The generalized index model for object-oriented database systems

A proposal is presented for a general indexing method, called a generalized index, for object-oriented databases which can be implemented on all kinds of hierarchical and nonhierarchical structures. A generalized index is a domain based indexing structure in which are maintained the value and object identities of an attribute, the class(es) to which that value belongs, and the name of the attribute and/or the path to which that attribute value belongs. This information is stored in a tree structure referred to as IndexTree. The necessary concepts for the object-oriented data model are discussed. A survey of some of the existing indexing methods is given. The authors show how the generalized index structure can be used for complex objects, class hierarchies, and nested objects as well as for primitive classes