Which function calculates the average of a column?

Which function calculates the average of a column?

• A. avg
• B. sum
• C. max
• D. min

Answer: (A)

Average means the arithmetic mean of the values in a column: you add up the valid numbers and divide by how many numbers there are. The function designed for this in most databases is AVG, used as AVG(column_name). Under the hood, this is like SUM(column_name) divided by COUNT(column_name), counting only non-null entries. For example, with values 2, 4, NULL, 6, the result is (2 + 4 + 6) / 3 = 4.0. The other functions do different things: SUM adds everything, MAX finds the largest value, and MIN finds the smallest. So AVG is the one that computes the average.

Average means the arithmetic mean of the values in a column: you add up the valid numbers and divide by how many numbers there are. The function designed for this in most databases is AVG, used as AVG(column_name). Under the hood, this is like SUM(column_name) divided by COUNT(column_name), counting only non-null entries. For example, with values 2, 4, NULL, 6, the result is (2 + 4 + 6) / 3 = 4.0. The other functions do different things: SUM adds everything, MAX finds the largest value, and MIN finds the smallest. So AVG is the one that computes the average.