Frequent or Infrequent Commit
Why are you doing this in PL/SQL in the first place?  The most efficient way to do anything in an Oracle database should be to do it in SQL

 UPDATE item_loc il
 SET il.status             = 'D',
    il.last_update_datetime = get_vdate,
    IL.LAST_UPDATE_ID       = 'CNVOBJ_RNG'
 WHERE EXISTS( SELECT 1
                 FROM dc_item_loc d
                WHERE d.item = il.item
                  AND d.loc  = il.loc );