The data populating the Vital Signs view comes from many VSTs, including _ActAILog, _ActPWLog, _ActBuffer, _ActSummary, _UserIO, and _ActIOType. If the database is also configured for alternate buffer pools, polling retrieves the alternate buffer pool values from the VST _ActBuffer. Therefore, the Buffer hit rate details shown in the page reflect the total buffer hits for both primary and alternate buffer pools.