A long transaction (LT) is an administration unit that is used to group conditional changes to objects. Depending on the situation, such a unit can contain conditional changes to one or to many objects. Long transactions are used to modify as-built data in the database without permanently changing the as-built data. Long transactions can be used to apply revisions or alternates to an object.
A root long transaction is a long transaction that represents permanent data and that has descendents. Any long transaction has a root long transaction as an ancestor in its long transaction dependency graph. A leaf long transaction does not have descendents.