For a relation R(A, B, C) with three attributes A, B and C, what is the…

A composite key is a candidate key or primary key that consists of two or more attributes.

To find the maximum number of possible composite keys for a relation R(A, B, C), we need to calculate how many unique combinations of attributes can be formed using at least 2 attributes, up to the total number of attributes available (n = 3).

Using the combination formula :

1. Combinations of exactly 2 attributes (3C2 )

   • {A, B}

   • {B, C}

   • {A, C}

   • Total = 3 combinations

2. Combinations of exactly 3 attributes (3C3):

   • {A, B, C}

   • Total = 1 combination

Total Composite Keys = 3 + 1 = 4