In database management, an aggregate function or aggregation function is a function where multiple values are processed together to form a single summary statistic.
(Figure 1) Entity relationship diagram representation of aggregation.
Common aggregate functions include:
Average (i.e., arithmetic mean)
Count
Maximum
Median
Minimum
Mode
Range
Sum
Others include:
Nanmean (mean ignoring NaN values, also known as "nil" or "null")
Stddev
Formally, an aggregate function takes as input a set, a multiset (bag), or a list from some input domain I and outputs an element of an output domain O.[1] The input and output domains may be the same, such as for SUM, or may be different, such as for COUNT.
Aggregate functions occur commonly in numerous programming languages, in spreadsheets, and in relational algebra.
The listagg function, as defined in the SQL:2016 standard[2]
aggregates data from multiple rows into a single concatenated string.
In the entity relationship diagram, aggregation is represented as seen in Figure 1 with a rectangle around the relationship and its entities to indicate that it is being treated as an aggregate entity.[3]
^Jesus, Baquero & Almeida 2011, 2 Problem Definition, pp. 3.
^Winand, Markus (2017-05-15). "Big News in Databases: New SQL Standard, Cloud Wars, and ACIDRain (Spring 2017)". DZone. Archived from the original on 2017-05-27. Retrieved 2017-06-10. In December 2016, ISO released a new version of the SQL standard. It introduces new features such as row pattern matching, listagg, date and time formatting, and JSON support.
^Elmasri, Ramez (2016). Fundamentals of database systems. Sham Navathe (Seventh ed.). Hoboken, NJ. p. 133. ISBN 978-0-13-397077-7. OCLC 913842106.{{cite book}}: CS1 maint: location missing publisher (link)
and 22 Related for: Aggregate function information
In database management, an aggregatefunction or aggregation function is a function where multiple values are processed together to form a single summary...
Aggregate data, in statistics, data combined from several measurements Aggregatefunction, aggregation function, in database management is a function...
reject the very concept of an aggregate production function. In general, economic output is not a (mathematical) function of input, because any given set...
Lucas aggregate supply function or Lucas "surprise" supply function, based on the Lucas imperfect information model, is a representation of aggregate supply...
type of aggregatorfunction which combines two or more types of consumption goods, or two or more types of production inputs into an aggregate quantity...
the downward sloping aggregate demand curve is derived with the help of three macroeconomic assumptions about the functioning of markets: Pigou's wealth...
on specific dimensions and aggregating up data along these dimensions, using an aggregatefunction (or aggregation function). The number of possible aggregations...
best approach to understanding the labor market. The functions that follow are aggregatefunctions that can be thought of as the summation of all the individual...
summarizing the data along a dimension. The summarization rule might be an aggregatefunction, such as computing totals along a hierarchy or applying a set of formulas...
PERFORM). Function groups - These are libraries of self-contained function modules (enclosed by FUNCTION/ENDFUNCTION and invoked with CALL FUNCTION). Object...
and/or columns of a table or join result, or may be a summary using an aggregatefunction. The process of setting up a materialized view is sometimes called...
The principle of effective demand is that the aggregate demand function and the aggregate supply function intersect each other at the point of effective...
but to any XML for Analysis (XMLA) OLAP standard-compliant server. Aggregatefunction Business reporting Comparison of office suites Comparison of OLAP...
energy utility monopoly and seek a greener energy service Aggregatefunction, a type of function in data processing Aggregation, a form of object composition...
computing, a news aggregator, also termed a feed aggregator, content aggregator, feed reader, news reader, or simply an aggregator, is client software...
In economics, aggregate supply (AS) or domestic final supply (DFS) is the total supply of goods and services that firms in a national economy plan on...
Aggregate income is the total of all incomes in an economy without adjustments for inflation, taxation, or types of double counting. Aggregate income is...
expenditure, and aggregate demand. For example, the consumption function is a relationship between aggregate demand for consumption and aggregate disposable...
treating laws and theorems that include aggregate variables. A typical example is the aggregate production function. Another famous problem is Sonnenschein-Mantel-Debreu...
as microeconomic foundations for a behaviorally-based aggregate consumption function. Aggregate demand Absolute income hypothesis Life cycle hypothesis...
Aggregate data is high-level data which is acquired by combining individual-level data. For instance, the output of an industry is an aggregate of the...
An Aggregate pattern can refer to concepts in either statistics or computer programming. Both uses deal with considering a large case as composed of smaller...
Global Information