set up a new password for root. The second line is necessary due to a MySQL bug # …

Dear MySQL users,

MySQL Connector/NET 6.10.8 is the fifth GA release with .NET Core
now supporting various connection-string options and MySQL 8.0 server
features.

To download MySQL Connector/NET 6.10.8 GA, see the “Generally Available
(GA) Releases” tab at http://dev.mysql.com/downloads/connector/net/

Changes in Connector/NET 6.10.8 (2018-08-14, General Availability)

Functionality Added or Changed

* Optimistic locking for database-generated fields was
improved with the inclusion of the [ConcurrencyCheck,
DatabaseGenerated(DatabaseGeneratedOption.Computed)]
attribute. Thanks to Tony Ohagan for the patch. (Bug
#28095165, Bug #91064)

* All recent additions to .NET Core 2.0 now are compatible
with the Connector/NET 6.10 implementation.

* With the inclusion of the Functions.Like extended method,
scalar-function mapping, and …

Recently, we initiated a new project, the Open Source Database Community Blog. One way to think of this is as an online, year round version of the Percona Live conferences. If you have a story to tell, an experience to share, or a lesson to be learned send it along. As long as it’s related to open source database software, their management and application. That’s right. Not just Percona software. Any open source database software of all formats.

Unlike Percona Live, though, we are not limited by time or space. All submissions are welcome as long as they follow some simple guidelines.

We have already had some excellent posts, and in case this is news to you, here’s a recap:

• Renato Losio wrote this succinct how-to article …