oracle常用脚本--Redo size
redo发生的总次数(以及因此写入log buffer),以byte为单位
select ss.snap_id as snap_id, to_char(sn.end_interval_time, 'yyyy-mm-dd hh24:mi:ss') as "snap_date", (sum(decode(stat_name, 'redo size', value, 0)) - lag(sum(decode(stat_name, 'redo size', value, 0)), 1) over(order by ss.snap_id)) / ((to_date(to_char(sn.end_interval_time, 'yyyymmddhh24miss'), 'yyyymmddhh24miss') - to_date(to_char(sn.begin_interval_time, 'yyyymmddhh24miss'), 'yyyymmddhh24miss')) * 24 * 60 * 60) "redo size" from SYS.DBA_HIST_sysstat ss, SYS.DBA_HIST_snapshot sn where ss.snap_id = sn.snap_id and ss.stat_name in ('redo size') and ss.dbid = sn.dbid and ss.instance_number = sn.instance_number and sn.instance_number = (select instance_number from v$instance) and sn.dbid = (select dbid from v$database) group by ss.snap_id, sn.begin_interval_time, sn.end_interval_time