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.
Not sure about that. Read this http://www.datamodel.org/NormalizationRules.html Madhivanan Failing to plan is Planning to fail
May be Denormalization can be called as Zero Normalization [<img src='/community/emoticons/emotion-2.gif' alt='' />]<br /><br />Madhivanan<br /><br />Failing to plan is Planning to fail
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)
Yes Frank, this is what the interviewer was talking about.Can you throw some more light onto the 0 normal form?
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
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)
