Shorten comments in the created timestamp cutoff

Signed-off-by: David <david-adeniji@hotmail.co.uk>
feast-dev · ntkathole · Jul 31, 2026 · Jul 19, 2026 · Jul 19, 2026 · Jul 19, 2026
commit 3d2ea3e0d43d18f0606659d1132402be640f8412
@@ -1207,17 +1207,16 @@ def _apply_created_timestamp_cutoff(
     entity_df_event_timestamp_col: str,
     preserved_columns: Set[str],
 ) -> dd.DataFrame:
-    # Blanking rather than dropping preserves entity-dataframe cardinality when every
-    # candidate is too new. A blanked row looks like an unmatched left join, which
-    # _drop_duplicates already resolves (nulls sort first, keep="last"). The isna() term
-    # keeps a matched row whose source timestamp is null, as _filter_ttl does.
+    # Versions created after the entity timestamp. The isna() term leaves rows with a
+    # null source timestamp untouched, matching _filter_ttl.
     too_new = ~df_to_join[timestamp_field].isna() & ~(
         df_to_join[created_timestamp_column]
         <= df_to_join[entity_df_event_timestamp_col]
     )
 
-    # One assign, not a per-column loop: chained assignments make optimization
-    # super-linear in column count. Lazy so it fuses into the next persist.
+    # Blank instead of drop, so the entity row survives when every candidate is too new.
+    # _drop_duplicates then prefers a real match (nulls sort first, keep="last").
+    # Single assign, left lazy: a per-column loop is super-linear to optimize.
     return df_to_join.assign(
         **{
             column: df_to_join[column].mask(too_new)

@@ -190,8 +190,8 @@ def read_fv(
         timestamp_field = feature_view.batch_source.timestamp_field
         created_timestamp_column = feature_view.batch_source.created_timestamp_column
 
-        # deduplicate() orders by created_timestamp_column regardless of the cutoff, so
-        # normalize both unconditionally. An already-tz-aware cast compiles away.
+        # deduplicate() orders by created_timestamp_column whether or not the cutoff is
+        # on, so this cannot be gated on it. Casting an already-UTC column is a no-op.
         utc_columns = [timestamp_field]
         if created_timestamp_column:
             utc_columns.append(created_timestamp_column)