Bug 1944375 - Improve data cycling for Main strategy

treeherder/model/data_cycling/removal_strategies.py

@@ -79,13 +79,45 @@ def max_timestamp(self):
         return self._max_timestamp
 
     def remove(self, using: CursorWrapper):
+        """
+        Raw SQL is used to avoid Django ORM cascade deletes on performance_datum_replicate.
+        Although the WHERE clause in del_replicate looks redundant, it is intentionally kept to guide
+        the PostgreSQL planner toward a more efficient execution plan.
+        """
         chunk_size = self._find_ideal_chunk_size()
-        deleted, _ = PerformanceDatum.objects.filter(
-            id__in=PerformanceDatum.objects.filter(
-                push_timestamp__lte=self._max_timestamp
-            ).values_list("id")[:chunk_size]
-        ).delete()
-        using.rowcount = deleted
+        using.execute(
+            """
+            WITH target_datum AS (
+                SELECT pd.id, pd.push_timestamp
+                FROM performance_datum pd
+                WHERE pd.push_timestamp <= %s
+                ORDER BY pd.push_timestamp
+                LIMIT %s
+            ),
+            del_replicate AS (
+                DELETE FROM performance_datum_replicate r1
+                WHERE r1.performance_datum_id IN (
+                    SELECT td.id
+                    FROM target_datum td
+                    WHERE td.push_timestamp <= %s
+                    AND EXISTS (
+                        SELECT 1
+                        FROM performance_datum_replicate r2
+                        WHERE r2.performance_datum_id = td.id
+                    )
+                )
+            ),
+            del_multi AS (
+                DELETE FROM perf_multicommitdatum pm
+                USING target_datum td
+                WHERE pm.perf_datum_id = td.id
+            )
+            DELETE FROM performance_datum pd
+            USING target_datum td
+            WHERE pd.id = td.id
+            """,
+            [self._max_timestamp, chunk_size, self._max_timestamp],
+        )
 
     @property
     def name(self) -> str: