Efficient management of materialized path aggregation

A data structure is given for storing materialized aggregated path information such that the evaluation of a traversal recursion that consists of the traversal of an acyclic directed graph with path aggregation is simply a look-up. The retrieval time is proportional to the size of the answer. Using the data structure, insertions and deletions of edges can also be performed efficiently. The scheme is effective in retrieval-intensive environments. The scheme is also easily extended to multiple-processor environments