今天碰到一个ASM归档磁盘空间异常的情况， 需要查询过去几小时、几天内的归档日志生成量 ，涉及到v$archived_log视图，借此机会学习总结一下。
一、v$archived_log与gv$archived_log
单实例情况下毋庸置疑查询v$archived_log
那么rac环境下varchived_log与gvarchived_log是个什么关系呢
我对比了两个视图，gv$archived_log仅多了一列INST_ID
执行查询看到gv$archived_log中，同一个归档日志记录了两行，区别仅是inst_id不同
所以集群环境也查询v$archived_log即可
二、归档数量及大小查询
下面列出四种查询的情况
1.查询当天每小时的归档日志生成量
alter session set nls_date_format='yyyy.mm.dd hh24:mi:ss';
select logtime,
count(*),
round(sum(blocks * block_size) / 1024 / 1024) mbsize
from (select trunc(first_time, 'hh') as logtime, a.BLOCKS, a.BLOCK_SIZE
from v$archived_log a
where a.DEST_ID = 1
and a.FIRST_TIME > trunc(sysdate))
group by logtime
order by logtime desc;
1、first_time 是归档日志的开头时间
2、DEST_ID指向本地归档，1代表log_archive_dest_1
3、trunc()函数中的hh代表小时，下面sql取dd代表天
上图可见每小时产生19G左右的归档，count(*)列代表每小时两节点一共产生了多少个归档日志。
2.查最近一周每天的归档日志生成量
select logtime,
count(*),
round(sum(blocks * block_size) / 1024 / 1024) mbsize
from (select trunc(first_time, 'dd') as logtime, a.BLOCKS, a.BLOCK_SIZE
from v$archived_log a
where a.DEST_ID = 1
and a.FIRST_TIME > trunc(sysdate - 7))
group by logtime
order by logtime desc;
3.查询当天每小时的各个实例的归档日志生成量
select THREAD#,
logtime,
count(*),
round(sum(blocks * block_size) / 1024 / 1024) mbsize
from (select a.THREAD#,
trunc(first_time, 'hh') as logtime,
a.BLOCKS,
a.BLOCK_SIZE
from v$archived_log a
where a.DEST_ID = 1
and a.FIRST_TIME > trunc(sysdate))
group by THREAD#, logtime
order by THREAD#, logtime desc;
4. 查询最近一周每天的各个实例的归档日志生成量
select THREAD#,
logtime,
count(*),
round(sum(blocks * block_size) / 1024 / 1024) mbsize
from (select THREAD#,
trunc(first_time, 'dd') as logtime,
a.BLOCKS,
a.BLOCK_SIZE
from v$archived_log a
where a.DEST_ID = 1
and a.FIRST_TIME > trunc(sysdate - 7))
group by THREAD#, logtime
order by THREAD#, logtime desc;
三、v$archived_log视图的部分常用列说明
详细说明见官方文档：
https://docs.oracle.com/en/database/oracle/oracle-database/19/refrn/V-ARCHIVED_LOG.html#GUID-51618DF3-0C20-40E1-B94F-212FDF7CD729