models: Index project series ordering

Support project-scoped name and date ordering without sorting all
series.

Signed-off-by: Stephen Finucane <stephen@that.guru>
Assisted-by: OpenAI gpt-6.1-sol (via pi)

Author: stephenfin

patchwork/migrations/0053_series_ordering_indexes.py

@@ -0,0 +1,26 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('patchwork', '0052_patch_filter_indexes'),
+    ]
+
+    operations = [
+        migrations.AddIndex(
+            model_name='series',
+            index=models.Index(
+                fields=['project', 'date', 'id'],
+                name='series_project_date_idx',
+            ),
+        ),
+        migrations.AddIndex(
+            model_name='series',
+            index=models.Index(
+                fields=['project', 'name', 'id'],
+                name='series_project_name_idx',
+            ),
+        ),
+    ]

patchwork/models.py

@@ -1021,6 +1021,16 @@ def __str__(self):
 
     class Meta:
         verbose_name_plural = 'Series'
+        indexes = [
+            models.Index(
+                fields=['project', 'date', 'id'],
+                name='series_project_date_idx',
+            ),
+            models.Index(
+                fields=['project', 'name', 'id'],
+                name='series_project_name_idx',
+            ),
+        ]
 
 
 class SeriesReference(models.Model):