Wikipedia says that “Relational calculus is essentially equivalent to first-order logic, and indeed, Codd’s Theorem had been known to logicians since the late 1940s.”  I couldn’t find the cited sources online, but did find these interesting papers:

“Applications of Alfred Tarski’s Ideas in Database Theory”

and

“Tarski’s influence on computer science.” (see the section starting “The final thing I want to tell something about is the connection of Tarski’s ideas and work with database theory.”)

If you’ve studied mathematical logic (or math, eg, topology), you are probably familiar with Tarski’s name.  The historical …

The call for participation for Percona Live Data Performance Conference 2016 is still open. Deadline for submission is November 29th.

There are two immediately noticeable novelties in this edition:

• The name change. Not "MySQL & Expo" but "Data Performance Conference." It makes the conference open to a broader set of topics.
• The community voting. Proposals can get evaluated by the community before the review committee takes decisions.

I think it's a good choice. Other conferences adopt the same method. The attendees choose what they want to see and hear. In this case, it's mixed method, where the community voting is used as an indication for the review committee, which, by my understanding, has the final say.

Vote for my proposals!

Below are my proposals. Clicking on the links below will …

The MariaDB CONNECT storage engine offers access to JSON file and allows you to see a external JSON file as a MariaDB table. A nice feature of the CONNECT storage Engine is its capability to auto discover a table structure when the table correspond to external data. In our case the CONNECT storage engine will automatically [...]

Introduction

Consensus is a key component to providing fault-tolerant services such as synchronously replicated data stores, non-blocking atomic commitment and Paxos and Raft are among the most popular consensus algorithms. Paxos has been widely studied by researchers while Raft has become very popular among engineers.…

A friend of mine asked me how they could automatically follow and unfollow people on Twitter. But they didn’t want to follow just anyone and everyone. He had a Twitter account which they used for recruiting in a very narrow construction industry.…

In the past four posts of the blog series, we covered deployment of clustering/replication (MySQL/Galera, MySQL Replication, MongoDB & PostgreSQL), management & monitoring of your existing databases and clusters, performance monitoring and health and in the last post, how to make your setup highly available through HAProxy and MaxScale.

So now that you have your databases up and running and highly available, how do you ensure that you have backups of …

The MariaDB project is pleased to announce the immediate availability of MariaDB 10.1.9 and MariaDB Connector/J 1.3.2. See the release notes and changelogs for details on each release. Download MariaDB 10.1.9 Release Notes Changelog What is MariaDB 10.1? MariaDB APT and YUM Repository Configuration Generator Download MariaDB Connector/J 1.3.2 Release Notes Changelog About MariaDB Connector/J […]

The post MariaDB 10.1.9 and Connector/J 1.3.2 now available appeared first on MariaDB.org.

MySQL introduces several improvements related to partitioning. Most importantly, work has been done to move InnoDB towards native partitioning support, which not only "paves the way for better overall partitioning" (source) in the future but already comes with measurable performance benefits.
This article focuses on memory usage in heavily partitioned InnoDB databases.
Background Over the last few weeks I've been (un)lucky enough to work with several MySQL databases suffering from stability issues due to extreme memory pressure. All databases belonged to the same DBA team, who tend to apply complex partitioning schemes even to very small tables. Discussion as to whether or not this approach is correct is beyond the scope of this article but the situation encouraged …

MySQL Server 5.7 was released around a month ago, and download numbers show huge interest in upgrading from older MySQL releases. As with any product that is frequently used as core infrastructure in complex systems with numerous interdependencies, major version upgrades of MySQL should be approached with some care. In this post, I will cover […]

Starting with the new release MySQL 5.7 there is support to store JSON documents in a column. During our recent Tech Tour events we got questions about document validation, so ensuring that a JSON document has a certain structure. (Funny. It all started with the idea to be schema-free. Now people seem to need schema enforcement.)
I have two ideas how to implement a schema validation for JSON columns. The first one is by leveraging generated columns together with a foreign key. The second idea is by implementing a trigger. Today I want to focus on the generated columns and foreign keys.
When defining foreign keys with generated columns there are two limitations we need to be aware of:

• Foreign keys require indexes. JSON columns cannot be indexed. We need to leverage other types.
• Only STORED generated columns are supported for foreign keys.

So here is an example of an address table that …