add index for models

announcement/migrations/0002_announcement_announcement_list_idx.py

@@ -0,0 +1,19 @@
+# Generated by Django 6.0 on 2026-04-23 20:07
+
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('announcement', '0001_initial'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.AddIndex(
+            model_name='announcement',
+            index=models.Index(fields=['visible', '-top', '-create_time'], name='announcement_list_idx'),
+        ),
+    ]

announcement/models.py

@@ -18,3 +18,6 @@ class Announcement(models.Model):
     class Meta:
         db_table = "announcement"
         ordering = ("-top", "-create_time",)
+        indexes = [
+            models.Index(fields=["visible", "-top", "-create_time"], name="announcement_list_idx"),
+        ]