diff --git a/migrations/20260601000009_chat_dedup.sql b/migrations/20260601000009_chat_dedup.sql
index d4e2e0d..e9ece19 100644
--- a/migrations/20260601000009_chat_dedup.sql
+++ b/migrations/20260601000009_chat_dedup.sql
@@ -1,3 +1,3 @@
--- 聊天记录去重索引
-CREATE UNIQUE INDEX IF NOT EXISTS idx_chat_records_message_id
+-- 聊天记录去重索引（普通索引，不用 UNIQUE 避免存量重复数据冲突）
+CREATE INDEX IF NOT EXISTS idx_chat_records_message_id
     ON chat_records (message_id) WHERE message_id != '';