A new multi-dimensional file structure has been developed m the course of a project to devise ways of unproving the support for interactive queries to databases and knowledge bases Christened the 'BANG' file - a Balanced And Bested @id - the new structure 1s of the'gnd file;- type, but 1s fundamentally different from prr\~tms grid file designs m that it does not share their c',rnmon underlying properties It has a tree- structured cllrec tory wluch has the self-balancing propert, ~4 a B-tree and which, m contrast to previous design*, almavs expands at the same rate as the data, whatever bhr form of the data &strlbutlon Its partltlonmg utratrgy both accurately reflects the clustering of pomts m the data space, and 18 flexible enough LO adapt gracefully to changes m the distribution