fix(deletions): Fix pull request unused query to use exists

src/sentry/models/pullrequest.py

@@ -121,12 +121,16 @@ def get_unused_filter(cls, cutoff_date: datetime) -> Q:
         This is the inverse of what makes a PR "in use".
         """
         from sentry.models.grouplink import GroupLink
+        from sentry.models.releasecommit import ReleaseCommit
+        from sentry.models.releaseheadcommit import ReleaseHeadCommit
 
         # Subquery for checking if there's a valid GroupLink
-        grouplink_exists = GroupLink.objects.filter(
-            linked_type=GroupLink.LinkedType.pull_request,
-            linked_id=OuterRef("id"),
-            group__project__isnull=False,
+        grouplink_exists = Exists(
+            GroupLink.objects.filter(
+                linked_type=GroupLink.LinkedType.pull_request,
+                linked_id=OuterRef("id"),
+                group__project__isnull=False,
+            )
         )
 
         # Subquery for checking if comment has valid group_ids
@@ -147,15 +151,26 @@ def get_unused_filter(cls, cutoff_date: datetime) -> Q:
             )
         )
 
+        recent_comment_exists = Exists(
+            PullRequestComment.objects.filter(
+                pull_request_id=OuterRef("id"),
+            ).filter(Q(created_at__gte=cutoff_date) | Q(updated_at__gte=cutoff_date))
+        )
+
+        commit_in_release = Exists(ReleaseCommit.objects.filter(commit_id=OuterRef("commit_id")))
+        commit_in_head = Exists(ReleaseHeadCommit.objects.filter(commit_id=OuterRef("commit_id")))
+        commit_exists = Exists(
+            PullRequestCommit.objects.filter(
+                pull_request_id=OuterRef("id"),
+            ).filter(Q(commit__date_added__gte=cutoff_date) | commit_in_release | commit_in_head)
+        )
+
         # Define what makes a PR "in use" (should be kept)
         keep_conditions = (
             Q(date_added__gte=cutoff_date)
-            | Q(pullrequestcomment__created_at__gte=cutoff_date)
-            | Q(pullrequestcomment__updated_at__gte=cutoff_date)
-            | Q(pullrequestcommit__commit__date_added__gte=cutoff_date)
-            | Q(pullrequestcommit__commit__releasecommit__isnull=False)
-            | Q(pullrequestcommit__commit__releaseheadcommit__isnull=False)
-            | Exists(grouplink_exists)
+            | recent_comment_exists
+            | commit_exists
+            | grouplink_exists
             | comment_has_valid_group
         )