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Thread: Normalisation

  1. #1
    Join Date
    Nov 2010
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    Normalisation

    Hi
    Just starting lectures in normalisation so this will seem a bit simple to some of you

    have a relation in 1NF

    carReg make model custNo custName hireDate

    R111EEE ford escort c100 smith J 14/05/01
    R111EEE ford escort c201 owen P 15/05/01
    T666TTT nissan sunny c100 smith J 20/06/01
    Y666YYY ford mondeo c413 blatt S 14/05/01
    Y666YYY ford mondeo c200 smith J 20/05/01
    H888HHH nissan sunny c295 owen P 20/05/01
    Y666YYY ford mondeo c413 blatt S 10/06/01
    R111EEE ford escort c100 smith J 12/07/01

    Assuming a customer can hire only one car on the same date but may hire the same car on different dates and that the functional dependencies represented by the data in the relation will hold for any additional data identify the functional dependencies represented by the data in the relation.

    I have the following

    (carReg, hireDate).......(make,model,custNo,custName) primary key
    (carReg,custNo)........(make,model,custName) candidate key
    (carReg)........(make,model) partial dependency
    (custNo,hireDate).........(carReg,make,model,custN o) candidate key
    (custNo).......(custame) transitive dependency

    Can someone let me know if I am on the right tracks

    Thanks

  2. #2
    Join Date
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    Along the right tracks but wrong.

    To start not all your keys are right.

    To what normal form are you expected to normalise?
    Last edited by pootle flump; 11-15-10 at 11:05.
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  3. #3
    Join Date
    Nov 2010
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    That is the full question

    ll I have to do is identify the functional dependencies

  4. #4
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    You can't do that without getting your keys right.
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    pootle flump
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  5. #5
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    Nov 2010
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    what keys have i got wrong

    What should be the candidate keys and primary keys

    Thanks

  6. #6
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    I'm not telling you; telling you this much is a massive help for you.

    Look at your keys again, and refer each of them back to the text. One or more of them are supported by the text. One or more of them is not supported by the text. The same is true of the data as well if you refer your keys back to that.
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  7. #7
    Join Date
    Nov 2010
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    Thanks for your help

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