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This appears to only return connections for the first 20 UIDs passed. Is this a known restraint?

There isn't a restraint. Did you try running the query in the test console? See if you get the same results there (I queried a test app against my ID and got all my connections, which number far more than 20). If you do, then file a bug. Thanks, Pete (563683308 13:49, 27 July 2009 (PDT))

After the 27th July or the next day, if i do "select target_id from connection where source_id=UID" where UID is a friend or a not friend of the current user, now it returns anything, some days before , it was working correctly. are there new restrictions? Nobody has never talked about this.