Intelligent control in expert database systems using a heuristic approach

The authors propose a general strategy for the design and implementation of an intelligent expert database system using semantic knowledge (integrity constraint) and heuristics (domain-specific knowledge, expert knowledge, approximate knowledge) to search for the answers. The authors present a graph model for representing rules and show how to use knowledge for answering a given query. Also, they suggest some heuristics for deciding the order of subgoals, identifying the useful constraints, and choosing the preferred path