In SQL, which aggregate function is used to return the maximum value from a result set or group of rows?

Introduction / Context:
Aggregate functions in SQL perform calculations across sets of rows and return a single value. When you want to find the highest or maximum value in a set of values, you need the appropriate aggregate function. This question checks whether you can recall the standard SQL function name for returning the maximum value.

Given Data / Assumptions:

• We are working with SQL aggregate functions in a SELECT statement.
• The goal is to find the maximum value from a column or expression.
• The options present several similar looking names such as MAX, MIN, MAXIMUM, MAXI, and TOP.
• We assume familiarity with basic SQL function naming conventions.

Concept / Approach:
In standard SQL, the aggregate function MAX(expression) returns the maximum non null value of the expression across the selected rows or group. It works with numeric, date, and even some character data types, depending on the database. MIN(expression) does the opposite, returning the minimum. Names such as MAXIMUM and MAXI are not standard SQL aggregate function names across major relational database systems. TOP is sometimes used as a clause to limit the number of rows, but it is not an aggregate function.

Step-by-Step Solution:
Step 1: Recall the standard aggregate functions: COUNT, SUM, AVG, MIN, and MAX. Step 2: Recognize that MAX is the function that returns the highest value. Step 3: Check that MIN is the minimum function, not the maximum function. Step 4: Note that MAXIMUM and MAXI are not valid standard function names in SQL syntax for the major database engines. Step 5: Observe that TOP is used to limit rows in some dialects like T SQL and is not an aggregate function that scans all rows to compute a value.

Verification / Alternative check:
Consider a table sales with a column amount. If you execute SELECT MAX(amount) FROM sales, the result is the largest amount value among all sales rows. This is a standard pattern in SQL tutorials and documentation. There is no widely supported function named MAXIMUM or MAXI that does the same job, which confirms that MAX is the correct function.

Why Other Options Are Wrong:
MIN is the opposite of MAX and returns the smallest value. MAXIMUM and MAXI are not valid aggregate function names in common SQL implementations such as Oracle, SQL Server, MySQL, and PostgreSQL. TOP can be used in clauses like SELECT TOP 10, but it is not an aggregate function and does not compute a maximum value by itself.

Common Pitfalls:
Sometimes learners confuse TOP with MAX because both can appear in queries that retrieve highest values, such as using ORDER BY and TOP. However, TOP simply limits the number of rows after sorting; it does not scan all rows to compute an aggregate. When you want a single maximum value, MAX is the correct function.

Final Answer:
The aggregate function that returns the maximum value in SQL is MAX.