Oracle-常用监控SQL

核心提示：1.监控事例的等待： select event,sum(decode(wait_time,0,0,1)) prev, sum(decode(wait_time,0,1,0)) curr,count(*)from v$session_waitgroup by event order by 4;2.回滚段的争用情况：sel

1.监控事例的等待：

　　　　 select event,sum(decode(wait_time,0,0,1)) prev, sum(decode(wait_time,0,1,0)) curr,count(*)
from v$session_wait
group by event order by 4;

2.回滚段的争用情况：

select name,waits,gets,waits/gets ratio from v$rollstat a,v$rollname b where a.usn=b.usn;

3.监控表空间的I/O比例：

select df.tablespace_name name,df.file_name "file",f.phyrds pyr,f.phyblkrd pbr,f.phywrts pyw,
f.phyblkwrt pbw
from v$filestat f,dba_data_files df
where f.file#=df.file_id

4.监空文件系统的I/O比例：

select substr(a.file#,1,2) "#",substr(a.name,1,30) "name",a.status,a.bytes,
b.phyrds,b.phywrts
from v$datafile a,v$filestat b
where a.file#=b.file#

5.在某个用户下找所有的索引：

select user_indexes.table_name, user_indexes.index_name,uniqueness, column_name
from user_ind_columns, user_indexes
where user_ind_columns.index_name = user_indexes.index_name
and user_ind_columns.table_name = user_indexes.table_name
order by user_indexes.table_type, user_indexes.table_name,
user_indexes.index_name, column_position;

6. 监控 SGA 的命中率

select a.value + b.value "logical_reads", c.value "phys_reads",
round(100 * ((a.value+b.value)-c.value) / (a.value+b.value)) "BUFFER HIT RATIO"
from v$sysstat a, v$sysstat b, v$sysstat c
where a.statistic# = 38 and b.statistic# = 39
and c.statistic# = 40;