1. A method of improving search of a database, the method comprising: monitoring user search activity in a user population; extracting search sessions, defined by search queries and paths, from user search activity; determining groups of semantically related queries or paths based on search session data; determining probabilities that records in the database are relevant for each query or path group; maintaining a table associating an index for each record in the database with the probability that the record is relevant for each query or path group; and, supplementing search results with information regarding records from the database with tabulated relevance probabilities.