Forum Replies Created

Viewing 15 posts - 16 through 30 (of 30 total)

  • RE: Normalization

    David Burrows (4/27/2011)


    If, as you state, the DDL in question does conform to Date's 1NF as in 'There's no top-to-bottom ordering to the rows' can you post example DDL that...

  • RE: Normalization

    ....

    You have never read 1NF definition or even the Relation definition.

    Example of 1NF definition, from the only book I have right now :

    Database Systems - The complete Book Second Edition...

  • RE: Normalization

    You'r so wrong about 1NF, I can't add anything.

  • RE: Normalization

    GSquared (4/26/2011)


    I'm not quoting me. I'm quoting Date. If you really think he doesn't know what 1NF is, that's another issue entirely...

    ........ I can't believe it...

    YOU are the...

  • RE: Normalization

    Obviously you don't know what a predicate is, or you'r just ignoring predicate variables. Nice 😉

    You'r calling Occam's razor on the number of tables ? What a joke... Why are...

  • RE: Normalization

    Well we have a problem here.

    I think you didn't understand what 1NF is.

    Let's take data example to make it clear !!

    What you are citing are the properties a TABLE must...

  • RE: Normalization

    tabraham 36699 (4/26/2011)

    Ideally, Chris Date's vision of an OO-Relational DB will emerge, with, among other things, a formally defined range for each attribute and an explicit value representing UNKNOWN, with...

  • RE: Normalization

    @tom.Thomson

    Tom.Thomson (4/25/2011)


    Assuming <S#> is a key, that's only slightly different from my version:

    For supplier S# the information we have about his name is indicated by SNAME and the...

  • RE: Normalization

    What the ??

    What is violating 1NF, and what is your definition of 1NF ?

    I give up, good luck guys 😉

  • RE: Normalization

    @tom.Thomson

    When you write Dace, I guess you mean Date.

    I actually own almost every books Chris published. He wrote hundred of pages on NULL topic.

    Maybe I'll come later and...

  • RE: Normalization

    Tom.Thomson (4/24/2011)


    Perhaps because Dace had to pervert them to get them to fit his strange world view? :hehe::-P

    I don't know Dace's work, but maybe you could explain it for me,...

  • RE: Normalization

    Tom.Thomson (4/24/2011)


    This of course relies on using the original definitions of the normal forms, not the perverted versions with an explicit forbidding of NULL added long after the definition was...

  • RE: Normalization

    I have no issues with you address solution but it requires an extra join and it can degrade performance.

    If the objective is perfect normalization then go with an extra table...

  • RE: Normalization

    Tom.Thomson (3/7/2011)


    if A is nullable, there can be no such functional dependency

    My demonstration was maybe too short, but this was my point.

    NULL impacts nomalization...

    Tom.Thomson (3/7/2011)


    But Heath's theorem isn't the point...

  • RE: Normalization

    Tom.Thomson (1/26/2011)


    David Portas (1/22/2010)


    Irrespective of that, the Normal Forms, upto and including 6NF don't leave any room for the possibility of nulls. Codd himself says so: "The concepts and rules...

Viewing 15 posts - 16 through 30 (of 30 total)