M359 - TMA01

Well, thats it. TMA 01 is submitted, for better or worse. I try and not submit TMA's until almost the last minute just in case something occurs to me (along the lines of: "So thats what the question meant! I'll have to redo all that bit"). But I found that for the last week or so I have just been fiddling and tinkering with it but not really making it any better. So the time has come to put it to rest and see what comes.

Never quite sure with a new course just how the marking is going to go, so all I hope at present is that I haven't fluffed it and have taken the correct approach and level in answering the questions. What I would like is to achieve above the 85% line (and generally, in previous courses, I do). But ...

M359 - Self-Help Session

We had our first 'self-help' session at Saturday. These sessions are rather like the chat you might have over a canteen table at a bricks and mortar university. We get the chance to meet up, talk about what we find difficult on the course, encourage each other and generally help each other out. I find these really useful, especially when I feel that I am stuck. It always useful to get someone else's take on something - perhaps they have a different point of view, perhaps they interpretted something differently. It all helps to widen out the way we think about problems and how we tackle them.

The only problem with these sessions is that so few fellow students turn up. On Saturday there were just three of us. Don't get me wrong, we covered a great deal of ground and it was very useful - but I am sure that other students would benefit too, and the more voices that chime in, the more we all learn.

But it is odd. When I did M206 a couple of years ago we held regular self-help sessions and only three or four people ever turned up for those too. And here's the really odd thing - on previous courses, the people that needed the help and advice the most where the ones who didn't turn up. Explain that!

OU Future Courses

Although I am working towards a Computing Degree, one of the modules that I have been wanting to do was S103 "Introducing Science". I heard towards the end of last year that S103 was being withdrawn and replaced by S104. I thought that I would wait for S104 on the assumption that it would be more up-to-date.

So I was surprised this morning to learn that S104 can not be counted towards my B13 Degree. A dilema! Do I enrol for the last run of S103 starting this September - which screws up my schedule, or do I wait until I have completed my B13 degree by other means (iem by NOT including S103) and then do S104 in a few years time?

Well, if you don't the answer to a question, ask someone who does know! So I contacted the OU this morning. The answer is that S104 CAN be counted towards B13 as the free-choice 60 points because the B13 already has 300 pts of compulsory modules. So it was worth asking! I can do S104 next year as planned after all.

M359 - Conceptual Data Model - problems

Its been a frustrating week. In the course materials we are given a scenario for a University (well, what a surprise!) and a Conceptual Data Model that goes with it. The problem that I have had is that the Entity-Relationship Diagram shows an entity called Staff and another called Course (there are many other entities too). These two entities are linked by a one-to-many 'TelephoneTutoredBy' relationship with the 'one' being at the Course end and the 'many' at the Staff end. My reading of this is that each Course must have one, or more, staff members who do TelephoneTutoring for it. There is also a constraint that says that the staff member doing the telephone tutoring must also tutor at least one enrolment on that course. All pretty straight-forwards.

But the course text then went on to say that a staff member could ONLY telephone tutor on ONE course - and I couldn't see where this was stated in the Conceptual Data Model - there didn't appear to be any constraint anywhere saying that. I raised this as a question on FirstClass. Some responses said that the phrase "...staff member can only be a telephone tutor for a course if they are..." really meant "...a staff member can only tutor for ONE course if they are...". I don't buy the idea that 'a' really means 'one' - its ambiguous. If they had meant 'one' then they would have written 'one', surely. Another respondent suggested that it didn't matter and that I should just ignore the ambiguity (really!). After several days of pondering over this, there was a posting by the conference moderator who had written a guide to interpretting CDM's that went some way towards explaining the situation - but I still felt uneasy.

In the end I think the penny has finally dropped - the Entity-Relationship Diagram is only part of the model. Following the ERD is a list of 'Additional Constraints' that go on to clarify, or complement, the ERD. I think my problem was that I had glossed over the word 'Additional' and had interpretted it as being the textual representation of the diagram (ie; two facets of the same thing - they are not).

Having said that, I still don't see anywhere in the whole Conceptual Data Model where it says that staff can only TelephoneTutor on one course - but I am going to let it lie - the course text clearly make the assumption that it is.

Time to worry about the TMA!

Someone has read my blog at last!

Had an email from my fellow student, Ian Macey, to say that he found this blog while googling. Ian, to my knowledge, you are the first and only person to read this blog! For a long while I had considered this to be a 'write only store' - a place where I just dump out an opinion or thought and that never gets read. Actually, the act of writing it is rather cathartic. I also have this picture in my mind of that lonely late -night radio DJ speaking into his microphone not knowing whether anyone is actually listening - but somehow enjoying the experience.

M359 - Constraint Checking

Just had an interesting, but inconclusive, FirstClass conversation regarding turning off Constraint Checking while performing a bulk load of data into a database. My view was that we have constraint checking for a very good reason: ensuring that the database remains consistent - because as soon as the data is inconsistent it then become unreliable, and if its unreliable then people will not use or trust it. So its pretty important!.

So the idea of turning off constraint checking during a bulk load sounds almost like suicide to me. But, it was pointed out that during a bulk load you are probably populating one table at a time, and if the table that a constraint depends upon is currently empty then the import will fail. So you HAVE to turn off constraint checking. A side effect is that it speeds up the import - well, to me that would be a side effect, but it has been suggested elsewhere that it might be considered to be a primary motive (!?).

But what really bothers me here, and so far no one has been able to convince me otherwise, is that if the data you are importing comes from another source over which you have no control, how do you know that the data is already consistent? And if it isn't consistent, and you have constraint checking turned off, you now have an inconsistent database! That can't be right.

One of the contributers to the discussion said that when constraint checking is turn back on after the import, error messages will be issued for any constraint that fails. I guess this is some help.

I'm still not convinced - there must be more to this.

M359 - Books

I have been reading this book by Chris Date. I have often found that reading the course books supplied by the university is not enough - not that I think that the university books are bad, they're not - its just that sometimes I need to see things written differently before they sink into my dense numbskull of a brain that I have.

Anyway, I like this book. There's no doubting that Date knows his field. And he worked alongside Ted Codd. Its also clear from the outset that Date's view of SQL is, how shall we say, not very favourable. In fact, on Page 2, he states "SQL /= The Relational Model" and goes on to say that if your only knowledge of the Relational Model comes from your knowledge of SQL then you don't know the Relational Model!. He couldn't really be any ore clear than that.

I like his writing style. Quite short and succinct. A little bit of humour - but just enough - not like one computing book I started to read, where the author dribbled on advising his readers to go and get a coffee while they thought about some stunning statement he had just made. He lost me as a reader almost immediately! Strangely enough, I can't remember the name of the book, or the author - thats the kind of impact it made upon me. Anyway, I digress.

But its early days - I'm still only on chapter 1. But my gut feeling right now is that I will last out until the end of the book and that it will help me with this course.

M359 - Studying Technique

I prevaricated earlier about which note taking technique to use. On previous courses I have taken copious hand-written notes and found that I very rarely ever went back to them, although the process of note taking seemed to help some of the information sink in.

This time I have forsaken the pen and paper approach and have been making notes in Microsft Word. Trouble is, I have realised that I am making even more notes than ever. This is going to make life harder than it need be I fear - so I have to find a way around this. I have also started to create my own glossary of terms (since one is not supplied as part of the course). For this I am using a good and trusty text editor. I can then use the sort command in the editor so that my glossary stays in alphbetical order. And in case you are wondering which text editor can sort lines, the anser is 'Kedit'. Kedit is based upon, and very similar to, Xedit that is used on IBM VM/CMS systems. I started using Xedit back in 1983 (when, for me, it replaced 'Edgar' its fore-runner). Xedit has always been a favourite of mine - very flexible, a decent language for writing macros (that language being REXX). So the editor is fully extendible, provides all kinds of sorting, manipulation and so on.

M359 - Making a Start

At last I am under way with M359. One week in and I have just finished chapter two of the first course book - which means that I am a week ahead of schedule. But there is to be no let up - I know that if I let it slip then it won't take long for me to be behind schedule, and catching up is always hard to do.
So, we have covered the usual sort of stuff for the beginning of a course - what is data, what is information, what happened with data historically - Mesopotamian tablets, 15th Century Tally Sticks, 16th Century Parish Registers. How computerised databases came about, why was there a need, what types, how they have evolved.
Now we have getting down to the three-schema model, seperation of concerns, and all that stuff.
First TMA is also available and due to be started yesterday but covers subject matter that, officially, we don't cover on the course for another two weeks!

Keep it comming.

M359 - Some progress

Still worried. I have access to the M359 Course Website as of yesterday, and to the M359 First Class Conference as from this morning - but still no sign of any course materials. That's nine days now since they were dispatched. I wonder which company they use for their deliveries.

In the meantime, I am puzzled as to why there is only one conference for M359. With other OU courses that I have studied there have always been several conferences - a general social chit-chat conference, a general course conference, a tutor-group conference, and then a seperate conference for each TMA. I hope that these other conferences will start to appear soon - the OU must have know that M359 was starting in February!

M359 - Still nothing

Well, two days to go until the course officially starts and still no sign of any course materials, access to the course website, or to the Course Conference on First Class. So, being slightly worried about this I telephoned the OU Computing Help Desk and explained the situation. A few checks by the man on the phone and his response was 'oh yes, you do seem to have some services missing' (which is fine, but I had already guessed that bit!). He said he will forward the request on to the appropriate team at the OU so that they can give me access. The good (I hope) news is that their records show that the course materials where dispatched by land-snail on 24th January.

So.....I'll just keep waiting and hoping.

Also today, I had an letter from the course Tutor, Dorothy Carrier (or, Dot Carrier, as she prefers to be called), just welcoming us all to the course and giving us some of her background. A useful letter I thought. I have responded by email and relayed some of my background to her.

M359 - Study Techniques

For each of the courses that I have done so far, I have used slightly differeing techniques for studying - and I was reviewing some of these yesterday. One thing I noticed that was common to all the techniques is that I tend to write down far to many things. I was looking at my notes for M206 that I did a couple of years ago and see that I managed to fill two A4 hardbound books with everything you could think of (and more). But I am not sure that it helped - especially at revision time - too much to take in, drowning in data but lacking in concise and clear information. In fact, when I studied MU120 I definitely found it hard to use my notes.

So, what to do? Two choices I guess. I could really cut down on my note taking, or, I could produce some kind of index to all my notes.

I think I favour the former approach for two reasons - one is that it takes so long to make all these notes, and thats time that could be better spent doing practical work and, secondly, having spent so much time making notes, I'm not sure that I want to spend even more time creating indexes. Unless I can find some good note taking software that will doing my indexing for me.

Watch this space....

M359 - Dispatch update

Good news according to my StudentHome page at the OU. It now says that I registered for the course on 23rd January (correct) and that the course materials for blocks 1 and 2 where dispatched yesterday. Hoorah!
Looks like my fear of starting the course without any course materials was unfounded - so just waiting for my friendly postman to deliver the package.

But I took the opportunity to read through the pdf course guide that I was sent yesterday (full of useful info about the course - what each block covers, how long it is expected to take etc) and noticed that Block 5 (out of 5) covers such topics as using Java and JDBC for connecting to databases and executing either SQL directly, or running Stored Procedures. This is great - and just what I have been doing at work this week. It's always comforting to know that a course is not going to be completely alien to me!

M359 - Course books

Well, having signed up for M359 at the last minute I am now in the situation of being on a course for which I do not have any course books!

Luckily, Ian Macey has emailed me the pdf's of the first block so that I can keep up-to-date (don't worry OU People, these pdf's aren't going anywhere, its just until you send me the real things in the post!).

So thanks Ian, at least I can see what we are all in for!!

M359 - Registered at last!

Aha! Good News - Email from the OU Student Registration dept to confirm that I have been successfully re-registered for M359. A relief - I was half convinced that my email would be at the back of a stack of others and not be acted upon until after the closing date for the course. I needn't have worried.

All I have to do is to worry about the course!

OU reply to my question

Received a reply from the Open University to my question about whether they had any information regarding the M358 and whether students had found it beneficial in a commercial environment. The answer from the OU is that it is a hard question to answer! Essentially what they are saying is that they don't know - and that they don't monitor the course from that perspective.
The reason that I posed the question is that I couldn't make up my mind whether studying M359 (the successor to M358) would be useful from a career point of view. As it turns out, the reply from the OU is pretty much what I anticipated, but have decided to register for the course - I think it will be useful - maybe not directly, but certainly indirectly.
And that brings me onto a curious incident that occured this evening......Having decided to register for M359 (and knowing that as a current student the registration is open until 26th January) I went to the online registering pages only to find that you can only register online for the 2008 course!. So I telephoned the Student Registration number only to be told that I had to apply in writing (Fax or Email will do, apparently). An email was sent off immediately and now I just have to hope that the email is seen and acted upon before Friday - the closing date for applications! More stress!

M359 - here we come!

Well, after enjoying the result from my last course, and taking it easy over Christmas and the New Year, have finally decided to do what I said I would and sign up for M359 "Relational Database Theory and Practice" with the Open University. I promised myself that if I managed to get a Distinction in M254 that I would do this course next, so now I am keep my promise.

Registration for the course closes on 26th January. Today is 18th so I phone the OU Registration Desk just to check - they confirm that I have until 26th and that there are some places left. All I need to do now is wait until Monday (because I need some confirmation on another matter before I know for sure that I can proceed witht this) and then enroll.

It turns out that the course has a start date of 3rd February, so I'm not sure that my course books and materials are going to arrive in time - but thats the penalty you pay for a late registration - just means that I'll have some catching up to do - and I'd rather have to catch up at the beginning of a course before it gets too difficult than half way through!

I had an email chat with Ian, who studied M206 in 2005 att he same time that I did, and he is also doing M359 so at least there will be a friendly, and helpful, face. I think that Nick A is also doing it, so that will be two friendly faces!

Lets see how it goes.

A man of Distinction!

Forgot to say what the result was: Distinction!

So you see, all that self-doubt was wrong, all that hard work paid off.

The problem now is what to do next. I had enrolled for M359, a top level course in Relational Database Design and Use (or whatever the correct title is), but then pulled out. I needed some time to myself, to catch up on family life, to catch up on a few good books (and if you are into travel books then I highly recommend William Dalrymple as a writer. I read his first book "In Xanadu" when it was first published - 1989 I think, and only got around to reading another of his books this year - "White Mughals". I was so enchanted and thrilled by this book that I then read "City of Djinns" and already have "From the Holy Mountain" lined up to read. Of course its wrong to think of Dalrymple as a 'travel writer' - though thats the bookshop section he usually ends up in - what he writes is more about people, culture, history, and place..and has the most fantastic eye and ear for wit, detail, smell, and colour).

I digress. What I was meaning to say is that I enrolled and then un-enrolled from M359 and decided to wait for the result of M254. I figured that if I got a Grade 2 then I would postpone further study for the year - just to take a well-earned break. But I also figured that if I gained a Distinction then I might plough ahead to jump into M359 and get it out of the way before the end of next year. I'll then be one step nearer my Diploma in Computing and another step nearer my BSc.

So watch this space!

M254 - Exams

Well, some while since the last posting! In fact, just after my previous ramblings I sat a 3 -Hour exam for the M254 course (October 11th 2006) and have been waiting until December 15th for the results to be posted. So today is December 14th but the results are now available. I was very confident that I had passed the course but not too sure how well I had fared in the exam. I really needed to achive at least 85% in the exam to get the Distinction that I really wanted, but had figured that a Grade 2 was the more likely outcome. Course work had been fine - a couple of 98% and a couple of 89% gave me a comfortable 94% overall on the marked course work. But the exam - well thats another matter altogether, no notes allowed, no reference sheets, no nothing, just a head full of half-remembered facts. I'm alright recalling concepts, knowing how things work, how things fit together (so to speak), but details and isolated facts present a problem sometimes. And that, I was sure, would be my Achilles Heel in the 3 hour chamber of hell.
I managed to complete all the questions in the given time and actually had 15 minutes spare in which to ponder and prevaricate over some answers I had given. One small flash of inspiration during that period help make a better answer for one of the questions. And that was it.
Finished, complete, consigned to history.

M254 - Tic-Tac-Toe

Well, long overdue for an update. And the reason for my silence, I hear you wondering, is that I had my head burried deep in TMA04 for M254. The task given was to create a client/server system that could be used for playing board games. Specifically, we were asked to write one for playing "Noughts and Crosses" (or "Tic-Tac-Toe" if you're American, which I'm not). There was no game logic required because this wasn't a case of man versus machine (at least, not in the game playing sence - although it felt like it times in the programming sence!). All that was required was that a game-server would be able to manage concurrent games being played by pairs of players who were connect over TCP from their client machines. The server would have to maintain the state of the each game, announce whose turn it was, and advise of interesting situations - like winning or drawing. The client side code had to create a game interface and send messages to, and receive messages from, the server.

Nothing too challenging or strenuous really. Once the server was working for managing a single game between two players, it had to be extended to handle multiple concurrent games - ie by using threads.

Good news - I wrote it all in time - and it worked. Not perfect code - even I could see that but a score of 89%, although my lowest of the course, is still satisfactory and means that, depending on how I do in the exam (!), I could still get a Distinction for this course.

We'll see.