The database can assign sequence Numbers to each node so that it knows the position of each node and can compare the document order of two nodes in constant time.
数据库可以为每个节点分配顺序号，这样就知道每个节点的位置，可以在常数时间内比较两个节点的文档顺序。
2
I now would like to write down, in most general form the equation for the position and the velocity as a function of time for a one-dimensional motion whereby the acceleration is constant.
A current cycle iterative learning algorism is presented in this paper for the periodic position relevant nonlinear disturbance in the constant speed state of turntable.