Efficient access methods in deductive and object-oriented databases

Recently, a new access method, the Hierarchical-Tree (H-tree) was proposed as an efficient access method for object-oriented database that supports superclass-subclass relationship. We show that, the H-tree indexing scheme is indeed a general access method for the new generation DBMS that most probably will support the object-oriented concept and have the deductive capability. The simplest form of the H-tree, like the widely used B+-tree, can be used to index simple objects for efficient associative search. Its nesting capability provides efficient support to different types of queries that reference objects in superclass-subclass hierarchy. Furthermore, by dynamically nesting the indexes to the objects generated iteratively during recursive query processing, it also supports the least fixed point computation in object-oriented database with deductive capability. This paper examines the use of the H-tree as uniform indexing structure to index objects for efficient query retrieval and, as an efficient implementation of the semi-naive evaluation of least fixed point computation.