Changes

DataStore is designed for sharing data among applications. Applications will assume make some assumptions on data types of attributes of objects in a data store. If the data type of an attributes is not consistent among applications, applications will may be broken for read reading data from other applications with different assumption on the data type. That is why the So, data types of attributes should be enforced.

Every object in a data store is a tree. The path from root to any node can be represented as an ordered list of attribute names. Incremental schema is to a way that define the type of an attribute while the path of the attribute was found first time. In an other word, once a new object was added to a data store, its tree of attributes will be traveled, and assigned the type of new attributes as with the type of their values. A new attribute is one an attribute whose path from root is never found before in a data store.