django: Switch to .alias() instead .annotate() where possible.

When using the sub-expression purely for filtering, and not for
accessing the value in the resultset, .alias() is potentially faster
since it does not pull the value in as well.

corporate/views/remote_billing_page.py

@@ -662,7 +662,7 @@ def has_live_plan_for_any_remote_realm_on_server(server: RemoteZulipServer) -> b
 
     return (
         RemoteRealm.objects.filter(server=server)
-        .annotate(has_plan=Exists(has_plan_with_status_lt_live_threshold))
+        .alias(has_plan=Exists(has_plan_with_status_lt_live_threshold))
         .filter(has_plan=True)
         .exists()
     )

zerver/lib/attachments.py

@@ -176,7 +176,7 @@ def get_old_unclaimed_attachments(
 
     # The Attachment vs ArchivedAttachment queries are asymmetric because only
     # Attachment has the scheduled_messages relation.
-    old_attachments = Attachment.objects.annotate(
+    old_attachments = Attachment.objects.alias(
         has_other_messages=Exists(
             ArchivedAttachment.objects.filter(id=OuterRef("id")).exclude(messages=None)
         )
@@ -186,7 +186,7 @@ def get_old_unclaimed_attachments(
         create_time__lt=delta_weeks_ago,
         has_other_messages=False,
     )
-    old_archived_attachments = ArchivedAttachment.objects.annotate(
+    old_archived_attachments = ArchivedAttachment.objects.alias(
         has_other_messages=Exists(
             Attachment.objects.filter(id=OuterRef("id")).exclude(
                 messages=None, scheduled_messages=None

zerver/lib/export.py

@@ -1359,7 +1359,7 @@ def export_partial_message_files(
                     user_profile_id__in=consented_user_ids, message_id=OuterRef("id")
                 )
             )
-            messages_we_received_in_protected_history_streams = Message.objects.annotate(
+            messages_we_received_in_protected_history_streams = Message.objects.alias(
                 has_usermessage=has_usermessage_expression
             ).filter(
                 # Uses index: zerver_message_realm_sender_recipient

zerver/lib/message.py

@@ -491,13 +491,13 @@ def bulk_access_stream_messages_query(
     ).exists():
         return Message.objects.none()
     if not stream.is_history_public_to_subscribers():
-        messages = messages.annotate(
+        messages = messages.alias(
             has_usermessage=Exists(
                 UserMessage.objects.filter(
                     user_profile_id=user_profile.id, message_id=OuterRef("id")
                 )
             )
-        ).filter(has_usermessage=1)
+        ).filter(has_usermessage=True)
     return messages
 
 

zerver/lib/onboarding.py

@@ -25,7 +25,7 @@ def missing_any_realm_internal_bots() -> bool:
         for bot in settings.REALM_INTERNAL_BOTS
     ]
     realm_count = Realm.objects.count()
-    return UserProfile.objects.filter(email__in=bot_emails).values("email").annotate(
+    return UserProfile.objects.filter(email__in=bot_emails).values("email").alias(
         count=Count("id")
     ).filter(count=realm_count).count() != len(bot_emails)
 

zerver/lib/soft_deactivation.py

@@ -203,7 +203,7 @@ def add_missing_messages(user_profile: UserProfile) -> None:
         recipient_ids.append(sub["recipient_id"])
 
     new_stream_msgs = (
-        Message.objects.annotate(
+        Message.objects.alias(
             has_user_message=Exists(
                 UserMessage.objects.filter(
                     user_profile_id=user_profile,
@@ -213,7 +213,7 @@ def add_missing_messages(user_profile: UserProfile) -> None:
         )
         .filter(
             # Uses index: zerver_message_realm_recipient_id
-            has_user_message=0,
+            has_user_message=False,
             realm_id=user_profile.realm_id,
             recipient_id__in=recipient_ids,
             id__gt=user_profile.last_active_message_id,

zerver/lib/streams.py

@@ -845,7 +845,7 @@ def get_occupied_streams(realm: Realm) -> QuerySet[Stream]:
     )
     occupied_streams = (
         Stream.objects.filter(realm=realm, deactivated=False)
-        .annotate(occupied=exists_expression)
+        .alias(occupied=exists_expression)
         .filter(occupied=True)
     )
     return occupied_streams
@@ -1002,7 +1002,7 @@ def get_subscribed_private_streams_for_user(user_profile: UserProfile) -> QueryS
     )
     subscribed_private_streams = (
         Stream.objects.filter(realm=user_profile.realm, invite_only=True, deactivated=False)
-        .annotate(subscribed=exists_expression)
+        .alias(subscribed=exists_expression)
         .filter(subscribed=True)
     )
     return subscribed_private_streams