What DFM and perf advisers versions you are using and likely to use?
the DFM suite can (in some ways) generate all the reports you mentioned.
i would avoid direct DB query as the filled tends to change. and netapp has no obligation to keep them. also - ther's a lot of room for erros with custom reports, as sometimes the data in the DB is not in friendly values like some KB some in Kb, some not completely self explained like in the GUI (when the size includes reserves and sanp, and when not)