SQL Server Performance

Zero Normalisation

Discussion in 'General DBA Questions' started by priyankaev, Mar 22, 2006.

  1. priyankaev New Member

    Does anybody know about zero normalisation? We are not actually sure if this is a specific concept or just a database without any normalisation.My friend was asked in an interview.
  2. Madhivanan Moderator

  3. Twan New Member

    nope never heard of zero normalisation either...

    Cheers
    Twan
  4. Madhivanan Moderator

    May be Denormalization can be called as Zero Normalization [<img src='/community/emoticons/emotion-2.gif' alt=':D' />]<br /><br />Madhivanan<br /><br />Failing to plan is Planning to fail
  5. FrankKalis Moderator

    If I recall that correctly, you'll sometimes find that phrase in academic literature.

    What is meant is that when you, for example, have a table like

    l_name, f_name, phone1, phone2, phone3, phone4....

    phone1 - phone4 is a repeated group that should be modelled in its own entity. Some authors or lecturers call this "Zero Normalform" or "0 Normalform".

    --
    Frank Kalis
    Microsoft SQL Server MVP
    http://www.insidesql.de
    Heute schon gebloggt?http://www.insidesql.de/blogs
    Ich unterstuetze PASS Deutschland e.V. http://www.sqlpass.de)
  6. priyankaev New Member

    Yes Frank, this is what the interviewer was talking about.Can you throw some more light onto the 0 normal form?
  7. Twan New Member

    That's just silly though because it isn't a normalform at all...

    in that case "0NF" is just chucking all of the data together in a single spreadsheet with no key columns and in fact no concern as to whether the columns actually relate to each other at all...

    Cheers
    Twan
  8. FrankKalis Moderator

    One requirement for 1 NF is that all columns contain "atomic" values. Basically this is aimed at lists stored in a single column. Now, a table structure like ...phone1, phone2, phone3... doesn't violate 1 NF's "atomic" values requirement as each value is in its own column. But the whole phone1-n column group itself can be viewed as a list (set) and as such is non-atomic, thus violating 1 NF. Hope I've recalled that correctly.

    But like I've said, you will find that this term is not frequently used. Mainly in academic papers likehttp://www.pp.bme.hu/ee/2004_1/pdf/ee2004_1_07.pdf

    What was your friend's answer to the question?

    --
    Frank Kalis
    Microsoft SQL Server MVP
    http://www.insidesql.de
    Heute schon gebloggt?http://www.insidesql.de/blogs
    Ich unterstuetze PASS Deutschland e.V. http://www.sqlpass.de)

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