1 根据进程号查找占用资源的sql语句
select sess.username,sql1.SQL_TEXT from v$session sess,v$sqltext sql1,v$process pro
where sess.SQL_ADDRESS=sql1.ADDRESS and pro.ADDR=sess.PADDR and pro.SPID='&1' order by sql1.PIECE;
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2 查找相关对象的锁
select oracle_username,os_user_name,process,object_name,o.SESSION_ID from v$locked_object o,dba_objects d where o.OBJECT_ID=d.object_id and object_name='T_PLY_BASE';
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3 杀掉某模块的session
SELECT distinct 'ALTER SYSTEM KILL SESSION '''||s.SID||','||s.SERIAL#||''';',p.PID
FROM V$SESSION S,v$process p
WHERE s.PADDR=p.ADDR
and s.PROGRAM like '&1%';
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4 杀掉某台机器的session
select s.username,s.sid,s.SERIAL#,machine,s.terminal,spid from v$session s , v$process p where machine like '%NZF%' and s.PADDR=p.ADDR;
对上面问题的补充，当上面语句不能解决问题时
select 'kill -9 '||p.spid
from v$process p,v$session s where p.ADDR=s.PADDR and s.PROGRAM like '&1%';
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5 决定pga_aggregate_target的最小值
select min(pga_target_for_estimate)
from v$pga_target_advice
where estd_pga_cache_hit_percentage>95;
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6 察看shared_pool_size实用情况
col value for 999,999,999,999 heading "Shared Pool Size";
col bytes for 999,999,999,999 heading "Free Bytes";
select to_number(v$parameter.value) value,v$sgastat.bytes,
(v$sgastat.bytes/v$parameter.value)*100 "Percent Free"
from v$sgastat,v$parameter
where v$sgastat.name='free memory'
and v$parameter.name='shared_pool_size'
and v$sgastat.pool='shared pool';
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7 如何监控 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$rowcache
where gets+getmisses <>0
group by parameter, gets, getmisses;
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8 如何监控 SGA 中共享缓存区的命中率，应该小于1% ？
select sum(pins) 'Total Pins', sum(reloads) 'Total Reloads',
sum(reloads)/sum(pins) *100 libcache
from v$librarycache;
select sum(pinhits-reloads)/sum(pins) "hit radio",sum(reloads)/sum(pins) "reload percent"
from v$librarycache;
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9 如何显示所有数据库对象的类别和大小？
select count(name) num_instances ,type ,sum(source_size) source_size ,
sum(parsed_size) parsed_size ,sum(code_size) code_size ,sum(error_size) error_size,
sum(source_size) +sum(parsed_size) +sum(code_size) +sum(error_size) size_required
from dba_object_size
group by type order by 2;
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10. 监控 SGA 中重做日志缓存区的命中率，应该小于1%
column name format A20;
SELECT name, gets, misses, immediate_gets, immediate_misses,
Decode(gets,0,0,misses/gets*100) ratio1,
Decode(immediate_gets+immediate_misses,0,0,
immediate_misses/(immediate_gets+immediate_misses)*100) ratio2
FROM v$latch WHERE name IN ('redo allocation', 'redo copy');
————————————————————————————————————————————————11. 如何知道使用CPU多的用户session? 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$sesstat c
where c.statistic#=11 and c.sid=a.sid and a.paddr=b.addr order by value desc;
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12. SQLPLUS下如何修改编辑器?
DEFINE _EDITOR="<编辑器的完整路经>" -- 必须加上双引号
来定义新的编辑器，也可以把这个写在$ORACLE_HOME/sqlplus/admin/glogin.sql里面使它永久有效。
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13.LINUX下查询磁盘竞争状况命令?
Sar -d
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14. 察看日志切换速度
select b.recid,to_char(b.first_time,'dd-mon-yy hh24:mi:ss') start_time,a.recid,
to_char(a.first_time,'dd-mon-yy hh24:mi:ss')end_time,round(((a.first_time-b.first_time)*24)*60,2) minutes
from v$log_history a,v$log_history b where a.recid=b.recid+1 order by a.first_time asc;
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15. 察看锁的情况
column sess format a15;
select decode(request,0,'Holder:','Waiter:')||sid sess,id1,id2,lmode,request,type
from v$lock where (id1,id2,type) in (select id1,id2,type from v$lock where request>0)
order by id1,request;
查出锁的情况和进程
select s.sid,s.serial#,s.program,s.machine,s.username,s.last_call_et,
s.logon_time,sw.event from v$session s,v$session_wait sw where s.sid=sw.sid and s.sid=2883625;
根据进程号查出是什么东西锁住了
select s.sid,s.serial#,s.program,s.machine,s.username,s.sql_hash_value,s.row_wait_obj# from v$session s
where .sid=377'
select * from v$sqltext a,v$session b where a.HASH_VALUE=b.SQL_HASH_VALUE and a.SID='&1' order by piece;
select 'alter system kill session '''||sid||','||serial#||''';' from v$session s,v$sqltext sq
where s.SQL_HASH_VALUE=sq.HASH_VALUE and sq.SQL_TEXT like '%CUX_GL_TAX%' order by logon_time
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16. 产生删除某个进程session的sql;
select distinct 'ALTER SYSTEM KILL SESSION '''||SID||','||s.SERIAL#||''';' from v$session s,v$process p where s.PADDR=p.ADDR and p.sPID like '%&1%';
产生删除某个进程模块的sql;
select distinct 'ALTER SYSTEM KILL SESSION '''||SID||','||s.SERIAL#||''';' from v$session s,v$process p where s.PADDR=p.ADDR and s.PROGRAM like 'svClaim%';
查询模块，机器，共执行的数目
select machine,schemaname,program,count(*) from (
select s.serial#,s.sid,s.MACHINE, p.pid,p.spid, s.SCHEMANAME,s.PROGRAM from v$process p,v$session s where p.ADDR=s.PADDR and s.SCHEMANAME not in ('SYS') /*and s.PROGRAM like 'sv%'*//* order by s.SCHEMANAME,s.PROGRAM*/
) group by machine,schemaname,program;
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17.logminer 检查执行步骤
execute dbms_logmnr.add_logfile('/oradata1/archive/abstandby/1_28456.dbf',dbms_logmnr.new);
select low_time,high_time,low_scn,next_scn from v$logmnr_logs;
exec dbms_logmnr.start_logmnr( dictfilename=>'/oradata1/utlfile/shwdict.ora',startscn=>2379878362,endscn=>2379976020,starttime=>to_date('20060930 01:15:00','yyyymmdd hh24:mi:ss'),endtime=>to_date('20060930 21:40:30','yyyymmdd hh24:mi:ss'));
Select SCN,timestamp, session# session_num, sql_redo
From V$LOGMNR_CONTENTS
Order by 1
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18. 清除已删除的arch log 信息
crosscheck archivelog all;
delete expired archivelog all;
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19。查找等待时间最长的语句
select a.USERNAME,a.OSUSER,a.PROCESS,a.MACHINE,a.ACTION,a.sid, a.last_call_et ,b.sql_text
from v$session a
,v$sqltext b
where a.username is not null
and a.status = 'ACTIVE'
and a.sql_address = b.address
order by a.last_call_et,a.sid,b.piece ;
根据查出来的sid判断等待的对象
select owner,segment_name,segment_type
from (select p1 file#, p2 block# from v$session_wait
where sid = 284
and event in ('buffer busy waits'
,'db file sequential read'
,'db file scattered read'
,'free buffer waits')) b
,dba_extents a
where a.file_id = b.file#
and b.block# between a.block_id and (a.block_id+blocks-1);
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20. 监控索引使用
select * from V$OBJECT_USAGE where used='YES'
select * from V$OBJECT_USAGE where used='NO'
select 'alter index '||index_name||' monitoring usage;' from dba_indexes where owner='ABSYS';
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21. 查找正在执行的存储过程
create or replace procedure sys.who_is_using(obj_name varchar2) is
begin
dbms_output.enable(1000000);
for i in (SELECT distinct b.username,b.sid
FROM SYS.x$kglpn a,v$session b,SYS.x$kglob c
WHERE a.KGLPNUSE = b.saddr
and upper(c.KGLNAOBJ) like upper(OBJ_NAME)
and a.KGLPNHDL = c.KGLHDADR)
loop
dbms_output.put_line('('||to_char(i.sid)||') - '||i.username);
end loop;
end;
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22.查找全表扫描的SQL语句
Select sql_text from v$sqltext t, v$sql_plan p
Where t.hash_value=p.hash_value
And p.operation='INDEX'
And p.OPTIONS='FULL SCAN'
Order by p.HASH_VALUE, t.piece;
查找Fast Full index 扫描的Sql语句可以这样；
Select sql_text from v$sqltext t, v$sql_plan p
Where t.hash_value=p.hash_value
And p.operation='INDEX'
And p.OPTIONS='FULL SCAN'
Order by p.HASH_VALUE, t.piece;
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23.已经alter system kill session 但是没有kill干净，查找进程号
select p.addr from v$process p where pid <> 1
minus
select s.paddr from v$session s;
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24.10g自动收集数据
select JOB_NAME,ENABLED,state from dba_scheduler_jobs;
exec dbms_scheduler.disable('GATHER_STATS_JOB');
exec dbms_scheduler.enable('GATHER_STATS_JOB');
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25.查询有enqueue等待的事件
SELECT b.SID, b.serial#, b.username, machine, event, wait_time,
CHR (BITAND (p1, -16777216) / 16777215)
|| CHR (BITAND (p1, 16711680) / 65535) "Enqueue Type"
FROM v$session_wait a, v$session b
WHERE a.event NOT LIKE 'SQL*N%'
AND a.event NOT LIKE 'rdbms%'
AND a.SID = b.SID
AND b.SID > 8
AND a.event = 'enqueue'
ORDER BY username;
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26.如何确定哪个表空间读写频繁?
select name,phyrds,phywrts,readtim,writetim
from v$filestat a,v$dbfile b
where a.file# = b.file#
order by readtim desc
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27.在磁盘上的物理写入和读取次数上如果出现很大的差别，就表明肯定有哪个磁盘负载过多！
如果出现磁盘负载不平衡，可以通过移动数据文件来均衡文件I/O：
alter tablespace tablespace_name offline;
$cp /disk1/a.dbf /disk2/a.dbf;
alter tablespace tablespace_name rename datafile ‘/disk1/a.dbf’ to ‘/disk2/a.dbf’;
alter tablespace tablespace online;
$rm /disk1/a.dbf
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28. 查询SQL语句执行时,硬语法分析的次数
select name,value
from v$sysstat
where name like ‘parse count%’;
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29.查询SQL语句中没有帮定变量的SQL语句,,按执行次数排序
SELECT SUBSTR (sql_text, 1, 40) “SQL”, COUNT (*),
SUM (executions) “TotExecs” FROM v$sqlarea WHERE executions < 5
GROUP BY SUBSTR (sql_text, 1, 40) HAVING COUNT (*) > 20 ORDER BY 2;
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30.该项显示buffer cache大小是否合适
公式：1-((physical reads-physical reads direct-physical reads direct (lob)) / session logical reads)
执行：
select 1-((a.value-b.value-c.value)/d.value)
from v$sysstat a,v$sysstat b,v$sysstat c,v$sysstat d
where a.name=’physical reads’ and
b.name=’physical reads direct’ and
c.name=’physical r
