SELECT messageid, time, type, flags, sender, message
FROM backlog
-JOIN buffer ON backlog.bufferid = buffer.bufferid
JOIN sender ON backlog.senderid = sender.senderid
-WHERE buffer.bufferid = :bufferid AND backlog.time >= :since
+WHERE bufferid = :bufferid AND time >= :since
ORDER BY messageid DESC
LIMIT -1 OFFSET :offset