hello , i heard its very good and new datastructure known as waterfall tree compared to btree.
It could be good if you think and research some datastructure or take a look at waterfalltree
Or it can be selectable by objectdb :
here what i talk about :
http://stsdb.com/stsdb-w4.0/technology/waterfalltree/overview
the documentation tells , it makes db very fast
here is algorithm on youtube :
http://www.youtube.com/watch?v=k9igsoqy_jc