SDB_Source - Source definition for a property

Sources are expressions that act as base for a view extents, transient properties or properties in view definitions. A source defines an expression, which generates the source data collection or attribute. This might be a collection name (extent or reference name) or a more complex expression.

An order key might be added, when the source refers to a database collection, which provides one or more sort indexes .

When defining sources for view paths, each source definition must have a unique name, which is used to assign the source to the from path having the same name in the view.

When defining sources for transient properties, the source name has to be the same as the property name. When several sources have been defined, ODABA looks for a source with the property name.

When defining mappings, the source name has to correspond to the mapping name. This allows defining several data mappings, supposed that the mappings are named differently.