I\'m trying to select all mutual friends\' connections with PHP/FQL. Using my UID (540 friends), which means >12,000 connections, of which >6500 are unique. So this code
FQL supports a LIMIT, just like regular SQL. You may try that. http://developers.facebook.com/docs/guides/performance
Otherwise, I suggest getting the friend IDs for each user, storing those in a SQL table, then performing your own join to get the crossover. You may be able to just get the friends lists once and then subscribe to realtime updates to keep your lists up to date. http://developers.facebook.com/docs/api/realtime