Understand how to summarize data using Aggregate Functions and how to perform advanced row-by-row analysis without collapsing your dataset using Window Functions.
Aggregate Functions
Aggregate functions take multiple rows of data and collapse them into a single output value. They are typically used with the GROUP BY clause.
Input
Multiple Rows
Process
SUM(), AVG()...
Output
Single Value
Window Functions
Window functions perform calculations across a set of table rows that are somehow related to the current row.
Key Distinction
unlike Aggregate functions, Window functions do NOT collapse rows. You represent the aggregated value alongside the original row details.