optimize events creation and improve indexes

care/facility/api/viewsets/events.py

@@ -31,7 +31,7 @@
     @extend_schema(tags=("event_types",))
     @method_decorator(cache_page(86400))
     @action(detail=True, methods=["GET"])
     def descendants(self, request, pk=None):
         event_type: EventType = get_object_or_404(self.queryset, pk=pk)
         queryset = self.get_queryset().filter(pk__in=event_type.get_descendants())
         serializer = self.get_serializer(queryset, many=True)
@@ -40,7 +40,7 @@
     @extend_schema(tags=("event_types",))
     @method_decorator(cache_page(86400))
     @action(detail=False, methods=["GET"])
     def roots(self, request):
         queryset = self.get_queryset().filter(parent__isnull=True)
         serializer = self.get_serializer(queryset, many=True)
         return Response(serializer.data)
@@ -56,11 +56,11 @@
 
     class Meta:
         model = PatientConsultationEvent
         fields = [
             "event_type",
             "caused_by",
             "is_latest",
         ]
 
 
 class PatientConsultationEventViewSet(ReadOnlyModelViewSet):
@@ -71,14 +71,14 @@
     permission_classes = (IsAuthenticated,)
     filter_backends = (filters.DjangoFilterBackend,)
     filterset_class = PatientConsultationEventFilterSet
     # lookup_field = "external_id"
     # lookup_url_kwarg = "external_id"
 
     def get_consultation_obj(self):
         return get_object_or_404(
-            get_consultation_queryset(self.request.user).filter(
-                external_id=self.kwargs["consultation_external_id"]
-            )
+            get_consultation_queryset(self.request.user)
+            .filter(external_id=self.kwargs["consultation_external_id"])
+            .only("id")
         )
 
     def get_queryset(self):

care/facility/events/handler.py

@@ -25,12 +25,13 @@
     fields: set[str] = (
         get_changed_fields(old_instance, object_instance)
         if old_instance
         else {field.name for field in object_instance._meta.fields}
     )
 
     fields_to_store = fields_to_store & fields if fields_to_store else fields
 
     batch = []
+    groups_to_mark_stale: list[int] = []
     groups = EventType.objects.filter(
         model=object_instance.__class__.__name__, fields__len__gt=0, is_active=True
     ).values_list("id", "fields")
@@ -44,14 +45,7 @@
             if all(not v for v in value.values()):
                 continue
 
-            PatientConsultationEvent.objects.select_for_update().filter(
-                consultation_id=consultation_id,
-                event_type=group_id,
-                is_latest=True,
-                object_model=object_instance.__class__.__name__,
-                object_id=object_instance.id,
-                taken_at__lt=taken_at,
-            ).update(is_latest=False)
+            groups_to_mark_stale.append(group_id)
             batch.append(
                 PatientConsultationEvent(
                     consultation_id=consultation_id,
@@ -71,6 +65,18 @@
                 )
             )
 
+    old_events_filter = {
+        "consultation_id": consultation_id,
+        "event_type__in": groups_to_mark_stale,
+        "is_latest": True,
+        "object_model": object_instance.__class__.__name__,
+        "taken_at__lt": taken_at,
+    }
+    if change_type == ChangeType.UPDATED:
+        old_events_filter["object_id"] = object_instance.id
+    PatientConsultationEvent.objects.select_for_update().filter(
+        **old_events_filter
+    ).update(is_latest=False)
     PatientConsultationEvent.objects.bulk_create(batch)
     return len(batch)
 
@@ -91,10 +97,10 @@
         taken_at = created_date
 
     with transaction.atomic():
         if isinstance(objects, (QuerySet, list, tuple)):
             if old is not None:
                 raise ValueError(
                     "diff is not available when objects is a list or queryset"
                 )
             for obj in objects:
                 create_consultation_event_entry(

care/facility/migrations/0465_merge_20240923_1043.py

@@ -0,0 +1,12 @@
+# Generated by Django 5.1.1 on 2024-09-23 05:13
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("facility", "0464_alter_facilitycapacity_room_type_and_more"),
+        ("facility", "0464_rename_spo2_dailyround_archived_spo2"),
+    ]
+
+    operations = []

care/facility/migrations/0466_remove_patientconsultationevent_facility_pa_consult_7b22fe_idx_and_more.py

@@ -0,0 +1,37 @@
+# Generated by Django 5.1.1 on 2024-09-23 05:13
+
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("facility", "0465_merge_20240923_1043"),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.RemoveIndex(
+            model_name="patientconsultationevent",
+            name="facility_pa_consult_7b22fe_idx",
+        ),
+        migrations.AlterField(
+            model_name="patientconsultationevent",
+            name="is_latest",
+            field=models.BooleanField(db_index=True, default=True),
+        ),
+        migrations.AddIndex(
+            model_name="patientconsultationevent",
+            index=models.Index(
+                condition=models.Q(("is_latest", True)),
+                fields=[
+                    "consultation_id",
+                    "is_latest",
+                    "event_type_id",
+                    "object_model",
+                    "taken_at",
+                ],
+                name="consultation_events_latest_idx",
+            ),
+        ),
+    ]

care/facility/models/events.py

@@ -61,7 +61,7 @@ class PatientConsultationEvent(models.Model):
     )
     object_id = models.IntegerField(null=False, blank=False)
     event_type = models.ForeignKey(EventType, null=False, on_delete=models.PROTECT)
-    is_latest = models.BooleanField(default=True)
+    is_latest = models.BooleanField(default=True, db_index=True)
     meta = models.JSONField(default=dict, encoder=CustomJSONEncoder)
     value = models.JSONField(default=dict, encoder=CustomJSONEncoder)
     change_type = models.CharField(
@@ -73,11 +73,16 @@ def __str__(self) -> str:
 
     class Meta:
         ordering = ["-created_date"]
-        indexes = [models.Index(fields=["consultation", "is_latest"])]
-        # constraints = [
-        #     models.UniqueConstraint(
-        #         fields=["consultation", "event_type", "is_latest"],
-        #         condition=models.Q(is_latest=True),
-        #         name="unique_consultation_event_type_is_latest",
-        #     )
-        # ]
+        indexes = [
+            models.Index(
+                fields=[
+                    "consultation_id",
+                    "is_latest",
+                    "event_type_id",
+                    "object_model",
+                    "taken_at",
+                ],
+                condition=models.Q(is_latest=True),
+                name="consultation_events_latest_idx",
+            ),
+        ]