Find the total marks in Maths only using SQL.

To calculate the total Maths marks, use a simple SUM with a WHERE clause:

SELECT SUM(marks) AS total_math

FROM student_marks

WHERE subject = 'Maths';

This query scans the student_marks table, filters for rows where subject equals 'Maths', and sums the marks column. The operation is linear in the number of rows, so its time complexity is O(n). If the table is large, ensure there is an index on the subject column to accelerate the filter. The result is a single numeric value representing the combined Maths marks for all students.