
256 9.4 Specialized Analytical Syntax
9.3.6 Aggregation Functions Allowing Analysis
Analytics is used to calculate cumulative, moving, centered, and reporting
summary aggregate values often used in data warehouse environments.
Unlike aggregate functions, analytical functions return multiple rows for
each group. Each grouping of rows is called a window and is effectively a
variable group, comprising of a range of rows. The number of rows in a
window can be based on a specified row count or an interval, such as a
period of time. Apart from the ORDER BY clause, analytical functions are
always executed at the end of a query statement. The following functions ...