View definition

In addition to ad hoc queries defined in terms of select statements, OSI supports defining views as part of the schema definition. A view definition is a structure definition, which provides computation rules for each view element and for the view extent. One may refer to views via transient, temporary or persistent properties or extent definitions referring to the view as data type.

ODABA views do not require a fixed data source, which allows applying views on different collections. Thus, a view is a structure definition on the one hand, but also a method definition on the other hand.

A view definition consists of the view header and the view definition. Several of the class header properties are shared with other type definitions and are described in topic "Type extensions":

• Type properties
• Inheritance specifications