Optimize alertgroups endpoint (#1186)

# What this PR does

## Which issue(s) this PR fixes

## Checklist

- [ ] Tests updated
- [ ] Documentation added
- [ ] `CHANGELOG.md` updated

engine/Dockerfile

@@ -20,7 +20,7 @@ COPY ./ ./
 
 # Collect static files and create an SQLite database
 RUN mkdir -p /var/lib/oncall
-RUN DJANGO_SETTINGS_MODULE=settings.prod_without_db DATABASE_TYPE=sqlite3 DATABASE_NAME=/var/lib/oncall/oncall.db SECRET_KEY="ThEmUsTSecretKEYforBUILDstage123" python manage.py collectstatic --no-input
+RUN DJANGO_SETTINGS_MODULE=settings.prod_without_db DATABASE_TYPE=sqlite3 DATABASE_NAME=/var/lib/oncall/oncall.db SECRET_KEY="ThEmUsTSecretKEYforBUILDstage123" SILK_PROFILER_ENABLED="True" python manage.py collectstatic --no-input
 RUN chown -R 1000:2000 /var/lib/oncall
 
 FROM base AS dev

engine/apps/api/views/alert_group.py

@@ -206,8 +206,14 @@ class AlertGroupView(
 
     def get_queryset(self):
         # no select_related or prefetch_related is used at this point, it will be done on paginate_queryset.
+        alert_receive_channels_ids = list(
+            AlertReceiveChannel.objects.filter(
+                organization_id=self.request.auth.organization.id,
+                team_id=self.request.user.current_team,
+            ).values_list("id", flat=True)
+        )
         queryset = AlertGroup.unarchived_objects.filter(
-            channel__organization=self.request.auth.organization, channel__team=self.request.user.current_team
+            channel_id__in=alert_receive_channels_ids,
         ).only("id")
 
         return queryset