倒地having子句支持列别名么?

Question

网上查找出的资料好乱啊- -汗
having子句支持列别名么?如果不支持,如何在having子句中进行诸如如下的比较呢?
问题:要处理部门平均工资大于总平均工资的部门SELECT vDepartmentName "Name",NVL(d_avg,0) "AVG" FROM Department,
(SELECT cDepartmentCode,avg(nAnnualSalary) d_avg,SUM(nAnnualSalary) d_sum FROM AnnualSalary,
(SELECT cDepartmentCode,cEmployeeCode FROM Department LEFT JOIN 
(SELECT cDepartmentCode,cEmployeeCode FROM Employee GROUP BY cDepartmentCode) 
USING(cDepartmentCode)) department 
WHERE nYear=1998 AND AnnualSalary.cEmployeeCode=department.cEmployeeCode 
GROUP BY cDepartmentCode HAVING d_avg>AVG(d_sum)) code WHERE Department.cDepartmentCode=code.cDepartmentCode(+)
我尝试用AVG(SUM(nAnnualSalary))结果提示套嵌太深,orz
另外,set timing on之类的语句想写到一个脚本中随数据库启动执行,请问linux下应该写到什么地方?谢谢您的回答.