CREATE TABLE salaryByMonth
(
employeeNo varchar2(20),
yearMonth varchar2(6),
salary number
) ;
insert into SALARYBYMONTH (EMPLOYEENO, YEARMONTH, SALARY)
values (1, '200805', 500);
insert into SALARYBYMONTH (EMPLOYEENO, YEARMONTH, SALARY)
values (1, '200802', 150);
insert into SALARYBYMONTH (EMPLOYEENO, YEARMONTH, SALARY)
values (1, '200803', 200);
insert into SALARYBYMONTH (EMPLOYEENO, YEARMONTH, SALARY)
values (1, '200804', 300);
insert into SALARYBYMONTH (EMPLOYEENO, YEARMONTH, SALARY)
values (1, '200708', 100);
commit;
SELECT EMPLOYEENO
,YEARMONTH
,SALARY
,MIN(SALARY) KEEP(DENSE_RANK FIRST ORDER BY YEARMONTH) OVER(PARTITION BY EMPLOYEENO) FIRST_SALARY -- 基比分析 salary/first_salary
,LAG(SALARY, 1, 0) OVER(PARTITION BY EMPLOYEENO ORDER BY YEARMONTH) AS PREV_SAL -- 环比分析，与上个月份进行比较
,LAG(SALARY, 12, 0) OVER(PARTITION BY EMPLOYEENO ORDER BY YEARMONTH) AS PREV_12_SAL -- 同比分析，与上个年度相同月份进行比较
,SUM(SALARY) OVER(PARTITION BY EMPLOYEENO, SUBSTR(YEARMONTH, 1, 4) ORDER BY YEARMONTH RANGE UNBOUNDED PRECEDING) LJ --累计值
from SALARYBYMONTH
ORDER BY EMPLOYEENO
,YEARMONTH
Oracle 的 9i/10g 中已经对内存管理逐步做了很大的简化，11g 则更进一步，引入了一个新的概念自动化内存管理(Automatic Memory Management,AMM) . 如果 DBA 真的想偷懒的话，只需要设定两个参数就可以把烦心的事情都交给 Oracle 折腾了(只要 DBA 足够心宽)。PGA 与 SGA 一起搞定。这两个参数分别是：
MEMORY_TARGET--操作� ......
对初学ORACLE的人一时很难分清ORACLE中关于“空间”的概念，比如表空间 临时表空间 用户表空间等，对于由SQL转到ORACLE的就更加混淆了，让人感觉ORACLE繁琐；繁琐在哪儿，我整理罗列如下：
1.ORACLE自带工具不十分易用；
2.ORACLE第三方工具易上手，但难深入；
&n ......
