A method, system and computer program product for clustered join graph generation based upon a log of previously executed database queries includes loading into memory of a computer, a log of a set of database queries previously executed against data in a database of the database management system, sequentially parsing each of the queries in the log to identify different semantically characterizable components of each of the queries, generating a join graph for each of the queries from corresponding ones of the components, clustering different generated join graphs according to semantic commonalities so as to form different clusters of join graphs, each for a different semantic commonality, combining the generated join graphs for each cluster into a combined join graph for the corresponding cluster and adding each of the combined join graphs to a set of join graphs in a data model for the data in the database.