**To describe dimension keys** This example requests the names of all wait events. The data is summarized by event name, and the aggregate values of those events over the specified time period. Command:: aws pi describe-dimension-keys --service-type RDS --identifier db-LKCGOBK26374TPTDFXOIWVCPPM --start-time 1527026400 --end-time 1527080400 --metric db.load.avg --group-by '{"Group":"db.wait_event"}' Output:: { "AlignedEndTime": 1.5270804E9, "AlignedStartTime": 1.5270264E9, "Keys": [ { "Dimensions": {"db.wait_event.name": "wait/synch/mutex/innodb/aurora_lock_thread_slot_futex"}, "Total": 0.05906906851195666 }, { "Dimensions": {"db.wait_event.name": "wait/io/aurora_redo_log_flush"}, "Total": 0.015824722186149193 }, { "Dimensions": {"db.wait_event.name": "CPU"}, "Total": 0.008014396230265477 }, { "Dimensions": {"db.wait_event.name": "wait/io/aurora_respond_to_client"}, "Total": 0.0036361612526204477 }, { "Dimensions": {"db.wait_event.name": "wait/io/table/sql/handler"}, "Total": 0.0019108398419382965 }, { "Dimensions": {"db.wait_event.name": "wait/synch/cond/mysys/my_thread_var::suspend"}, "Total": 8.533847837782684E-4 }, { "Dimensions": {"db.wait_event.name": "wait/io/file/csv/data"}, "Total": 6.864181956477376E-4 }, { "Dimensions": {"db.wait_event.name": "Unknown"}, "Total": 3.895887056379051E-4 }, { "Dimensions": {"db.wait_event.name": "wait/synch/mutex/sql/FILE_AS_TABLE::LOCK_shim_lists"}, "Total": 3.710368625122906E-5 }, { "Dimensions": {"db.wait_event.name": "wait/lock/table/sql/handler"}, "Total": 0 } ] }