The invention, in an embodiment, relates to optimizing database
performance by taking advantage of sleepy drives. The invention analyzes
queries to indexes based on usage frequency, and determines whether to
access an index stored on a sleepy drive, or perform an alternate access
plan based on green optimization. Furthermore, the invention transfers
data, such as, for example, indexes, files, data areas, journals, and
statistics, between active and sleepy drives based on usage frequency. In
another embodiment, the invention provides an improved sleepy drive which
optimizes energy savings by a graduated degree based on a speed setting.
In yet another embodiment, the invention controls when read-write heads
are unloaded from disks to reduce drag and power consumption by a disk
drive.