Index build times are an important operational measurement to gather. The tests made to check the data warehouse management systems should check, in particular, the effects of using differing degrees of parallelism. This can prove to be very important in keeping the overnight processing within the limits required. In a data warehouse, indexes are often required to be re-created because, for data loads and other bulk data movements, it is generally quicker to drop indexes, perform the data movement and create a new index, than to perform the data move with indexes in place.