Layer

Layer

A database can be divided into layers (see CLASSIX.INI) to achieve logical data separation within a database. Depending on the layer set, a different storage is accessed from the file and thus objects are allocated in a different segment and entered in a different REP collection(CreatePersObject) and searched for(FindAll).

It is also possible (and sometimes useful) to use the same storage in different layers. An object can then be in several layers at the same time (see: CX_OBJECT_MANAGER::QueryAllLayers).

By specifying AutoLayer, the storages for further physical databases can be created automatically according to the schema from the first database. In such a configuration, the objects are distributed by the layers not only logically but also physically to different databases and with the change of the layer another database is addressed.

If objects from different physical databases are to be linked with each other, then the databases must be linked beforehand, otherwise a cross-connection across database boundaries is not permitted. The utility cxgosuo.exe /AffA is available for this purpose.

Layers are managed by the object manager.

In order to visualise information about the database layout with InstantView®, layers are represented by objects of the class CXS_LAYER, which can be obtained from the object manager with the function GetLayers.

CXS_LAYER refers (with Collection domains) to all domains existing in this layer.