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【DM版本】:DM8
【操作系统】：麒麟
【CPU】:ARM
【问题描述】*：我们有一套库，主备的，内存已经90%了，TOP查看mem%大概是75%，通过以下语句查询的大小与mem%差不多，但是我就没法判定我的数据库是分配内存就那么大，是不是够用还是不够用？select
(select sum(n_pages) * page()/1024/1024 from v$bufferpool)||'MB' as BUFFER_SIZE,
(select sum(total_size)/1024/1024 from v$mem_pool)||'MB' as mem_pool,
(select sum(n_pages) * page()/1024/1024 from v$bufferpool)+(select sum(total_size)/1024/1024 from v$mem_pool)||'MB' as TOTAL_SIZE
from dual;
可以使用如下语句，查下BUFFER和MEMORY的实际使用情况
--buffer使用
select name,sum(page_size1.0n_pages)/1024/1024.0 as size_mb,
sum(page_size1.0(n_clear+n_dirty))/1024/1024.0 as used_mb,
sum(page_size1.0free)/1024/1024.0 as free_mb
from v$bufferpool group by cube(name);
--memory使用
select substr(name,1,12),count(*) ,sum(total_size)/1024/1024.0 total_MB,sum(reserved_size)/1024/1024.0 used_MB
from v$mem_pool group by cube(substr(name,1,12))
order by total_MB desc;