Glossary

abstract base class
A class that defines the requirements and behavior of descendant classes by specifying methods and variables. An abstract base class does not support the creation of instances.

Related terms
class, descendant class, method, variable

Contrast with
object

abstraction
A technique that reduces duplication of program code. Abstraction provides a framework for related classes in an object-oriented system.

Related terms
class, object-oriented programming

aggregate function
A function that performs a calculation over a set of data rows. For example, SUM calculates the sum of values of a specified numeric field over a set of data rows. Examples of aggregate functions include AVERAGE, COUNT, MAX, MIN, and SUM.

Related terms
data row, field, function, value