以下的文章主要是浅谈Oracle性能检测sql语句 ，我在一个信誉度很好的网站找到一个关于Oracle性能检测sql语句的资料以及相关代码的示例，拿出来供大家分享。以下就是文章的详细内容介绍。
Oracle性能检测sql语句
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(*) "Tot"
- 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
- order by df.tablespace_name;
4. 监控文件系统的 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Oracle性能检测中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$sysstat c
- where a.statistic# = 38 and b.statistic# = 39
- and c.statistic# = 40;
7. 监控 SGA 中字典缓冲区的命中率
- select parameter, gets,Getmisses , getmisses/
(gets+getmisses)*100 "miss ratio",- (1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio"
- from v$rowcache
- where gets+getmisses <>0
- group by parameter, gets, getmisses;
以上的相关内容就是对Oracle性能检测sql语句的介绍，望你能有所收获。
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