A database system with methodology for automated determination and
selection of optimal indexes is described. In one embodiment, for
example, in a database system, a method of the present invention is
described for recommending database indexes to be created for optimizing
system performance, the method comprises steps of: capturing a workload
representative of database queries employed during system use; creating
virtual indexes for optimizing system performance during execution of the
database queries captured in the workload; computing cost benefits for
different combinations of the virtual indexes; and recommending physical
indexes to be created based on virtual indexes that have favorable cost
benefits for the captured workload.