--估算每天日志生成量
select (select value / 1024 / 1024 / 1024 from v$sysstat where name = 'redo size') /
(select round(sysdate - (select startup_time from v$instance)) from dual) REDO_GB_PER_DAY
from dual;
select name,COMPLETION_TIME,BLOCKS*BLOCK_SIZE/1024/1024 Mb
from v$archived_log where rownum <11
and COMPLETION_TIME between trunc(sysdate) -2 and trunc(sysdate) -1;
--某日全天的日志生成量
select trunc(COMPLETION_TIME), sum(Mb) / 1024 DAY_GB
from (select name, COMPLETION_TIME, BLOCKS * BLOCK_SIZE / 1024 / 1024 Mb
from v$archived_log
where COMPLETION_TIME between trunc(sysdate) - 2 and
trunc(sysdate) - 1)
group by trunc(COMPLETION_TIME);
最近日期的日志生成统计：
SELECT TRUNC(completion_time), SUM(mb) / 1024 day_gb
FROM (SELECT NAME, completion_time, blocks * block_size / 1024 / 1024 mb
FROM v$archived_log)
GROUP BY TRUNC(completion_time);
