On Oct 9, 2005, at 6:24 PM, Patrick K. O'Brien wrote: > Well, we call a single Durus commit or rollback for the entire > transaction. And a transaction can be quite extensive. For example, > the population of sample data into a new Schevo database is a single > transaction - either every single object is created, or none are > created. There is no limit to how many objects may be created, > updated, > or deleted, in the same transaction. In fact, database objects may be > created and later deleted in the same transaction, such that they serve > their purpose within the transaction but are never visible outside of > it. Is this what was (is?) known as the EditingContext in Apple's WebObjects? I never used that system, but I did use the python Modeling ORB, that was heavily inspired by it, and also implemented EditingContexts, that could also be nested, i.e. you can create child contexts, and committing those will only affect the parent context... for things to be persisted in the db, a top-level EditingContext has to be committed. mario