性能监控之监控SQL语句
分析表
analyze table tablename compute statistics for all indexes;
analyze table tablename compute statistics for all indexed columns;
analyze table tablename compute statistics for table;
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$session_Wait
group by event order by 4;
查看碎片程度高的表
SELECT segment_name table_name , COUNT(*) extents
FROM dba_segments WHERE owner NOT IN (SYS, SYSTEM) GROUP BY segment_name
HAVING COUNT(*) = (SELECT MAX( COUNT(*) FROM dba_segments GROUP BY segment_name);
表、索引的存储情况检查
select segment_name,sum(bytes),count(*) ext_quan from dba_extents where
tablespace_name=&tablespace_name and segment_type=TABLE group by tablespace_name,segment_name;
select segment_name,count(*) from dba_extents where segment_type=INDEX and owner=&owner
group by segment_name;
找使用CPU多的用户session
12是cpu used by this session
select a.sid,spid,status,substr(a.program,1,40) prog,a.terminal,osuser,value/60/100 value
from v$session a,v$process b,v$sesstat c
where c.statistic#=12 and c.sid=a.sid and a.paddr=b.addr order by value desc;
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$filestat f, dba_data_files df
where f.file# = df.file_id
order by df.tablespace_name;
回滚段的争用情况
select name, waits, gets, waits/gets "Ratio"
from v$rollstat a, v$rollname b
where a.usn = b.usn;
在某个用户下找所有的索引
select user_indexes.table_name, user_indexes.index_name,uniqueness, column_name
from user_ind_columns, user_indexes
where user_ind_columns.index_name = user_indexes.index_name
and user_ind_columns.table_name = user_indexes.table_name
order by user_indexes.table_type, user_indexes.table_name,
user_indexes.index_name, column_position;
监控文件系统的 I/O 比例
select substr(a.file#,1,2) "#", substr(a.name,1,30) "Name",
a.status, a.bytes, b.phyrds, b.phywrts
from v$datafile a, v$filestat b
where a.file# = b.file#;
监控 SGA 中字典缓冲区的命中率
select parameter, gets,Getmisses , getmisses/(gets+getmisses)*100 "miss ratio",
(1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio"
from v$rowcache
where gets+getmisses <>0
group by parameter, gets, getmisses;
监控 SGA 中共享缓存区的命中率,应该小于1%
select sum(pins) "Total Pins", sum(reloads) "Total Reloads",
sum(reloads)/sum(pins) *100 libcache
from v$librarycache;
select sum(pinhits-reloads)/sum(pins) "hit radio",sum(reloads)/sum(pins) "reload percent"
from v$librarycache;
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$sysstat c
where a.statistic# = 38 and b.statistic# = 39
and c.statistic# = 40;
监控 SGA 中重做日志缓存区的命中率,应该小于1%
SELECT name, gets, misses, immediate_gets, immediate_misses,
Decode(gets,0,0,misses/gets*100) ratio1,
Decode(immediate_gets+immediate_misses,0,0,
immediate_misses/(immediate_gets+immediate_misses)*100) ratio2
FROM v$latch WHERE name IN (redo allocation, redo copy);
显示所有数据库对象的类别和大小
select count(name) num_instances ,type ,sum(source_size) source_size ,
sum(parsed_size) parsed_size ,sum(code_size) code_size ,sum(error_size) error_size,
sum(source_size) +sum(parsed_size) +sum(code_size) +sum(error_size) size_required
from dba_object_size
group by type order by 2;
监控内存和硬盘的排序比率,最好使它小于 .10,增加 sort_area_size
SELECT name, value FROM v$sysstat WHERE name IN (sorts (memory), sorts (disk));
监控当前数据库谁在运行什么SQL语句
SELECT osuser, username, sql_text from v$session a, v$sqltext b
where a.sql_address =b.address order by address, piece;
监控字典缓冲区
SELECT (SUM(PINS - RELOADS)) / SUM(PINS) "LIB CACHE" FROM V$LIBRARYCACHE;
SELECT (SUM(GETS - GETMISSES - USAGE - FIXED)) / SUM(GETS) "ROW CACHE" FROM V$ROWCACHE;
SELECT SUM(PINS) "EXECUTIONS", SUM(RELOADS) "CACHE MISSES WHILE EXECUTING" FROM V$LIBRARYCACHE;
后者除以前者,此比率小于1%,接近0%为好。
SELECT SUM(GETS) "DICTIONARY GETS",SUM(GETMISSES) "DICTIONARY CACHE GET MISSES"
FROM V$ROWCACHE
监控 MTS
select busy/(busy+idle) "shared servers busy" from v$dispatcher;
此值大于0.5时,参数需加大
select sum(wait)/sum(totalq) "dispatcher waits" from v$queue where type=dispatcher;
select count(*) from v$dispatcher;
select servers_highwater from v$mts;
servers_highwater接近mts_max_servers时,参数需加大
碎片程度
select tablespace_name,count(tablespace_name) from dba_free_space group by tablespace_name
having count(tablespace_name)>10;
alter tablespace name coalesce;
alter table name deallocate unused;
create or replace view ts_blocks_v as
select tablespace_name,block_id,bytes,blocks,free space segment_name from dba_free_space
union all
select tablespace_name,block_id,bytes,blocks,segment_name from dba_extents;
select * from ts_blocks_v;
select tablespace_name,sum(bytes),max(bytes),count(block_id) from dba_free_space
group by tablespace_name;
性能监控之监控SQL语句的更多相关文章
- oracle 监控执行的sql语句
oracle 监控执行的sql语句 select * from v$sqlarea a where module='PL/SQL Developer' order by a.FIRST_LOAD_TI ...
- sql server 查询性能最差的sql语句
SELECT TOP 10 TEXT AS 'SQL Statement' ,last_execution_time AS 'Last Execution Time' ,(total_logical_ ...
- Mysql性能优化一:SQL语句性能优化
这里总结了52条对sql的查询优化,下面详细来看看,希望能帮助到你 1, 对查询进行优化,应尽量避免全表扫描,首先应考虑在 where 及 order by 涉及的列上建立索引. 2,应尽量避免在 w ...
- 性能相差极大的SQL语句
等价的SQL,性能差异极大,数据库里设计了一个字段存储日期时间,但不是datetime类型,用了时间戳(int 11), 下面有2个SQL语句用于查询数据库,一个是把时间戳转成date进行查询,一个是 ...
- sql server 性能调优之 SQL语句阻塞查询
在生产环境下,有时公司客服反映网页半天打不到,除了在浏览器按F12的Network响应来排查,确定web服务器无故障后.就需要检查数据库是否有出现阻塞 当时数据库的生产环境中主表数据量超过2000w, ...
- Mysql性能监控项及sql语句
推荐一款mysql监控软件MONyog 1.查询缓存: mysql> show variables like '%query_cache%'; 2.缓存在Cache中线程数量thread_cac ...
- mysql监控执行的sql语句
转载 https://blog.csdn.net/nzjdsds/article/details/77513869 MySQL用SQL开启general_log并设置路径 2017年08月24日 00 ...
- 如何监控执行的SQL语句?
环境: SQL Server 2012. 打开SQL Server Profiler. 在菜单中选择New Trace, 连接上SQL Server. 在弹出的窗口中选择Event selection ...
- Informix 11.5 SQL 语句性能监控方法及实现
我们知道,在数据库应用系统中,SQL 语句的性能好坏至关重要.如果 SQL 语句性能很差,可能会导致整个数据库应用系统的性能也非常差.那么,如何监控数据库系统中 SQL 语句的性能,导致 SQL 语句 ...
- 走向DBA[MSSQL篇] - 从SQL语句的角度提高数据库的访问性能(转)
最近公司来一个非常虎的DBA,10几年的经验,这里就称之为蔡老师吧,在征得我们蔡老同意的前提下 ,我们来分享一下蔡老给我们带来的宝贵财富,欢迎其他的DBA来拍砖. 目录 1.什么是执行计划?执行计划 ...
随机推荐
- 2015.04.29,外语,读书笔记-《Word Power Made Easy》 14 “如何谈论日常现象” SESSION 39
HOW TO TALK ABOUT COMMON PHENOMENA AND OCCURRENCES TEASER PREVIEW dire(['daiә(r)] adj. 可怕的,悲惨的,灾难警告的 ...
- Spring Boot + Bootstrap + jQuery + Freemarker
Spring Boot + Bootstrap + jQuery + Freemarker 原文地址:http://qilu.me/post/tech/2018-03-18 最近在写一些Web的东西, ...
- NEU 1040 Count
1040: Count 时间限制: 1 Sec 内存限制: 128 MB提交: 59 解决: 23[提交][状态][讨论版] 题目描述 Many ACM team name may be very ...
- Regexp-Utils:身份证号校验
ylbtech-Regexp-Utils:身份证号校验 1.返回顶部 1.方法 var idCardNoUtil = { /*省,直辖市代码表*/ provinceAndCitys: { 11: &q ...
- HTML5学习笔记(四):关于表格
在一个实例中碰到表格,总结下,先上代码,例: <table border="1"> <thead> <th>表头</th> < ...
- js接收文件流并下载
js接收文件流并下载 标签(空格分隔): js 在此输入正文 <script type="text/javascript"> function download(fil ...
- POJ 2239 匈牙利算法
思路:最大匹配 也是很裸的一道题-. // by SiriusRen #include <cstdio> #include <cstring> #include <alg ...
- 后端向服务器发送客户端请求--HttpWebRequest
HttpWebRequest类与HttpRequest类的区别 HttpRequest类的对象用于服务器端,获取客户端传来的请求的信息,包括HTTP报文传送过来的所有信息. HttpWebReques ...
- Java 多线程(一)Thread
线程的六种状态 1.新建状态 new了但是没有启动的线程的状态,如“Thread thread = new Thread()”,thread就是一个处于新建状态的线程. 2.运行状态 new出来的线程 ...
- DataBaseFactory基础了解
<add name="Connection str" connectionString="data source=.;pwd=12;uid=sa;database ...