The horror that is M359 continues. I’ve just finished Block 2, the final part of which was all about Normal Forms – 1NF, 2NF, 3NF, BCNF… The chapter started with the ominous warning that…

..students often find the topic of normal forms to be quite difficult. Be aware that you might have to spend more time on this section than on some of the previous sections and that you may have to read parts of the material several times.”

It then launched into a series of examples and mathematical definitions of the various Normal Forms, and I admit a lot of it just went whoosh over my head – I was working through the relevant TMA question along with the chapter, and the chapter introduction wasn’t wrong about having to read and re-read everything before enough of it sank in to make the TMA understandable, never mind doable. Not a pleasant experience.

But right at the end of the chapter, the short section of BCNF takes all that information, all the finding of Functional Dependencies, all the details explanations, and cuts it down to one simple concept: if you have a relation with duplicate data, project over it to create 2-3 new relations that match the FDs. If you still have duplication, do it again. Read that, it looks to be as though 1NF is your original table, 2NF is 2nd attempt (after splitting once), 3NF the third attempt (after splitting twice) – and put like that, it suddenly seems so much more simple.

Now why couldn’t they have put it like that in the first place!? The obvious answer is that the exam is going to ask about the gory details behind the fairly simple explanations – that worries me, but for now I’m just glad to get another chapter out of the way. Onwards to SQL itself…