WJEC CG3 January 2013

What a brilliant paper, couldn't have asked fr anything better. Myself, i never did the dry run of the equation. Wanted to come back but never had the time, every other question was good, 1 or 2 i may have slipped up.

Big marker ones were good, compilation, file structures, etc. The programming one was good, as was the BNF and the 3rd Normal form.

The only one which i had no clue was the "Why not store the age"? I was like why!!!!??? So i just wrote that it will need regular updating? May as well try for the mark. All in all. Good.

Exactly what I put - store the date of birth so it doesn't require updating every year.

Did anybody have a Town table for the 3NF question? I was debating whether to put it in but decided against it in the end - for some reason I wasn't very confident on that question.

Reply 61

Huwtrosky

Original post by Enginerd.

What a brilliant paper, couldn't have asked fr anything better. Myself, i never did the dry run of the equation. Wanted to come back but never had the time, every other question was good, 1 or 2 i may have slipped up.

Big marker ones were good, compilation, file structures, etc. The programming one was good, as was the BNF and the 3rd Normal form.

The only one which i had no clue was the "Why not store the age"? I was like why!!!!??? So i just wrote that it will need regular updating? May as well try for the mark. All in all. Good.

I said the age needed updating. Date of Birth would be better because it would be a constant variable. Bar that dry run question the rest of the paper was amazing

Reply 62

Huwtrosky

Original post by PatrickM

Exactly what I put - store the date of birth so it doesn't require updating every year.

Did anybody have a Town table for the 3NF question? I was debating whether to put it in but decided against it in the end - for some reason I wasn't very confident on that question.

I had tables for bookings, pupils, instructors and branches

Reply 63

archdd

6

Original post by Huwtrosky

I had tables for bookings, pupils, instructors and branches

Same, my primary key for branches was town though because it said one branch each town o_O

Reply 64

Huwtrosky

Original post by archdd

Same, my primary key for branches was town though because it said one branch each town o_O

that should be fine if each town is unique I just did Branch ID as the primary key

Reply 65

archdd

6

What did everyone put for the 10 mark question?
I was fairly confident with sequential files but not for the other two.

Sequential:
Advantage - Faster when many records are to be accessed
Disadvantage - Slower when individual records are accessed
Adding - Copy until location , add record, copy rest
Removing - Copy all and skip the ones to be removed

Random Access:
Advantage - Faster for individual/direct access
Disadvantage - Slower for access to many
Adding - Hashing algorithm / Overflow area
Removing - Was not sure, I just said it uses the hashing algorithm to find the location of the record and remove it

Indexed Sequential:
Advantage - Two kind of access depending on situation
Disadvantage - Data integrity issues? I put both files need to be updated and harder to create/maintain
Adding & Removing I didn't felt the need to repeat it so I just said as above :s

Reply 66

vinnie667

Thought it was a very easy paper, wasn't too sure why computers would need to use analogue data though, other than that it was all fine.

Reply 67

vinnie667

Original post by archdd

Me neither I kept writing it out and it was like 0,1,1,2,3,5,8,13... So I said it was the sum of the last two values of the function.

fibonacci sequence

Reply 68

Enginerd.

21

Original post by LewisRichardson

What more could you ask on a paper like this? They were practically giving marks away with multiprogramming, compilation and the last question. The BNF and third normal form were straightforward. The only tricky part was the algorithm in the middle I suppose.
Also above guy, you're right with that database question.

Oh thats good, DOB would have been a good replacement, but i quickly wrote address down before the time was up. Reckon i have the 2 marks??

Original post by PatrickM

Exactly what I put - store the date of birth so it doesn't require updating every year.

Did anybody have a Town table for the 3NF question? I was debating whether to put it in but decided against it in the end - for some reason I wasn't very confident on that question.

DOB would be a good option, but you reckon address would also give me a mark?
And theirs only 1 town per branch, so i did branch and primary key as Townname

Reply 69

vinnie667

Original post by Enginerd.

Oh thats good, DOB would have been a good replacement, but i quickly wrote address down before the time was up. Reckon i have the 2 marks??

DOB would be a good option, but you reckon address would also give me a mark?
And theirs only 1 town per branch, so i did branch and primary key as Townname

I used address as the primary key for branch, which is correct. Also Branch id could have been created and used

Reply 70

vinnie667

Original post by nm786

I think i messed this paper up big time! :frown:

how come ? :/

Reply 71

vinnie667

Original post by nm786

I revised a lot for this paper but when I went into the exam hall I just couldn't remember stuff such as definitions such as what scheduling is and I just don't think i got most of the marks :/
I did finish the paper and wrote down what i could remember but i got a feeling i messed up really badly. :frown:

did you do all the past papers?

Reply 72

LewisRichardson

7

What was a computer application for a stack? I couldn't think of one :frown:

Posted from TSR Mobile

Reply 73

PatrickM

Original post by LewisRichardson

What was a computer application for a stack? I couldn't think of one :frown:

Posted from TSR Mobile

I used the 'undo' function on a word processor - actions placed into a stack or something. I don't think I'll have got full marks for that to be fair.

Original post by Huwtrosky

that should be fine if each town is unique I just did Branch ID as the primary key

Ahh of course. I wondered why they mentioned the town was unique - so people could use it as the primary key. I didn't do this though - I did exactly as you did and used Branch ID.

Original post by vinnie667

Thought it was a very easy paper, wasn't too sure why computers would need to use analogue data though, other than that it was all fine.

For this I used the example of a microphone recording a signal, and this then being digitised to be stored on a computer. Not sure if that was right though. Probably not according to WJECs Mark Scheme anyway ...

(edited 10 years ago)

Reply 74

PatrickM

The question which eluded me was the advantages and disadvantages of binary trees over arrays. Wasn't my finest hour that one....

Reply 75

LewisRichardson

7

The only reason I used BranchID rather than just the address is that there may be more than one town in the country of the same name, should be okay though.

I think an ordered binary tree is simply easier/quicker to search for data over an array. Perhaps a disadvantage was that binary trees are more complex to program than arrays.

Posted from TSR Mobile

Reply 76

Enginerd.

21

For Stack i did Undo button!
Because you need to wind back nesting of subprograms

For Queue i did keyboard buffer!
Because the keys that are pressed should be executed in order.

Reply 77

archdd

6

Sometimes even though I know the answer, I don't know how to write it out clearly and instead I extend my answers until it becomes unconvincing/wrong (epic fail).

For the analogue question I put recording and outputting sounds which is a form of wave and can be variable o_O

I think the advantages of a binary tree over an array is that the array would have to go through one by one until the target whereas the binary tree moves closer each step (by comparing the whether to move left or right if the current node is higher or lower than the target). A disadvantage would be accessing all the records where an array would be done at once by looping through the subscript but binary tree would be harder to do so and you might have to go back and forth in steps.

For stack I put storing return addresses of sub procedures so they could continue where it left off allowing the code to execute in desired order.

Reply 78

vinnie667

Original post by Enginerd.

For Stack i did Undo button!
Because you need to wind back nesting of subprograms

For Queue i did keyboard buffer!
Because the keys that are pressed should be executed in order.

Keyboard buffer is correct for sure, and I used the example of a systems stack which stores the address of the sub program's to be called winding back etc, you might get the mark for winding back but not sure about undo button

Posted from TSR Mobile

Reply 79

vinnie667

Original post by archdd

Sometimes even though I know the answer, I don't know how to write it out clearly and instead I extend my answers until it becomes unconvincing/wrong (epic fail).

For the analogue question I put recording and outputting sounds which is a form of wave and can be variable o_O

I think the advantages of a binary tree over an array is that the array would have to go through one by one until the target whereas the binary tree moves closer each step (by comparing the whether to move left or right if the current node is higher or lower than the target). A disadvantage would be accessing all the records where an array would be done at once by looping through the subscript but binary tree would be harder to do so and you might have to go back and forth in steps.

For stack I put storing return addresses of sub procedures so they could continue where it left off allowing the code to execute in desired order.

I know what you mean, you have it all explained in your head and the me you write the worse your answer becomes...

Posted from TSR Mobile

WJEC CG3 January 2013

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you