Abstract: Methods, systems, and apparatus, including computer program products, for synchronizing database changes among multiple devices. In one aspect, a method includes determining one or more primary differences between a primary database and a local synchronization database; receiving, from a secondary device, one or more secondary differences associated with a secondary database; merging the primary differences and the secondary differences to generate a set of merged differences; providing the set of merged differences to the secondary device; receiving, from the secondary device, an acknowledgment indicating receipt of the set of merged differences; and updating the primary database in accordance with the set of merged differences after receipt of the acknowledgment. Further, at least one conflict can be detected between the primary differences and the secondary differences, and can be resolved prior to generating the set of merged differences.

Abstract: Methods, systems, and apparatus, including computer program products, for synchronizing database changes among multiple devices. In one aspect, a method includes determining one or more primary differences between a primary database and a local synchronization database; receiving, from a secondary device, one or more secondary differences associated with a secondary database; merging the primary differences and the secondary differences to generate a set of merged differences; providing the set of merged differences to the secondary device; receiving, from the secondary device, an acknowledgment indicating receipt of the set of merged differences; and updating the primary database in accordance with the set of merged differences after receipt of the acknowledgment. Further, at least one conflict can be detected between the primary differences and the secondary differences, and can be resolved prior to generating the set of merged differences.

Abstract: Methods, apparatuses, and systems for managing digital content in hierarchies are described. A first version of a digital image is received from an external device which tracks changes to the first version. It is determined that a second version of the digital image, changes to which have been tracked, exists. Based on comparing the tracked changes of both versions, the versions are combined. The first version is created by splitting the second version, which is stored in a master hierarchy, and transmitting the split version to the external device. During splitting, a child hierarchy of information is split from the master hierarchy, the child hierarchy including portions of the master hierarchy to access the second version such that the second version can be accessed independent of the master hierarchy. Changes to the versions are tracked in change tables, for example, using values that are mashed into a single record.