Search Algorithms for Conceptual Graph Databases

We consider a database composed of a set of conceptual graphs. Using conceptual graphs and graphhomomorphism it is possible to build a basic query-answering mechanism based on semantic search.Graph homomorphism defines a partial order over conceptual graphs. Since graph homomorphismchecking is an NP-Complete problem, the main requirement for database organizing and managingalgorithms is to reduce the number of homomorphism checks. Searching is a basic operation for databasemanipulating problems. We consider the problem of searching for an element in a partially ordered set.The goal is to minimize the number of queries required to find a target element in the worst case. First weanalyse conceptual graph database operations. Then we propose a new algorithm for a subclass of lattices.Finally, we suggest a parallel search algorithm for a general poset.