Spatial database indices for large extended objects

An analytic model is given for the behavior of dynamic spatial index structures under insertions and deletions. Based on this model a new tool, called the oversize shelf to improve the performance of tree-based indices by minimizing redundancy, is optimized and evaluated. Oversize shelves are extra disk pages that are attached to the interior nodes of a tree-based spatial index structure. These pages are used to accommodate very large data objects in order to avoid their excessive fragmentation. Whenever inserting a new object into the tree, it should be decided whether to store it on an oversize shelf or to insert it into the subtrees. From the analytic model a threshold q* for the object size is obtained. If the object is larger than q*, it is more favorable to put it on the oversize shelf, otherwise the insertion into the subtrees is preferable