使用多个案例优化查询

Question

我需要一些帮助来优化下面的查询。查询的主要思想是我需要运行一组计算机（a.group =＆＃39; 3008000204＆＃39;）以找出选择组中哪些计算机没有列出的应用程序（app_id）他们和我也想确保他们不是一个单独的机器列表（其中a.mach_name不是IN）的一部分。

有更好的方法吗？

  SELECT mach_name, costcenter, mach_type, make, model, opsys, firstname, lastname, userid,

    CASE WHEN NOT EXISTS(select 1 from Workstations f 
    where a.mach_name not IN('WD-KSA699YBK625','WN-MN14GLY8E00U','WN-MN14GLY8E950','WN-MN14GLY8E00R','WN-MNA79GY0V0DM','WN-MNA79GY0V0E2','WN-MNA79GY0V0J4','WN-MNA79GY0V808','WN-MN14GLY8E0J5','WN-MN14GLA66532','WN-MNA79GY0V0E7','WN-MNA79GY0V01D')
        )
            THEN 'yes' 
        ELSE 'no'
    END as dups,

    CASE WHEN NOT EXISTS(SELECT 1 FROM Workstations d
        left join Assignments e
        on d.WsID = e.WsID
        where a.mach_Name = d.Mach_Name
        and e.app_id in( 15317,15340,12998,13001,15429)
        )
            THEN 'yes' 
        ELSE 'no'
    END AS readycheck
        FROM Workstations a
        where a.group = '3008000204'
    and ((a.opsys != 'OS X')
    and (a.mach_type != 'V')
    and (a.opsys != 'Windows 10'))