that supposed to be faster, if clustered index applied on (PersonID, Version )

select distinct a.PersonID,a.Version, a.DEDate , case when b.PersonID is null then 0 else 1 end AS [Is ImProper]

from PersonRecord a

left join (

select a.PersonID, a.Version

from PersonRecord a

inner join PersonRecord b on a.PersonID = b.PersonID and a.Version>b.Version and a.DEDate<b.DEDate

) b on a.PersonID = b.PersonID and a.Version=b.Version

thanks