Dummy and Placeholder Objects

This document covers the following topics:


Dummies

Each component of an information processing system is related to other components (for example, a program uses a file, a field is contained in a file). A dummy object is an object which has not yet been created but is referenced by another object.

A dummy can be created in one of two ways:

  • When a link is added from an existing object to an object that has not yet been created in Predict, a dummy object is created. A record is also stored physically in the Predict file for this dummy object.

  • When an object that is linked to another object is loaded/imported with the Predict Coordinator without internal ID, and the referenced object is not loaded/imported and does not exist in the target environment, a dummy is added in the target environment for the referenced object. (If the object is loaded/imported with internal ID, a placeholder is created. See below.)

See the Predict Coordinator documentation for details of importing with and without internal ID.

See Support of Dummy and Placeholder Objects in the section Maintenance in the Predict Reference documentation for the rules which apply when processing dummies with maintenance functions.

Placeholders

When an object that is linked to another object is loaded/imported with the Predict Coordinator with internal ID, and the referenced object is not loaded/imported and does not exist in the target environment, a Placeholder is added in the target environment for the referenced objects. (If the object is loaded/imported without internal ID, a dummy is created. See above).

This placeholder reserves the object ID of the referenced object in the target environment so that the link in the old environment can be recreated in the new environment at a later time.

The following rules apply:

  • Placeholders cannot be modified. The only maintenance function available is Purge.

  • Placeholders are marked with § in the Link Editor.

  • The status of a placeholder can only be changed by importing the "real" object.