Is the dataset always normalized in some form in Databases
Suppose I have a dataset, given the data and relationship schemas, it can be assumed that the dataset is normalized in one form or another. In my opinion, the raw data needs to be normalized in some form. However, a discussion with a friend led to asking me this question.
To go into more detail on this issue, I would say given the set of functional dependencies for a relationship or table, it is guaranteed that the table will be at least in 1NF, if not others.
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In my experience, in real life you will come across databases that cover the whole gamut from perfectly normalized to complete mishmash of wierd that you never expected to see anywhere, let alone a database.
You certainly cannot expect to find data even in 1NF (which is presumably the most "basic" form of normalization).
Also, this does not mean that normalized data should be the "target" of database design. You need to weigh clean design against performance criteria, and a fully normalized database can often work against your performance criteria.
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No. The raw data is not necessarily normalized to 1NF. It depends on the schemas. There may be a circuit diagram that is not even in 1NF.
Let me give you an example, Suppose there is a table that stores the grades of an entire semester student. Each semester has student 5. Suppose the schema for signs as
Marks(studentid,marks)
This table is not in 1NF as it will have duplicate values.
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