ORACLE常用性能监控SQL【一】

网友投稿 783 2022-05-28

文章目录

系列

死锁后的解决办法

生成Kill Session语句

查看导致死锁的 SQL

查看谁锁了谁

ORA-00054 资源正忙,要求指定 NOWAIT

查询绑定变量使用的实际值

监控事例的等待

回滚段的争用情况

查看回滚段名称及大小

查看控制文件

查看日志文件

查看前台正在发出的SQL语句

数据表占用空间大小情况

查看表空间碎片大小

查看表空间占用磁盘情况

查看表的大小,倒序排列

查看表空间物理文件的名称及大小

查看oracle 表空间使用率

查看Temp 表空间实际使用磁盘大小

查看session使用回滚段

查看当前临时表空间使用大小与正在占用临时表空间的sql语句

Temp表空间上进程的查询

查看SGA区剩余可用内存

监控表空间I/O比例

监控SGA命中率

监控 SGA 中字典缓冲区的命中率

监控 SGA **享缓存区的命中率,应该小于1%

监控 SGA 中重做日志缓存区的命中率,应该小于1%

监控内存和硬盘的排序比率,最好使它小于 .10

监控字典缓冲区

非系统用户建在SYSTEM表空间中的表

性能最差的SQL

读磁盘数超100次的sql

查找消耗资源比较的sql语句

最频繁执行的sql

查询使用CPU多的用户session

当前每个会话使用的对象数

查看数据库库对象

查看数据库的版本

查看数据库的创建日期和归档方式

检查角色和权限设置

根据用户名进行授权的对象级特权

根据被授权人进行授权的对象级特权

根据用户名进行授予的系统级特权

根据被授权人进行授予的系统级特权

根据用户名授予的角色

根据被授权人授予的角色

用户名及已被授予的相应权限

查询用户名及相应的配置文件、默认的表空间和临时表空间

等待事件V$视图

马上该谁等待--查询`V$SESSION_WAIT / V$SESSION`

马上该谁等待;SPECIFIC Waits--查询V$SESSION_WAIT

谁在等待 - 最后10 个等待数--查询V$SESSION_WAIT_HISTORY

查找P1, P2, P3代表什么--查询 V$EVENT_NAME

会话开始后的所有等待数--查询 V$SESSION_EVENT

类的所有会话等待数--查询V$SESSION_WAIT_CLASS

系统启动后的所有等待数--查询V$SYSTEM_EVENT

类的系统等待数--查询V$SYSTEM_WAIT_CLASS

类的系统等待数--查询V$ACTIVE_SESSION_HISTORY

自动工作量仓库(AWR) 的基本信息

获取生成的trace文件

系列

ORACLE常用性能监控SQL【一】

ORACLE常用性能监控SQL【二】

Oracle-动态性能视图解读

死锁后的解决办法

如果死锁不能自动释放,就需要我们手工的 kill session

生成Kill Session语句

查看有无死锁对象,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);

1

2

3

4

5

如果有,会返回类似与如下的信息:

alter system kill session '761,876'; .....

1

2

kill session:

执行 alter system kill session ‘761,876’(sid 为 761);

注意: 应当注意对于 sid 在 100 以下的应当谨慎,可能该进程对应某个application,如对应某个事务,可以 kill

查看导致死锁的 SQL

SELECT s.sid, q.sql_text FROM v$sqltext q, v$session s WHERE q.address = s.sql_address AND s.sid = &sid -- 这个&sid 是第一步查询出来的 ORDER BY piece;

1

2

3

4

执行后,输入对应的sid即可查看对应的sql.

查看谁锁了谁

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 s2.sid = l2.sid AND l1.BLOCK = 1 AND l2.request > 0 AND l1.id1 = l2.id1 AND l2.id2 = l2.id2;

1

2

3

4

5

6

7

8

9

10

或者

推荐这个,因为使用的是 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;

1

2

3

4

5

6

7

8

9

10

V$LOCKED_OBJECT只能报发生等待的表级锁,不能报发生等待的行级锁。

ORA-00054 资源正忙,要求指定 NOWAIT

演示:

select * from emp for update ;--通过for update 获取一个排它锁

1

SQL>select object_name as 对象名称,s.sid,s.serial#,p.spid as 系统进程号 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; 对象名称 SID SERIAL# 系统进程号 -------------------------------------------------------------------------------- ---------- ---------- ------------------------ EMP 1411 8865 32720

1

2

3

4

5

6

7

8

在另外一个会话中执行

ALTER SYSTEM KILL SESSION '1411,8865';

1

查询绑定变量使用的实际值

1, SQL还在shared pool中,没有被aged out 替换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;

1

2

3

2.请自行替换sql_id,此时是从awr中查询(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;

1

2

3

4

5

6

7

8

9

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 ;

1

2

3

4

5

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;

1

2

3

4

查看回滚段名称及大小

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;

1

2

3

4

5

6

7

8

9

10

查看控制文件

SELECT NAME FROM v$controlfile;

1

查看日志文件

SELECT MEMBER FROM v$logfile;

1

2

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'));

1

2

3

4

5

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;

1

2

3

4

5

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;

1

2

3

4

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, sum(nvl(a.bytes,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;

1

2

3

4

5

6

7

8

9

10

11

查看表的大小,倒序排列

每张表都是作为“段”来存储的,可以通过user_segments视图查看其相应信息。

段(segments)的定义:如果创建一个堆组织表,则该表就是一个段

SELECT SEGMENT_NAME, SUM(BYTES) / 1024 / 1024 MBYTESE FROM USER_SEGMENTS WHERE SEGMENT_TYPE = 'TABLE' GROUP BY SEGMENT_NAME order by MBYTESE desc;

1

2

3

4

5

查看表空间物理文件的名称及大小

SELECT tablespace_name, file_id, file_name, round(bytes / (1024 * 1024), 0) total_space FROM dba_data_files ORDER BY tablespace_name;

1

2

3

4

5

6

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, 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 --如果有临时表空间 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;

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

SELECT a.tablespace_name "表空间名", total "表空间大小", free "表空间剩余大小", (total - free) "表空间使用大小", total / (1024 * 1024 * 1024) "表空间大小(G)", free / (1024 * 1024 * 1024) "表空间剩余大小(G)", (total - free) / (1024 * 1024 * 1024) "表空间使用大小(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

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

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, 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;

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

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, 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;

1

2

3

4

5

6

7

8

9

10

11

12

13

查看当前临时表空间使用大小与正在占用临时表空间的sql语句

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;

1

2

3

4

5

6

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,b.sid,b.serial#,c.address, c.piece;

1

2

3

4

5

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';

1

2

3

4

5

6

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;

1

2

3

4

5

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 ;

1

2

3

4

5

6

7

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 ;

1

2

3

4

5

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;

1

2

3

监控 SGA 中重做日志缓存区的命中率,应该小于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');

1

2

3

4

5

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)') ;

1

2

3

监控字典缓冲区

SELECT SUM(GETS) "DICTIONARY GETS",SUM(GETMISSES) "DICTIONARY CACHE GET MISSES" FROM V$ROWCACHE ;

ORACLE常用性能监控SQL【一】

1

2

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');

1

2

3

4

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;

1

2

3

4

读磁盘数超100次的sql

select * from sys.v_$sqlarea where disk_reads>100;

1

查找消耗资源比较的sql语句

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;

1

2

3

4

5

6

7

8

9

10

11

12

13

最频繁执行的sql

select * from sys.v_$sqlarea where executions>100;

1

查询使用CPU多的用户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;

1

2

3

4

5

6

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

1

2

3

4

5

查看数据库库对象

SELECT owner, object_type, status, COUNT(*) count# FROM all_objects GROUP BY owner, object_type, status;

1

2

3

4

查看数据库的版本

SELECT version FROM product_component_version WHERE substr(product, 1, 6) = 'Oracle';

1

2

3

查看数据库的创建日期和归档方式

SELECT created, log_mode, log_mode FROM v$database;

1

检查角色和权限设置

根据用户名进行授权的对象级特权

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;

1

2

3

4

5

6

7

8

根据被授权人进行授权的对象级特权

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;

1

2

3

4

5

6

7

根据用户名进行授予的系统级特权

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;

1

2

3

4

根据被授权人进行授予的系统级特权

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;

1

2

3

4

5

6

根据用户名授予的角色

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;

1

2

3

4

5

6

7

根据被授权人授予的角色

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;

1

2

3

4

5

6

7

用户名及已被授予的相应权限

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;

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

查询用户名及相应的配置文件、默认的表空间和临时表空间

Select username, profile, default_tablespace, temporary_tablespace, created from sys.dba_users order by username;

1

2

3

等待事件V$视图

在Oracle 10g中V$SESSION_WAIT中的所有等待事件列现在都在V$SESSION中。因此,确保查询等待信息的 V$SESSION,因为它是一个更快的视图。V$ACTIVE_SESSION_HISTORY (ASH)将许多重要统计数据合并为一个视图或一个报表(ASH报表)。

马上该谁等待–查询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(*);

1

2

3

4

5

6

7

马上该谁等待;SPECIFIC Waits–查询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;

1

2

3

4

5

6

7

8

9

10

11

谁在等待 - 最后10 个等待数–查询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;

1

2

3

4

5

6

7

8

查找P1, P2, P3代表什么–查询 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');

1

2

3

会话开始后的所有等待数–查询 V$SESSION_EVENT

select sid, event, total_waits, time_waited, event_id from v$session_event where time_waited > 0 order by time_waited;

1

2

3

4

5

类的所有会话等待数–查询V$SESSION_WAIT_CLASS

select sid, wait_class, total_waits from v$session_wait_class;

1

系统启动后的所有等待数–查询V$SYSTEM_EVENT

select event, total_waits, time_waited, event_id from v$system_event where time_waited > 0 order by time_waited;

1

2

3

4

5

类的系统等待数–查询V$SYSTEM_WAIT_CLASS

select wait_class, total_waits from v$system_wait_class order by total_waits desc;

1

2

3

4

类的系统等待数–查询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;

1

2

3

4

–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;

1

2

3

4

5

6

7

8

自动工作量仓库(AWR) 的基本信息

自动工作量仓库(AWR)在默认情况下,仓库用小时填充,保留期是7天。

AWR使用多少空间

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>

1

2

3

4

5

6

7

系统上最原始的AWR信息是什么?

SQL> select dbms_stats.get_stats_history_availability from dual; GET_STATS_HISTORY_AVAILABILITY ------------------------------------------------------------- 20-OCT-16 12.04.49.088829000 AM -04:00

1

2

3

4

5

什么是AWR信息的保留期?

SQL> select dbms_stats.get_stats_history_retention from dual; GET_STATS_HISTORY_RETENTION --------------------------- 31

1

2

3

4

5

将AWR信息的保留期更改为15天?

SQL> EXEC dbms_stats.alter_stats_history_retention(15); PL/SQL 过程已成功完成。

1

2

3

获取生成的trace文件

开启SQL跟踪后,会生成一个trace文件,通过初始化参数user_dump_dest配置其所在目录,该参数的值可以通过下面方法获取到:

select name, value from v$parameter where name = 'user_dump_dest'

1

2

trace文件的名字是独立于版本和平台的,在大部分常见的平台下,命名结构如下:

{instance name}_{process name}_{process id}.trc

1

1)instance name

初始化参数instance_name的小写值。通过v$instance视图的instance_name列可以得到这个值。

2)process name

产生跟踪文件进程的名字的小写值。对于专有服务器进程,使用ora,对于共享服务器进程,可以通过v$diapatcher或v$shared_server视图的name列获得。对于并行从属进程,可以通过v$px_process视图server_name列获得,对于其他多数后台进程来说,可以通过v$bgprocess视图的name列获得。

3)process id

操作系统层面的进程标记。这个值可以通过v$process视图的spid列获取。

根据这些信息,可以通过下面的方式获取trace文件名:

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

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

将上面的’your sid’替换为你的session的sid就可以查出指定session生成的trace文件的名字,session的sid在v$session视图中得到,或者直接查询当前session的sid:

select userenv('sid') from dual 或者 select sid from v$mystat a where rownum=1 ;

1

2

3

将路径(user_dump_dest)和文件名结合在一起,我们就得到了trace文件的完整路径。

而在Oracel 11g中,查询当前会话生成的trace文件则非常简单:

select value from v$diag_info where name = 'Default Trace File'

1

Oracle SQL

版权声明:本文内容由网络用户投稿,版权归原作者所有,本站不拥有其著作权,亦不承担相应法律责任。如果您发现本站中有涉嫌抄袭或描述失实的内容,请联系我们jiasou666@gmail.com 处理,核实后本网站将在24小时内删除侵权内容。

上一篇:[springboot一本通]-4.1.整合SpringJDBC操作数据
下一篇:MySQL索引优化分析
相关文章