Provided is a method, system, program, and computer readable medium for maintaining a database of objects. At least one structured document is received representing an instance of an object including attributes and attribute values defined for a class. Content of the structured document representing the object is added into the database, wherein the database is capable of storing multiple structured documents representing multiple objects. In another implementation, an instance of at least one object including attributes and attribute values defined for a class is generated. For each generated object, a structured document is generated representing the object and including a representation of the attributes and attribute values in the object. Each structured document is transferred to the database to maintain.