This exercise asks you to converting business statements into dependencies. Consider the following relation DiskDrive(serialNumber, manufacturer, model, batch, capacity, retailer). Each tuple in the relation DiskDrive contains information about a disk drive with a unique serialNumber, made by a manufacturer, with a particular model, released in a certain batch, which has a certain storage capacity, and is sold by a certain retailer. For example, the tuple DiskDrive(1978619, WesternDigital, A2235X, 765234, 500, CompUSA) specifies that WesternDigital made a disk drive with serial number 1978619, model number A2235X in batch 765235 with 500GB that is sold by CompUSA.
Write each of the following dependencies as an FD:
a. The manufacturer and serial number uniquely identifies the drive
b. A model number is registered by a manufacturer and hence can't be used by another manufacturer.
c. All disk drives in a particular batch are the same model.
d. All disk drives of a particular model of a particular manufacturer have exactly the same capacity.