A Little Database Theory – Part 3

At last! My original intention was to write an article about the difference between relational calculus and relational algebra. In order to get here we needed to see what databases looked like before the relational model and what the relational model actually means....

A Little Database Theory – Part 2

The first part of this article discussed what databases looked like before Codd’s seminal paper in 1969 introduced the relation model. This post describes what the relational model actually is. By the way, the last article gave some examples from non-relational...

A Little Database Theory – Part 1

The other day I came across a forum on the web and spotted a post by someone who wanted to know the difference between relational calculus and relational algebra. As happens so often on the web, all of the responses were written by people who had virtually no idea...

Turing Machines and the Turing Test

  Everyone these days has heard of Alan Turing, the father of computer science, the man who cracked the Enigma code and the eponymous “inventor” of both Turing Machines and the Turing Test. Science fiction tends to conflate the two, but they are...

So What exactly is a Virus?

We all have anti-virus software and naturally  take precautions against viruses, but do we know what a virus actually is? It’s obviously a piece of software that does something nasty, but how does that nastiness manage to find its way onto our computer? The...