Is it possible to state that the scheme is normalized in 3FN?

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Explaining the Context

In the internet I found an example of a scheme described in this way:

  

account (num-account, descr-account, post (num-lanc, tipolanc, data-lanc,

Notice that the way this scheme is, it is not normalized.

Now consider the following criteria:

  

  • The account and post are occurrence groups of attributes in parentheses and juxtaposed with them;

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  • Underlined attributes are identifiers of the relationship to which they belong;

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  • The num-lanc is dependent on num-conta , ie in addition to num-lanc , num-conta is required to identify a specific launch;

      
  • No it is necessary to save history, that is, the appearance of a num-account pair and num-lanc equal to one already registered, replaces the registry. li>   

    • Visto os critérios, agora devemos normalizar o esquema até a 3FN.

    A possible alternative

    account (num-account, descr-account) and post (numconta, num-lanc, date-lanc,

    Doubt

    Would the example above be normalized to 3FN?

        
    asked by anonymous 11.11.2017 / 17:37

    1 answer

    3

    Well let's see ... this possible alternative that you show in the question, I come to that conclusion ...

    It is in 1FN, because all fields contain only atomic and monovalued values, ie it does not contain repeating groups.

    It is also in 2FN, as there is no non-key attribute that is dependent on only part of the primary key.

    And it's in 3FN too, as there are no non-key attributes being dependent on other non-key attributes.

    So I'd say it's in 3FN, yes.

        
    11.11.2017 / 17:52
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