KB5263: Manage schema integrity with schema locking in MicroStrategy.

Schema locking in Strategy provides controlled access and modification of schema objects by different users. There are two different locks each performing a specific task:

• Automatic control of concurrent schema manipulation via the temporary lock: This lock provides a transparent schema integrity protection where only one user session can modify the project schema at one time. Strategy Developer temporarily locks the schema of a project when User 1 opens an editor or wizard that affects schema objects (attribute editor, fact editor, schema update, warehouse catalog, etc). When User 2 with a schema modification privilege opens any schema object on the same project, User 2 be prompted with the following dialog:
  

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  This temporary lock is removed automatically once User1 closes the last schema-related editor or wizard. At that point, if User 2 wishes to edit any schema object User 2 should not receive any message and should be able to edit the object.
   
  Special Case: If the same user (User 1 in this example) connects again to the project through another instance of Strategy Developer, User 2 will get the following message.
  

• This dialog serves the purpose of releasing the temporary lock in the event Strategy Developer is abnormally terminated, leaving the lock on. If the second user session chooses to leave the lock on, the user will be able to view the schema objects in the read-only mode.
   
  The temporary lock also interacts with Strategy Administrator-Object Manager, Command Manager, and ScanMD.
   
  
• Schema lock: This is an exposed feature on the interface that will allow the project administrator to freeze the schema state. When the lock is turned on under the schema menu, no one, including the administrator, can perform changes on the schema objects. The purpose of this lock is to prevent accidental modification to the schema in a project. Anyone with the proper privilege will be able to turn off the lock.
  

The behavior observed when opening any schema related editors is the same as the temporary lock; the user will be prompted to view the object in the read-only mode.
 
Note that these two locks function independently. When the temporary lock is in effect, it cannot be removed by going to the schema menu and remove the schema lock. In fact, the option will be grayed out. To release the temporary lock, the user should log into the same project from another user session and release the lock using the dialog mentioned above.