Index Labelling.message_created_on and use for searching

casepro/msgs/migrations/0062_auto_20180126_2250.py

@@ -0,0 +1,24 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.7 on 2018-01-26 22:50
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('msgs', '0061_backfill_labelling_created_on'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='labelling',
+            name='message_created_on',
+            field=models.DateTimeField(),
+        ),
+        migrations.AddIndex(
+            model_name='labelling',
+            index=models.Index(fields=['label', '-message_created_on'], name='msgs_messag_label_i_e44df4_idx'),
+        ),
+    ]

casepro/msgs/models.py

@@ -291,10 +291,13 @@ class Labelling(models.Model):
 
     label = models.ForeignKey(Label, on_delete=models.CASCADE)
 
-    message_created_on = models.DateTimeField(null=True)
+    message_created_on = models.DateTimeField()
 
     class Meta:
         db_table = 'msgs_message_labels'
+        indexes = [
+            models.Index(fields=['label', '-message_created_on'])
+        ]
         unique_together = ('message', 'label')
 
 
@@ -385,13 +388,17 @@ def search(cls, org, user, search):
         queryset = org.incoming_messages.filter(is_active=True, is_handled=True)
         all_label_access = user.can_administer(org)
 
+        order_by_labels = False
+
         if all_label_access:
             if folder == MessageFolder.inbox or (folder == MessageFolder.archived and label_id):
                 queryset = queryset.filter(has_labels=True)
                 if label_id:
                     label = Label.get_all(org, user).filter(pk=label_id).first()
                     queryset = queryset.filter(labels=label)
 
+                order_by_labels = True
+
             elif folder == MessageFolder.unlabelled:
                 # only show inbox messages in unlabelled
                 queryset = queryset.filter(type=Message.TYPE_INBOX, has_labels=False)
@@ -406,6 +413,8 @@ def search(cls, org, user, search):
 
             queryset = queryset.filter(has_labels=True, labels__in=list(labels))
 
+            order_by_labels = True
+
             if folder == MessageFolder.unlabelled:
                 raise ValueError("Unlabelled folder is only accessible to administrators")
 
@@ -441,7 +450,12 @@ def search(cls, org, user, search):
 
         queryset = queryset.prefetch_related('contact', 'labels', 'case__assignee', 'case__user_assignee')
 
-        return queryset.order_by('-created_on')
+        if order_by_labels:
+            queryset = queryset.order_by('-labelling__message_created_on')
+        else:
+            queryset = queryset.order_by('-created_on')
+
+        return queryset
 
     def get_history(self):
         """