read_from_hits_with_aio 5000 30000 once hits_1000m_single SELECT count() FROM hits_1000m_single where UserID=1234567890 SETTINGS max_threads = 1, min_bytes_to_use_direct_io = 1, max_read_buffer_size = 10485760; SELECT count() FROM hits_1000m_single where EventDate between toDate('2013-07-10') and toDate('2013-07-16') and UserID=123 SETTINGS max_threads = 1, min_bytes_to_use_direct_io = 1, max_read_buffer_size = 10485760; SELECT count() FROM hits_1000m_single where UserID=1234567890 SETTINGS max_threads = 1, min_bytes_to_use_direct_io = 0, max_read_buffer_size = 10485760; SELECT count() FROM hits_1000m_single where EventDate between toDate('2013-07-10') and toDate('2013-07-16') and UserID=123 SETTINGS max_threads = 1, min_bytes_to_use_direct_io = 0, max_read_buffer_size = 10485760;