🛢DBMS: Scalar Aggregate (Definitions)

"An aggregate function that produces a single value from a select statement that does not include a group by clause. This is true whether the aggregate function is operating on all the rows in a table or on a subset of rows defined by a where clause." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

[vector aggregate:] "A value that results from using an aggregate function with a group by clause." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)

"When aggregate functions are applied to the whole or partial table without the GROUP BY clause and return only one row." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

[vector aggregates:] "When aggregate functions are used with the GROUP BY clause, they return values for each group. These are called vector aggregates." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"A function applied to all of the rows in a table (producing a single value per function). An aggregate function in the select list with no GROUP BY clause applies to the whole table and is an example of a scalar." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

[vector aggregate:] "Functions applied to all rows that have the same value in a specified column or expression by using the GROUP BY clause and, optionally, the HAVING clause (producing a value for each group per function)." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"An aggregate value that is calculated on the data source. Depending on the data source, server aggregates can be treated as detail data or as aggregates based on the dataset option InterpretSubtotalsAsDetails." (Microsoft Technet)

[aggregate of aggregates:] "A summary value calculated from aggregates, such as the maximum of a set of sums." (Microsoft Technet)

 "An aggregate function, such as MIN(), MAX(), or AVG(), that is specified in a SELECT statement column list that contains only aggregate functions." (Microsoft Technet)