Hierarchies on Dimensions Hierarchy on dimension attributes:lets dimensions to be viewed at different levels of detail E.g.the dimension DateTime can be used to aggregate by hour of day,date,day of week,month,quarter or year Year Quarter Region Day of week Month Country Hour of day Date State Date Time City a)Time Hierarchy b)Location Hierarchy Database System Concepts-5th Edition,Aug 26,2005 18.10 ©Silberschat乜，Korth and SudarshanDatabase System Concepts - 5 18.10 ©Silberschatz, Korth and Sudarshan th Edition, Aug 26, 2005 Hierarchies on Dimensions Hierarchy on dimension attributes: lets dimensions to be viewed at different levels of detail E.g. the dimension DateTime can be used to aggregate by hour of day, date, day of week, month, quarter or year