SQL语句性能优化问题，在线等！！！

[donet_hli]

下面2段SQL语句都封装成了视图，代码如下:

--视图名称为：_en_wk_vAppAndLog
SELECT  a.wfappid, a.wfappname, l.processid, l.duedt, l.alarmdt, l.path, l.todoid, l.elapsedwksec, p.tp, 
		p.name, p.wkid, l.createdate, l.actiondate, l.actionby, 
		l.actionbyname, f.endby, t.wftypename, t.wftypeid
FROM  dbo._en_wk_log AS l INNER JOIN
      dbo._en_wk_flow AS f ON l.flowid = f.id LEFT OUTER JOIN
      dbo._en_wk_process AS p ON f.wkid = p.wkid AND p.id = l.processid LEFT OUTER JOIN
      dbo._en_wk_master AS msc ON msc.id = f.wkid LEFT OUTER JOIN
      dbo._en_wk_diagram AS d ON d.diagid = msc.diagid LEFT OUTER JOIN
      dbo._en_wk_application AS a ON a.diagid = d.diagid INNER JOIN
      dbo._en_wk_applicationtype AS t ON a.wftypeid = t.wftypeid
WHERE     (f.wfappid IS NULL OR f.wfappid = ' ') AND (a.wfappname <> '选择审计流程类型') AND (a.wfappname <> '项目总览表')

下面的视图效率极慢，导致页面无法正常展示，SQL语句如下：

--视图名称为：_en_wk_vAppModelStat
SELECT     a.wfappid, a.wfappname, a.summin, s.startprocess, e.endprocess, t.totalprocess, 
		   t.wftypename, t.wftypeid, CAST(a.summin AS float) / t.totalprocess AS avgmin,
	       p.sumelapse, ps.sumelapseint, CAST(em.emsummin AS float) / e.endprocess AS emavgmin
FROM   (SELECT wfappid, wfappname, SUM(CAST(elapsedwksec / 60 AS int)) AS summin FROM dbo._en_wk_vAppAndLog
				GROUP BY wfappid, wfappname) AS a INNER JOIN
       (SELECT wfappid, wfappname, COUNT(*) AS startprocess FROM dbo._en_wk_vAppAndLog WHERE (tp = 'start')
				GROUP BY wfappid, wfappname) AS s ON a.wfappid = s.wfappid LEFT OUTER JOIN
       (SELECT wfappid, wfappname, COUNT(*) AS endprocess FROM dbo._en_wk_vAppAndLog WHERE (tp = 'end')
				GROUP BY wfappid, wfappname) AS e ON a.wfappid = e.wfappid LEFT OUTER JOIN
       (SELECT wfappid, wfappname, SUM(CAST(elapsedwksec / 60 AS int)) AS emsummin FROM dbo._en_wk_vAppAndLog WHERE (NOT (endby IS NULL))
				GROUP BY wfappid, wfappname) AS em ON a.wfappid = em.wfappid INNER JOIN
       (SELECT wfappid, wfappname, wftypename, wftypeid, COUNT(*) AS totalprocess FROM dbo._en_wk_vAppAndLog
				GROUP BY wfappid, wfappname, wftypename, wftypeid) AS t ON a.wfappid = t.wfappid LEFT OUTER JOIN
       (SELECT wfappid, wfappname, COUNT(*) AS sumelapse FROM dbo._en_wk_vAppAndLog WHERE (actiondate > duedt)
				GROUP BY wfappid, wfappname) AS p ON a.wfappid = p.wfappid LEFT OUTER JOIN
       (SELECT wfappid, wfappname, COUNT(*) AS sumelapseint 
				FROM (SELECT wfappid, wfappname, processid FROM dbo._en_wk_vAppAndLog
                    WHERE (actiondate > duedt)
						GROUP BY wfappid, wfappname, processid) AS pe
				GROUP BY wfappid, wfappname) AS ps ON a.wfappid = ps.wfappid

执行该视图语句Select * From "_en_wk_vAppModelStat" p order by p.wfappname的耗时为20秒左右。。。
请教各位牛人如下优化，小弟感激不尽，在线等！！！

[开着拖拉机泡妞]

where ,group后面的字段加索引

[donet_hli]

页面展示效果为：

[justin_hli]

[勿勿]

图没了

[勿勿]

create index in_wfappname on en_wk_vAppModelStat (wfappname)  
 看行吗