Final answer:
Given the functional dependencies, the order table schema is in Boyce-Codd Normal Form (BCNF) as each determinant is a candidate key and all other normal form conditions are also satisfied.
Step-by-step explanation:
To determine the highest normal form for the order table schema in an online bookstore schema, one must analyze the given functional dependencies. The functional dependencies provided are:
- custid→name, address, state, zip
- bookid→title, author, price, category
- orderid→custid, bookid, shipdate
For a table to be in the first normal form (1NF), it must have atomic values; that is, no repeating groups or arrays. The specifications given do not indicate violations of 1NF. To reach the second normal form (2NF), a table in 1NF must have no partial dependencies on a composite primary key. Given that orderid uniquely identifies a record, there are no composite primary keys to consider here, so no partial dependencies exist, satisfying 2NF.
In third normal form (3NF), besides meeting all the requirements of 2NF, all the attributes must be functionally dependent only on the primary key. Since orderid determines custid and bookid, and these in turn determine all other attributes via transitive dependencies, all non-primary key attributes are fully functionally dependent on orderid alone. This satisfies 3NF criteria.
Lastly, Boyce-Codd Normal Form (BCNF) is an extension of 3NF where every determinant is a candidate key. Here, both custid and bookid depend on orderid which is a candidate key. This implies that the highest normal form attainable by the order table schema, as described, is BCNF.