In Sandbox mode, UBIK® holds its data in a relatively flat table structure in the database. While this is very nice in terms of flexibility, it is certainly a disadvantage when it comes to the management of large object models with lots of data. So the general recommendation is to use the Sandbox only during the customizing phase or for any task that requires rapid prototyping. Before providing productive data, the relevant classes should released, which basically means switching them to Live mode.
Use the Class Browser's context menu to switch the mode of a MetaClass. Once a MetaClass is switched into Sandbox mode, all its instances are in Sandbox mode as well.