aggregate function

Aggregate functions operate on a series of values but return a single, summarizing value.

Among other things this means the preference conditions (with the possible exception of continuity) simply don't apply to the aggregate function.

While executing an aggregate function like sum, the following strategy is used:

There are five aggregate functions that are included with most relational database systems.

SQL aggregate functions return a single value, calculated from values in a column.

It was added to the SQL language because the keyword could not be used with aggregate functions.

Integrated testing-e.g., in software, aggregate functions formed by groups of modules and intermodule communication links are tested.

The functions that follow are aggregate functions that can be thought of as the summation of all the individual participants in the market.

Views are defined with aggregate functions and filters are computed in parallel, much like MapReduce.

Except for the function, all aggregate functions perform a Null-elimination step, so that Null values are not included in the final result of the calculation.

Common aggregate functions include:

A window function in SQL:2003 is an aggregate function applied to a partition of the result set.

SQL defines aggregate functions to simplify server-side aggregate calculations on data.

These functions can be used to build triggers (functions invoked upon modification of certain data) and custom aggregate functions.

Useful aggregate functions:

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

Extensions to Standard SQL include user-defined aggregate functions.

Several extensions have been made to Datalog, e.g. to support aggregate functions, to allow object-oriented programming, or to allow disjunctions as heads of clauses.

The equivalent product from Solaris called DTrace offers an aggregation data type and a powerful set of aggregating functions to represent statistical data.

The list data type offers only basic aggregating functions on a single item (as opposed to an associative arrays of aggregations that DTrace offers).

Postgres provided an object relational programming model in which fields could be complex datatypes, and where users could register new types as well as scalar and aggregate functions over those types.

In computer science, 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.

In XLeratorDB there are some functions which have characteristics of aggregate functions (operating on multiple series of values) but cannot be processed in SQL CLR using single column inputs, such as AVG does.

In the Teradata implementation, specified columns, aggregate functions on columns, or components of date columns from one or more tables are specified using a syntax similar to the definition of a database view: up to 64 columns/column expressions can be specified in a single join index.

If, on the other hand, the mind is no more than the aggregated functions of the brain, then it will be possible to create a machine with a recognisable mind (though possibly only with computers much different from today's), by simple virtue of the fact that such a machine already exists in the form of the human brain.