Question

All columns can be determined by the primary FD, even if the primary FD doesn't involve the key on the LHS.

Therefore, if you have any 1:1 relationship (functional dependency) between any columns where one of them isn't the key, then you have to separate them. Remove one of the columns from the OG table and create another table with the 1:1 relationship columns.
When it's in the second normal form (every non-prime attribute is fully functional on the primary, and no non-prime attribute is transitively dependent on the primary key.
Options:
A. Second Normal Form (2NF)
B. Third Normal Form (3NF)
C. Fourth Normal Form (4NF)
D. Fifth Normal Form (5NF)

Answer 1

The question involves database normalization and the need to separate a 1:1 relationship between non-key columns to satisfy Second Normal Form (2NF). While this separation aligns with the goals of 2NF, even higher normal forms may require additional separation to eliminate more complex types of dependencies.

Step-by-step explanation:

The student is asking about the right approach to database normalization, particularly when dealing with a 1:1 functional dependency (FD) that does not involve the primary key on the left-hand side (LHS). When there is any non-trivial functional dependency between two attributes where neither is a part of a candidate key for the table, in order to maintain the Second Normal Form (2NF), those attributes need to be separated into a different table.

The question refers to the Third Normal Form (3NF), which requires that in addition to being in 2NF, no non-prime attribute has a transitive dependency on the primary key. In 3NF, every non-prime attribute must be directly dependent on the primary key, not through some other non-prime attribute.

Therefore, the correct response in this context, where a 1:1 relationship between non-key columns necessitates their separation, is aimed at achieving Second Normal Form (2NF), as the question description clarifies the condition for 2NF. However, it is worth noting that as database normalization progresses through different forms, further separations might be necessary to satisfy higher normal forms beyond 2NF.