A data store in which changes are not tracked is synchronized with a data
store in which changes are tracked utilizing a shadow store. The shadow
store contains shadow data indicative of the most recent synchronization
operation between the data stores. The shadow data comprises hash values
of the data items in the limited or non-change-tracked data store.
Changes to data items in the limited or non-change-tracked data store are
operated on to provide respective hash values. The hash values are
compared with the hash values in the shadow data. If the hash values
differ, changes are appropriately applied to the data store, and the
shadow data is appropriately updated. In an example embodiment, hash
values are obtained from one-way hash functions, such MD5, SHA-1,
SHA-256, or the like.