A database system with methodology for parallel schedule generation in a query optimizer is described. In one embodiment, for example, in a database system, a method is described for parallel optimization of a query, the method comprises steps of: generating a plurality of parallel plans for obtaining data requested by the query, the parallel plans including parallel operators for executing portions of the query in parallel; adjusting parallel operators of each parallel plan if necessary based on resources available for executing the query; creating a schedule for each parallel plan indicating a sequence for execution of operators of each parallel plan; determining execution cost of each parallel plan based on its schedule; and selecting a particular parallel plan having lowest execution cost for obtaining data requested by the query.