Less redundancy thanks to database normalization

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 normalization. Find out what it’s all about with practical examples.

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...

INNER JOIN: definition and application

The INNER JOIN is the most important JOIN type in the relational database model. If you want to query database tables in a group, you would usually use INNER JOINs based on equality relationships between primary and foreign keys. We will show you how to use INNER JOINs in practice, delineate the JOIN type from OUTER JOINs, and also deal with the different subtypes of INNER JOINs.

SQL JOIN – queries across multiple data tables

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 normalization, 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...

All you need to know: what is a hostname?

A computer’s unique name on a network is the hostname, site name or computer name. The hostname is part of the fully qualified domain name, which can be used (for example) to find and access websites on the internet. Here you’ll learn what a hostname looks like, and we’ll show you various ways to determine the hostname using an IP address or how to change it.

The relational database model

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,...

Hyper-converged systems: The compact data center

The traditional data center could be significantly streamlined by migrating to a hyper-converged system. By eliminating the need for highly complex infrastructures and multiple work areas, the company’s IT department could function more efficiently, dynamically, and cost-effectively. This is made possible using preconfigured standard hardware and a complete virtualization of the IT infrastructure....

QUIC: What is behind the experimental Google Protocol?

Quick UDP Internet Connections (QUIC for short), is an experimental network protocol from Google. Further development of the protocol is being driven by IETF, which has set up a dedicated group working towards it. The QUIC protocol is intended to offer a speed-optimized alternative to the current transport standard TCP and builds on the connectionless protocol UDP to achieve this.

HTTP Error “405 Method Not Allowed”: How to solve the problem

HTTP is indispensable as a mediator between the browser and web server: Both communicate with each other using the transmission protocol on the application layer by sending various types of messages. With an HTTP request, for example, the browser can request a resource or return its own data to the server. If one of these HTTP methods doesn’t work, error 405 (Method Not Allowed) occurs. But what...

Error 401: Unauthorized – No access to the website

You’re surfing around on the internet, but instead of getting the desired content you only receive an error message: annoying or even downright frustrating. Especially if you don’t exactly know what the status is supposed to mean. How are you expected to solve the problem, if you don’t know what’s causing it? This also goes for the error 401. Here we explain what the error means and what you can...