Percentage Aggregation Functions by Extending SQL

Current SQL aggregation functions have evident limitations for computing percentages, for which this paper proposes two SQL aggregation functions. The two novel aggregation functions are easy to use, which have wide applicability and can be efficiently evaluated. They may be used as a framework to study percentage queries and to generate efficient SQL code. Experiments compare our proposed percentage aggregations against queries using OLAP aggregations. The results show that both proposed aggregations are significantly faster than existing OLAP aggregate functions.