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  1. #1
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    Unanswered: General DB Help Needed

    I am not going to lie, I am taking a DB course and am finding it extremely difficult to understand.

    We are doing Relational DB & ER modeling as well as table normalization.

    I only have 1 hour to take an upcoming and know I will score poor on my own.

    Anyone want to help me out with my quiz?

    I can post the Q's here.

    Thanks much

  2. #2
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    you can post the questions here,
    whether you will get sensible accurate and correct answers is another thing.
    you may get entirely correct answers, but not neccessarily the answers you or you teacher require.

    have you read and understood the references (rudy [r937.com]) has a good section by paul litwin

    if you must post your questions, then I'd suggest you also post your answers so that you can make an attempt to understand where your areas of weaknesss are.

    however I wouldn't hold your breath.....
    I'd rather be riding on the Tiger 800 or the Norton

  3. #3
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    If you post the questions and your answers, we may give you some good tips and critiques.

    If you post just the questions and expect us to help you cheat, well, then the fun begins...
    If it's not practically useful, then it's practically useless.

    blindman
    www.chess.com: "sqlblindman"
    www.LobsterShot.blogspot.com

  4. #4
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    Here is an example of some of the questions. They are multiple choice.

    The final outcome of a natural JOIN yields a table that provides only the copies of the unmatched pairs.

    True or False. I said False

    Functional dependence can be defined most easily as the attribute A is functionally dependent on B if A determines B.
    True or Flase. I said False

    In the context of a database table, the statement "A determines B" indicates that:
    1) knowing the value of Attribute A, you can look up the value of attribute B
    2) knowing the value of Attribute B, you can look up the value of attribute A
    I choose 1.

    Attributes ar types of entities. True or False. I said False

    (_______) expresses the specific number of entity occurrences associated with an occurrence of a related entity.
    1. Cardinality
    2. Optionality
    3. Mandatory
    4. Unary

    Consider a schema R = (A, B, C, D, E).
    and the following set F of functional dependencies:
    A->BC
    CD->E
    B->D
    E->A

    Is CD a superkey?
    Is AB a candidate key?
    Is E->B in F+?
    Is the following decompostion R1 = (A, B, C) and R2 = (C, D, E) a lossless-join decomposition?
    Is the following decompostion R1 = (A, B, C) and R2 = (A, D, E) a lossless-join decomposition?

    Thanks

    This stuff seems like anything but basic to me

  5. #5
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    Well, I'll tell you that the ones you answered appear to be correct.

    The ones you did not answer appear to simply require an understanding of the terms mentioned.

    Google and your textbook are your friends.

    "lossless-join decomposition"? I don't know what the heck that is.
    If it's not practically useful, then it's practically useless.

    blindman
    www.chess.com: "sqlblindman"
    www.LobsterShot.blogspot.com

  6. #6
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    Thanks. Yeah and those are just a sample of the questions. The book could be written in Chinese as far as my understanding of it goes. The basic terms and definitions are easy it it the graphical interpretations and relationship information I just can't seem to get.

  7. #7
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    Quote Originally Posted by tjm0852
    The book could be written in Chinese as far as my understanding of it goes.
    Really? Is our vernacular nomenclature that recondite?
    If it's not practically useful, then it's practically useless.

    blindman
    www.chess.com: "sqlblindman"
    www.LobsterShot.blogspot.com

  8. #8
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    If by 'our' you mean DB people, then, yes your terminology can be difficult to understand at times. I was not meaning that towards you or anyone on this board, but rather to the author text I am reading.

  9. #9
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    So does anyone want to seriously help me out?

  10. #10
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    Quote Originally Posted by tjm0852
    So does anyone want to seriously help me out?
    I guess that I assumed that Blindman already had helped you out... What more did you want?

    -PatP

  11. #11
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    That was my assumption too.....
    I'd rather be riding on the Tiger 800 or the Norton

  12. #12
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    What I posted was an example of some questions.
    I was asking if I posted some similar questions (don't have them yet) if anyone was familiar enough with the material to offer some help.

  13. #13
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    It is rather unlikely that we'll be able to help in the one-hour timeframe of your exam. Most of us have jobs and only offer to help here on a "time available" basis.

    You seem to have a good understanding of the topics that you've mentioned, and while you might be a bit put-off by the presentation (or lack thereof) of the material from your class, you also seem to have a good command of what you've taken the time to read.

    I really don't think you need someone to be "on deck". A little bit of time spent covering the material should be all that you need. If you have questions about points in the material, I'm sure that we'd be glad to help explain or conjour examples, but I don't really think that you'll even need that.

    -PatP

  14. #14
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    Short answer: No.
    If it's not practically useful, then it's practically useless.

    blindman
    www.chess.com: "sqlblindman"
    www.LobsterShot.blogspot.com

  15. #15
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    Mar 2006
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    Thanks, I will post up if I get stuck.

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