ORACLE常用性能监控SQL
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Temp表空间上进程的查询
select a.tablespace, b.sid, b.serial#, a.blocks,c.sql_text from v$sort_usage a,v$session b,v$sqltext c where a.session_addr = b.saddr and b.sql_address = c.address order by a.tablespace,b.sid,b.serial#,c.address, c.piece;
查看表锁
select * from sys.v_$sqlarea where disk_reads>100;
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$session_Wait group by event order by 4 ;
回滚段的争用情况
select name, waits, gets, waits/gets "Ratio" from v$rollstat a, v$rollname b where a.usn = b.usn;
查看前台正在发出的SQL语句
select user_name,sql_text from v$open_cursor where sid in (select sid from (select sid,serial#,username,program from v$session where status=‘ACTIVE‘));
数据表占用空间大小情况
select segment_name,tablespace_name,bytes,blocks from user_segments where segment_type=‘TABLE‘ ORDER BY bytes DESC ,blocks DESC;
查看表空间碎片大小
select tablespace_name,round(sqrt(max(blocks)/sum(blocks))* (100/sqrt(sqrt(count(blocks)))),2) FSFI from dba_free_space group by tablespace_name order by 1;
查看表空间占用磁盘情况
select b.file_id 文件ID号, b.tablespace_name 表空间名, b.bytes 字节数, (b.bytes-sum(nvl(a.bytes,0))) 已使用, sum(nvl(a.bytes,0)) 剩余空间, sum(nvl(a.bytes,0))/(b.bytes)*100 剩余百分比 from dba_free_space a,dba_data_files b where a.file_id=b.file_id group by b.tablespace_name,b.file_id,b.bytes order by b.file_id;
查看Oracle 表空间使用率
SELECT D.TABLESPACE_NAME, SPACE || ‘M‘ "SUM_SPACE(M)", SPACE - NVL (FREE_SPACE, 0) || ‘M‘ "USED_SPACE(M)", ROUND ( (1 - NVL (FREE_SPACE, 0) / SPACE) * 100, 2) || ‘%‘ "USED_RATE(%)", FREE_SPACE || ‘M‘ "FREE_SPACE(M)" FROM ( SELECT TABLESPACE_NAME, ROUND (SUM (BYTES) / (1024 * 1024), 2) SPACE, SUM (BLOCKS) BLOCKS FROM DBA_DATA_FILES GROUP BY TABLESPACE_NAME) D, ( SELECT TABLESPACE_NAME, ROUND (SUM (BYTES) / (1024 * 1024), 2) FREE_SPACE FROM DBA_FREE_SPACE GROUP BY TABLESPACE_NAME) F WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME(+) UNION ALL --如果有临时表空间 SELECT D.TABLESPACE_NAME, SPACE || ‘M‘ "SUM_SPACE(M)", USED_SPACE || ‘M‘ "USED_SPACE(M)", ROUND (NVL (USED_SPACE, 0) / SPACE * 100, 2) || ‘%‘ "USED_RATE(%)", NVL (FREE_SPACE, 0) || ‘M‘ "FREE_SPACE(M)" FROM ( SELECT TABLESPACE_NAME, ROUND (SUM (BYTES) / (1024 * 1024), 2) SPACE, SUM (BLOCKS) BLOCKS FROM DBA_TEMP_FILES GROUP BY TABLESPACE_NAME) D, ( SELECT TABLESPACE_NAME, ROUND (SUM (BYTES_USED) / (1024 * 1024), 2) USED_SPACE, ROUND (SUM (BYTES_FREE) / (1024 * 1024), 2) FREE_SPACE FROM V$TEMP_SPACE_HEADER GROUP BY TABLESPACE_NAME) F WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME(+) ORDER BY 1;
查看Temp 表空间实际使用磁盘大小
Select f.tablespace_name, d.file_name "Tempfile name", round((f.bytes_free + f.bytes_used) / 1024 / 1024, 2) "total MB", round(((f.bytes_free + f.bytes_used) - nvl(p.bytes_used, 0)) / 1024 / 1024, 2) "Free MB", round(nvl(p.bytes_used, 0) / 1024 / 1024, 2) "Used MB", round((round(nvl(p.bytes_used, 0) / 1024 / 1024, 2) / round((f.bytes_free + f.bytes_used) / 1024 / 1024, 2)) * 100, 2) as "Used_Rate(%)" from SYS.V_$TEMP_SPACE_HEADER f, DBA_TEMP_FILES d, SYS.V_$TEMP_EXTENT_POOL p where f.tablespace_name(+) = d.tablespace_name and f.file_id(+) = d.file_id and p.file_id(+) = d.file_id;
查看session使用回滚段
SELECT r.name 回滚段名, s.sid, s.serial#, s.username 用户名, t.status, t.cr_get, t.phy_io, t.used_ublk, t.noundo, substr(s.program, 1, 78) 操作程序 FROM sys.v_$session s,sys.v_$transaction t,sys.v_$rollname r WHERE t.addr = s.taddr and t.xidusn = r.usn ORDER BY t.cr_get,t.phy_io;
查看SGA区剩余可用内存
select name, sgasize/1024/1024 "Allocated(M)", bytes/1024 "**空间(K)", round(bytes/sgasize*100, 2) "**空间百分比(%)" from (select sum(bytes) sgasize from sys.v_$sgastat) s, sys.v_$sgastat f where f.name = ‘free memory‘;
–监控表空间I/O比例
select df.tablespace_name name,df.file_name “file”,f.phyrds pyr, f.phyblkrd pbr,f.phywrts pyw, f.phyblkwrt pbw from v$filestat f, dba_data_files df where f.file# = df.file_id order by df.tablespace_name;
监控SGA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 **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$librarycache;
监控 SGA 中重做日志缓存区的命中率，应该小于1%
SELECT name, gets, misses, immediate_gets, immediate_misses, Decode(gets,0,0,misses/gets*100) ratio1, Decode(immediate_gets+immediate_misses,0,0, immediate_misses/(immediate_gets+immediate_misses)*100) ratio2 FROM v$latch WHERE name IN (‘redo allocation‘, ‘redo copy‘);
监控内存和硬盘的排序比率，最好使它小于 .10
SELECT name, value FROM v$sysstat WHERE name IN (‘sorts (memory)‘, ‘sorts (disk)‘) ;
监控字典缓冲区
SELECT SUM(GETS) "DICTIONARY GETS",SUM(GETMISSES) "DICTIONARY CACHE GET MISSES" FROM V$ROWCACHE ;
系统用户建在system表空间中的表">非系统用户建在SYSTEM表空间中的表
SELECT owner,table_name FROM DBA_TABLES WHERE tablespace_name in(‘SYSTEM‘,‘USER_DATA‘) AND owner NOT IN(‘SYSTEM‘,‘SYS‘,‘OUTLN‘, ‘ORDSYS‘,‘MDSYS‘,‘SCOTT‘, ‘HOSTEAC‘);
性能最差的SQL
SELECT * FROM ( SELECT PARSING_USER_ID EXECUTIONS,SORTS,COMMAND_TYPE,DISK_READS,sql_text FROM v$sqlarea ORDER BY disk_reads DESC) WHERE ROWNUM<100;
读磁盘数超100次的sql
select * from sys.v_$sqlarea where disk_reads>100;
最频繁执行的sql
select * from sys.v_$sqlarea where executions>100;
查询使用CPU多的用户session
select a.sid,spid,status,substr(a.program,1,40) prog,a.terminal,osuser,value/60/100 value from v$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;
当前每个会话使用的对象数
SELECT a.sid,s.terminal,s.program,count(a.sid) FROM V$ACCESS a,V$SESSION s WHERE a.owner <> ‘SYS‘AND s.sid = a.sid GROUP BY a.sid,s.terminal,s.program ORDER BY count(a.sid) ;
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