Q:

How to identify the highest normal form of a relation schema?

Let's say we have a relation schema. How can we state the highest normal of that relation?

For example:

Art_Object (Art_Id, Title, Description, Country, Artist, Epoch, Year) 

A:

"i wanna know What normal form Art_Object is in? this is the test from my school."
Normal form of any given design depends on which functional dependencies hold.
Without being given that set of functional dependencies, the question is simply unanswerable.
If the only FD that holds is Art_ID -> {all attributes}, then your design is in 5NF.
If on the contrary there were some additional FD like Artist -> Country, then this design isn't even 3NF.

