Improve the performance of the table

opentech/apply/funds/tables.py

@@ -36,7 +36,7 @@ class SubmissionsTable(tables.Table):
     phase = tables.Column(verbose_name="Status", order_by=('status',))
     stage = tables.Column(verbose_name="Type", order_by=('status',))
     page = tables.Column(verbose_name="Fund")
-    comments = tables.Column(accessor='activities.comments.all', verbose_name="Comments")
+    comments = tables.Column(accessor='comment_count', verbose_name="Comments")
     last_update = tables.DateColumn(accessor="last_update", verbose_name="Last updated")
 
     class Meta:
@@ -57,10 +57,6 @@ class SubmissionsTable(tables.Table):
     def render_phase(self, value):
         return format_html('<span>{}</span>', value)
 
-    def render_comments(self, value):
-        request = self.context['request']
-        return str(value.visible_to(request.user).count())
-
     def order_last_update(self, qs, desc):
         update_order = getattr(F('last_update'), 'desc' if desc else 'asc')(nulls_last=True)
 

opentech/apply/funds/templates/funds/tables/column_reviews.html

@@ -4,12 +4,12 @@
     <tr class="reviews-summary__tr">
         <td class="reviews-summary__td">
             {% if record.stage.has_external_review %}
-                {{ record.reviewers.count }}
+                {{ record.review_count|default:'0' }}
             {% else %}
-                {{ record.reviewers.staff.count }}
+                {{ record.review_staff_count|default:'0' }}
             {% endif %}
         </td>
-        <td class="reviews-summary__td">{{ record.reviews.submitted.count }}</td>
-        <td class="reviews-summary__td">{{ record.reviews.submitted.recommendation|traffic_light }}</td>
+        <td class="reviews-summary__td">{{ record.review_submitted_count|default:'0' }}</td>
+        <td class="reviews-summary__td">{{ record.review_reccomendation|traffic_light }}</td>
     </tr>
 </table>

opentech/apply/funds/views.py

@@ -3,7 +3,7 @@ from copy import copy
 from django.contrib.auth.decorators import login_required
 from django.contrib import messages
 from django.core.exceptions import PermissionDenied
-from django.db.models import OuterRef, Subquery
+from django.db.models import Count, IntegerField, OuterRef, Subquery, Sum
 from django.http import HttpResponseRedirect
 from django.shortcuts import get_object_or_404
 from django.urls import reverse_lazy
@@ -46,10 +46,42 @@ class SubmissionListView(AllActivityContextMixin, SingleTableMixin, FilterView):
 
         activities = model.activities.field.model
         latest_activity = activities.objects.filter(submission=OuterRef('id')).select_related('user')
+        comments = activities.comments.filter(submission=OuterRef('id')).visible_to(self.request.user)
+
+        reviews = model.reviews.field.model.objects.filter(submission=OuterRef('id'))
 
         return self.filterset_class._meta.model.objects.current().select_related('previous').annotate(
             last_user_update=Subquery(latest_activity[:1].values('user__full_name')),
             last_update=Subquery(latest_activity.values('timestamp')[:1]),
+            comment_count=Subquery(
+                comments.values('submission').order_by().annotate(count=Count('pk')).values('count'),
+                output_field=IntegerField(),
+            ),
+            review_count=Subquery(
+                reviews.values('submission').annotate(count=Count('pk')).values('count'),
+                output_field=IntegerField(),
+            ),
+            review_staff_count=Subquery(
+                reviews.by_staff().values('submission').annotate(count=Count('pk')).values('count'),
+                output_field=IntegerField(),
+            ),
+            review_submitted_count=Subquery(
+                reviews.submitted().values('submission').annotate(count=Count('pk')).values('count'),
+                output_field=IntegerField(),
+            ),
+            review_reccomendation=Subquery(
+                reviews.submitted().values('submission').annotate(calc_recommendation=Sum('recommendation') / Count('recommendation')).values('calc_recommendation'),
+                output_field=IntegerField(),
+            ),
+        ).prefetch_related(
+            'reviews__author'
+        ).select_related(
+            'page',
+            'round',
+            'lead',
+            'user',
+            'previous__page',
+            'previous__round',
         )
 
     def get_context_data(self, **kwargs):