Validates the backward compatibility of the content database schema for the DLLs on the Web front end. This method is called each time a connection is made to the content database to verify that the database schema is compatible.
Public Sub ValidateBackwardsCompatibility
Dim instance As SPPersistedUpgradableObject
Running a query on a content database with an incompatible schema can irrevocably corrupt user data.
This method can be called only one time for a given process. If a call was already made to this method for the current process, a second call to this method has no effect.