论文标题：Access Characteristic Guided Partition for Read Performance Improvement on Solid State Drives
作者：Yina Lv, Liang Shi, Qiao Li, Chun Jason Xue, Edwin H.-M. Sha
单位：华东师范大学；香港城市大学；
问题提出
先造一些测试数据以说明题目：
DECLARE TestData TABLE(ID INT,Col1 VARCHAR(20),Col2 VARCHAR(20))
INSERT INTO TestData(ID,Col1,Col2)
SELECT 1,'New','Approved' UNION ALL
SELECT 2,'Approved','Commited' UNION ALL
SELECT 3,'Commited','In Progress' UNION ALL
SELECT 4
今天大概弄懂了partition by和group by的区别联系。
1. group by是分组函数，partition by是分析函数（然后像sum()等是聚合函数）；
2. 在执行顺序上，
以下是常用sql关键字的优先级
from > where > group by > having > order by
而partition by应用在以上关键字之后，实际上就是在执行完select之后，在所得结果集之上进行partition。
3.partition by相比较
The main difficulties in modeling yaw dynamics of a helicopter arise from the high nonlinearities, cross-couplings and dynamic uncertainties of these aerocraft. This paper proposes a new identification approach for yaw dynamics modeling through modes
