From: Stewart Smith <stewart@linux.ibm.com>
Date: Fri, 10 Aug 2018 08:00:58 +0000 (+1000)
Subject: Add index for patchwork_comment (submission_id,date)
X-Git-Tag: v2.2.0-rc1~299
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c757b305b12c3574f0cc283a66d7f59efa5e34ed;p=thirdparty%2Fpatchwork.git

Add index for patchwork_comment (submission_id,date)

This (at least theoretically) should speed up displaying comments
on patches/cover letters. It's an index that will return rows
in-order for the query that we always do ("give me the comments
on this submission in date order"), rather than having to have
the database server do a sort for us.

I haven't been able to benchmark something locally that shows
this is an actual improvement, but I don't have as large data
set as various production instances. The query plan does look
a bit nicer though. Although the benefit of index maintenance
versus how long it takes to sort things is a good question.

Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
[stephenfin: Regenerate migrations per addition of 0027 in earlier
 patch]
Signed-off-by: Stephen Finucane <stephen@that.guru>
---

diff --git a/patchwork/migrations/0028_add_comment_date_index.py b/patchwork/migrations/0028_add_comment_date_index.py
new file mode 100644
index 00000000..69a35c2e
--- /dev/null
+++ b/patchwork/migrations/0028_add_comment_date_index.py
@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.15 on 2018-08-31 23:44
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('patchwork', '0027_remove_series_ordering'),
+    ]
+
+    operations = [
+        migrations.AddIndex(
+            model_name='comment',
+            index=models.Index(fields=['submission', 'date'], name='submission_date_idx'),
+        ),
+    ]
diff --git a/patchwork/models.py b/patchwork/models.py
index 52e7a69c..fea71c87 100644
--- a/patchwork/models.py
+++ b/patchwork/models.py
@@ -618,6 +618,10 @@ class Comment(EmailMixin, models.Model):
     class Meta:
         ordering = ['date']
         unique_together = [('msgid', 'submission')]
+        indexes = [
+            models.Index(name='submission_date_idx',
+                         fields=['submission', 'date'])
+        ]
 
 
 @python_2_unicode_compatible