Join order restrictions

A query that is submitted to a database is analyzed so as to determine a join order restriction. The join order restriction is associated with a join between two tables of a plurality of tables of the database that participate in the query. The join order restriction constrains its associated join to be executed prior to another join of the query. At least one join plan is generated, the join plan being constrained by the join order restriction. Different join plans include different join orders. A join plan is selected from among the join plans for execution of the query.