View Full Version : You get to help me with exam questions, yay!
samureye
05-25-2007, 02:58 PM
Prepping for my own exam - take a look.
1(a) In the past, several authorities suggested that software development was in a state of chronic affliction and spoke about the effects of the "software crisis". Briefly describe FIVE factors that may have caused these crises in previous software development projects [10 marks]
A local Cable company receives requests from customers to open a subscription to its cable TV servic. Customer information is stored in a subscription file and the customer is connected to the service. At monthly intervals, an invoice is generated for each subscriber in the subscriber file. This invoice is sent to the customer and the amount owing is recorded in an accounts receivable file. WHen the customer pays, the copany processes the payment by updating both the accounts receivable file and the subscriber file.
1. Draw a data flow diagram to illustrate the processing described above. [12 marks]
2. Using an example, explain what is a data dictionary [4 marks]
3. Differentiate between a data dictionary and an entity relationship diagram [4 marks]
Help please? Make me smart.
phatlip12
05-25-2007, 09:57 PM
Wait, how do you know the questions on your exam? Did you steal it? LOL
comhcinc
05-25-2007, 11:35 PM
isn't this cheating?
samureye
05-26-2007, 12:16 AM
This is an old exam, don't you get past exams to do?
Oh wait, I remember I did the SAT and they're all secretive and whatnot, but once an exam has passed it's open season man, so this isn't cheating - it's an exam that passed already but I am using the questions as revision.
magunwarrior
05-26-2007, 12:18 AM
This is an old exam, don't you get past exams to do?
Oh wait, I remember I did the SAT and they're all secretive and whatnot, but once an exam has passed it's open season man, so this isn't cheating - it's an exam that passed already but I am using the questions as revision.
Yeah that's what they do at my school, especially for the English high school assessment we just took, we used questions from last year's to review.
comhcinc
05-26-2007, 01:43 AM
so this isn't cheating - it's an exam that passed already but I am using the questions as revision.
the cheating i am referring to is you not finding the answers on your own.
phatlip12
05-26-2007, 03:30 AM
This is an old exam, don't you get past exams to do?
Oh wait, I remember I did the SAT and they're all secretive and whatnot, but once an exam has passed it's open season man, so this isn't cheating - it's an exam that passed already but I am using the questions as revision.
If this is true then why not ask your teacher?
klitzy
05-26-2007, 03:36 AM
Is this an IB Computer Science HL exam?
rabidbadger
05-26-2007, 03:41 AM
You askin' us? Disaster waiting to happen...
I'll point you in the right direction on one of them. The first one is free and then when you're hooked I'll start charging.
3. Differentiate between a data dictionary and an entity relationship diagram [4 marks]
Simply put, the main difference between and ERD and a data dictionary is the level of detail and the reason for their existence. An entity relationship diagram is used to show all of the tables in a database and how they interconnect. A data dictionary will show all of the tables in a database as well, but it will also show the fields in the tables, the field data types, keys, constraints, etc.
As an example: if I were working with a simple database (very very simple) that was being used on a forum I would have a User table, a Thread Table, and a Post table.
My ERD would show the 3 tables with a lines connecting User to Thread, User to Post, and Thread to Post. This allows you to see what your entities are and how they interact in a quick and easy manner. You can use it to find dependencies, plan, and anticipate unintended consequences in post-launch changes.
The Data Dictonary would show the 3 tables with much more detail and no lines. I'll describe one table below and you will see what all 3 would more or less look like. You can use the DD for overarching db and table design as well as developing detail-oriented solutions to programming goals during the planning and execution phases of your project.
User
user_id int primary key not null auto_increment
user_name varchar(32) not null
user_password varchar(16) not null
user_joinDate DateTime null
user_email varchar(100) not null
user_active bit default 0
samureye
05-26-2007, 06:00 PM
Is this an IB Computer Science HL exam?
................Huh?
samureye
05-26-2007, 06:01 PM
the cheating i am referring to is you not finding the answers on your own.
Most answers are in my notes in Google Documents, I can ask my teacher as well but I don't always understand it, I really wish I didn't take computer oddly enough. Don't get me started on algorithms or java, don't understand it. Guess I can't work at Google :(
samureye
05-26-2007, 06:04 PM
I'll point you in the right direction on one of them. The first one is free and then when you're hooked I'll start charging.
Simply put, the main difference between and ERD and a data dictionary is the level of detail and the reason for their existence. An entity relationship diagram is used to show all of the tables in a database and how they interconnect. A data dictionary will show all of the tables in a database as well, but it will also show the fields in the tables, the field data types, keys, constraints, etc.
As an example: if I were working with a simple database (very very simple) that was being used on a forum I would have a User table, a Thread Table, and a Post table.
My ERD would show the 3 tables with a lines connecting User to Thread, User to Post, and Thread to Post. This allows you to see what your entities are and how they interact in a quick and easy manner. You can use it to find dependencies, plan, and anticipate unintended consequences in post-launch changes.
The Data Dictonary would show the 3 tables with much more detail and no lines. I'll describe one table below and you will see what all 3 would more or less look like. You can use the DD for overarching db and table design as well as developing detail-oriented solutions to programming goals during the planning and execution phases of your project.
User
user_id int primary key not null auto_increment
user_name varchar(32) not null
user_password varchar(16) not null
user_joinDate DateTime null
user_email varchar(100) not null
user_active bit default 0
Hey thanks, I think it's good to get other people's perspectives on things - I've found that only one math teacher was ever able to make me pass the subject in school so that's why I ask here.
I think the way you explain DD is a bit technical, Fred, I mean, isn't it basically just that - a dictionary of data showing off various elements in something alphabetically and saying what they are and what they are for? Or something like that.
phatlip12
05-26-2007, 09:21 PM
Most answers are in my notes in Google Documents, I can ask my teacher as well but I don't always understand it, I really wish I didn't take computer oddly enough. Don't get me started on algorithms or java, don't understand it. Guess I can't work at Google :(
That and you need a PhD in Computer Science along with 15 years worth of experience (not exactly, but their known for taking the best of the best). Google is VERY competitive. Of course they treat their employees like gold though...