性能监控之监控SQL语句

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.t