Looping is very slow on large data set

Using your example data (thanks!) I put this together.

It should show you the pairings:

SELECT  t.RwNum, t.JobParentID, t.JobSource, t.PackageType, t.UpdateType, t.IsAutoPassed, t.IsCanceled, t.IsSkipped, t.Result, t.Fired, t.RuleName, t2.*
  FROM @Tab t
    LEFT OUTER JOIN @tab t2 
          ON t.jobParentID = t2.JobParentID
          AND t.RwNum <> t2.RwNum
          AND (t.JobSource = t2.JobSource               OR (NULLIF(t.JobSource          ,'') IS NULL    AND NULLIF(t2.JobSource         ,'') IS NOT NULL) OR (NULLIF(t2.JobSource               ,'') IS NULL AND NULLIF(t.JobSource             ,'') IS NOT NULL))
          AND (t.PackageType = t2.PackageType   OR (NULLIF(t.PackageType        ,'') IS NULL    AND NULLIF(t2.PackageType       ,'') IS NOT NULL) OR (NULLIF(t2.PackageType             ,'') IS NULL AND NULLIF(t.PackageType   ,'') IS NOT NULL))
          AND (t.UpdateType = t2.UpdateType             OR (NULLIF(t.UpdateType         ,'') IS NULL    AND NULLIF(t2.UpdateType        ,'') IS NOT NULL) OR (NULLIF(t2.UpdateType              ,'') IS NULL AND NULLIF(t.UpdateType    ,'') IS NOT NULL))
          AND (t.IsAutoPassed = t2.IsAutoPassed OR (NULLIF(t.IsAutoPassed       ,'') IS NULL    AND NULLIF(t2.IsAutoPassed      ,'') IS NOT NULL) OR (NULLIF(t2.IsAutoPassed    ,'') IS NULL AND NULLIF(t.IsAutoPassed  ,'') IS NOT NULL))
          AND (t.IsCanceled = t2.IsCanceled             OR (NULLIF(t.IsCanceled         ,'') IS NULL    AND NULLIF(t2.IsCanceled        ,'') IS NOT NULL) OR (NULLIF(t2.IsCanceled              ,'') IS NULL AND NULLIF(t.IsCanceled    ,'') IS NOT NULL))
          AND (t.IsSkipped = t2.IsSkipped               OR (NULLIF(t.IsSkipped          ,'') IS NULL    AND NULLIF(t2.IsSkipped         ,'') IS NOT NULL) OR (NULLIF(t2.IsSkipped               ,'') IS NULL AND NULLIF(t.IsSkipped             ,'') IS NOT NULL))
          AND (t.result = t2.Result                             OR (NULLIF(t.Result                     ,'') IS NULL    AND NULLIF(t2.Result            ,'') IS NOT NULL) OR (NULLIF(t2.Result                  ,'') IS NULL AND NULLIF(t.Result                ,'') IS NOT NULL))
          AND (t.Fired = t2.Fired                               OR (NULLIF(t.Fired                      ,'') IS NULL    AND NULLIF(t2.Fired                     ,'') IS NOT NULL) OR (NULLIF(t2.Fired                   ,'') IS NULL AND NULLIF(t.Fired                 ,'') IS NOT NULL))
          AND (t.RuleName = t2.RuleName                 OR (NULLIF(t.RuleName           ,'') IS NULL    AND NULLIF(t2.RuleName          ,'') IS NOT NULL) OR (NULLIF(t2.RuleName                ,'') IS NULL AND NULLIF(t.RuleName              ,'') IS NOT NULL))
  ORDER BY 2 DESC ,1  ASC