Relation<String> lblrel = DatabaseUtil.guessLabelRepresentation(database);
for(SpatialIndexTree<?, ?> index : indexes) {
List<? extends SpatialEntry> leaves = index.getLeaves();
MeanVariance mv = new MeanVariance();
for(SpatialEntry e : leaves) {
SpatialDirectoryEntry leaf = (SpatialDirectoryEntry) e;
Node<?> n = index.getNode(leaf.getEntryID());
final int total = n.getNumEntries();
HashMap<String, Integer> map = new HashMap<String, Integer>(total);
for(int i = 0; i < total; i++) {
DBID id = ((SpatialPointLeafEntry) n.getEntry(i)).getDBID();