Aggregations and Windowing
In this chapter, we will look at several of the built-in functions that are frequently used when querying data for reporting purposes. We’ll start off with the aggregate functions in their nonwindowed form. We’ll then explore the windowing functions: aggregate functions, ranking functions, analytic functions, and the NEXT VALUE FOR sequence generation function.
Aggregate functions are used to perform a calculation on one or more values, resulting in a single value. If your query has any columns with any nonwindowed aggregate functions, then a GROUP BY clause is required ...