Eliminated queries for distinct related object counts for better performance

netbox/dcim/tables.py

@@ -65,6 +65,10 @@ RACK_ROLE = """
 {% endif %}
 """
 
+RACK_DEVICE_COUNT = """
+<a href="{% url 'dcim:device_list' %}?rack_id={{ record.pk }}">{{ value }}</a>
+"""
+
 RACKRESERVATION_ACTIONS = """
 {% if perms.dcim.change_rackreservation %}
     <a href="{% url 'dcim:rackreservation_edit' pk=record.pk %}" class="btn btn-xs btn-warning"><i class="glyphicon glyphicon-pencil" aria-hidden="true"></i></a>
@@ -83,6 +87,14 @@ MANUFACTURER_ACTIONS = """
 {% endif %}
 """
 
+DEVICEROLE_DEVICE_COUNT = """
+<a href="{% url 'dcim:device_list' %}?role={{ record.slug }}">{{ value }}</a>
+"""
+
+DEVICEROLE_VM_COUNT = """
+<a href="{% url 'virtualization:virtualmachine_list' %}?role={{ record.slug }}">{{ value }}</a>
+"""
+
 PLATFORM_DEVICE_COUNT = """
 <a href="{% url 'dcim:device_list' %}?platform={{ record.slug }}">{{ value }}</a>
 """
@@ -226,12 +238,16 @@ class RackTable(BaseTable):
 
 
 class RackDetailTable(RackTable):
-    devices = tables.Column(accessor=Accessor('device_count'))
+    device_count = tables.TemplateColumn(
+        template_code=RACK_DEVICE_COUNT,
+        verbose_name='Devices'
+    )
     get_utilization = tables.TemplateColumn(UTILIZATION_GRAPH, orderable=False, verbose_name='Utilization')
 
     class Meta(RackTable.Meta):
         fields = (
-            'pk', 'name', 'site', 'group', 'facility_id', 'tenant', 'role', 'u_height', 'devices', 'get_utilization'
+            'pk', 'name', 'site', 'group', 'facility_id', 'tenant', 'role', 'u_height', 'device_count',
+            'get_utilization',
         )
 
 
@@ -370,12 +386,25 @@ class DeviceBayTemplateTable(BaseTable):
 class DeviceRoleTable(BaseTable):
     pk = ToggleColumn()
     name = tables.LinkColumn(verbose_name='Name')
-    device_count = tables.Column(verbose_name='Devices')
+    device_count = tables.TemplateColumn(
-    vm_count = tables.Column(verbose_name='VMs')
+        template_code=DEVICEROLE_DEVICE_COUNT,
+        accessor=Accessor('devices.count'),
+        orderable=False,
+        verbose_name='Devices'
+    )
+    vm_count = tables.TemplateColumn(
+        template_code=DEVICEROLE_VM_COUNT,
+        accessor=Accessor('virtual_machines.count'),
+        orderable=False,
+        verbose_name='VMs'
+    )
     color = tables.TemplateColumn(COLOR_LABEL, verbose_name='Label')
     slug = tables.Column(verbose_name='Slug')
-    actions = tables.TemplateColumn(template_code=DEVICEROLE_ACTIONS, attrs={'td': {'class': 'text-right'}},
+    actions = tables.TemplateColumn(
-                                    verbose_name='')
+        template_code=DEVICEROLE_ACTIONS,
+        attrs={'td': {'class': 'text-right'}},
+        verbose_name=''
+    )
 
     class Meta(BaseTable.Meta):
         model = DeviceRole
@@ -388,8 +417,18 @@ class DeviceRoleTable(BaseTable):
 
 class PlatformTable(BaseTable):
     pk = ToggleColumn()
-    device_count = tables.TemplateColumn(template_code=PLATFORM_DEVICE_COUNT, verbose_name='Devices')
+    device_count = tables.TemplateColumn(
-    vm_count = tables.TemplateColumn(template_code=PLATFORM_VM_COUNT, verbose_name='VMs')
+        template_code=PLATFORM_DEVICE_COUNT,
+        accessor=Accessor('devices.count'),
+        orderable=False,
+        verbose_name='Devices'
+    )
+    vm_count = tables.TemplateColumn(
+        template_code=PLATFORM_VM_COUNT,
+        accessor=Accessor('virtual_machines.count'),
+        orderable=False,
+        verbose_name='VMs'
+    )
     actions = tables.TemplateColumn(
         template_code=PLATFORM_ACTIONS,
         attrs={'td': {'class': 'text-right'}},

netbox/dcim/views.py

@@ -276,7 +276,7 @@ class RackListView(ObjectListView):
     ).prefetch_related(
         'devices__device_type'
     ).annotate(
-        device_count=Count('devices', distinct=True)
+        device_count=Count('devices')
     )
     filter = filters.RackFilter
     filter_form = forms.RackFilterForm
@@ -715,10 +715,7 @@ class DeviceBayTemplateBulkDeleteView(PermissionRequiredMixin, BulkDeleteView):
 #
 
 class DeviceRoleListView(ObjectListView):
-    queryset = DeviceRole.objects.annotate(
+    queryset = DeviceRole.objects.all()
-        device_count=Count('devices', distinct=True),
-        vm_count=Count('virtual_machines', distinct=True)
-    )
     table = tables.DeviceRoleTable
     template_name = 'dcim/devicerole_list.html'
 
@@ -756,10 +753,7 @@ class DeviceRoleBulkDeleteView(PermissionRequiredMixin, BulkDeleteView):
 #
 
 class PlatformListView(ObjectListView):
-    queryset = Platform.objects.annotate(
+    queryset = Platform.objects.all()
-        device_count=Count('devices', distinct=True),
-        vm_count=Count('virtual_machines', distinct=True)
-    )
     table = tables.PlatformTable
     template_name = 'dcim/platform_list.html'
 

netbox/ipam/models.py

@@ -196,14 +196,6 @@ class Role(models.Model):
             self.weight,
         )
 
-    @property
-    def count_prefixes(self):
-        return self.prefixes.count()
-
-    @property
-    def count_vlans(self):
-        return self.vlans.count()
-
 
 @python_2_unicode_compatible
 class Prefix(CreatedUpdatedModel, CustomFieldModel):

netbox/ipam/tables.py

@@ -228,9 +228,18 @@ class AggregateDetailTable(AggregateTable):
 
 class RoleTable(BaseTable):
     pk = ToggleColumn()
-    prefix_count = tables.TemplateColumn(accessor=Accessor('count_prefixes'), template_code=ROLE_PREFIX_COUNT, orderable=False, verbose_name='Prefixes')
+    prefix_count = tables.TemplateColumn(
-    vlan_count = tables.TemplateColumn(accessor=Accessor('count_vlans'), template_code=ROLE_VLAN_COUNT, orderable=False, verbose_name='VLANs')
+        accessor=Accessor('prefixes.count'),
-    slug = tables.Column(verbose_name='Slug')
+        template_code=ROLE_PREFIX_COUNT,
+        orderable=False,
+        verbose_name='Prefixes'
+    )
+    vlan_count = tables.TemplateColumn(
+        accessor=Accessor('vlans.count'),
+        template_code=ROLE_VLAN_COUNT,
+        orderable=False,
+        verbose_name='VLANs'
+    )
     actions = tables.TemplateColumn(template_code=ROLE_ACTIONS, attrs={'td': {'class': 'text-right'}}, verbose_name='')
 
     class Meta(BaseTable.Meta):

netbox/virtualization/views.py

@@ -159,10 +159,7 @@ class ClusterBulkEditView(PermissionRequiredMixin, BulkEditView):
 class ClusterBulkDeleteView(PermissionRequiredMixin, BulkDeleteView):
     permission_required = 'virtualization.delete_cluster'
     cls = Cluster
-    queryset = Cluster.objects.annotate(
+    queryset = Cluster.objects.all()
-        device_count=Count('devices', distinct=True),
-        vm_count=Count('virtual_machines', distinct=True)
-    )
     table = tables.ClusterTable
     default_return_url = 'virtualization:cluster_list'