Modifying the data model by using the Class Manager
The Common Data Model (CDM) is the set of Configuration Item (CI) and relationship classes that ship with BMC CMDB. If you must extend the data model, you can either create your own classes or extend an existing class with additional attributes.
Whenever you extend the data model, use your own namespace instead of
BMC.CORE. This prevents your extensions from being overwritten by new classes when you upgrade to a future version of the CDM.
Never modify the core CDM class attributes because upgrades across versions overwrite these customizations. Modifications to the CDM, such as changing the attribute field length in a class are not preserved during upgrades.
On the other hand, a new class or an extended class with additional attributes is not overwritten during an upgrade. Creating or extending a class may have a significant business impact and you must perform these modifications only after careful planning and consideration of all eventualities.
This section contains information on the following tasks and concepts:
|Task or concept||Reference|
Use the Class Manager interface to view the CDM and extensions.
|The purpose of partitions and name spaces in the data model.||Partitions and namespaces in the data model|
Create or modify classes using the Class Manager.
Define the class properties in the Class Manager, including the type, how the class stores data, and (for relationship classes) the relationship type.
Specify permissions for classes. If you do not specify permissions for a class, BMC CMDB assigns default permissions.
Customize the CDM by creating CI and relationship class attributes.
Propagate attributes in a weak relationship to another class.
|Specify indexes for a class. |
Indexing can reduce database query time.
|Configure instance auditing for the class. Auditing enables you to track the changes made to instances of a class.|
|Common CI relationship class properties you can define when creating a class.||Common CI and relationship class properties|
|Attributes that you can define for classes using the Class Manager.||Common class attributes you can define in Class Manager|
|Different types of audits and options related to them.||Audit types and options in classes|
|Document your data model and its customization be creating an HTML version of your data model.||Generating Help for the data model by using the cdm2html utility|
|Package the modified classes and attributes created in the Class Manager.||Packaging the modified data model by using Remedy Deployment Application|