30. The computer program product of claim 29 , wherein the storage medium further includes instructions configured to cause the data processing apparatus to: generate a mapping table that identifies levels of the physical hierarchy and levels of the attribute hierarchy; and use the mapping table to recreate the attribute hierarchy.
30. The computer program product of claim 29 , wherein the storage medium further includes instructions configured to cause the data processing apparatus to: generate a mapping table that identifies levels of the physical hierarchy and levels of the attribute hierarchy; and use the mapping table to recreate the attribute hierarchy. 34. The computer program product of claim 30 , wherein the mapping table identifies all levels in the attribute hierarchy.