What is the purpose of the Grow by grouping?

GROUP BY is used to aggregate rows with the same values in one or more columns into a single result row. This allows applying aggregate functions (such as COUNT, SUM, AVG, MIN, MAX) to groups of rows, obtaining summarized data.

Common use cases include:

• Counting the number of records per category.
• Calculating the total order value for each customer.
• Finding the highest grade among students in each group.

Without GROUP BY, aggregate functions would process the entire dataset as a single group.