Facebook ql在where子句本身可索引时要求索引列

Question

我在Facebook上尝试过以下FQL：

SELECT checkin_id FROM checkin WHERE author_uid = me()

Test this query

但是，我收到以下回复：

{
  "error": {
    "message": "Your statement is not indexable. The WHERE clause must contain an indexable column. Such columns are marked with * in the tables linked from http://developers.facebook.com/docs/reference/fql ", 
    "type": "NoIndexFunctionException", 
    "code": 604
  }
}

但checkin在文档中被标记为可索引。

现在可以做些什么？