perf(organizations): speed up filtered API lists

src/organizations/views.py

@@ -285,9 +285,7 @@ class CachedReadOnlyMixin:
 class OrganizationViewSet(CachedReadOnlyMixin, ReadOnlyModelViewSet):
     """Read-only API for canonical organizations."""
 
-    queryset = Organization.objects.select_related("data_snapshot").order_by(
-        "name", "uid"
-    )
+    queryset = Organization.objects.order_by("name", "uid")
     serializer_class = OrganizationSerializer
     permission_classes = [IsAuthenticated]
     lookup_field = "uid"
@@ -307,7 +305,10 @@ class OrganizationViewSet(CachedReadOnlyMixin, ReadOnlyModelViewSet):
         return super().get_permissions()
 
     def get_queryset(self):
-        queryset = super().get_queryset()
+        queryset = super().get_queryset().select_related("data_snapshot")
+        if self._should_defer_snapshot_data():
+            queryset = queryset.defer("data_snapshot__data")
+
         if self.action != "list" or "has_registry" in self.request.query_params:
             return queryset
 
@@ -320,6 +321,20 @@ class OrganizationViewSet(CachedReadOnlyMixin, ReadOnlyModelViewSet):
             return filterset.qs
         return queryset
 
+    def _should_defer_snapshot_data(self) -> bool:
+        if getattr(self, "action", None) != "list":
+            return False
+
+        return not any(
+            name in self.request.query_params
+            for name in (
+                "data",
+                "data_sources",
+                "exclude_data",
+                "exclude_data_sources",
+            )
+        )
+
     @swagger_auto_schema(
         tags=[ORGANIZATIONS_TAG],
         operation_id="v2_organizations_list",