def drop_index(index_name)
			transaction {
				ODBA.storage.drop_index(index_name)
				self.delete(self.indices[index_name]) 
			}
		end
def drop_index(index_name)
			transaction {
				ODBA.storage.drop_index(index_name)
				self.delete(self.indices[index_name]) 
			}
		end
Permanently deletes the index named _index_name_