Thrown when a database handle has been invalidated because a replication
election unrolled a committed transaction.
When this happens the handle is no longer able to be used and the application
must close the handle using the
Database.close
method and open a new
handle. This exception is thrown when a client unrolls a transaction in order
to synchronize with a new master. If the application was permitted to use the
original handle, it's possible the handle might attempt to access nonexistent
resources.