Functions that allow you to perform analytic operations over a set of input rows are referred to as window functions. For example, all ranking functions, and most aggregate functions, are window functions. You can use them to perform additional analysis on your data. This is achieved by partitioning and sorting the input rows before being processed, and then processing the rows in a configurable-sized window that moves through the input.

There are three types of window functions: window aggregate functions, window ranking functions, and row numbering functions.