Reduce number of queries required to render an entries list, especially the home page

entries/models.py

@@ -42,7 +42,7 @@ class Cat(models.Model):
 class EntryManager(models.Manager):
     def get_queryset(self):
         qs = super(EntryManager, self).get_queryset()
-        return qs.select_related('author').prefetch_related('syndications')
+        return qs.select_related('author').prefetch_related('cats', 'syndications')
 
 
 class Entry(ModelMeta, TimeStampedModel):

home/views.py

@@ -16,11 +16,14 @@ def index(request, page):
     def url(page):
         kwargs = {'page': page} if page != 1 else {}
         return reverse('home:index', kwargs=kwargs)
-    query = User.objects.prefetch_related('entries', 'profiles', 'keys')
-    user = get_object_or_404(query, pk=1)
-    entries = user.entries.filter(kind__in=kinds.on_home)
 
+    user = request.user
+    if not user:
+        user = get_object_or_404(User, pk=1)
+
+    entries = user.entries.filter(kind__in=kinds.on_home)
     entries = pagination.paginate(queryset=entries, reverse=url, page=page)
+
     # If we got a valid HTTP response, just return it without rendering.
     if hasattr(entries, 'content'):
         return entries

users/migrations/0011_auto_20180124_1311.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.9 on 2018-01-24 02:11
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('users', '0010_auto_20171206_2211'),
+    ]
+
+    operations = [
+        migrations.AlterModelManagers(
+            name='user',
+            managers=[
+            ],
+        ),
+    ]

users/models.py

@@ -31,7 +31,14 @@ class Site(models.Model):
         ordering = ('name',)
 
 
+class UserManager(models.Manager):
+    def get_queryset(self):
+        return super(UserManager, self).get_queryset().prefetch_related('keys', 'profiles')
+
+
 class User(ModelMeta, AbstractUser):
+    objects = UserManager()
+
     avatar = models.ImageField(upload_to=avatar_path)
     note = models.TextField(blank=True)
     xmpp = models.EmailField(blank=True)
@@ -61,17 +68,17 @@ class User(ModelMeta, AbstractUser):
 
     @cached_property
     def facebook_id(self):
-        try:
+        for p in self.profiles.all():
-            return self.profiles.filter(site__name='Facebook').values('username')[0]['username']
+            if p.site.name == 'Facebook':
-        except IndexError:
+                return p.username
-            return None
+        return None
 
     @cached_property
     def twitter_username(self):
-        try:
+        for p in self.profiles.all():
-            return '@' + self.profiles.filter(site__name='Twitter').values('username')[0]['username']
+            if p.site.name == 'Twitter':
-        except IndexError:
+                return '@' + p.username
-            return None
+        return None
 
     @property
     def json_ld(self):