add database indexes to speed up oai-pmh

trove/migrations/0005_indexes_for_oaipmh.py

@@ -0,0 +1,23 @@
+# Generated by Django 3.2.25 on 2024-05-21 19:11
+
+from django.db import migrations, models
+from django.contrib.postgres.operations import AddIndexConcurrently
+
+
+class Migration(migrations.Migration):
+    atomic = False  # allow adding indexes concurrently (without locking tables)
+
+    dependencies = [
+        ('trove', '0004_auto_20230804_2021'),
+    ]
+
+    operations = [
+        AddIndexConcurrently(
+            model_name='indexcard',
+            index=models.Index(fields=['deleted'], name='trove_index_deleted_bcffde_idx'),
+        ),
+        AddIndexConcurrently(
+            model_name='latestindexcardrdf',
+            index=models.Index(fields=['modified'], name='trove_lates_modifie_c6b0b1_idx'),
+        ),
+    ]

trove/models/indexcard.py

@@ -121,6 +121,11 @@ class Indexcard(models.Model):
         related_name='+',
     )
 
+    class Meta:
+        indexes = [
+            models.Index(fields=('deleted',)),
+        ]
+
     @property
     def latest_rdf(self) -> Optional['LatestIndexcardRdf']:
         '''convenience for the "other side" of LatestIndexcardRdf.indexcard
@@ -242,6 +247,9 @@ class Meta:
                 name='%(app_label)s_%(class)s_uniq_indexcard',
             ),
         ]
+        indexes = [
+            models.Index(fields=('modified',)),
+        ]
 
 
 class ArchivedIndexcardRdf(IndexcardRdf):