oracle IO CPU统计

　　IO表现在两个方面，IOPS和吞吐量，我们OLTP系统，一般比较关心IOPS，及每个IO的响应时间，

　　以前针对IOPS统计，我们一直是按照statspack的physical reads+physical writes来统计，这个是很不准确的

　　按照文档的解释：

　　physical reads：Total number of data blocks read from disk

　　这个是按照block读取的数量来统计的，oracle的IO种类有很多，如果是scatter read或者parallel read，一个IO会读取多块的，

　　这样计算IOPS会偏大，重新调整后，发现统计出来的曲线和从存储段观察的比较吻合

　　9I:

　　–IOPS&MBPS

　　select sum(iops) as iops,sum(mbps) as mbps

　　from (

　　select sum(phyrds + phywrts) as IOPS,

　　sum(phyblkrd + phyblkwrt) as MBPS

　　from (select a.phyrds,a.phywrts,a.phyblkrd * b.block_size / 1024 / 1024 as phyblkrd,a.phyblkwrt * b.BLOCK_SIZE / 1024 / 1024 as phyblkwrt

　　from v$filestat a,v$datafile b

　　where a.file# = b.file#)

　　union all

　　select sum(decode(name,’redo writes’,value,’0′)) as IOPS,

　　sum(decode(name,’redo size’,value,’0′)) / 1024 / 1024 as MBPS

　　from v$sysstat where name in( ‘redo writes’,'redo size’));

　　10G/11G

　　–IOPS&MBPS

　　select sum(decode(name,’physical read IO requests’,value,’physical write IO requests’,value,0)) as iops,

　　sum(decode(name,’physical read bytes’,value,’physical write bytes’,value,0)) / 1024 / 1024 as mbps

　　from v$sysstat

　　where name in (’physical read IO requests’,'physical write IO requests’,

　　‘physical read bytes’,'physical read total bytes’,

　　‘physical write bytes’,'physical write total bytes’,'physical read total IO requests’,'physical write total IO requests’

　　);

　　最近将这些统计指标做进了监控系统，看看效果怎么样

oracle数据库查询表空间使用率，IO吞吐量，内存使用率sql

1.查询表空间使用率

select a.tablespace_name, total, free,(total-free) as usage from

(select tablespace_name, sum(bytes)/1024/1024 as total from dba_data_files group by tablespace_name) a,

(select tablespace_name, sum(bytes)/1024/1024 as free from dba_free_space group by tablespace_name) b

where a.tablespace_name = b.tablespace_name;

结果展示：

2.查看总消耗时间最多的前10条SQL语句

select *

from (select v.sql_id,

v.child_number,

v.sql_text,

v.elapsed_time,

v.cpu_time,

v.disk_reads,

rank() over(order by v.elapsed_time desc) elapsed_rank

from v$sql v) a

where elapsed_rank <= 10;

3.查看CPU消耗时间最多的前10条SQL语句

select *

from (select v.sql_id,

v.child_number,

v.sql_text,

v.elapsed_time,

v.cpu_time,

v.disk_reads,

rank() over(order by v.cpu_time desc) elapsed_rank

from v$sql v) a

where elapsed_rank <= 10;

4.查看消耗磁盘读取最多的前10条SQL语句

select *

from (select v.sql_id,

v.child_number,

v.sql_text,

v.elapsed_time,

v.cpu_time,

v.disk_reads,

rank() over(order by v.disk_reads desc) elapsed_rank

from v$sql v) a

where elapsed_rank <= 10;

5. IOps和IO吞吐量（oracle 11g）

select sum(decode(name,'physical read IO requests',value,'physical write IO requests',value,0)) as iops,

sum(decode(name,'physical read bytes',value,'physical write bytes',value,0)) / 1024 / 1024 as mbps from v$sysstat

where name in ('physical read IO requests','physical write IO requests','physical read bytes','physical read total bytes',

'physical write bytes','physical write total bytes','physical read total IO requests','physical write total IO requests');

结果展示：

参考：https://www.2cto.com/database/201309/241170.html

6.内存使用情况

SGA / PGA 使用情况

-- pctused: 使用率

select name,total,round(total-free,2) used, round(free,2) free,round((total-free)/total*100,2) pctused from

(select 'SGA' name,(select sum(value/1024/1024) from v$sga) total,

(select sum(bytes/1024/1024) from v$sgastat where name='free memory')free from dual)

union

select name,total,round(used,2)used,round(total-used,2)free,round(used/total*100,2)pctused from (

select 'PGA' name,(select value/1024/1024 total from v$pgastat where name='aggregate PGA target parameter')total,

(select value/1024/1024 used from v$pgastat where name='total PGA allocated')used from dual);

--内存使用率（待续）