Path Schema Research Articles

Efficient compilation of large rule bases using logical access paths

This paper presents an efficient way to compile and store large deductive databases. Deductive rules are modeled through logical access paths and then integrated into a global structure, the Rule-base Access Path Schema (RAP Schema). The RAP Schema stores information on the interrelationships that exist among the computations required for rule executions. Ground data as well as data derived through some rule executions and cached for later reuse are also modeled in the RAP Schema. Some of the advantages of using this rule base organization scheme include the automatic detection of shared computations, the inclusion of cached results of rule executions and query results in the knowledge base. The details of the compilation and query processing phases are the focus of the paper.

The Logical Access Path Schema of a Database

A new schema which models the usage of the logical access paths of the database is proposed. The schema models all database activities (i.e., retrievals and updates), and integrates their logical access paths by recognizing common subpaths and increasing the weight of the shared subpaths. The logical access path schema provides a comprehensive picture of the logical access paths, and the cumulative usage of the shared subpaths and/or intermediate results. The schema serves a dual purpose. Firstly, it is used as a model of the access requirements during the database design, and secondly, as the basis for optimization during the operation of the database.