Merge pull request #1380 from open-zaak/issue/1363-speedup-eio

⚡ [#1363] Optimize EIO endpoint performance

src/openzaak/components/documenten/api/pagination.py

@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: EUPL-1.2
+# Copyright (C) 2023 Dimpact
+from django.conf import settings
+from django.core.paginator import Paginator as DjangoPaginator
+from django.utils.functional import cached_property
+
+from rest_framework.pagination import PageNumberPagination
+
+
+class EnkelvoudigInformatieObjectPaginator(DjangoPaginator):
+    @cached_property
+    def count(self):
+        """
+        ⚡ restricts values to PK to remove implicit join from SQL query
+        """
+        if not settings.CMIS_ENABLED:
+            # Objects in CMISQuerySet do not have `pk`s
+            return self.object_list.values("pk").count()
+        return super().count
+
+
+class EnkelvoudigInformatieObjectPagination(PageNumberPagination):
+    django_paginator_class = EnkelvoudigInformatieObjectPaginator

src/openzaak/components/documenten/api/viewsets.py

@@ -12,7 +12,6 @@
 from notifications_api_common.viewsets import NotificationViewSetMixin
 from rest_framework import mixins, status, viewsets
 from rest_framework.decorators import action
-from rest_framework.pagination import PageNumberPagination
 from rest_framework.parsers import FormParser, MultiPartParser
 from rest_framework.response import Response
 from rest_framework.serializers import ValidationError
@@ -44,6 +43,7 @@
 )
 from .kanalen import KANAAL_DOCUMENTEN
 from .mixins import UpdateWithoutPartialMixin
+from .pagination import EnkelvoudigInformatieObjectPagination
 from .permissions import InformationObjectAuthRequired
 from .renderers import BinaryFileRenderer
 from .scopes import (
@@ -187,12 +187,13 @@ class EnkelvoudigInformatieObjectViewSet(
         EnkelvoudigInformatieObject.objects.select_related(
             "canonical", "_informatieobjecttype"
         )
+        .prefetch_related("canonical__bestandsdelen")
         .order_by("canonical", "-versie")
         .distinct("canonical")
     )
     lookup_field = "uuid"
     serializer_class = EnkelvoudigInformatieObjectSerializer
-    pagination_class = PageNumberPagination
+    pagination_class = EnkelvoudigInformatieObjectPagination
     permission_classes = (InformationObjectAuthRequired,)
     required_scopes = {
         "list": SCOPE_DOCUMENTEN_ALLES_LEZEN,