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,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,0,1)) "Prev",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,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,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,USED_SPACE || 'M' "USED_SPACE(M)",ROUND (NVL (USED_SPACE,0) / SPACE * 100,NVL (FREE_SPACE,0) || 'M' "FREE_SPACE(M)" FROM ( SELECT TABLESPACE_NAME,SUM (BLOCKS) BLOCKS FROM DBA_TEMP_FILES GROUP BY TABLESPACE_NAME) D,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,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,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,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,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,misses,immediate_gets,immediate_misses,Decode(gets,misses/gets*100) ratio1,Decode(immediate_gets+immediate_misses,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 ;

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,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.program ORDER BY count(a.sid) ;