diff --git a/cloud/db.py b/cloud/db.py
index 9b08d57..0eda9e1 100644
--- a/cloud/db.py
+++ b/cloud/db.py
@@ -415,6 +415,13 @@ _OR_REPLACE_PK = {
     "project_members": ("project_id", "user_id"),
     "slack_users": ("slack_id",),
     "github_app_config": ("id",),
+    # 自动记忆三张表：主键登记缺失时 Postgres 翻译退化为
+    # ON CONFLICT DO NOTHING，首写之后的所有更新静默丢弃
+    # （2026-10-28 生产实测：提取日志永远停在首写原因，
+    # 改设置同理；SQLite 原生 OR REPLACE 测不出来）。
+    "memory_settings": ("user_id",),
+    "task_memory_flags": ("task_id",),
+    "memory_extraction_log": ("task_id",),
 }
 
 _IDENTITY_TABLES = frozenset(
diff --git a/cloud/tests/test_postgres_backend.py b/cloud/tests/test_postgres_backend.py
index 8166ab3..b292b1c 100644
--- a/cloud/tests/test_postgres_backend.py
+++ b/cloud/tests/test_postgres_backend.py
@@ -198,6 +198,33 @@ class PlaceholderTranslationTestCase(unittest.TestCase):
         self.assertIn("%s", translated)
         self.assertNotIn("?", translated)
 
+    def test_auto_memory_tables_replace_updates_not_ignores(self):
+        # 2026-10-28 生产教训：这三张表未登记主键时翻译退化为
+        # ON CONFLICT DO NOTHING，首写之后的更新静默丢弃；SQLite
+        # 原生 OR REPLACE 测不出来，必须在翻译层断言。
+        cases = [
+            ("INSERT OR REPLACE INTO memory_settings"
+             "(user_id, generate_memories, updated_at) VALUES(?, ?, ?)",
+             "ON CONFLICT (user_id) DO UPDATE SET",
+             "generate_memories = EXCLUDED.generate_memories"),
+            ("INSERT OR REPLACE INTO task_memory_flags"
+             "(task_id, use_memories, generate_memories, updated_at)"
+             " VALUES(?, ?, ?, ?)",
+             "ON CONFLICT (task_id) DO UPDATE SET",
+             "use_memories = EXCLUDED.use_memories"),
+            ("INSERT OR REPLACE INTO memory_extraction_log"
+             "(task_id, status, reason, processed_at) VALUES(?, ?, ?, ?)",
+             "ON CONFLICT (task_id) DO UPDATE SET",
+             "status = EXCLUDED.status"),
+        ]
+        for sql, conflict, setter in cases:
+            translated, kind = _translate_sql(sql)
+            self.assertEqual(kind, "normal")
+            self.assertIn(conflict, translated)
+            self.assertIn(setter, translated)
+            self.assertNotIn("DO NOTHING", translated)
+            self.assertNotIn("OR REPLACE", translated)
+
     def test_autoincrement_becomes_identity(self):
         translated, _ = _translate_sql(
             "CREATE TABLE t(id INTEGER PRIMARY KEY AUTOINCREMENT, x TEXT)")