SQL Server proc运行速度比普通查询慢5倍

I have the following query:

我有以下查询:

DECLARE @DaysNotUsed int = 14
DECLARE @DaysNotPhoned int = 7

--Total Unique Students
DECLARE @totalStudents TABLE (SchoolID uniqueidentifier, TotalUniqueStudents int)
INSERT INTO @totalStudents
SELECT 
        SSGG.School,
        COUNT(DISTINCT S.StudentID)
    FROM Student S
        INNER JOIN StudentStudents_GroupGroups SSGG ON (SSGG.Students = S.StudentID AND SSGG.School = S.School)
        INNER JOIN [Group] G ON (G.GroupID = SSGG.Groups AND G.School = SSGG.School)
        INNER JOIN SessionHistory SH ON (SH.Student = S.StudentID AND SH.School = S.School AND SH.StartDateTime > GETDATE() - @DaysNotUsed)
    WHERE G.IsBuiltIn = 0
        AND S.HasStartedProduct = 1
    GROUP BY SSGG.School

--Last Used On
DECLARE @lastUsed TABLE (SchoolID uniqueidentifier, LastUsedOn datetime)
INSERT INTO @lastUsed
SELECT
        vi.SchoolID,
        MAX(sh.StartDateTime)
    FROM View_Installation as vi
        INNER JOIN SessionHistory as sh on sh.School = vi.SchoolID
    GROUP BY vi.SchoolID

SELECT 
        VI.SchoolID, 
        INS.DateAdded,
        INS.Removed,
        INS.DateRemoved,
        INS.DateToInclude,
        VI.SchoolName AS [School Name], 
        VI.UsersLicensed AS [Licenses],
        ISNULL(TS.TotalUniqueStudents, 0) as [Total Unique Students],
        ISNULL(TS.TotalUniqueStudents, 0) * 100 / VI.UsersLicensed as [% of Students Using],
        S.State,
        LU.LastUsedOn,
        DATEDIFF(DAY, LU.LastUsedOn, GETDATE()) AS [Days Not Used],
        SI.AreaSalesManager AS [Sales Rep],
        SI.CaseNumber AS [Case #],
        SI.RenewalDate AS [Renewal Date],
        SI.AssignedTo AS [Assigned To],
        SI.Notes AS [Notes]
    FROM View_Installation VI
        INNER JOIN School S ON S.SchoolID = VI.SchoolID
        LEFT OUTER JOIN @totalStudents TS on TS.SchoolID = VI.SchoolID
        INNER JOIN @lastUsed LU on LU.SchoolID = VI.SchoolID
        LEFT OUTER JOIN InactiveReports..SchoolInfo SI ON S.SchoolID = SI.SchoolID
        LEFT OUTER JOIN InactiveReports..InactiveSchools INS ON S.SchoolID = INS.SchoolID
    WHERE VI.UsersLicensed > 0
        AND VI.LastPhoneHome > GETDATE() - @DaysNotPhoned
        AND
        (
            (
                SELECT COUNT(DISTINCT S.StudentID)
                    FROM Student S
                        INNER JOIN StudentStudents_GroupGroups SSGG ON (SSGG.Students = S.StudentID AND SSGG.School = S.School)
                        INNER JOIN [Group] G ON (G.GroupID = SSGG.Groups AND G.School = SSGG.School)
                    WHERE G.IsBuiltIn = 0
                        AND S.School = VI.SchoolID
            ) * 100 / VI.UsersLicensed < 50
            OR
            VI.SchoolID NOT IN 
            (
                SELECT DISTINCT SH1.School
                FROM SessionHistory SH1
                WHERE SH1.StartDateTime > GETDATE() - @DaysNotUsed
            ) 
        )
    ORDER BY [Days Not Used] DESC
DECLARE