Ensure database integrity

Never use Alfabet Expand in a production environment. Configuration should be carried out in a configuration environment with an own Alfabet database. When the configurationis complete and tested, you can apply it to the Alfabet database in the production environment.

Technically, multiple instances of Alfabet Expand can connect to the Alfabet database in parallel in a solution environment. This may cause the following issues:

• Changes made to the meta-model by one user might be overwritten by changes made by another user working with another instance of Alfabet Expand if they are attempting to save the same configuration object.
• All instances of Alfabet Expand load a working copy of the meta-model during connection to the meta-model. If the meta-model is changed by another user working with another instance of Alfabet Expand, the changes are not automatically uploaded to the currently active Alfabet Expand sessions. The solution designer will not be aware of changes unless he/she uses the menu option Meta-Model > Reread Meta-Model.

The following mechanisms are implemented to reduce the risk of overwriting concurrently made changes:

• When a user saves changes to object classes, object class properties and class keys, the connection of all other Alfabet components to the Alfabet database will be closed to inhibit the overwriting of changes by other active Alfabet Expand instances and prevent inconsistencies that may result from users checking in data for which the configuration has changed.
• You can configure Alfabet Expand to detect the changes made by other instances. If the meta-model is changed in one of the instances of Alfabet Expand and the changes are saved to the meta-model, the users of the other Alfabet Expand instances are informed via a message on the Alfabet Expand host that the meta-model has changed. Clicking on the message opens a report in the center pane of Alfabet Expand providing information about the change made to the meta-model and the user performing the change. This mechanism is only valid if the following applies:
  • A different user name is used for login to the Alfabet Expand instances.
  • The Track Meta-Model Changes parameter is activated in the server alias of the Alfabet Expand instances.

In addition, you should do the following to prevent overwriting data and inconsistencies in the Alfabet database when using Alfabet Expand:

• A backup of the Alfabet database should always be made before making changes in order to prevent the inadvertent and irrevocable loss of important configuration data.
• Only one instance of Alfabet Expand should be used at a time. If it is necessary to use multiple instances in parallel, the tracking of meta-model changes should be activated in the server alias configurations of all Alfabet Expand instances.