ORACLE常用效能監控SQL【一】
阿新 • • 發佈：2018-12-30
系列
死鎖後的解決辦法
如果死鎖不能自動釋放，就需要我們手工的 kill session
生成Kill Session語句
- 檢視有無死鎖物件，如有 kill session
SELECT 'alter system kill session ''' || sid || ',' || serial# || ''';' "Deadlock"
FROM v$session
WHERE sid IN (SELECT sid FROM v$lock WHERE block = 1);
如果有，會返回類似與如下的資訊：
alter system kill session kill session：
執行 alter system kill session ‘761,876’(sid 為 761);
注意： 應當注意對於 sid 在 100 以下的應當謹慎，可能該程序對應某個application，如對應某個事務,可以 kill
檢視導致死鎖的 SQL
SELECT s.sid, q.sql_text
FROM v$sqltext q, v$session s
WHERE q.address = s.sql_address AND s.sid = &sid -- 這個&sid 是第一步查詢出來的
ORDER 執行後，輸入對應的sid即可檢視對應的sql.
檢視誰鎖了誰
SELECT s1.username || '@' || s1.machine || ' ( SID=' || s1.sid ||
' ) is blocking ' || s2.username || '@' || s2.machine || ' ( SID=' ||
s2.sid || ' ) ' AS blocking_status
FROM v$lock l1, v$session s1, v$lock l2, v$session s2
WHERE s1.sid = l1.sid
AND 或者
推薦這個，因為使用的是 v$locked_object
SELECT LPAD(' ', DECODE(l.xidusn, 0, 3, 0)) || l.oracle_username User_name,
o.owner,
o.object_name,
o.object_type,
s.sid,
s.serial#
FROM v$locked_object l, dba_objects o, v$session s
WHERE l.object_id = o.object_id
AND l.session_id = s.sid
ORDER BY o.object_id, xidusn DESC;V$LOCKED_OBJECT只能報發生等待的表級鎖,不能報發生等待的行級鎖。
ORA-00054 資源正忙，要求指定 NOWAIT
演示：
select * from emp for update ;--通過for update 獲取一個排它鎖SQL>select object_name as 物件名稱,s.sid,s.serial#,p.spid as 系統程序號
from v$locked_object l , dba_objects o , v$session s , v$process p
where l.object_id=o.object_id and l.session_id=s.sid and s.paddr=p.addr;
物件名稱 SID SERIAL# 系統程序號
-------------------------------------------------------------------------------- ---------- ---------- ------------------------
EMP 1411 8865 32720
在另外一個會話中執行
ALTER SYSTEM KILL SESSION '1411,8865';查詢繫結變數使用的實際值
1, SQL還在shared pool中，沒有被aged out 替換SQL ID 值即可
select sql_id, name, datatype_string, last_captured, value_string
from v$sql_bind_capture where sql_id = '7nqt558g5gmyr' order by LAST_CAPTURED,
POSITION;2.請自行替換sql_id，此時是從awr中查詢(sql 被 aged out 出 shared pool)
select instance_number,
sql_id,
name,
datatype_string,
last_captured,
value_string
from dba_hist_sqlbind
where sql_id = 'fahv8x6ngrb50'
order by LAST_CAPTURED, POSITION;監控事例的等待
select event,sum(decode(wait_Time,0,0,1)) "Prev",
sum(decode(wait_Time,0,1,0)) "Curr",count(*) "Tot"
from v$session_Wait
group by event order by 4 ;
回滾段的爭用情況
select name, waits, gets, waits / gets "Ratio"
from v$rollstat a, v$rollname b
where a.usn = b.usn;
查看回滾段名稱及大小
SELECT segment_name,
tablespace_name,
r.status,
(initial_extent / 1024) initialextent,
(next_extent / 1024) nextextent,
max_extents,
v.curext curextent
FROM dba_rollback_segs r, v$rollstat v
WHERE r.segment_id = v.usn(+)
ORDER BY segment_name;檢視控制檔案
SELECT NAME FROM v$controlfile; 檢視日誌檔案
SELECT MEMBER FROM v$logfile;
檢視前臺正在發出的SQL語句
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'));資料表佔用空間大小情況
select segment_name, tablespace_name, bytes, blocks
from user_segments
where segment_type = 'TABLE'
ORDER BY bytes DESC, blocks DESC;
查看錶空間碎片大小
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;查看錶空間佔用磁碟情況
select
b.file_id 檔案ID號,
b.tablespace_name 表空間名,
b.bytes 位元組數,
(b.bytes-sum(nvl(a.bytes,0))) 已使用,
sum(nvl(a.bytes,0)) 剩餘空間,
sum(nvl(a.bytes,0))/(b.bytes)*100 剩餘百分比
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;查看錶的大小，倒序排列
每張表都是作為“段”來儲存的，可以通過user_segments檢視檢視其相應資訊。
段（segments）的定義：如果建立一個堆組織表，則該表就是一個段
SELECT SEGMENT_NAME, SUM(BYTES) / 1024 / 1024 MBYTESE
FROM USER_SEGMENTS
WHERE SEGMENT_TYPE = 'TABLE'
GROUP BY SEGMENT_NAME
order by MBYTESE desc;查看錶空間物理檔案的名稱及大小
SELECT tablespace_name,
file_id,
file_name,
round(bytes / (1024 * 1024), 0) total_space
FROM dba_data_files
ORDER BY tablespace_name;檢視Oracle 表空間使用率
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 --如果有臨時表空間
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$TEMP_SPACE_HEADER
GROUP BY TABLESPACE_NAME) F
WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME(+)
ORDER BY 1;SELECT a.tablespace_name "表空間名",
total "表空間大小",
free "表空間剩餘大小",
(total - free) "表空間使用大小",
total / (1024 * 1024 * 1024) "表空間大小(G)",
free / (1024 * 1024 * 1024) "表空間剩餘大小(G)",
(total - free) / (1024 * 1024 * 1024) "表空間使用大小(G)",
round((total - free) / total, 4) * 100 "使用率 %"
FROM (SELECT tablespace_name, SUM(bytes) free
FROM dba_free_space
GROUP BY tablespace_name) a,
(SELECT tablespace_name, SUM(bytes) total
FROM dba_data_files
GROUP BY tablespace_name) b
WHERE a.tablespace_name = b.tablespace_name檢視Temp 表空間實際使用磁碟大小
Select f.tablespace_name,
d.file_name "Tempfile name",
round((f.bytes_free + f.bytes_used) / 1024 / 1024, 2) "total MB",
round(((f.bytes_free + f.bytes_used) - nvl(p.bytes_used, 0)) / 1024 / 1024,
2) "Free MB",
round(nvl(p.bytes_used, 0) / 1024 / 1024, 2) "Used MB",
round((round(nvl(p.bytes_used, 0) / 1024 / 1024, 2) /
round((f.bytes_free + f.bytes_used) / 1024 / 1024, 2)) * 100,
2) as "Used_Rate(%)"
from SYS.V_$TEMP_SPACE_HEADER f,
DBA_TEMP_FILES d,
SYS.V_$TEMP_EXTENT_POOL p
where f.tablespace_name(+) = d.tablespace_name
and f.file_id(+) = d.file_id
and p.file_id(+) = d.file_id;
檢視session使用回滾段
SELECT r.name 回滾段名,
s.sid,
s.serial#,
s.username 使用者名稱,
t.status,
t.cr_get,
t.phy_io,
t.used_ublk,
t.noundo,
substr(s.program, 1, 78) 操作程式
FROM sys.v_$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;檢視當前臨時表空間使用大小與正在佔用臨時表空間的sql語句
select sess.SID, segtype, blocks * 8 / 1000 "MB", sql_text
from v$sort_usage sort, v$session sess, v$sql sql
where sort.SESSION_ADDR = sess.SADDR
and sql.ADDRESS = sess.SQL_ADDRESS
order by blocks desc;
Temp表空間上程序的查詢
select a.tablespace, b.sid, b.serial#, a.blocks,c.sql_text
from v$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;檢視SGA區剩餘可用記憶體
select name,
sgasize/1024/1024 "Allocated(M)",
bytes/1024 "**空間(K)",
round(bytes/sgasize*100, 2) "**空間百分比(%)"
from (select sum(bytes) sgasize from sys.v_$sgastat) s, sys.v_$sgastat f
where f.name = 'free memory';監控表空間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$filestat f, dba_data_files df
where f.file# = df.file_id
order by df.tablespace_name;監控SGA命中率
select a.value + b.value "logical_reads",
c.value "phys_reads",
round(100 * ((a.value+b.value)-c.value) / (a.value+b.value)) "BUFFER HIT RATIO"
from v$sysstat a, v$sysstat b, v$sysstat c
where a.statistic# = 38 and
b.statistic# = 39 and
c.statistic# = 40 ;監控 SGA 中字典緩衝區的命中率
select parameter, gets,Getmisses , getmisses/(gets+getmisses)*100 "miss ratio",
(1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio"
from v$rowcache
where gets+getmisses <>0
group by parameter, gets, getmisses ;監控 SGA **享快取區的命中率，應該小於1%
select sum(pins) "Total Pins", sum(reloads) "Total Reloads",
sum(reloads)/sum(pins) *100 libcache
from v$librarycache;監控 SGA 中重做日誌快取區的命中率，應該小於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$latch WHERE name IN ('redo allocation', 'redo copy');監控記憶體和硬碟的排序比率，最好使它小於 .10
SELECT name, value
FROM v$sysstat
WHERE name IN ('sorts (memory)', 'sorts (disk)') ;監控字典緩衝區
SELECT SUM(GETS) "DICTIONARY GETS",SUM(GETMISSES) "DICTIONARY CACHE GET MISSES"
FROM V$ROWCACHE ;非系統使用者建在SYSTEM表空間中的表
SELECT owner,table_name
FROM DBA_TABLES
WHERE tablespace_name in('SYSTEM','USER_DATA') AND
owner NOT IN('SYSTEM','SYS','OUTLN', 'ORDSYS','MDSYS','SCOTT', 'HOSTEAC');效能最差的SQL
SELECT * FROM ( SELECT PARSING_USER_ID EXECUTIONS,SORTS,COMMAND_TYPE,DISK_READS,sql_text
FROM v$sqlarea
ORDER BY disk_reads DESC)
WHERE ROWNUM<100;讀磁碟數超100次的sql
select * from sys.v_$sqlarea where disk_reads>100;查詢消耗資源比較的sql語句
Select se.username,
se.sid,
su.extents,
su.blocks * to_number(rtrim(p.value)) as Space,
tablespace,
segtype,
sql_text
from v$sort_usage su, v$parameter p, v$session se, v$sql s
where p.name = 'db_block_size'
and su.session_addr = se.saddr
and s.hash_value = su.sqlhash
and s.address = su.sqladdr
order by se.username, se.sid;最頻繁執行的sql
select * from sys.v_$sqlarea where executions>100;查詢使用CPU多的使用者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$sesstat c
where c.statistic#=12 and
c.sid=a.sid and
a.paddr=b.addr
order by value desc;當前每個會話使用的物件數
SELECT a.sid,s.terminal,s.program,count(a.sid)
FROM V$ACCESS a,V$SESSION s
WHERE a.owner <> 'SYS'AND s.sid = a.sid
GROUP BY a.sid,s.terminal,s.program
ORDER BY count(a.sid) ;檢視資料庫庫物件
SELECT owner, object_type, status, COUNT(*) count#
FROM all_objects
GROUP BY owner, object_type, status;
檢視資料庫的版本
SELECT version
FROM product_component_version
WHERE substr(product, 1, 6) = 'Oracle'; 檢視資料庫的建立日期和歸檔方式
SELECT created, log_mode, log_mode FROM v$database; 檢查角色和許可權設定
根據使用者名稱進行授權的物件級特權
select b.owner || '.' || b.table_name obj,
b.privilege what_granted,
b.grantable,
a.username
from sys.dba_users a, sys.dba_tab_privs b
where a.username = b.grantee
order by 1, 2, 3;
根據被授權人進行授權的物件級特權
Select owner || '.' || table_name obj,
privilege what_granted,
grantable,
grantee
from sys.dba_tab_privs
where not exists (select 'x' from sys.dba_users where username = grantee)
order by 1, 2, 3;根據使用者名稱進行授予的系統級特權
select b.privilege what_granted, b.admin_option, a.username
from sys.dba_users a, sys.dba_sys_privs b
where a.username = b.grantee
order by 1, 2;根據被授權人進行授予的系統級特權
select privilege what_granted, admin_option, grantee
from sys.dba_sys_privs
where not exists (select 'x' from sys.dba_users where username = grantee)
order by 1, 2;
根據使用者名稱授予的角色
select b.granted_role ||
decode(admin_option, 'YES', ' (With Admin Option)', null) what_granted,
a.username
from sys.dba_users a, sys.dba_role_privs b
where a.username = b.grantee
order by 1;
根據被授權人授予的角色
select granted_role ||
decode(admin_option, 'YES', ' (With Admin Option)', null) what_granted,
grantee
from sys.dba_role_privs
where not exists (select 'x' from sys.dba_users where username = grantee)
order by 1;
使用者名稱及已被授予的相應許可權
select a.username,
b.granted_role ||
decode(admin_option, 'YES', ' (With Admin Option)', null) what_granted
from sys.dba_users a, sys.dba_role_privs b
where a.username = b.grantee
UNION
select a.username,
b.privilege ||
decode(admin_option, 'YES', ' (With Admin Option)', null) what_granted
from sys.dba_users a, sys.dba_sys_privs b
where a.username = b.grantee
UNION
select a.username,
b.table_name || '-' || b.privilege ||
decode(grantable, 'YES', ' (With Grant Option)', null) what_granted
from sys.dba_users a, sys.dba_tab_privs b
where a.username = b.grantee
order by 1;
查詢使用者名稱及相應的配置檔案、預設的表空間和臨時表空間
Select username, profile, default_tablespace, temporary_tablespace, created
from sys.dba_users
order by username;等待事件V$檢視
在Oracle 10g中V$SESSION_WAIT中的所有等待事件列現在都在V$SESSION中。因此，確保查詢等待資訊的 V$SESSION，因為它是一個更快的檢視。V$ACTIVE_SESSION_HISTORY (ASH)將許多重要統計資料合併為一個檢視或一個報表(ASH報表)。
馬上該誰等待–查詢V$SESSION_WAIT / V$SESSION
select event,
sum(decode(wait_time, 0, 1, 0)) "Waiting Now",
sum(decode(wait_time, 0, 0, 1)) "Previous Waits",
count(*) "Total"
from v$session_wait
group by event
order by count(*);馬上該誰等待；SPECIFIC Waits–查詢V$SESSION_WAIT
SELECT /*+ ordered */
sid, event, owner, segment_name, segment_type, p1, p2, p3
FROM v$session_wait sw, dba_extents de
WHERE de.file_id = sw.p1
AND sw.p2 between de.block_id and de.block_id + de.blocks - 1
AND (event = 'buffer busy waits' OR event = 'write complete waits')
AND p1 IS NOT null
ORDER BY event, sid;
誰在等待 - 最後10 個等待數–查詢V$SESSION_WAIT_HISTORY
SELECT /*+ ordered */
sid, event, owner, segment_name, segment_type, p1, p2, p3
FROM v$session_wait sw, dba_extents de
WHERE de.file_id = sw.p1
AND sw.p2 between de.block_id and de.block_id + de.blocks - 1
AND (event = 'buffer busy waits' OR event = 'write complete waits')
AND p1 IS NOT null
ORDER BY event, sid;查詢P1, P2, P3代表什麼–查詢 V$EVENT_NAME
select event#, name, parameter1 p1, parameter2 p2, parameter3 p3
from v$event_name
where name in ('buffer busy waits', 'write complete waits');會話開始後的所有等待數–查詢 V$SESSION_EVENT
select sid, event, total_waits, time_waited, event_id
from v$session_event
where time_waited > 0
order by time_waited;
類的所有會話等待數–查詢V$SESSION_WAIT_CLASS
select sid, wait_class, total_waits from v$session_wait_class;系統啟動後的所有等待數–查詢V$SYSTEM_EVENT
select event, total_waits, time_waited, event_id
from v$system_event
where time_waited > 0
order by time_waited;
類的系統等待數–查詢V$SYSTEM_WAIT_CLASS
select wait_class, total_waits
from v$system_wait_class
order by total_waits desc;
類的系統等待數–查詢V$ACTIVE_SESSION_HISTORY
–In the query below, the highest count session is leader in non-idle wait events.
select session_id, count(1)
from v$active_session_history
group by session_id
order by 2;–In the query below, find the SQL for the leader in non-idle wait events.
select c.sql_id, a.sql_text
from v$sql a,
(select sql_id, count(1)
from v$active_session_history b
where sql_id is not null
group by sql_id order by 2 desc) c
where rownum <= 5
order by rownum;自動工作量倉庫(AWR) 的基本資訊
自動工作量倉庫(AWR)在預設情況下，倉庫用小時填充，保留期是7天。
AWR使用多少空間
SQL> Select occupant_name,occupant_desc,space_usage_kbytes from v$sysaux_occupants where occupant_name like '%AWR%';
OCCUPANT_NAME OCCUPANT_DESC SPACE_USAGE_KBYTES
----------------- ---------------------------------- ------------------
SM/AWR Server Manageability - Automatic Workload Repository 215616
SQL> 系統上最原始的AWR資訊是什麼？
SQL> select dbms_stats.get_stats_history_availability from dual;
GET_STATS_HISTORY_AVAILABILITY
-------------------------------------------------------------
20-OCT-16 12.04.49.088829000 AM -04:00什麼是AWR資訊的保留期？
SQL> select dbms_stats.get_stats_history_retention from dual;
GET_STATS_HISTORY_RETENTION
---------------------------
31將AWR資訊的保留期更改為15天？
SQL> EXEC dbms_stats.alter_stats_history_retention(15);
PL/SQL 過程已成功完成。
獲取生成的trace檔案
開啟SQL跟蹤後，會生成一個trace檔案，通過初始化引數user_dump_dest配置其所在目錄，該引數的值可以通過下面方法獲取到：
select name, value from v$parameter where name = 'user_dump_dest'
trace檔案的名字是獨立於版本和平臺的，在大部分常見的平臺下，命名結構如下：
{instance name}_{process name}_{process id}.trc1）instance name
初始化引數instance_name的小寫值。通過v$instance檢視的instance_name列可以得到這個值。
2）process name
產生跟蹤檔案程序的名字的小寫值。對於專有伺服器程序，使用ora，對於共享伺服器程序，可以通過v$diapatcher或v$shared_server檢視的name列獲得。對於並行從屬程序，可以通過v$px_process檢視server_name列獲得，對於其他多數後臺程序來說，可以通過v$bgprocess檢視的name列獲得。
3）process id
作業系統層面的程序標記。這個值可以通過v$process檢視的spid列獲取。
根據這些資訊，可以通過下面的方式獲取trace檔名：
select s.SID,
s.SERVER,
lower(case
when s.SERVER in ('DEDICATED', 'SHARED') then
i.INSTANCE_NAME || '_' || nvl(pp.SERVER_NAME, nvl(ss.NAME, 'ora')) || '_' ||
p.SPID || '.trc'
else
null
end) as trace_file_name
from v$instance i,
v$session s,
v$process p,
v$px_process pp,
v$shared_server ss
where s.PADDR = p.ADDR
and s.SID = pp.SID(+)
and s.PADDR = ss.PADDR(+)
and s.TYPE = 'USER'
and s.SID = 'your sid'
order by s.SID
將上面的’your sid’替換為你的session的sid就可以查出指定session生成的trace檔案的名字，session的sid在v$session檢視中得到，或者直接查詢當前session的sid：
select userenv('sid') from dual
或者
select sid from v$mystat a where rownum=1 ; 將路徑（user_dump_dest）和檔名結合在一起，我們就得到了trace檔案的完整路徑。
而在Oracel 11g中，查詢當前會話生成的trace檔案則非常簡單：
select value from v$diag_info where name = 'Default Trace File'