Add a proper index to Upload (aka ReportSession)

shared/django_apps/reports/migrations/0035_upload_indices_part1.py

@@ -0,0 +1,25 @@
+# Generated by Django 4.2.16 on 2024-11-28 12:26
+
+from django.contrib.postgres.operations import AddIndexConcurrently
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    atomic = False
+
+    dependencies = [
+        (
+            "reports",
+            "0034_remove_flake_created_at_remove_flake_updated_at",
+        ),
+    ]
+
+    operations = [
+        AddIndexConcurrently(
+            model_name="reportsession",
+            index=models.Index(
+                name="upload_report_type_idx",
+                fields=["report_id", "upload_type"],
+            ),
+        ),
+    ]

shared/django_apps/reports/models.py

@@ -199,8 +199,13 @@ class Meta:
         db_table = "reports_upload"
         indexes = [
             models.Index(
-                fields=["report_id", "upload_type", "order_number"],
+                name="upload_report_type_idx",
+                fields=["report_id", "upload_type"],
+            ),
+            # TODO(swatinem): remove the index below in a followup migration:
+            models.Index(
                 name="upload_index_id_type_number",
+                fields=["report_id", "upload_type", "order_number"],
             ),
         ]