Aggregate function

In database management an aggregate function is a function where the values of multiple rows are grouped together as input on certain criteria to form a single value of more significant meaning or measurement such as a set, a bag or a list.

Common aggregate functions include :

• Average() (i.e., arithmetic mean)
• Count()
• Maximum()
• nanmean() (mean ignoring NaN values, also known as "nil" or "null")
• Median()
• Minimum()
• Mode()
• Sum()

Aggregate functions are common in numerous programming languages, spreadsheets, and relational algebra.

See also

• Group by (SQL), SQL clause
• Online analytical processing
• OLAP cube
• Fold (higher-order function)
• Pivot table
• Extract, transform, load
• Data drilling
• Drill down
• Data mining
• Data processing
• Relational algebra
• XML for Analysis
• Cross-tabulation a.k.a. Contingency table
• Utility functions on indivisible goods#Aggregates of utility functions

References

https://msdn.microsoft.com/en-IN/library/ms173454.aspx

Further reading

• Grabisch, Michel; Marichal, Jean-Luc; Mesiar, Radko; Pap, Endre (2009). Aggregation functions. Encyclopedia of Mathematics and its Applications. Vol. 127. Cambridge: Cambridge University Press. ISBN 978-0-521-51926-7. Zbl 1196.00002.