Exploring ordered analytic functions
The Online Analytical Processing (OLAP) function, according to Wikipedia, is used to analyze multi-dimensional analytical queries quickly and efficiently. OLAP is part of the broader category of business intelligence, which also encompasses relational reporting and data mining. The typical applications of OLAP are business reporting for sales, marketing, management reporting, business process management (BPM), budgeting and forecasting, financial reporting, and similar areas.
The term OLAP was created as a slight modification of the traditional database term OLTP (Online Transaction Processing). Databases configured for OLAP use a multidimensional data model, allowing for complex analytical and ad hoc queries with a rapid execution time.
Like traditional aggregate functions, window aggregate functions operate on groups of rows and permit the qualification and filtering of the group result. Unlike aggregations, OLAP functions also return individual detail...