diff --git a/boards/migrations/0026_post_opening.py b/boards/migrations/0026_post_opening.py
new file mode 100644
--- /dev/null
+++ b/boards/migrations/0026_post_opening.py
@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('boards', '0025_auto_20150825_2049'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='post',
+            name='opening',
+            field=models.BooleanField(default=False),
+            preserve_default=False,
+        ),
+    ]
diff --git a/boards/migrations/0027_auto_20150912_1632.py b/boards/migrations/0027_auto_20150912_1632.py
new file mode 100644
--- /dev/null
+++ b/boards/migrations/0027_auto_20150912_1632.py
@@ -0,0 +1,22 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    def build_opening_flag(apps, schema_editor):
+        Post = apps.get_model('boards', 'Post')
+        for post in Post.objects.all():
+            op = Post.objects.filter(threads__in=[post.thread]).order_by('pub_time').first()
+            post.opening = op.id == post.id
+            post.save(update_fields=['opening'])
+
+    dependencies = [
+        ('boards', '0026_post_opening'),
+    ]
+
+    operations = [
+        migrations.RunPython(build_opening_flag),
+    ]
diff --git a/boards/models/post/__init__.py b/boards/models/post/__init__.py
--- a/boards/models/post/__init__.py
+++ b/boards/models/post/__init__.py
@@ -20,7 +20,7 @@ from boards import utils
 from boards.models.post.export import get_exporter, DIFF_TYPE_JSON
 from boards.models.user import Notification, Ban
 import boards.models.thread
-
+from boards.utils import cached_result
 
 APP_LABEL_BOARDS = 'boards'
 
@@ -106,7 +106,8 @@ class PostManager(models.Manager):
                            poster_ip=ip,
                            thread=thread,
                            last_edit_time=posting_time,
-                           tripcode=tripcode)
+                           tripcode=tripcode,
+                           opening=new_thread)
         post.threads.add(thread)
 
         logger = logging.getLogger('boards.post.create')
@@ -202,6 +203,7 @@ class Post(models.Model, Viewable):
     uid = models.TextField(db_index=True)
 
     tripcode = models.CharField(max_length=50, null=True)
+    opening = models.BooleanField()
 
     def __str__(self):
         return 'P#{}/{}'.format(self.id, self.title)
@@ -241,7 +243,7 @@ class Post(models.Model, Viewable):
         Checks if this is an opening post or just a reply.
         """
 
-        return self.get_thread().get_opening_post_id() == self.id
+        return self.opening
 
     def get_absolute_url(self):
         if self.url:
@@ -271,12 +273,6 @@ class Post(models.Model, Viewable):
         """
 
         thread = self.get_thread()
-        is_opening = kwargs.get(PARAMETER_IS_OPENING, self.is_opening())
-
-        if is_opening:
-            opening_post_id = self.id
-        else:
-            opening_post_id = thread.get_opening_post_id()
 
         css_class = 'post'
         if thread.archived:
@@ -291,10 +287,9 @@ class Post(models.Model, Viewable):
 
         params.update({
             PARAMETER_POST: self,
-            PARAMETER_IS_OPENING: is_opening,
+            PARAMETER_IS_OPENING: self.is_opening(),
             PARAMETER_THREAD: thread,
             PARAMETER_CSS_CLASS: css_class,
-            PARAMETER_OP_ID: opening_post_id,
         })
 
         return render_to_string('boards/post.html', params)
diff --git a/boards/models/thread.py b/boards/models/thread.py
--- a/boards/models/thread.py
+++ b/boards/models/thread.py
@@ -151,7 +151,8 @@ class Thread(models.Model):
         """
 
         query = Post.objects.filter(threads__in=[self])
-        query = query.order_by('pub_time').prefetch_related('images', 'thread', 'threads')
+        query = query.order_by('pub_time').prefetch_related(
+            'images', 'thread', 'threads', 'attachments')
         if view_fields_only:
             query = query.defer('poster_ip')
         return query.all()
diff --git a/boards/templates/boards/all_threads.html b/boards/templates/boards/all_threads.html
--- a/boards/templates/boards/all_threads.html
+++ b/boards/templates/boards/all_threads.html
@@ -93,7 +93,7 @@
 
         {% for thread in threads %}
             <div class="thread">
-                {% post_view thread.get_opening_post moderator=moderator is_opening=True thread=thread truncated=True need_open_link=True %}
+                {% post_view thread.get_opening_post moderator=moderator thread=thread truncated=True need_open_link=True %}
                 {% if not thread.archived %}
                     {% with last_replies=thread.get_last_replies %}
                         {% if last_replies %}
@@ -108,7 +108,7 @@
                             {% endwith %}
                             <div class="last-replies">
                                 {% for post in last_replies %}
-                                    {% post_view post is_opening=False moderator=moderator truncated=True %}
+                                    {% post_view post moderator=moderator truncated=True %}
                                 {% endfor %}
                             </div>
                         {% endif %}
diff --git a/boards/templates/boards/post.html b/boards/templates/boards/post.html
--- a/boards/templates/boards/post.html
+++ b/boards/templates/boards/post.html
@@ -57,16 +57,12 @@
         Post images. Currently only 1 image can be posted and shown, but post model
         supports multiple.
     {%  endcomment %}
-    {% if post.images.exists %}
-        {% with post.images.first as image %}
-            {{ image.get_view|safe }}
-        {% endwith %}
-    {% endif %}
-    {% if post.attachments.exists %}
-        {% with post.attachments.first as file %}
-            {{ file.get_view|safe }}
-        {% endwith %}
-    {% endif %}
+    {% for image in post.images.all %}
+        {{ image.get_view|safe }}
+    {% endfor %}
+    {% for file in post.attachments.all %}
+        {{ file.get_view|safe }}
+    {% endfor %}
     {% comment %}
         Post message (text)
     {% endcomment %}