47. A system as claimed in claim 38 further comprising means for adding columns to indexes where the cardinality of the index is below a threshold.
38. In a physical design system for a database having plural tables, each of plural columns, stored in memory, a processor and a physical design program stored in memory comprising: means for identifying importance values for individual database requests; and means for designing indexes to tables for the requests by identifying by order of request importance, candidate indexes, searching previously identified indexes for an index that is similar to each candidate index, and building upon previously identified indexes by reusing existing indexes and modifying existing indexes based upon match between indexes and upon importance values of requests for which the indexes are created.