Proper detection

proper_detection.sql

%sql
with annotated_data as (
  SELECT
    object_id,
    sample_id,
    feature_1,
    lag(feature_1) OVER tracked_id_timeline as prev_feature_1,
    feature_2,
    lag(feature_2) OVER tracked_id_timeline prev_feature_2,
    row_number() over tracked_id_timeline as rr
  FROM
    VALUES ('A1', 2, 1, 5), ('A1', 1, null, null), ('A2', 3, 3, 7), ('A1', 3, null, null) tab
      (object_id, sample_id, feature_1, feature_2)
  WINDOW tracked_id_timeline as (PARTITION BY object_id ORDER BY sample_id)
)
select
  * except(rr, prev_feature_1, prev_feature_2)
from
  annotated_data
where
  rr = 1 or not (equal_null(feature_1, prev_feature_1) and equal_null(feature_2, prev_feature_2))