Determine the functional dependencies that exist in the following table; then convert this table to an equivalent collection of tables that are in third normal form: Marina, (MarinaNum, Name, (SlipNum, Length, RentalFee, BoatName) )
*Note MarinaNum is underlined
To determine the functional dependencies in the given table, we need to identify the relationships between the attributes. Functional dependency refers to the relationship between two sets of attributes in a database table, where the value of one attribute determines the value of another attribute.
In the given table, we have the following attributes:
- MarinaNum (underlined)
- Name
- SlipNum
- Length
- RentalFee
- BoatName
To identify the functional dependencies, we need to analyze the dependencies between the attributes. Here are the possible functional dependencies in the given table:
1. MarinaNum → Name (MarinaNum determines the Name)
2. MarinaNum, SlipNum → Length (MarinaNum and SlipNum together determine Length)
3. MarinaNum, SlipNum → RentalFee (MarinaNum and SlipNum together determine RentalFee)
4. MarinaNum, SlipNum → BoatName (MarinaNum and SlipNum together determine BoatName)
Now, let's proceed to convert this table into an equivalent collection of tables that are in third normal form (3NF).
To normalize the table to 3NF:
1. Create a new table (Table 1) with the attributes MarinaNum and Name.
2. Create another new table (Table 2) with the attributes MarinaNum, SlipNum, Length, RentalFee, and BoatName.
Table 1:
- MarinaNum (underlined)
- Name
Table 2:
- MarinaNum (underlined)
- SlipNum
- Length
- RentalFee
- BoatName
In this normalization process, we eliminate the redundancy caused by repeating the MarinaNum and Name attributes. Each table now represents a distinct entity, and the functional dependencies are preserved between the attributes in each table.
Now we have transformed the original table into two tables that are in third normal form (3NF).