DataSourceHandle - Data source

A data source describes an ODABA data source on a certain level (Dictionary, Database, DBObjectHandle, Extent, Instance). A data source can be parametrized by means of an configuration or ini-file. The ini-file contains the names for the objects on the different levels. Not specified lower levels are not opened and have to be opened in the application (e.g. when defining only dictionary and database the extent is not opened and no instance is selected), The data source is defined as section in the ini-file starting with the [data source name] or as xml-element with that name in an configuration file.

A data source can be directed to a server. In this case the data source has to be opened with a connected ODABA client or the ini-file must contain a server specification. In the last case the data source connects to the server automatically when opening the data source. The connection is owned by the data source in this case.

A data source can be opened and closed as a whole (Open(), Close()) or separately on each definition level (Connect(), OpenDictionary(), ...).

A data source may have a connection name, which is used to cache the connection when running in client/server mode. The connection name is used to reconnect to the server using a cached connection, which is faster than reestablishing the connection from scratch.

An application may refer to any number of data sources. Usually, the first data source opened will initialize the application environment, which contains the currently set options from the configuration and from the application.