sql - database normalisation -

i'm building query , i'm building it, i'm realizing it'd easier write if of tables contained redundant fields; it'd save few joins. however, doing mean database model not totally normalized.

i'm aiming performance; having denormalized database impede performance? i'm using sql server.

thanks.

i don't know implementation is, helps have redundant index references, not redundant fields per se.

for example, have 3 tables: tbl_building, tbl_room, , tbl_equipment. (an equipment belongs room, belongs buildng)

tbl_building has buildingid, tbl_room has roomid , reference buildingid. save join if tbl_equipment had reference both roomid , buildingid, though infer buildingid roomid.

now, not if, example, have field buildingsize on tbl_building , copy buildingsize field tbl_room , tbl_equipment.