PB-1403: Only update asset timestamp when the underlying file has changed.

app/stac_api/migrations/0073_remove_asset_update_asset_auto_variables_trigger_and_more.py

@@ -0,0 +1,37 @@
+# Generated by Django 5.2.11 on 2026-06-03 10:52
+
+import pgtrigger.compiler
+import pgtrigger.migrations
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stac_api', '0072_remove_collectionasset_upd_dec_col_asset_proj_epsg_trigger_and_more'),
+    ]
+
+    operations = [
+        pgtrigger.migrations.RemoveTrigger(
+            model_name='asset',
+            name='update_asset_auto_variables_trigger',
+        ),
+        pgtrigger.migrations.AddTrigger(
+            model_name='asset',
+            trigger=pgtrigger.compiler.Trigger(
+                name='update_asset_auto_variables_trigger',
+                sql=pgtrigger.compiler.UpsertTriggerSql(
+                    condition=
+                    'WHEN (OLD."checksum_multihash" IS DISTINCT FROM (NEW."checksum_multihash") OR OLD."file" IS DISTINCT FROM (NEW."file"))',
+                    func=
+                    "\n    -- update auto variables\n    NEW.etag = gen_random_uuid();\n    NEW.updated = now();\n\n    RAISE INFO 'Updated auto fields of %.id=% due to table updates.', TG_TABLE_NAME, NEW.id;\n\n    RETURN NEW;\n    ",
+                    hash='ec15994d80ec852d8e7d8aa3b50a915b49a32a2e',
+                    operation='UPDATE',
+                    pgid='pgtrigger_update_asset_auto_variables_trigger_003e1',
+                    table='stac_api_asset',
+                    when='BEFORE'
+                )
+            ),
+        ),
+    ]

app/stac_api/pgtriggers.py

@@ -212,7 +212,7 @@ class ItemFileSizeTrigger(pgtrigger.Trigger):
         '''
 
     return [
-        *auto_variables_triggers('asset'),
+        *auto_variables_triggers('asset', 'file', 'checksum_multihash'),
         *child_triggers('item', 'Asset'),
         *asset_counter_trigger('gsdcount', 'eo_gsd'),
         *asset_counter_trigger('geoadminlangcount', 'geoadmin_lang'),

app/tests/tests_10/test_pgtriggers.py

@@ -89,12 +89,13 @@ def setUp(self):
         ).model
 
     @parameterized.expand([
-        ('asset', 'asset', 'checksum_multihash'),
-        ('asset', 'item', 'checksum_multihash'),
-        ('item', 'collection', 'name'),
-        ('collection_asset', 'collection', 'checksum_multihash'),
+        ('asset', 'asset', 'checksum_multihash', True),
+        ('asset', 'asset', 'description', False),
+        ('asset', 'item', 'checksum_multihash', True),
+        ('item', 'collection', 'name', True),
+        ('collection_asset', 'collection', 'checksum_multihash', True),
     ])
-    def test_timestamp_updated(self, source_name, destination_name, field_name):
+    def test_timestamp_updated(self, source_name, destination_name, field_name, expect_update):
         destination = getattr(self, destination_name)
         source = getattr(self, source_name)
 
@@ -104,8 +105,12 @@ def test_timestamp_updated(self, source_name, destination_name, field_name):
         source.save()
         destination.refresh_from_db()
 
-        self.assertGreater(destination.updated, prev_mtime)
-        self.assertNotEqual(destination.etag, prev_etag)
+        if expect_update:
+            self.assertGreater(destination.updated, prev_mtime)
+            self.assertNotEqual(destination.etag, prev_etag)
+        else:
+            self.assertEqual(destination.updated, prev_mtime)
+            self.assertEqual(destination.etag, prev_etag)
 
 
 class PgTriggerAssetUploads(MockS3PerTestMixin, StacBaseTransactionTestCase):