Added an index for (doc, type) on DocEvent to speed up latest_event() queries.

- Legacy-Id: 14990

ietf/doc/migrations/0003_auto_20180401_1231.py

@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.11 on 2018-04-01 12:31
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('doc', '0002_auto_20180220_1052'),
+    ]
+
+    operations = [
+        migrations.AddIndex(
+            model_name='docevent',
+            index=models.Index(fields=[b'type', b'doc'], name='doc_doceven_type_43e53e_idx'),
+        ),
+    ]

ietf/doc/models.py

@@ -1000,6 +1000,9 @@ class DocEvent(models.Model):
 
     class Meta:
         ordering = ['-time', '-id']
+        indexes = [
+            models.Index(fields=['type', 'doc']),
+        ]
         
 class NewRevisionDocEvent(DocEvent):
     pass