zOs/TX/PER15RID

delete from qtxcrx.tper15 d
    where exists (select 1 from qtxcrx.tper15 q
                      where d.txt = q.txt and rid(q) > rid(d)
                 )
;
rollback
;x;
select count(*)
    from t s
    where not exists (select 1 from qtxcrx.tper15 q
                          where s.txt = q.txt and rid(q) > s.ridT
with t as
(
   select t.*, rid(t) ridT
    from qtxcrx.tper15 t
)
select count(*)
    from t s
    where not exists (select 1 from qtxcrx.tper15 q
                          where s.txt = q.txt and rid(q) > s.ridT
                     )
;y;
select count(*) "cnt", min(rid(t)) "ridMin", max(rid(t)), txt
    from qtxcrx.tper15 t
    group by txt