Question

What is the degree of the resulting table when performing a Cartesian product of two tables with degrees 3 and 4?

• A. 3
• B. 4
• C. 7
• D. 12

Hint:

Degree means number of columns. Columns of both tables are placed side by side.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
In a relational table, the degree is the number of columns (attributes). The cardinality is the number of rows (tuples).

Step 2: Key Formula:
The Cartesian product pairs every row of table 1 with every row of table 2. Each result row carries all columns of both tables. So \(\text{degree} = d_1 + d_2\) and \(\text{cardinality} = c_1 \times c_2\).

Step 3: Apply the formula.
Here \(d_1 = 3\) and \(d_2 = 4\). So the degree of the result is \(3 + 4 = 7\).

Step 4: Check option 1 (3).
3 is only the degree of the first table. The result also has the 4 columns of the second table. So option 1 is wrong.

Step 5: Check option 2 (4).
4 is only the degree of the second table. The 3 columns of the first table are also present. So option 2 is wrong.

Step 6: Check option 3 (7).
7 equals 3 plus 4, the total number of columns. So option 3 is correct.

Step 7: Check option 4 (12).
12 equals 3 times 4. A product is used for the cardinality (number of rows), not for the degree. So option 4 is wrong.

Final Answer:
The degree of the Cartesian product is 3 + 4 = 7, option 3. \[ \boxed{7} \]