Most of the drools examples that I seen, will for have an example that process address, look for address with a given post/zip code etc on a data source that is already loaded in the knowledge session, but it include no description of how the data was loaded in the knowledge session. I have a reference database of trading containers , the database describes the source, destination, contents etc, relationships between for example a container may have have many sources and many destinations. Destinations and sources may be shared between different containers. The database is normalised to keep source/destination information as a single place table, with link tables to define the relationship between the different containers and places Q. What is the best way of loading my information in to a knowledge session? Expand all the many to many relationship in to a single pojo objects with multiple references to other pojos or is there a better way? source destination eg Container foo England, England England France England Scotland France England bar England Germany England France regards Dave. /* */