FQL query response randomly omits some results

I'm tryin开发者_运维百科g to make a simple "only status updates, nothing else" app (since FB doesn't seem too interested in this sort of thing). However, my queries seem to omit some results:

"select status_id,uid,time,message from status where uid in (select uid2 from friend where uid1= $my_id) ORDER BY time DESC LIMIT 25", for instance, when I last tested it, only returned 21 results (and yes, I've got enough friends who have made enough updates that there are definitely more than 25 historical statuses).

This is with the PHP API, by way of Heroku, but I've had similar issues for a while, going back to before FBML was deprecated, with basically the same query.

I haven't tested enough to determine absolutely that this is the case, but it seems only to return one status per user (if Bob posted six updates, it only returns his newest status and ignores the previous ones).

Is this a known issue/bug? Any workarounds?

facebook trades accuracy for performance it has been always the case , so it usually returns a limited number of results per query

It's probably because a user has not given access for a friends apps to access their posts. Apparently making an FQL request, facebook does the initial request, including your limit param. Then it filters the list removing anything that you don't have permissions to see. Hence receiving less than 25 results.