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香港!

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Does anyone have some practise questions on...
"Normalising" a table and also drawing a Flow Chart of Data FLow Diagram.. etc..
that sort of thing..

yea... anyone can gimme would be nice thx!!:)
 

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香港! said:
Does anyone have some practise questions on...
"Normalising" a table ...
by that do you mean normalising a database??

if so;


1) what is normalisation?
2) describe how 1st norm form works.
3) list advantages and disadvantages for normalising(beyond 3rd norm form) a huge database (although this might not be required within the hsc scope)





just a question: do you guys know how to normalise a table if i were to give you one?
 

goan_crazy

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... said:
just a question: do you guys know how to normalise a table if i were to give you one?
We got one in the CSSA trial and I got it wrong
can you please explain how to ...?
 

skyrockets1530

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goan_crazy said:
We got one in the CSSA trial and I got it wrong
can you please explain how to ...?
Normalisation is just the reduction of the unnecessary duplication of data. That said, you would just go through the database logically and link fields in different tables which have the same data.

For example, say you have two table, one with the details of transactions, and another with hte details of your customers. Instead of having all the customer details in the transactions table, you could just link it to the customer details table and pull up all the info from there. hope that makes sense
 
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skyrockets1530 said:
Normalisation is just the reduction of the unnecessary duplication of data. That said, you would just go through the database logically and link fields in different tables which have the same data.

For example, say you have two table, one with the details of transactions, and another with hte details of your customers. Instead of having all the customer details in the transactions table, you could just link it to the customer details table and pull up all the info from there. hope that makes sense
In addition to the above post ^ normalisation of data reduces data redundancy. Normalisation occurs when flat file databases are "split" to form a relational database.
Whenever normalising a db in the HSC (although it may not always be required) it is advised that the primary and foreign keys (in addition to any relationships - i.e. 1-1, 1-many, many-many - are labelled.
 
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miss_gtr said:
What are the chances of us having to normalise something............ getting us to do a data dictionary, context diagram, data flow diagram is slim......... i'd bet on a relational database.
But normalising the database is very common. Btw, not to sound rude but I think you're somewhat confused. Normalisation of a database is creating a relational database from a f.file one.

So when they ask to normalise a db, it's saying "make this flat file db a relational one"
lol

=[EDiT]=

Also - It may be skating on thin ice between DFDs etc - I just did the 2oo2 paper and they asked for a DFD. It wasnt hard, just time consuming and somewhat confusing with all the various processes. So we need to know this too .. just incase =P
 
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...?

You can normalise a database without making it relational :S

Your just trying to rid data redundancy.
Just so happens one of the key features of a relational is less data redundancy, but the database is still flat file S
 
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DigitalFortress said:
...?

You can normalise a database without making it relational :S

Your just trying to rid data redundancy.
Just so happens one of the key features of a relational is less data redundancy, but the database is still flat file S
oh crap
relational is when it has relationships
wait .. but i thought that wehn normalising a db it's put into more than one table aye?
anyway - as soon as that happens and you link them in some way doesnt that become a relational database?
gosh .. i think i've got my wires crossed.
 

skyrockets1530

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-MuNcHKiN- said:
oh crap
relational is when it has relationships
wait .. but i thought that wehn normalising a db it's put into more than one table aye?
anyway - as soon as that happens and you link them in some way doesnt that become a relational database?
gosh .. i think i've got my wires crossed.
Well, when you normalise a database you do usually put things into more than one table. For example, instead of storing customer details and the details of the products they pruchased in a single table, you would create one table for products and another for customers and then link them. I think you can reduce data redunancy to a certain extent without splitting a table however I cant see it being done often.

Munchkin, you are correct in saying when you link two tables it becomes a relational database, as a relational database is just a series of related or linked tables.
 
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skyrockets1530 said:
Well, when you normalise a database you do usually put things into more than one table. For example, instead of storing customer details and the details of the products they pruchased in a single table, you would create one table for products and another for customers and then link them. I think you can reduce data redunancy to a certain extent without splitting a table however I cant see it being done often.

Munchkin, you are correct in saying when you link two tables it becomes a relational database, as a relational database is just a series of related or linked tables.
i've never seen it being done before - that's why i'm a little iffy on it

so .. i think i shall just stick to thinking normalisation=relational databases are used for
(until the textbook proves me wrong)
hehehe
 

skyrockets1530

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-MuNcHKiN- said:
i've never seen it being done before - that's why i'm a little iffy on it

so .. i think i shall just stick to thinking normalisation=relational databases are used for
(until the textbook proves me wrong)
hehehe
ha, yea- makes sense to me, i really doubt they could say something like 'normalise this database without splitting it into tables' cause that would just be cheap, kinda like that 7 mark question in legal which wasnt in the syllabus.. hmm *goes and tries to determine how to normalise databse with single table*
 
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skyrockets1530 said:
ha, yea- makes sense to me, i really doubt they could say something like 'normalise this database without splitting it into tables' cause that would just be cheap, kinda like that 7 mark question in legal which wasnt in the syllabus.. hmm *goes and tries to determine how to normalise databse with single table*
stuff normalising without splitting it
nawr, so far - from what i've done - they've asked to normalise the db's like into a certain number of tables. They dont necessarily state that the relationships and primary/foreign keys be stated - but i've got this habit of stating them anyway .. kinda like "see - i actually know something!" LOL
awwww man, i heard about that Legal question - are they gonna do anything about it? I was talking to one of my mates who does it and apparantly our school teachers (head of the commerce/business faculty) called up and complained ..

.. that's what they get though, for incorporating a load of NON-SYLLABUS related material!

*yawns*
rawwrrr .. im feeling sleeeeeeeeeepy

zzzZZZZZZZ!
 

skyrockets1530

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haha yea, i state primary and foreign keys all the time, if you know and you've got the time stick it in- you cant lose marks!

I dont think they'll do anything about it, they said they got very few complaints, but they'll probably just adjust the marks up, if the top mark is 95 or something cause of that it'll just go to 99 or whatever, and everyone should get moved up. but its hard to say...
 
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skyrockets1530 said:
haha yea, i state primary and foreign keys all the time, if you know and you've got the time stick it in- you cant lose marks!

I dont think they'll do anything about it, they said they got very few complaints, but they'll probably just adjust the marks up, if the top mark is 95 or something cause of that it'll just go to 99 or whatever, and everyone should get moved up. but its hard to say...
ahhh

well good luck to all that did it ayez!

hmm

*thinks*
do you reckon they'd do that with ipt. . .. maybe - no wait, that'd be bad .. worse marks!
*rawrrrrrrrr!
 

skyrockets1530

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-MuNcHKiN- said:
ahhh

well good luck to all that did it ayez!

hmm

*thinks*
do you reckon they'd do that with ipt. . .. maybe - no wait, that'd be bad .. worse marks!
*rawrrrrrrrr!
ha yea, I honestly can't say what they'd do, i wouldnt expect them to include something thats not in the syllabus, and dont think i'll do as well as i was hoping cause of the lengthyness of that maths exam- and they asked for three poems instaed of two in english (though i dont do that text) So this year anything goes!!

If you have a good knowledge of IPT or computer stuff you should be able to get a few marks but you never know. lol just have to wait and see.
 
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skyrockets1530 said:
ha yea, I honestly can't say what they'd do, i wouldnt expect them to include something thats not in the syllabus, and dont think i'll do as well as i was hoping cause of the lengthyness of that maths exam- and they asked for three poems instaed of two in english (though i dont do that text) So this year anything goes!!

If you have a good knowledge of IPT or computer stuff you should be able to get a few marks but you never know. lol just have to wait and see.
well .. coming second may be good for something

..
haha

woo wooooo - i just really wanna kick these guys asses in my grade - they think chicks are sooo stupid.. proved them wrong so far - gotta keep it up
=)
 

skyrockets1530

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-MuNcHKiN- said:
well .. coming second may be good for something

..
haha

woo wooooo - i just really wanna kick these guys asses in my grade - they think chicks are sooo stupid.. proved them wrong so far - gotta keep it up
=)
haha, goodwork- mabey you should show them the stats on how girls outperformed guys in the hsc... its not good news for me- but then again it depends on the individual.
 
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skyrockets1530 said:
haha, goodwork- mabey you should show them the stats on how girls outperformed guys in the hsc... its not good news for me- but then again it depends on the individual.
oOooo .. i heard that the girls didnt go too crash hot in the ipt exam last year
haha

ahh - this year will be better - so i hope anyway!
wooooooot

ahhh
okay

now
*sleeepayyyy

nitey nitey!

=)
 

skyrockets1530

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-MuNcHKiN- said:
oOooo .. i heard that the girls didnt go too crash hot in the ipt exam last year
haha

ahh - this year will be better - so i hope anyway!
wooooooot

ahhh
okay

now
*sleeepayyyy

nitey nitey!

=)
haha, yea should be all good, goodnight- good cross thread convo, that was fun!
 

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