Using One Catalog As a Model for Another Catalog

When you define a BCS or VVDS, you can use an existing BCS or VVDS as a model for the new one. The attributes of the existing data set are copied to the newly defined data set, unless you explicitly specify a different value for an attribute. You can override any of a model's attributes.

If you do not want to change or add any attributes, you need only supply the entry name of the object being defined and the MODEL parameter. When you define a BCS, you must also specify the volume and space information for the BCS.

When you use the MODEL parameter, ensure that the job is not terminated due to allocation problems when you explicitly do any of the following:

Specify a different type of device with the VOLUMES parameter.
Change the size of records, buffer space, or control intervals with the RECORDSIZE, BUFFERSPACE, or CONTROLINTERVALSIZE parameters.
Change the unit of allocation with the CYLINDERS, TRACKS, KILOBYTES, MEGABYTES, or RECORDS parameters.

When you explicitly specify any of the above parameters for the BCS or VVDS to be defined, you might need to make corresponding changes to other related parameters.

If MODEL is specified as a parameter of USERCATALOG, the following steps occur:

The attributes of the model are copied for the BCS being defined.
Any attributes explicitly specified as parameters in the DEFINE command override those of the model.

If MODEL is specified as a parameter of CLUSTER (at the cluster level) but is not specified as a subparameter of the DATA or INDEX parameter, the following steps occur:

The attributes of the model are copied for the VVDS being defined.
Any attributes explicitly specified as parameters of CLUSTER override those of the model for the VVDS.
The attributes of the model's data and index components are copied for the VVDS's data and index components.
Attributes explicitly specified as parameters of CLUSTER are reproduced to the data and index components, overriding those of the model.
Attributes explicitly specified with subparameters of the DATA or INDEX parameters override the previous two steps.

If MODEL is specified both as a subparameter of DATA or INDEX and as a parameter of CLUSTER, the following steps occur:

The attributes of the CLUSTER model are copied for the cluster entry of the defined VVDS.
Any attributes explicitly specified as parameters of CLUSTER override those of the model for the VVDS.
Attributes explicitly specified as parameters of CLUSTER are reproduced to the VVDS's data and index components.
Attributes of the model specified with the MODEL subparameter of the DATA or INDEX parameters are copied, overriding the previous step.
Attributes explicitly specified with the subparameters of the DATA or INDEX parameters are copied, overriding the previous two steps.