I’m currently doing a part time degree in Internet and Information Technology and earlier this evening I finished the databases module (I hope!) with a 2 hour exam. So I can now empty my head of the following:
- Normalisation
- Entity Relationship Modelling
- Formal Database Models (Network, Hierarchical and Relational + Others)
- Types of DBMS (Database Management System)
- The Layers of Abstraction (External, Logical and Physical)
- Transactions – The ACID model
- Serial / Serializable Execution
- Concurrency Control Methods
- Two Stage Commit Process
- Locking methods (Exclusive, Share, Pessimistic, Optimistic)
- Timestamping
- Distributed Databases
- Horizontal and Vertical Table Fragmentation
- Lost, Assumed and Phantom reads
- etc…
Well maybe not, some of it might actually stick!
At least it brings to an end 3 weeks of hard graft and 2am+ nights / mornings. I’ve had to do a group project about websites (lots of PHP coding plus Apache security tweaking), a presentation of that, a two part assignment (1500 word essay and 15 SQL questions) and an exam. The latter two of which were due in the same day (today). So I’ve had to make sure I was organised, but I still had to take some days off work to make sure I was prepared enough. Which is a bit annoying, since I took extra time off work at the beginning of January to get a start on it. Thankfully where I work is very understanding.
Getting back to databases, I found Databases Demystified (book) incredibly useful. It was the cheapest database book at the local Waterstones, but I doubt any of the the others could do a better job. It covered pretty much everything except distributed databases and table fragmentation. The notes we were given were a bit lacking in substance and examples so I needed something!
I found tons of stuff on the net as you’d expect, but it was hard to work out what was right and what was wrong. I found a great example on distributed databases two phase commit (its like a wedding apparently) but it never came up in the exam (I thought it might do, it was in the previous years). I read one example about vertical and horizontal tables where 3 “experts” answered a related question. The first chap waffled on and mixed the two up, the second was straight to the point and the third obviously didn’t care! The majority of stuff just isn’t worth a light.
Sadly Wikipedia fairs no better and is average to poor on the subject. Don’t get me wrong, there is a lot of stuff there, but some of its badly written, poorly linked and at worst inconsistent. I’ve gone and edited a page or two so they link together better but what it really needs is an expert in the field to give the entire section a good going over. Amusingly I thought that back in December when my first databases assignment was due and now some of the pages say exactly that.
With that over with, I’ve got a two one week break until the second semester fires up!
