Chapter 8. Analytic Functions
Online Analytic Processing (OLAP) queries perform multi-dimensional aggregation and are useful in business decision-making processes in areas such as sales, marketing, and business intelligence. Fast execution is important for OLAP queries as key decisions hinge on the outcome of OLAP queries and reports.
Although conventional SQL statements can be used to implement OLAP queries, these statements usually result in multiple self-joins, leading to poorly performing queries. In addition, multi-dimensional analysis usually requires aggregation at various levels, and both aggregated and non-aggregated rows must be returned. In the case of conventional SQL statements, fetching the aggregated and non-aggregated ...