來自http://blog.csdn.net/cn_chenfeng/archive/2004/09/17/108119.aspx
查看錶空間的名稱及大小:
SQL>select t.tablespace_name, round(sum(bytes/(1024*1024)),0) ts_size
from dba_tablespaces t, dba_data_files d where t.tablespace_name = d.tablespace_name group by t.tablespace_name;
查看錶空間物理文件的名稱及大小:
SQL>select tablespace_name, file_id, file_name,round(bytes/(1024*1024),0) total_space from dba_data_files order by tablespace_name;
查看回滾段名稱及大小:
SQL>select segment_name, tablespace_name, r.status,
(initial_extent/1024) InitialExtent,(next_extent/1024) NextExtent,
max_extents, v.curext CurExtent From dba_rollback_segs r, v$rollstat v
Where r.segment_id = v.usn(+) order by segment_name;
如何查看某個回滾段裏面，跑的什麼事物或者正在執行什麼sql語句:
SQL>select d.sql_text,a.name
from v$rollname a,v$transaction b,v$session c,v$sqltext d
where a.usn=b.xidusn and b.addr=c.taddr and c.sql_address=
d.address and c.sql_hash_value=d.hash_value
and a.usn=1;
(備註：你要看哪個，就把usn=?寫成幾就行了)
查看控制文件:
SQL>select * from v$controlfile;
查看日誌文件:
SQL> col member format a50
SQL>select * from v$logfile;
如何查看當前SQL*PLUS用戶的sid和serial#:
SQL>select sid, serial#, status from v$session where audsid=userenv('sessionid');
如何查看當前數據庫的字符集:
SQL>select userenv('language') from dual;
SQL>select userenv('lang') from dual;
怎麼判斷當前正在使用何種SQL優化方式:
用explain plan產生EXPLAIN PLAN，檢查PLAN_TABLE中ID=0的POSITION列的值。
SQL>select decode(nvl(position,-1),-1,'RBO',1,'CBO') from plan_table where id=0;
如何查看系統當前最新的SCN號：
SQL>select max(ktuxescnw * power(2,32) + ktuxescnb) from x$ktuxe;
在ORACLE中查找TRACE文件的腳本:
SQL>select u_dump.value || '/' || instance.value || '_ora_' ||
v$process.spid || nvl2(v$process.traceid, '_' || v$process.traceid, null ) || '.trc'"Trace File" from v$parameter u_dump cross join v$parameter instance cross join v$process join v$session on v$process.addr = v$session.paddr where u_dump.name = 'user_dump_dest' and
instance.name = 'instance_name' and v$session.audsid=sys_context('userenv','sessionid');
SQL>select d.value || '/ora_' || p.spid || '.trc' trace_file_name
from (select p.spid from sys.v_$mystat m,sys.v_$session s,
sys.v_$process p where m.statistic# = 1 and
s.sid = m.sid and p.addr = s.paddr) p,(select value from sys.v_$parameter where name ='user_dump_dest') d;
如何查看客戶端登陸的IP地址:
SQL>select sys_context('userenv','ip_address') from dual;
如何在生產數據庫中創建一個追蹤客戶端IP地址的觸發器：
SQL>create or replace trigger on_logon_trigger
after logon on database
begin
dbms_application_info.set_client_info(sys_context('userenv', 'ip_address'));
end;
REM 記錄登陸信息的觸發器
CREATE OR REPLACE TRIGGER LOGON_HISTORY
AFTER LOGON ON DATABASE --WHEN (USER='WACOS') --ONLY FOR USER 'WACOS'
BEGIN
insert into session_history
select username,sid,serial#,AUDSID,OSUSER,ACTION,SYSDATE,null,SYS_CONTEXT('USERENV','IP_ADDRESS'),TERMINAL,machine,PROGRAM
from v$session where audsid = userenv('sessionid');
END;
查詢當前日期:
SQL> select to_char(sysdate,'yyyy-mm-dd,hh24:mi:ss') from dual;
查看所有表空間對應的數據文件名：
SQL>select distinct file_name,tablespace_name,AUTOEXTENSIBLE from dba_data_files;
查看錶空間的使用情況:
SQL>select sum(bytes)/(1024*1024) as free_space,tablespace_name
from dba_free_space group by tablespace_name;
SQL>SELECT A.TABLESPACE_NAME,A.BYTES TOTAL,B.BYTES USED, C.BYTES FREE,
(B.BYTES*100)/A.BYTES "% USED",(C.BYTES*100)/A.BYTES "% FREE"
FROM SYS.SM$TS_AVAIL A,SYS.SM$TS_USED B,SYS.SM$TS_FREE C
WHERE A.TABLESPACE_NAME=B.TABLESPACE_NAME AND A.TABLESPACE_NAME=C.TABLESPACE_NAME;
column tablespace_name format a18;
column Sum_M format a12;
column Used_M format a12;
column Free_M format a12;
column pto_M format 9.99;
select s.tablespace_name,ceil(sum(s.bytes/1024/1024))||'M' Sum_M,ceil(sum(s.UsedSpace/1024/1024))||'M' Used_M,ceil(sum(s.FreeSpace/1024/1024))||'M' Free_M, sum(s.UsedSpace)/sum(s.bytes) PTUSED
from (select b.file_id,b.tablespace_name,b.bytes,
(b.bytes-sum(nvl(a.bytes,0))) UsedSpace,
sum(nvl(a.bytes,0)) FreeSpace,(sum(nvl(a.bytes,0))/(b.bytes)) * 100 FreePercentRatio from sys.dba_free_space a,sys.dba_data_files b
where a.file_id(+)=b.file_id group by b.file_id,b.tablespace_name,b.bytes
order by b.tablespace_name) s group by s.tablespace_name
order by sum(s.FreeSpace)/sum(s.bytes) desc;
查看數據文件的hwm（可以resize的最小空間）和文件頭大小:
SELECT v1.file_name,v1.file_id,
num1 totle_space,
num3 free_space,
num1-num3 "USED_SPACE(HWM)",
nvl(num2,0) data_space,
num1-num3-nvl(num2,0) file_head
FROM
(SELECT file_name,file_id,SUM(bytes) num1 FROM Dba_Data_Files GROUP BY file_name,file_id) v1,
(SELECT file_id,SUM(bytes) num2 FROM dba_extents GROUP BY file_id) v2,
(SELECT file_id,SUM(BYTES) num3 FROM DBA_FREE_SPACE GROUP BY file_id) v3
WHERE v1.file_id=v2.file_id(+)
AND v1.file_id=v3.file_id(+);
數據文件大小及頭大小:
SELECT v1.file_name,v1.file_id,
num1 totle_space,
num3 free_space,
num1-num3 Used_space,
nvl(num2,0) data_space,
num1-num3-nvl(num2,0) file_head
FROM
(SELECT file_name,file_id,SUM(bytes) num1 FROM Dba_Data_Files GROUP BY file_name,file_id) v1,
(SELECT file_id,SUM(bytes) num2 FROM dba_extents GROUP BY file_id) v2,
(SELECT file_id,SUM(BYTES) num3 FROM DBA_FREE_SPACE GROUP BY file_id) v3
WHERE v1.file_id=v2.file_id(+)
AND v1.file_id=v3.file_id(+);
(運行以上查詢，我們可以如下信息：
Totle_pace:該數據文件的總大小，字節爲單位
Free_space:該數據文件的剩於大小，字節爲單位
Used_space:該數據文件的已用空間，字節爲單位
Data_space:該數據文件中段數據佔用空間，也就是數據空間，字節爲單位
File_Head:該數據文件頭部佔用空間，字節爲單位)
數據庫各個表空間增長情況的檢查：
SQL>select A.tablespace_name,(1-(A.total)/B.total)*100 used_percent
From (select tablespace_name,sum(bytes) total from dba_free_space group by tablespace_name) A,(select tablespace_name,sum(bytes) total from dba_data_files group by tablespace_name) B where A.tablespace_name=B.tablespace_name;
SQL>SELECT UPPER(F.TABLESPACE_NAME) "表空間名",
D.TOT_GROOTTE_MB "表空間大小(M)",
D.TOT_GROOTTE_MB - F.TOTAL_BYTES "已使用空間(M)", TO_CHAR(ROUND((D.TOT_GROOTTE_MB - F.TOTAL_BYTES) / D.TOT_GROOTTE_MB * 100, 2), '990.99') "使用比", F.TOTAL_BYTES "空閒空間(M)",
F.MAX_BYTES "最大塊(M)" FROM (SELECT TABLESPACE_NAME,
ROUND(SUM(BYTES) / (1024 * 1024), 2) TOTAL_BYTES,
ROUND(MAX(BYTES) / (1024 * 1024), 2) MAX_BYTES
FROM SYS.DBA_FREE_SPACE GROUP BY TABLESPACE_NAME) F,
(SELECT DD.TABLESPACE_NAME,ROUND(SUM(DD.BYTES) / (1024 * 1024), 2) TOT_GROOTTE_MB FROM SYS.DBA_DATA_FILES DD
GROUP BY DD.TABLESPACE_NAME) D WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME
ORDER BY 4 DESC;
查看各個表空間佔用磁盤情況:
SQL>col tablespace_name format a20;
SQL>select b.file_id file_ID,
b.tablespace_name tablespace_name,
b.bytes Bytes,
(b.bytes-sum(nvl(a.bytes,0))) used,
sum(nvl(a.bytes,0)) free,
sum(nvl(a.bytes,0))/(b.bytes)*100 Percent
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;
數據庫對象下一擴展與表空間的free擴展值的檢查：
SQL>select a.table_name, a.next_extent, a.tablespace_name
from all_tables a,(select tablespace_name, max(bytes) as big_chunk
from dba_free_space group by tablespace_name ) f where f.tablespace_name = a.tablespace_name and a.next_extent > f.big_chunk
union select a.index_name, a.next_extent, a.tablespace_name
from all_indexes a,(select tablespace_name, max(bytes) as big_chunk
from dba_free_space group by tablespace_name ) f where f.tablespace_name = a.tablespace_name and a.next_extent > f.big_chunk;
Disk Read最高的SQL語句的獲取：
SQL>select sql_text from (select * from v$sqlarea order by disk_reads)
where rownum<=5;
查找前十條性能差的sql
SELECT * FROM (SELECT PARSING_USER_ID
EXECUTIONS,SORTS,COMMAND_TYPE,DISK_READS,
sql_text FROM v$sqlarea ORDER BY disk_reads DESC)
WHERE ROWNUM<10 ;
等待時間最多的5個系統等待事件的獲取：
SQL>select * from (select * from v$system_event where event not like 'SQL%' order by total_waits desc) where rownum<=5;
查看當前等待事件的會話:
col username format a10
set line 120
col EVENT format a30
select SE.Sid,s.Username,SE.Event,se.Total_Waits,SE.Time_Waited,SE.Average_Wait
from v$session S,v$session_event SE where S.Username is not null and SE.Sid=S.Sid
and S.Status='ACTIVE' and SE.Event not like '%SQL*Net%';
select sid, event, p1, p2, p3, wait_time, seconds_in_wait, state from v$session_wait where event not like '%message%' and event not like 'SQL*Net%' and event not like '%timer%' and event != 'wakeup time manager';
找到與所連接的會話有關的當前等待事件：
select SW.Sid,S.Username,SW.Event,SW.Wait_Time,SW.State,SW.Seconds_In_Wait SEC_IN_WAIT
from v$session S,v$session_wait SW where S.Username is not null and SW.Sid=S.Sid
and SW.event not like '%SQL*Net%' order by SW.Wait_Time Desc;
Oracle所有回滾段狀態的檢查：
SQL>select segment_name,owner,tablespace_name,initial_extent,next_extent,dba_rollback_segs.status from dba_rollback_segs,v$datafile where file_id=file#;
Oracle回滾段擴展信息的檢查:
col name format a10
set linesize 140
select substr(name,1,40) name,extents,rssize,optsize,aveactive,extends,wraps,shrinks,hwmsize
from v$rollname rn,v$rollstat rs where (rn.usn=rs.usn);
extents:回滾段中的盤區數量。
Rssize:以字節爲單位的回滾段的尺寸。
optsize：爲optimal參數設定的值。
Aveactive:從回滾段中刪除盤區時釋放的以字節爲單位的平均空間的大小。
Extends:系統爲回滾段增加的盤區的次數。
Shrinks:系統從回滾段中清除盤區（即回滾段收縮）的次數。回滾段每次清除盤區時，系統可能會從這個回滾段中消除一個或多個盤區。
Hwmsize:回滾段尺寸的上限，即回滾段曾經達到的最大尺寸。
(如果回滾段平均尺寸接近OPTIMAL的值，那麼說明OPTIMAL的值設置正確，如果回滾段動態增長次數或收縮次數很高，那麼需要提高OPTIMAL的值)
查看回滾段的使用情況，哪個用戶正在使用回滾段的資源:
select s.username, u.name from v$transaction t,v$rollstat r,
v$rollname u,v$session s where s.taddr=t.addr and
t.xidusn=r.usn and r.usn=u.usn order by s.username;
如何查看一下某個shared_server正在忙什麼:
SELECT a.username,a.machine,a.program,a.sid,
a.serial#,a.status,c.piece,c.sql_text
FROM v$session a,v$process b,v$sqltext c
WHERE b.spid=13161 AND b.addr=a.paddr
AND a.sql_address=c.address(+) ORDER BY c.piece;
數據庫共享池性能檢查:
Select namespace,gets,gethitratio,pins,pinhitratio,reloads,
Invalidations from v$librarycache where namespace in
('SQLAREA','TABLE/PROCEDURE','BODY','TRIGGER');
檢查數據重載比率:
select sum(reloads)/sum(pins)*100 "reload ratio" from
v$librarycache;
檢查數據字典的命中率:
select 1-sum(getmisses)/sum(gets) "data dictionary hit
ratio" from v$rowcache;
(對於library cache, gethitratio和pinhitratio應該大於90%,對於數據重載比率,reload ratio應該小於1%,對於數據字典的命中率,data dictionary hit ratio應該大於85%)
檢查共享內存的剩餘情況:
select request_misses, request_failures from v$shared_pool_reserved;
(對於共享內存的剩餘情況, request_misses 和request_failures應該接近0)
數據高速緩衝區性能檢查:
select 1-p.value/(b.value+c.value) "db buffer cache hit
ratio" from v$sysstat p,v$sysstat b,v$sysstat c where
p.name='physical reads' and b.name='db block gets' and
c.name='consistent gets';
檢查buffer pool HIT_RATIO執行
select name, (physical_reads/(db_block_gets+consistent_gets))
"MISS_HIT_RATIO" FROM v$buffer_pool_statistics WHERE (db_block_gets+ consistent_gets)> 0;
(正常時db buffer cache hit ratio 應該大於90%,正常時buffer pool MISS_HIT_RATIO 應該小於10%)
數據庫回滾段性能檢查:
檢查Ratio執行
select sum(waits)* 100 /sum(gets) "Ratio", sum(waits)
"Waits", sum(gets) "Gets" from v$rollstat;
檢查count/value執行:
select class,count from v$waitstat where class like '%undo%';
select value from v$sysstat where name='consistent gets';
(兩者的value值相除)
檢查average_wait執行:
select event,total_waits,time_waited,average_wait from v$system_event
where event like '%undo%';
檢查RBS header get ratio執行:
select n.name,s.usn,s.wraps, decode(s.waits,0,1,1- s.waits/s.gets)"RBS
header get ratio" from v$rollstat s,v$rollname n where s.usn=n.usn;
(正常時Ratio應該小於1%, count/value應該小於0.01%,average_wait最好爲0，該值越小越好,RBS header get ratio應該大於95%)
殺會話的腳本:
select A.SID,B.SPID,A.SERIAL#,a.lockwait,A.USERNAME,A.OSUSER,a.logon_time,a.last_call_et/3600 LAST_HOUR,A.STATUS,
'orakill '||sid||' '||spid HOST_COMMAND,
'alter system kill session '''||A.sid||','||A.SERIAL#||'''' SQL_COMMAND
from v$session A,V$PROCESS B where A.PADDR=B.ADDR AND SID>6;
查看排序段的性能:
SQL>SELECT name, value FROM v$sysstat WHERE name IN ('sorts (memory)', 'sorts (disk)');
7、查看數據庫庫對象:
select owner, object_type, status, count(*) count# from all_objects group by owner, object_type, status;
8、查看數據庫的版本:
Select * from v$version;
9、查看數據庫的創建日期和歸檔方式:
Select Created, Log_Mode, Log_Mode From V$Database;
10、捕捉運行很久的SQL:
column username format a12
column opname format a16
column progress format a8
select username,sid,opname,round(sofar*100 / totalwork,0) || '%' as progress,time_remaining,sql_text from v$session_longops , v$sql where time_remaining <> 0 and sql_address=address and sql_hash_value = hash_value;
11、查看數據表的參數信息:
SELECT partition_name, high_value, high_value_length, tablespace_name,pct_free, pct_used, ini_trans, max_trans, initial_extent,next_extent, min_extent, max_extent, pct_increase, FREELISTS,freelist_groups, LOGGING, BUFFER_POOL, num_rows, blocks,empty_blocks, avg_space, chain_cnt, avg_row_len, sample_size,last_analyzed FROM dba_tab_partitions
--WHERE table_name = :tname AND table_owner = :towner
ORDER BY partition_position;
12、查看還沒提交的事務:
select * from v$locked_object;
select * from v$transaction;
13、查找object爲哪些進程所用:
select p.spid,s.sid,s.serial# serial_num,s.username user_name,
a.type object_type,s.osuser os_user_name,a.owner,a.object object_name,decode(sign(48 - command),1,
to_char(command), 'Action Code #' || to_char(command) ) action,
p.program oracle_process,s.terminal terminal,s.program program,s.status session_status from v$session s, v$access a, v$process p where s.paddr = p.addr and s.type = 'USER' and a.sid = s.sid and a.object='SUBSCRIBER_ATTR'order by s.username, s.osuser;
14、查看回滾段:
SQL>col name format a10
SQL>set linesize 100
SQL>select rownum, sys.dba_rollback_segs.segment_name Name, v$rollstat.extents Extents, v$rollstat.rssize Size_in_Bytes, v$rollstat.xacts XActs, v$rollstat.gets Gets, v$rollstat.waits Waits, v$rollstat.writes Writes, sys.dba_rollback_segs.status status from v$rollstat, sys.dba_rollback_segs, v$rollname where v$rollname.name(+) = sys.dba_rollback_segs.segment_name and v$rollstat.usn (+) = v$rollname.usn order by rownum;
15、耗資源的進程(top session):
select s.schemaname schema_name,decode(sign(48 - command), 1, to_char(command), 'Action Code #' || to_char(command) ) action,status session_status,s.osuser os_user_name,s.sid,p.spid,s.serial# serial_num,nvl(s.username,'[Oracle process]') user_name,s.terminal terminal,s.program program,st.value criteria_value from v$sesstat st,v$session s,v$process p where st.sid = s.sid and st.statistic# = to_number('38') and ('ALL'='ALL' or s.status ='ALL') and p.addr=s.paddr order by st.value desc,p.spid asc,s.username asc,s.osuser asc;
根據PID查找相應的語句:
SELECT a.username,
a.machine,a.program,a.sid,a.serial#,a.status,c.piece,c.sql_text
FROM v$session a,v$process b,v$sqltext c WHERE b.spid=spid
AND b.addr=a.paddr AND a.sql_address=c.address(+) ORDER BY c.piece;
根據SID找ORACLE的某個進程:
SQL> select pro.spid from v$session ses,v$process pro where ses.sid=21 and ses.paddr=pro.addr;
監控當前數據庫誰在運行什麼SQL語句:
SQL>SELECT osuser, username, sql_text from v$session a, v$sqltext b
where a.sql_address =b.address order by address, piece;
如何查看數據庫中某用戶，正在運行什麼SQL語句
SQL>SELECT SQL_TEXT FROM V$SQLTEXT T, V$SESSION S WHERE T.ADDRESS=S.SQL_ADDRESS
AND T.HASH_VALUE=S.SQL_HASH_VALUE AND S.MACHINE='XXXXX' OR USERNAME='WACOS';
如何查出前臺正在發出的sql語句:
SQL> select user_name,sql_text from v$open_cursor where sid in(select sid from (select sid,serial# from v$session where status='ACTIVE'));
查詢當前所執行的SQL語句：
SQL> select program ,sql_address from v$session where paddr in (select addr
from v$process where spid=3556);
PROGRAM SQL_ADDRESS
------------------------------------------------ ----------------
sqlplus@ctc20 (TNS V1-V3) 000000038FCB1A90
SQL> select sql_text from v$sqlarea where address='000000038FCB1A90';
找出消耗CPU最高的進程對應的SQL語句：
set line 240
set verify off
column sid format 999
column pid format 999
column S_# format 999
column username format A9 heading "ORA User"
column program format a29
column SQL format a60
COLUMN OSname format a9 Heading "OS User"
SELECT P.pid pid,S.sid sid,P.spid spid,S.username username,
S.osuser osname,P.serial# S_#,P.terminal,P.program program,
P.background,S.status,RTRIM(SUBSTR(a.sql_text, 1, 80)) SQL
FROM v$process P, v$session S,v$sqlarea A WHERE P.addr = s.paddr
AND S.sql_address = a.address (+) AND P.spid LIKE '%&1%';
Enter value for 1: PID（這裏輸入佔用CPU最高的進程對應的PID）
set termout off
spool maxcpu.txt
SELECT '++'||S.username username,
RTRIM(REPLACE(a.sql_text,chr(10),''))||';'FROM v$process P, v$session S,
v$sqlarea A WHERE P.addr = s.paddr AND S.sql_address = a.address (+)
AND P.spid LIKE '%&&1%';
Enter value for 1: PID（這裏輸入佔用CPU最高的進程對應的PID）
spool off(這句放在最後執行)
CPU用率最高的2條SQL語句的獲取
執行：top，通過top獲得CPU佔用率最高的進程的pid。
SQL>select sql_text,spid,v$session.program,process from v$sqlarea,v$session,v$process where v$sqlarea.address=v$session.sql_address and v$sqlarea.hash_value=v$session.sql_hash_value
and v$session.paddr=v$process.addr and v$process.spid in (pid);
col machine format a30
col program format a40
set line 200
SQL>select sid,serial# ,username,osuser,machine,program,process,to_char(logon_time,'yyyy/mm/dd hh24:mi:ss') from v$session where paddr in(select addr from v$process where spid in([$spid]));
select sql_text from v$sqltext_with_newlines
where hash_value=(select SQL_HASH_VALUE from v$session where sid=&sid)
order by piece;
16、查看鎖（lock）情況:
SQL>select /*+ RULE */ ls.osuser os_user_name, ls.username user_name,
decode(ls.type,'RW','Row wait enqueue lock','TM','DML enqueue lock','TX','Transaction enqueue lock','UL','User supplied lock') lock_type,o.object_name object,decode(ls.lmode, 1, null, 2,'Row Share',3,'Row Exclusive',4,'Share',5,'Share Row Exclusive',6,'Exclusive',null)lock_mode,o.owner,ls.sid,ls.serial# serial_num,ls.id1,ls.id2 from sys.dba_objects o,(select s.osuser,s.username,l.type,l.lmode,s.sid,s.serial#,l.id1,l.id2 from v$session s,v$lock l where s.sid=l.sid)ls where o.object_id=ls.id1 and o.owner<>'SYS' order by o.owner, o.object_name;
SQL>select sys.v_$session.osuser,sys.v_$session.machine,v$lock.sid,
sys.v_$session.serial#,decode(v$lock.type,'MR','Media Recovery',
'RT','Redo Thread','UN','User Name','TX', 'Transaction','TM','DML',
'UL','PL/SQL User Lock','DX','Distributed Xaction','CF','Control File',
'IS','Instance State','FS','File Set','IR','Instance Recovery',
'ST','Disk Space Transaction','TS','Temp Segment','IV','Library Cache Invalida-tion','LS','Log Start or Switch','RW','Row Wait','SQ','Sequence Number','TE','Extend Table','TT','Temp Table','Unknown') LockType,
rtrim(object_type) || ' ' || rtrim(owner) || '.' || object_name object_name,decode(lmode, 0, 'None',1, 'Null',2, 'Row-S',3, 'Row-X',4, 'Share',
5, 'S/Row-X',6, 'Exclusive','Unknown') LockMode,decode(request, 0, 'None',1, 'Null',2, 'Row-S',3, 'Row-X', 4, 'Share',5, 'S/Row-X',
6, 'Exclusive', 'Unknown') RequestMode,ctime, block b
from v$lock, all_objects, sys.v_$session
where v$Lock.sid > 6
and sys.v_$session.sid = v$lock.sid
and v$lock.id1 = all_objects.object_id;
以DBA角色, 查看當前數據庫裏鎖的情況可以用如下SQL語句：
col owner for a12
col object_name for a16
select b.owner,b.object_name,l.session_id,l.locked_mode
from v$locked_object l, dba_objects b
where b.object_id=l.object_id;
SQL>select t2.username,t2.sid,t2.serial#,t2.logon_time
from v$locked_object t1,v$session t2
where t1.session_id=t2.sid order by t2.logon_time;
SQL>Select sql_address from v$session where sid=
SQL>Select * from v$sqltext where address=
SQL>select COMMAND_TYPE,PIECE,sql_text from v$sqltext where address=(select sql_address from v$session a where sid=18);
SQL>select object_id from v$locked_object;
SQL>select object_name,object_type from dba_objects where object_id=’’;
如果有長期出現的一列，可能是沒有釋放的鎖。我們可以用下面SQL語句殺掉長期沒有釋放非正常的鎖：
SQL>alter system kill session 'sid,serial#';
17、查看等待（wait）情況:
SQL>SELECT v$waitstat.class,v$waitstat.count count, SUM(v$sysstat.value) sum_value FROM v$waitstat,v$sysstat WHERE v$sysstat.name IN('db block gets','consistent gets') group by v$waitstat.class,v$waitstat.count;
18、查看sga情況:
SQL>SELECT NAME, BYTES FROM SYS.V_$SGASTAT ORDER BY NAME ASC;
19、查看catched object:
SQL>SELECT owner,name,db_link,namespace,type,sharable_mem,loads, executions,locks,pins,kept FROM v$db_object_cache;
20、查看V$SQLAREA:
SQL>SELECT SQL_TEXT,SHARABLE_MEM,PERSISTENT_MEM,RUNTIME_MEM,SORTS,
VERSION_COUNT,LOADED_VERSIONS,OPEN_VERSIONS,USERS_OPENING,EXECUTIONS,
USERS_EXECUTING,LOADS,FIRST_LOAD_TIME,INVALIDATIONS,PARSE_CALLS,
DISK_READS,BUFFER_GETS,ROWS_PROCESSED FROM V$SQLAREA;
21、查看object分類數量:
select decode(o.type#,1,'INDEX',2,'TABLE',3,'CLUSTER',4,'VIEW',5,'SYNONYM',6, 'SEQUENCE','OTHER') object_type , count(*) quantity from sys.obj$ o where o.type# > 1 group by decode(o.type#,1,'INDEX',2,'TABLE',3,'CLUSTER' ,4,'VIEW',5,'SYNONYM',6,'SEQUENCE','OTHER') union select 'COLUMN', count(*) from sys.col$ union select 'DB LINK' , count(*) from all_objects;
22、有關connection的相關信息:
1）查看有哪些用戶連接
select s.osuser os_user_name,decode(sign(48 - command),1,to_char(command),
'Action Code #' || to_char(command))action,p.program oracle_process,
status session_status,s.terminal terminal,s.program program,
s.username user_name,s.fixed_table_sequence activity_meter,''query,
0 memory,0 max_memory,0 cpu_usage,s.sid,s.serial# serial_num
from v$session s,v$process p where s.paddr=p.addr and s.type = 'USER'
order by s.username, s.osuser;
2）根據v.sid查看對應連接的資源佔用等情況
select n.name,v.value,n.class,n.statistic#
from v$statname n,v$sesstat v where v.sid=18 and v.statistic# = n.statistic# order by n.class, n.statistic#;
3）根據sid查看對應連接正在運行的sql
select /*+ PUSH_SUBQ */ command_type,sql_text,sharable_mem, persistent_mem,runtime_mem,sorts,version_count,
loaded_versions,open_versions,users_opening,executions, users_executing,loads,first_load_time,invalidations, parse_calls,disk_reads,buffer_gets,rows_processed,sysdate start_time,sysdate finish_time,'>'|| address sql_address,
'N' status from v$sqlarea where address = (select sql_address from v$session where sid=8);
根據pid查看sql語句:
select sql_text from v$sql
where address in
(select sql_address from v$session
where sid in
(select sid from v$session where paddr in (select addr from v$process where spid=&pid)));
23、查詢表空間使用情況:
select a.tablespace_name "表空間名稱",
100-round((nvl(b.bytes_free,0)/a.bytes_alloc)*100,2) "佔用率(%)",
round(a.bytes_alloc/1024/1024,2) "容量(M)",
round(nvl(b.bytes_free,0)/1024/1024,2) "空閒(M)",
round((a.bytes_alloc-nvl(b.bytes_free,0))/1024/1024,2) "使用(M)",
Largest "最大擴展段(M)",to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') "採樣時間" from (select f.tablespace_name,sum(f.bytes) bytes_alloc,
sum(decode(f.autoextensible,'YES',f.maxbytes,'NO',f.bytes)) maxbytes
from dba_data_files f group by tablespace_name) a,
(select f.tablespace_name,sum(f.bytes) bytes_free
from dba_free_space f group by tablespace_name) b,
(select round(max(ff.length)*16/1024,2) Largest,ts.name tablespace_name
from sys.fet$ ff, sys.file$ tf,sys.ts$ ts
where ts.ts#=ff.ts# and ff.file#=tf.relfile# and ts.ts#=tf.ts#
group by ts.name, tf.blocks) c where a.tablespace_name = b.tablespace_name and a.tablespace_name = c.tablespace_name;
SELECT UPPER(F.TABLESPACE_NAME) "表空間名",
D.TOT_GROOTTE_MB "表空間大小(M)",
D.TOT_GROOTTE_MB - F.TOTAL_BYTES "已使用空間(M)",
TO_CHAR(ROUND((D.TOT_GROOTTE_MB - F.TOTAL_BYTES) / D.TOT_GROOTTE_MB * 100,
2),
'990.99') "使用比",
F.TOTAL_BYTES "空閒空間(M)",
F.MAX_BYTES "最大塊(M)"
FROM (SELECT TABLESPACE_NAME,
ROUND(SUM(BYTES) / (1024 * 1024), 2) TOTAL_BYTES,
ROUND(MAX(BYTES) / (1024 * 1024), 2) MAX_BYTES
FROM SYS.DBA_FREE_SPACE
GROUP BY TABLESPACE_NAME) F,
(SELECT DD.TABLESPACE_NAME,
ROUND(SUM(DD.BYTES) / (1024 * 1024), 2) TOT_GROOTTE_MB
FROM SYS.DBA_DATA_FILES DD
GROUP BY DD.TABLESPACE_NAME) D
WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME
ORDER BY 4 DESC;
24、查詢表空間的碎片程度:
SQL>select tablespace_name,count(tablespace_name) from dba_free_space group by tablespace_name having count(tablespace_name)>10;
SQL>alter tablespace name coalesce;
SQL>alter table table_name deallocate unused;
SQL>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;
SQL>select * from ts_blocks_v;
SQL>select tablespace_name,sum(bytes),max(bytes),count(block_id) from dba_free_space group by tablespace_name;
SQL>select 'alter tablespace '||TABLESPACE_NAME||' coalesce;'
from DBA_FREE_SPACE_COALESCED where PERCENT_EXTENTS_COALESCED<100
or PERCENT_BLOCKS_COALESCED<100;
由於自由空間碎片是由幾部分組成，如範圍數量、最大範圍尺寸等，我們可
用fsfi--free space fragmentation index（自由空間碎片索引）值來直觀體現:
fsfi=100*sqrt(max(extent)/sum(extents))*1/sqrt(sqrt(count(extents)))
rem fsfi value compute
rem fsfi.sql
column fsfi format 999,99
select tablespace_name,sqrt(max(blocks)/sum(blocks))*
(100/sqrt(sqrt(count(blocks)))) fsfi
from dba_free_space
group by tablespace_name order by 1;
spool fsfi.rep;
/
spool off;
可以看出，fsfi的最大可能值爲100（一個理想的單文件表空間）。隨着範
圍的增加，fsfi值緩慢下降，而隨着最大範圍尺寸的減少，fsfi值會迅速下降。
比如，在某數據庫運行腳本fsfi.sql,得到以下fsfi值：
tablespace_name fsfi
------------------------------ -------
rbs 74.06
system 100.00
temp 22.82
tools 75.79
users 100.00
user_tools 100.00
ydcx_data 47.34
ydcx_idx 57.19
ydjf_data 33.80
ydjf_idx 75.55
---- 統計出了數據庫的fsfi值，就可以把它作爲一個可比參數。在一個有着足夠
有效自由空間，且fsfi值超過30的表空間中，很少會遇見有效自由空間的問題。
當一個空間將要接近可比參數時，就需要做碎片整理了。
25、查詢有哪些數據庫實例在運行:
select inst_name from v$active_instances;
26、以DBA角色, 查看當前數據庫裏鎖的情況：
select object_id,session_id,locked_mode from v$locked_object;
select t2.username,t2.sid,t2.serial#,t2.logon_time from v$locked_object t1,v$session t2
where t1.session_id=t2.sid order by t2.logon_time;
27、查看錶是否是分區表：
select TABLE_NAME,PARTITIONED from user_tables where TABLE_NAME='LOCALUSAGE';
TABLE_NAME PAR
------------------------------ --- ---------
LOCALUSAGE YES
28、查看分區表的分區名和相應的表空間名：
select TABLE_NAME, PARTITION_NAME,TABLESPACE_NAME from user_tab_partitions where table_name like ‘%USAGE%’;
29、查看索引是否是分區索引：
SELECT INDEX_NAME, TABLE_NAME, STATUS, PARTITIONED FROM USER_INDEXES WHERE TABLE_NAME LIKE '%USAGE';
30、如果返回的PATITIONED爲YES，請再執行如下語句來查詢分區索引的類型：SELECT index_name,table_name,locality FROM user_part_indexes;
31、Dual是Oracle中的一個實際存在的表，任何用戶均可讀取，常用在沒有目標表的Select中.
查看系統時間：
select to_char(sysdate,'yy-mm-dd hh24:mi:ss') shijian from dual;
32、查看索引段中extent的數量：
select segment_name,count(*) from dba_extents
where segment_type='INDEX' and owner='SCOTT' group by segment_name;
33、查看系統表中的用戶索引（用來檢查在system表空間內其他用戶索引的存在）：
SQL>select count(*) from dba_indexes where tablespace_name=’SYSTEM’ and owner NOT IN(‘SYS’,’SYSTEM’);
34、查看wacos表空間內的索引的擴展情況：
SELECT SUBSTR(segment_name,1,20) "SEGMENT NAME",bytes, COUNT(bytes)
FROM dba_extents WHERE segment_name IN( SELECT index_name FROM dba_indexes
WHERE tablespace_name = 'WACOS') GROUP BY segment_name,bytes ORDER BY segment_name;
35、查看錶空間數據文件的讀寫性能:
SQL>Select name,phyrds,phywrts,avgiotim,miniotim,maxiowtm,maxiortm from v$filestat,v$datafile where v$filestat.file#=v$datafile.file#;
SQL>Select fs.name name,f.phyrds,f.phyblkrd,f.phywrts,f.phyblkwrt ,f.readtim,f.writetim
from v$filestat f, v$datafile fs where f.file# = fs.file# order by fs.name;
(注意：如果phyblkrd與phyrds很接近的話，則表明這個表空間中存在全表掃描的表，這些表需要調整索引或優化SQL語句)
36、轉換表空間爲local方式管理:
SQL> exec sys.dbms_space_admin.tablespace_migrate_to_local('TBS_TEST') ;
37、查看一下哪個用戶在用臨時段:
SELECT username,sid,serial#,sql_address,machine,program,tablespace,segtype,
contents FROM v$session se,v$sort_usage su WHERE se.saddr=su.session_addr;
38、查看佔io較大的正在運行的session:
SELECT se.sid,se.serial#,pr.SPID,se.username,se.status,se.terminal,se.program, se.MODULE,se.sql_address,st.event,st.p1text,si.physical_reads,si.block_changes FROM v$session se,v$session_wait st,v$sess_io si,v$process pr WHERE st.sid=se.sid AND st.sid=si.sid AND se.PADDR=pr.ADDR AND se.sid>6 AND st.wait_time=0 AND st.event NOT LIKE '%SQL%' ORDER BY physical_reads DESC;
39、查找前十條性能差的sql:
SELECT * FROM(SELECT PARSING_USER_ID EXECUTIONS,SORTS,COMMAND_TYPE,DISK_READS,sql_text FROM v$sqlarea ORDER BY disk_reads DESC) WHERE ROWNUM<10;
40、刪除用戶下所有表的語句:
select 'drop table '||table_name||' cascade constraints;' from user_tables;
41、查看LOCK，並殺掉會話：
set linesize 132 pagesize 66
break on Kill on username on terminal
column Kill heading 'Kill String' format a13
column res heading 'Resource Type' format 999
column id1 format 9999990
column id2 format 9999990
column lmode beading 'Lock Held' format a20
column request heading 'Lock Requested' format a20
column serial# format 99999
column username format a10 heading "Username"
column terminal heading Term format a6
column tab format a35 heading "table Name"
column owner format a9
column Address format a18
select nvl(S.USERNAME,'Internal') username,
nvl(S.TERMINAL,'None') terminal,
L.SID||','||S.SERIAL# Kill,
U1.NAME||','||substr(T1.NAME,1,20) tab,
decode(L.LMODE, 1,'No Lock',
2,'Row Share',
3,'Row Exclusive',
4,'Share',
5,'Share Row Exclusive',
6,'Exclusive',null) lmode,
decode(L.REQUEST,1,'No Lock',
2,'Row Share',
3,'Row Exclusive',
4,'Share',
5,'Share Row Exclusive',
6,'Exclusive',null) request
from V$LOCK L,
V$SESSION S,
SYS.USER$ U1,
SYS.OBJ$ T1
where L.SID = S.SID
and T1.OBJ# = decode(L.ID2,0,L.ID1,L.ID2)
and U1.USER#= T1.OWNER#
and S.TYPE != 'BACKGROUND'
order by 1,2,5;
--alter system kill session ' , ';
column username format A15
column sid format 9990 heading SID
column type format A4
column lmode format 990 heading 'HELD'
column request format 990 heading 'REQ'
column id1 format 9999990
column id2 format 9999990
break on id1 skip 1 dup
spool tfslckwt.lst
select sn.username,
m.sid,
m.type,
DECODE(m.lmode,0,'None',
1,'Null',
2,'Row Share',
3,'Row Excl.',
4,'Share',
5,'S/Row Excl.',
6,'Exclusive',
lmode,ltrim(to_char(lmode,'990'))) lmode,
DECODE(m.request,0,'None',
1,'Null',
2,'Row Share',
3,'Row Excl.',
4,'Share',
5,'S/Row Excl.',
6,'Exclusive',
request,ltrim(to_char(m.request,'990'))) request,
m.id1,
m.id2
from v$session sn,
v$lock m
where (sn.sid = m.sid and m.request!= 0)
or (sn.sid = m.sid and
m.request = 0 and lmode != 4 and
(id1 ,id2) in (select s.id1,
s.id2
from v$lock s
where request != 0 and s.id1 = m.id1 and s.id2 = m.id2)
)
order by id1,id2,m.request;
spool off
clear breaks
42.查看WACOS表空間下所有的索引:
SQL>select 'analyze index '||segment_name||' validate structure;' from dba_segments where tablespace_name=’WACOS’and segment_type=’INDEX’;
43. 怎樣識別IO競爭和負載平衡:
col 文件名 format a35
select
df.name 文件名,
fs.phyrds 讀次數,
fs.phywrts 寫次數,
(fs.readtim/decode(fs.phyrds,0,-1,fs.phyrds)) 讀時間,
(fs.writetim/decode(fs.phywrts,0,-1,fs.phywrts)) 寫時間
from
v$datafile df,
v$filestat fs
where df.file#=fs.file#
order by df.name
/
文件名 讀次數 寫次數 讀時間 寫時間
-------------------------------------------- ---------- ---------- ---------- ----------
C:/ORACLE/ORADATA/ORADB/DR01.DBF 885 883 0 0
C:/ORACLE/ORADATA/ORADB/INDX01.DBF 885 883 0 0
C:/ORACLE/ORADATA/ORADB/OEM_REPOSITORY.ORA 885 883 0 0
C:/ORACLE/ORADATA/ORADB/RBS01.DBF 925 22306 0 0
C:/ORACLE/ORADATA/ORADB/SYSTEM01.DBF 50804 155025 0 0
C:/ORACLE/ORADATA/ORADB/TEMP01.DBF 887 894 0 0
C:/ORACLE/ORADATA/ORADB/TOOLS01.DBF 886 892 0 0
C:/ORACLE/ORADATA/ORADB/USERS01.DBF 885 883 0 0
已選擇8行。
其中：ORADB爲數據庫名，因爲本例中數據庫使默認安裝，沒有進行過優化、調整，
所以，一直在system表空間上做操作，導致system表空間所在的數據文件SYSTEM01.DBF被讀寫的次數最多，
這也說明了，儘量不要在system表空間做與系統無關的操作，應給各個用戶建立單獨的表空間。
44. 查看哪些session正在使用哪些回滾段:
col 回滾段名 format a10
col SID format 9990
col 用戶名 format a10
col 操作程序 format a80
col status format a6 trunc
SELECT r.name 回滾段名,
s.sid,
s.serial#,
s.username 用戶名,
t.status,
t.cr_get,
t.phy_io,
t.used_ublk,
t.noundo,
substr(s.program, 1, 78) 操作程序
FROM sys.v_$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;
45.檢查誰Lock了什麼對象:
set line 200
col "O/S-User" format a10
col "Ora-User" format a10
col "Obj Locked" format a30
select /*+RULE*/s.machine, s.osuser "O/S-User", s.username "Ora-User", s.sid "Session-ID",
s.serial# "Serial", s.process "Process-ID", s.status "Status",l.name "Obj Locked",
l.mode_held "Lock Mode"
from v$session s,dba_dml_locks l,v$process p
where l.session_id = s.sid and p.addr = s.paddr
/
46.造成等待的LOCK的信息，比如LOCK類型等：
col event format a30
set line 160
col machine format a10
col username format a15
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 event not like 'SQL*N%' and event not like 'rdbms%' and a.sid=b.sid
and b.sid>8 and event='enqueue'
order by username
/
47. List of the locked Oracle objects
set line 120
column object_name format a32
column OS_USER_NAME format a12
column orauser format a12
column sql_text format a32
column serial# format 999999
column sid format 99999
SELECT OS_USER_NAME, ORACLE_USERNAME AS orauser, s.sid, o.object_name,
o.object_type, s.serial#, a.sql_text
FROM v$locked_object l, dba_objects o, v$session s, v$sqlarea a
WHERE l.object_id = o.object_id
AND s.SQL_ADDRESS = a.address
AND l.SESSION_ID = s.sid;
SELECT 'ALTER SYSTEM KILL SESSION '''||TO_CHAR(s.sid)||','||TO_CHAR(s.serial#)||''';'
AS "Statement to kill"
FROM v$locked_object l, dba_objects o, v$session s
WHERE l.object_id = o.object_id
AND l.SESSION_ID = s.sid;
oracle數據庫性能監控的SQL
1. 監控事例的等待
SQL>select event,sum(decode(wait_Time,0,0,1)) "Prev",sum(decode(wait_Time,0,1,0)) "Curr",count(*) "Tot" from v$session_Wait group by event order by 4;
2. 回滾段的爭用情況
SQL>select name, waits, gets, waits/gets "Ratio" from v$rollstat a, v$rollname b where a.usn = b.usn;
3. 監控表空間的 I/O 比例
SQL>select df.tablespace_name name,df.file_name "file",f.phyrds pyr,
f.phyblkrd pbr,f.phywrts pyw, f.phyblkwrt pbw from v$filestat f, dba_data_files df where f.file# = df.file_id
order by df.tablespace_name;
4. 監控文件系統的 I/O 比例
SQL>select substr(a.file#,1,2) "#", substr(a.name,1,30) "Name",
a.status,a.bytes,b.phyrds,b.phywrts from v$datafile a, v$filestat b
where a.file# = b.file#;
5.在某個用戶下找所有的索引
SQL>select user_indexes.table_name, user_indexes.index_name,uniqueness, column_name from user_ind_columns, user_indexes where user_ind_columns.index_name = user_indexes.index_name
and user_ind_columns.table_name = user_indexes.table_name
order by user_indexes.table_type, user_indexes.table_name,
user_indexes.index_name, column_position;
6. 監控 SGA 的命中率
SQL>select a.value + b.value "logical_reads", c.value "phys_reads",
round(100 * ((a.value+b.value)-c.value) / (a.value+b.value)) "BUFFER HIT RATIO" from v$sysstat a, v$sysstat b, v$sysstat c where a.statistic# = 38 and b.statistic# = 39 and c.statistic# = 40;
7. 監控 SGA 中字典緩衝區的命中率
SQL>select parameter, gets,Getmisses , getmisses/(gets+getmisses)*100 "miss ratio",(1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio" from v$rowcache where gets+getmisses <>0 group by parameter, gets, getmisses;
8. 監控 SGA 中共享緩存區的命中率，應該小於1%
SQL>select sum(pins) "Total Pins", sum(reloads) "Total Reloads",
sum(reloads)/sum(pins) *100 libcache from v$librarycache;
SQL>select sum(pinhits-reloads)/sum(pins) "hit radio",sum(reloads)/sum(pins) "reload percent" from v$librarycache;
9. 顯示所有數據庫對象的類別和大小
SQL>select count(name) num_instances ,type ,sum(source_size) source_size,sum(parsed_size) parsed_size ,sum(code_size) code_size ,sum(error_size) error_size,sum(source_size) +sum(parsed_size) +sum(code_size) +sum(error_size) size_required from dba_object_size group by type order by 2;
10. 監控 SGA 中重做日誌緩存區的命中率，應該小於1%
SQL>SELECT name, gets, misses, immediate_gets, immediate_misses,
Decode(gets,0,0,misses/gets*100) ratio1, Decode(immediate_gets+immediate_misses,0,0, immediate_misses/(immediate_gets+immediate_misses)*100) ratio2
FROM v$latch WHERE name IN ('redo allocation', 'redo copy');
11. 監控內存和硬盤的排序比率，最好使它小於 .10，增加 sort_area_size
SQL>SELECT name, value FROM v$sysstat WHERE name IN ('sorts (memory)', 'sorts (disk)');
12. 監控當前數據庫誰在運行什麼SQL語句
SQL>SELECT osuser, username, sql_text from v$session a, v$sqltext b
where a.sql_address =b.address order by address, piece;
13. 監控字典緩衝區
SQL>SELECT (SUM(PINS - RELOADS)) / SUM(PINS) "LIB CACHE" FROM V$LIBRARYCACHE;
SQL>SELECT (SUM(GETS - GETMISSES - USAGE - FIXED)) / SUM(GETS) "ROW CACHE" FROM V$ROWCACHE;
SQL>SELECT SUM(PINS) "EXECUTIONS", SUM(RELOADS) "CACHE MISSES WHILE EXECUTING" FROM V$LIBRARYCACHE;(後者除以前者,此比率小於1%,接近0%爲好)
SQL>SELECT SUM(GETS) "DICTIONARY GETS",SUM(GETMISSES) "DICTIONARY CACHE GET MISSES" FROM V$ROWCACHE;
14. 查找ORACLE字符集
SQL>select * from sys.props$ where name='NLS_CHARACTERSET';
15. 監控 MTS
SQL>select busy/(busy+idle) "shared servers busy" from v$dispatcher;
(此值大於0.5時，參數需加大)
SQL>select sum(wait)/sum(totalq) "dispatcher waits" from v$queue where type='dispatcher';
SQL>select count(*) from v$dispatcher;
SQL>select servers_highwater from v$mts;
(servers_highwater接近mts_max_servers時，參數需加大)
16. 碎片程度
SQL>select tablespace_name,count(tablespace_name) from dba_free_space group by tablespace_name having count(tablespace_name)>10;
SQL>alter tablespace name coalesce;
SQL>alter table name deallocate unused;
SQL>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;
SQL>select tablespace_name,sum(bytes),max(bytes),count(block_id) from dba_free_space group by tablespace_name;
查看碎片程度高的表
SQL>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);
17. 表、索引的存儲情況檢查
SQL>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;
SQL>select segment_name,count(*) from dba_extents where segment_type='INDEX' and owner='&owner' group by segment_name;
18、找使用CPU多的用戶session
SQL>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;
(12是cpu used by this session)
表空間統計
A、 腳本說明：
這是我最常用的一個腳本，用它可以顯示出數據庫中所有表空間的狀態，如表空間的大小、已使用空間、使用的百分比、空閒空間數及現在表空間的最大塊是多大。
B、腳本原文:
SELECT upper(f.tablespace_name) "表空間名",
d.Tot_grootte_Mb "表空間大小(M)",
d.Tot_grootte_Mb - f.total_bytes "已使用空間(M)",
to_char(round((d.Tot_grootte_Mb - f.total_bytes) / d.Tot_grootte_Mb * 100,2),'990.99') "使用比",
f.total_bytes "空閒空間(M)",
f.max_bytes "最大塊(M)"
FROM
(SELECT tablespace_name,
round(SUM(bytes)/(1024*1024),2) total_bytes,
round(MAX(bytes)/(1024*1024),2) max_bytes
FROM sys.dba_free_space
GROUP BY tablespace_name) f,
(SELECT dd.tablespace_name, round(SUM(dd.bytes)/(1024*1024),2) Tot_grootte_Mb
FROM sys.dba_data_files dd
GROUP BY dd.tablespace_name) d
WHERE d.tablespace_name = f.tablespace_name
ORDER BY 4 DESC;
查看無法擴展的段
A、 腳本說明：
ORACLE對一個段比如表段或索引無法擴展時，取決的並不是表空間中剩餘的空間是多少，而是取於這些剩餘空間中最大的塊是否夠表比索引的“NEXT”值大，所以有時一個表空間剩餘幾個G的空閒空間，在你使用時ORACLE還是提示某個表或索引無法擴展，就是由於這一點，這時說明空間的碎片太多了。這個腳本是找出無法擴展的段的一些信息。
B、腳本原文：
SELECT segment_name,
segment_type,
owner,
a.tablespace_name "tablespacename",
initial_extent/1024 "inital_extent(K)",
next_extent/1024 "next_extent(K)",
pct_increase,
b.bytes/1024 "tablespace max free space(K)",
b.sum_bytes/1024 "tablespace total free space(K)"
FROM dba_segments a,
(SELECT tablespace_name,MAX(bytes) bytes,SUM(bytes) sum_bytes FROM dba_free_space GROUP BY tablespace_name) b
WHERE a.tablespace_name=b.tablespace_name
AND next_extent>b.bytes
ORDER BY 4,3,1;
查看段(表段、索引段)所使用空間的大小
A、 腳本說明：
有時你可能想知道一個表或一個索引佔用多少M的空間，這個腳本就是滿足你的要求的，把<>中的內容替換一下就可以了。
B、腳本原文：
SELECT owner,
segment_name,
SUM(bytes)/1024/1024
FROM dba_segments
WHERE owner=
And segment_name=
GROUP BY owner,segment_name
ORDER BY 3 DESC;
查看數據庫中的表鎖
A、 腳本說明：
這方面的語句的樣式是很多的，各式一樣，不過我認爲這個是最實用的，不信你就用一下，無需多說，鎖是每個DBA一定都涉及過的內容，當你相知道某個表被哪個session鎖定了，你就用到了這個腳本。
B、腳本原文：
SELECT A.OWNER,
A.OBJECT_NAME,
B.XIDUSN,
B.XIDSLOT,
B.XIDSQN,
B.SESSION_ID,
B.ORACLE_USERNAME,
B.OS_USER_NAME,
B.PROCESS,
B.LOCKED_MODE,
C.MACHINE,
C.STATUS,
C.SERVER,
C.SID,
C.SERIAL#,
C.PROGRAM
FROM ALL_OBJECTS A,
V$LOCKED_OBJECT B,
SYS.GV_$SESSION C
WHERE ( A.OBJECT_ID = B.OBJECT_ID )
AND (B.PROCESS = C.PROCESS )
-- AND
ORDER BY 1,2 ;
處理存儲過程被鎖
A、 腳本說明：
實際過程中可能你要重新編譯某個存儲過程理總是處於等待狀態，最後會報無法鎖定對象，這時你就可以用這個腳本找到鎖定過程的那個sid，需要注意的是查v$access這個視圖本來就很慢，需要一些布耐心。
B、腳本原文：
SELECT * FROM V$ACCESS
WHERE owner=””