Database

Database normalisation

Redundancies occur when various details are combined in a single database table. These redundancies use up storage capacity and prevent efficient data processing. The relational database model offers strategies for splitting datasets among several linked tables, in a process called database normalisation. Find out what it’s all about with practical examples.

Raspberry Pi at a glance: 10 great Raspberry Pi projects

Raspberry Pi is an inexpensive small form factor PC that can behave like a standard computer in many respects. Users can use this innovative mini-computer for all kinds of functions, from setting up an operating system to surfing the web, to using it as a server or a media center, and much more besides. Discover 10 interesting Raspberry Pi projects to try out at home.

Protect sensitive data with a strong password

It only takes a few seconds for a hacker to gain access to your private data without you having any idea. More often than not, a password is the only means of protection when logging into online services; and if it is too obvious, it will not prove too much of a challenge for criminals to crack. There are numerous options to increase password security.

SQL JOIN

A major strength of the relational database model is that information is stored in separate database tables structured according to semantic relationships. This concept, known as normalisation, is the basis for data storage that is as redundancy-free as possible, but requires a mechanism with which data from different tables can be merged for queries. The different JOIN types provide users with...

SQL OUTER JOIN

OUTER JOINs are queries that take place across several database tables. There are LEFT OUTER JOINs, RIGHT OUTER JOINs and FULL OUTER JOINs. Each of these JOIN types has a larger result set than the INNER JOIN. But what exactly is the difference between the individual types? Here, we will distinguish OUTER JOINs from INNER JOINs, compare the different subtypes of OUTER JOINs and explain how they...

Relational databases

With relational database systems, you use tables to store and manage information. This sounds simple but involves quite complex concepts such as normal forms, key relationships, and JOINs. This article will introduce the basics of the relational database model, compare its advantages and disadvantages, and delimit this type of data storage from alternative approaches, like object databases,...

Set up ownCloud with Raspberry Pi

With ownCloud software, your Raspberry Pi can be used as a private cloud, performing the same kind of tasks as clouds from major providers such as Google, Amazon, and Dropbox. Cost-effectiveness is just one of many the benefits of creating your own personal cloud; another is the privacy and security of your data. This step-by-step Raspberry Pi cloud tutorial explains how to set up ownCloud.

MongoDB: an introduction and comparison to MySQL

NoSQL databases have long since been serious competitors to classic relational database systems, like MySQL. They replace the strictly-defined storage structures of traditional models through flexible saving procedures. This allows data pools to be easily distributed onto multiple servers in order to guarantee high availability of web applications. But are these new systems really all that they’re...

What is Big Data?

When we shop online, book holidays, and search for gift ideas, we hardly give a second thought to the fact that each search entry leaves behind a trail of our identity. Busy web bots are never far behind and sweep up this information. The result of all of this is Big Data: massive volumes of data that is analysed and used for a variety of reasons. But is there reason to be wary of leaving behind...

How does data backup work for databases?

Backing up your data is a popular option for securing your database. In order to create backup copies, you need additional hardware and to install a suitable backup structure. How do you secure your own network and web server against attacks and proceed to protect your databases?