+ # Validate that all ref_tables refer to the names of tables
+ # that exist.
+ #
+ # Also force certain columns to be persistent, as explained in
+ # __check_ref_table(). This requires 'is_root' to be known, so this
+ # must follow the loop updating 'is_root' above.
+ for table in self.tables.itervalues():
+ for column in table.columns.itervalues():
+ self.__check_ref_table(column, column.type.key, "key")
+ self.__check_ref_table(column, column.type.value, "value")
+