Spatial query performance

Spatial objects will be query as other objects. So, using native query or SODA, (and may be using QBE). Well, but what about performance. SODA uses B-Trees index structure. Spatial objects needs other index structure, for example R-Tree. SODA should be extended for new index structures. But, for now, there is no direct API hook to implement own indexing strategy (for more information see http://community.versant.com/Forums/tabid/98/aft/11961/Default.aspx).