月归档:六月 2012

To find the TX Enqueue contention in a RAC or OPS environment

今天查找TX Enqueue看到的一篇文章,拿出来共享下

PURPOSE 
------------- 
To find the TX Enqueue contention in a RAC or OPS environment 

What is TX Enqueue ? 
In one word oracle is maintaining queue for transaction. 

How Many Resources ? 
1/ active transaction 

How Many Locks? 
1/transaction + 1/process waiting for a locked row by that 
transaction. 

How Many Users? 
1 + 1/ process waiting for something locked by this transaction. 

Who Uses? 
All processes 

What need to investigate? 
The mode of TX (6/4), Holding/Waiting/Requesting 

SCOPE & APPLICATION 
===================== 

This document will help to analyze the application design related to transaction bottlenecks 
and database performance tuning. 

Let start with an example: 
=================== 
create table akdas (A1 number, Col1 Varchar2(10), Col2 Varchar2(10)); 
insert into akdas values(5,'Hello','Hi'); 
insert into akdas values(6,'Sudip','Datta'); 
insert into akdas values(7,'Preetam','Roy'); 
insert into akdas values(8,'Michael','Polaski'); 

From Node 1: 
========== 
update akdas set a1=11 where a1=6; 

From Node 2: 
========== 
update akdas set a1=12 where a1=7; 
update akdas set a1=11 where a1=6;  /* this will wait for Node1: to complete the transaction */ 

This Note Is Made To Analyzing Only the TX-Mode-6 (Exclusive). 


1. Now run the following query to track down the problem: Who is waiting 
=================================================================== 
prompt 
prompt Query 1. Waiting for TX Enqueue where mode is Exclusive 
prompt ===================================== 
prompt 
set linesize 100 
set pagesize 66 
col c1 for a15 
col c1 heading "Program Name " 
select l.inst_id,l.SID,program c1,l.TYPE,l.ID1,l.ID2,l.LMODE,l.REQUEST 
from gv$lock l,gv$session s 
where l.type like 'TX' and l.REQUEST =6 
and l.inst_id=s.inst_id and l.sid=s.sid 
order by id1 
/ 

Output will be here 
=============== 
   INST_ID      SID     Program Name       TY     ID1     ID2       LMODE      REQUEST 
-----------  ---------- ------------------ ---   -------- --------  ---------- --------
         2           13  sqlplus@opcbsol   TX     393236  780       0          6 
                         2 (TNS V1-V3) 

It is clear that SID 12 of instance 2 is doing a DML and waiting on REQUEST Mode 6. 


2. Let's run the next query to find who is holding 
=========================================== 

prompt 
prompt 
prompt Query 2. Holding for TX Enqueue where mode greater than 6 
prompt ======================================= 
prompt 
set linesize 100 
set pagesize 66 
col c1 for a15 
col c1 heading "Program Name " 
select l.inst_id,l.SID,program c1,l.TYPE,l.ID1,l.ID2,l.LMODE,l.REQUEST 
from gv$lock l,gv$session s 
where l.type like 'TX' and l.LMODE =6 and (l.ID1,l.ID2) in 
(select id1,id2 from gv$lock where type like 'TX' and REQUEST =6) 
and l.inst_id=s.inst_id and l.sid=s.sid 
order by id1 
/ 

Output will be here 
=============== 
   INST_ID      SID     Program Name      TY        ID1        ID2      LMODE    REQUEST 
   ----------  ---------- -------------- ---   ---------- --------   ----------- --------
         1          12    sqlplus@opcbsol TX     393236        780      6          0 
                          1 (TNS V1-V3) 

So holder is SID 12 on instance 1. Where LMODE = 6. 


3. Let's find out the exact file#, block# and Record# where it is waiting 
=============================================================== 

prompt 
prompt 
prompt Query 3. Object# ,File#, Block# and Slot# TX Enqueue in detail 
prompt ======================================== 
prompt 
set linesize 110 
col c0 for 999 
col c0 heading "INS" 
col c1 for a15 
col c1 heading "Program Name " 
select inst_id c0,sid,program c1,ROW_WAIT_OBJ# object_no, ROW_WAIT_FILE# Rfile_no,
ROW_WAIT_BLOCK# Block_no ,ROW_WAIT_ROW# Row_no 
from gv$session 
where (inst_id,sid) in (select inst_id,sid from gv$session_wait where p1='1415053318') 
/ 

Output Will be here 
=============== 
 INS     SID    Program Name     OBJECT_NO RFILE_NO BLOCK_NO  ROW_NO 
----- ---------- -------------   ---------------    --------- -------
   2         13     sqlplus@opcbsol  7261      9        12346     1 
                      2 (TNS V1-V3) 
  

From the output, it is clear that it is waiting on Relative_File# 9, Block# 12346, Row Number 1. 
Here Row Number 1 means the slot number in the block 12346. This Row_No start from 0 (zero). 


4. Let's Find the object details 
============================= 

prompt 
prompt 
prompt Query 4. Object Involve for TX Enqueue in detail 
prompt =============================== 
prompt 
set linesize 100 
set pagesize 100 
col owner for a10 
col object_name for a20 
col object_type for a10 
select owner,object_name,object_id,object_type 
from dba_objects 
where 
object_id in (select ROW_WAIT_OBJ# from gv$session 
where (inst_id, sid) in (select inst_id,sid from gv$session_wait where p1='1415053318')) 
/ 

Output Will be here 
=============== 
OWNER      OBJECT_NAME  OBJECT_ID   OBJECT_TYP 
---------  ------------ --------    -----------
AKDAS      AKDAS        7261        TABLE 


5. Let’s find the row value details 
============================= 

prompt 
prompt 
prompt Query 5. Finding the row value 
prompt ==================== 
prompt 
select * from <Owner>.<Table Name>  where rowid like 
DBMS_ROWID.ROWID_CREATE(1,&Object_No,&Rfile_No, &Block_No, &Row_Number) 
/ 
From query 3 and 4  we will get the value for all variables. 
Owner = AKDAS 
Table_Name = AKDAS 
Object_No = 7261 
Rfile_No =  9 
Block_No = 12346 
Row_Number = 1 

Output Will be here 
=============== 
        A1    Col1                 Col2 
  ---------- --------------- ---------- 
         6      Hello                Hi 

So we can drag down to the row value where TX Enqueue contention exists. 


6. Let’s find the user activity that is "Holder" and "Waiter" 
==================================================== 

set linesize 120 
set pagesize 66 
col c0 for 999 
col c0 heading "INS" 
col c1 for a9 
col c1 heading "OS User" 
col c2 for a9 
col c2 heading "Oracle User" 
col c3 for a15 
col c3 heading "Program Name" 
col b1 for a9 
col b1 heading "Unix PID" 
col b2 for 9999 justify left 
col b2 heading "ORA SID" 
col b3 for 999999 justify left 
col b3 heading "SERIAL#" 
col sql_text for a45 
set space 1 
break on b1 nodup on c0 nodup on c3 nodup on c1 nodup on c2 nodup on b2 nodup on b3 skip 2 
select a.inst_id c0,b.sid b2,c.spid b1, b.program c3, b.username c2,b.serial# b3, a.sql_text 
  from gv$sql a, gv$session b, gv$process c 
 where 
   a.address = b.sql_address 
   and b.paddr = c.addr 
   and a.hash_value = b.sql_hash_value 
   and a.inst_id=b.inst_id and a.inst_id=c.inst_id 
   and a.inst_id like '&inst_id' and b.sid like '&sid' 
 order by c.spid,a.hash_value 
/ 

This query asks the Instance Number and Sid number, which you can get from step 1 and 2. 
But remember , you can see the waiter activity, but you may not see the holder activity. 
Reason is, the holder is sitting idle after doing the DML operation. So SQL for Holder 
should not be seen under gv$sql. 

This all query can be run for single instance database, but all GV$ view need to replace to V$ 
and there is no INST_ID for V$ View, that part need to be taken care. 

来自:How to Find TX Enqueue Contention in RAC or OPS [ID 179582.1]

发表在 Oracle性能优化 | 评论关闭

Oracle 11g丢失access$恢复方法

最近接触到两个案例都是11g数据库因为异常关闭导致access$表丢失,使得数据库不能正常open.为什么这个表会丢失还未找到原因.我这里提供一种在upgrade模式下解决给问题方法.
数据库版本

SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - Production
PL/SQL Release 11.2.0.3.0 - Production
CORE    11.2.0.3.0      Production
TNS for Linux: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - Production

SQL> select to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') "xifenfei" from dual;

xifenfei
--------------------------------------
2012-06-22 05:28:57

数据库启动报ORA-00704

SQL> startup
ORACLE instance started.

Total System Global Area  523108352 bytes
Fixed Size                  1346052 bytes
Variable Size             448792060 bytes
Database Buffers           67108864 bytes
Redo Buffers                5861376 bytes
Database mounted.
ORA-01092: ORACLE instance terminated. Disconnection forced
ORA-00704: bootstrap process failure
ORA-00604: error occurred at recursive SQL level 1
ORA-00942: table or view does not exist
Process ID: 1782
Session ID: 125 Serial number: 5

找出ORA-00704报错原因

SQL> conn / as sysdba
Connected to an idle instance.
SQL> startup mount;
ORACLE instance started.

Total System Global Area  523108352 bytes
Fixed Size                  1346052 bytes
Variable Size             448792060 bytes
Database Buffers           67108864 bytes
Redo Buffers                5861376 bytes
Database mounted.
SQL> oradebug setmypid
Statement processed.
SQL> oradebug EVENT 10046 TRACE NAME CONTEXT FOREVER, LEVEL 12
Statement processed.
SQL> oradebug TRACEFILE_NAME
/u01/oracle/diag/rdbms/ora11g/ora11g/trace/ora11g_ora_2010.trc
SQL> alter database open;
alter database open
*
ERROR at line 1:
ORA-01092: ORACLE instance terminated. Disconnection forced
ORA-00704: bootstrap process failure
ORA-00604: error occurred at recursive SQL level 1
ORA-00942: table or view does not exist
Process ID: 2010
Session ID: 125 Serial number: 5

查看trace文件发现

PARSE ERROR #3063868604:len=56 dep=1 uid=0 oct=3 lid=0 tim=1340312320595472 err=942
select order#,columns,types from access$ where d_obj#=:1
ORA-00704: bootstrap process failure
ORA-00604: error occurred at recursive SQL level 1
ORA-00942: table or view does not exist
ORA-00704: bootstrap process failure
ORA-00604: error occurred at recursive SQL level 1
ORA-00942: table or view does not exist

*** 2012-06-22 04:58:40.596
USER (ospid: 2010): terminating the instance due to error 704

启动数据库至upgrade模式

SQL> startup  upgrade
ORACLE instance started.

Total System Global Area  523108352 bytes
Fixed Size                  1346052 bytes
Variable Size             448792060 bytes
Database Buffers           67108864 bytes
Redo Buffers                5861376 bytes
Database mounted.
Database opened.

创建access$表和index

SQL> create table access$
  2  ( d_obj#        number not null,
  3    order#        number not null,
  4    columns       raw(126),
  5    types         number not null)
  6    storage (initial 10k next 100k maxextents unlimited pctincrease 0)
  7  /

Table created.

SQL> create index i_access1 on
  2    access$(d_obj#, order#)
  3    storage (initial 10k next 100k maxextents unlimited pctincrease 0)
  4  /

Index created.
--创建语句可以在?\RDBMS\ADMIN\dcore.bsq中找到

重启数据库

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.

Total System Global Area  523108352 bytes
Fixed Size                  1346052 bytes
Variable Size             448792060 bytes
Database Buffers           67108864 bytes
Redo Buffers                5861376 bytes
Database mounted.
Database opened.

access$表作用(感谢vmcd同学提供)
When a database object is first referenced in a PL/SQL program, the PL/SQL engine checks the ACCESS$ table (owned by SYS) to see if the executor of the program has authority on that database object.
对于access$表丢失以前记录是否对系统产生严重影响还未知,希望知道的朋友告知下

发表在 Oracle备份恢复 | 标签为 | 2 条评论

使用dul恢复asm中数据

大家都知道新版本的odu可以在asm不启动的情况下挖数据文件,其实在新版本的dul中,也可以绕过asm挖数据文件,而且操作起来更加方便.
环境准备

SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod
PL/SQL Release 10.2.0.1.0 - Production
CORE    10.2.0.1.0      Production
TNS for Linux: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production

--查询asm disk
SQL> select group_number,DISK_NUMBER,PATH
  2  from v$asm_disk where group_number<>0;
 
GROUP_NUMBER DISK_NUMBER PATH
------------ ----------- --------------------
           1           0 /dev/raw/raw2
           1           1 /dev/raw/raw3 

SQL> conn chf/xifenfei
Connected.

--创建测试表
SQL> create table t_xifenfei
  2  as
  3   select object_id,object_name from dba_objects where rownum<10;

Table created.

SQL> select * from t_xifenfei;

 OBJECT_ID OBJECT_NAME
---------- --------------------------------
        44 I_USER1
        28 CON$
        15 UNDO$
        29 C_COBJ#
         3 I_OBJ#
        25 PROXY_ROLE_DATA$
        39 I_IND1
        51 I_CDEF2

9 rows selected.

--数据文件
SQL> select name from v$datafile;

NAME
----------------------------------------------------------------------
+XIFENFEI/asm10g/datafile/system.256.786578479
+XIFENFEI/asm10g/datafile/undotbs1.258.786578481
+XIFENFEI/asm10g/datafile/sysaux.257.786578481
+XIFENFEI/asm10g/datafile/users.259.786578481
+XIFENFEI/asm10g/datafile/xff.265.786578851

--关闭数据库
SQL> shutdown immediate;
ORA-01031: insufficient privileges
SQL> conn / as sysdba
Connected.
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> exit
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

--关闭asm
[oracle@xifenfei home]$ export ORACLE_SID=+ASM
[oracle@xifenfei home]$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on Fri Jun 22 00:18:18 2012

Copyright (c) 1982, 2005, Oracle.  All rights reserved.


Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> shutdown immediate
ASM diskgroups dismounted
ASM instance shutdown
SQL> exit
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
[oracle@xifenfei home]$ ps -ef|grep ASM
oracle   18885 10980  0 00:18 pts/0    00:00:00 grep ASM
[oracle@xifenfei home]$ ps -ef|grep ora_
oracle   18887 10980  0 00:18 pts/0    00:00:00 grep ora_

初始化参数配置

[oracle@xifenfei dul]$ vi init.dul 
db_block_size=8192
control_file = control.dul
dc_segments=100000
osd_word_size = 32
osd_big_endian_flag=false
osd_dba_file_bits=10
osd_c_struct_alignment=32
osd_file_leader_size=1
osd_word_size = 32
dc_columns=2000000
dc_tables=10000
dc_objects=1000000
dc_users=400
dc_segments=100000
control_file = control.dul
db_block_size=8192
export_mode=false
compatible=10
BUFFER=10485760

控制文件配置

[oracle@xifenfei dul]$ more control.dul 
disk /dev/raw/raw2
disk /dev/raw/raw3  
0          1 +XIFENFEI/asm10g/datafile/system.256.786578479
1          2 +XIFENFEI/asm10g/datafile/undotbs1.258.786578481
2          3 +XIFENFEI/asm10g/datafile/sysaux.257.786578481
4          4 +XIFENFEI/asm10g/datafile/users.259.786578481
6          5 +XIFENFEI/asm10g/datafile/xff.265.786578851

使用dul恢复表测试

--启动dul
[oracle@xifenfei dul]$ ./dul

Data UnLoader: 10.2.0.5.13 - Internal Only - on Thu Jun 21 23:49:46 2012
with 64-bit io functions

Copyright (c) 1994 2012 Bernard van Duijnen All rights reserved.

 Strictly Oracle Internal Use Only


DUL: Warning: Recreating file "dul.log"
Disk group XIFENFEI, dul group_cid 0
Discovered disk /dev/raw/raw2 as diskgroup XIFENFEI, disk number 0 size 784 Mb File1 starts at 2, dul_disk_cid 0
Discovered disk /dev/raw/raw3 as diskgroup XIFENFEI, disk number 1 size 7059 Mb without File1 meta data, dul_disk_cid 1

DUL: Warning: Dictionary cache DC_ASM_EXTENTS is empty
DUL: Error: Filedir block not allocated, file does not exist
DUL: Error: Could not load asm meta data for group XIFENFEI file 9
Oracle data file size 503324672, block size 8192
Found db_id = 123111609
Found db_name = ASM10G
Oracle data file size 26222592, block size 8192
Oracle data file size 251666432, block size 8192
Oracle data file size 5251072, block size 8192

--加载数据字典
DUL> bootstrap;
Probing file = 1, block = 377
. unloading table                BOOTSTRAP$
DUL: Warning: block number is non zero but marked deferred trying to process it anyhow
      57 rows unloaded
DUL: Warning: Dictionary cache DC_BOOTSTRAP is empty
Reading BOOTSTRAP.dat 57 entries loaded
Parsing Bootstrap$ contents
DUL: Warning: Recreating file "dict.ddl"
Generating dict.ddl for version 10
 OBJ$: segobjno 18, file 1 block 121
 TAB$: segobjno 2, tabno 1, file 1  block 25
 COL$: segobjno 2, tabno 5, file 1  block 25
 USER$: segobjno 10, tabno 1, file 1  block 89
Running generated file "@dict.ddl" to unload the dictionary tables
. unloading table                      OBJ$   50806 rows unloaded
. unloading table                      TAB$    1560 rows unloaded
. unloading table                      COL$   54822 rows unloaded
. unloading table                     USER$      57 rows unloaded
Reading USER.dat 57 entries loaded
Reading OBJ.dat 50806 entries loaded and sorted 50806 entries
Reading TAB.dat 1560 entries loaded
Reading COL.dat 54822 entries loaded and sorted 54822 entries
Reading BOOTSTRAP.dat 57 entries loaded

DUL: Warning: Recreating file "dict.ddl"
Generating dict.ddl for version 10
 OBJ$: segobjno 18, file 1 block 121
 TAB$: segobjno 2, tabno 1, file 1  block 25
 COL$: segobjno 2, tabno 5, file 1  block 25
 USER$: segobjno 10, tabno 1, file 1  block 89
 TABPART$: segobjno 266, file 1 block 2121
 INDPART$: segobjno 271, file 1 block 2161
 TABCOMPART$: segobjno 288, file 1 block 2297
 INDCOMPART$: segobjno 293, file 1 block 2345
 TABSUBPART$: segobjno 278, file 1 block 2217
 INDSUBPART$: segobjno 283, file 1 block 2257
 IND$: segobjno 2, tabno 3, file 1  block 25
 ICOL$: segobjno 2, tabno 4, file 1  block 25
 LOB$: segobjno 2, tabno 6, file 1  block 25
 COLTYPE$: segobjno 2, tabno 7, file 1  block 25
 TYPE$: segobjno 181, tabno 1, file 1  block 1297
 COLLECTION$: segobjno 181, tabno 2, file 1  block 1297
 ATTRIBUTE$: segobjno 181, tabno 3, file 1  block 1297
 LOBFRAG$: segobjno 299, file 1 block 2393
 LOBCOMPPART$: segobjno 302, file 1 block 2425
 UNDO$: segobjno 15, file 1 block 105
 TS$: segobjno 6, tabno 2, file 1  block 57
 PROPS$: segobjno 96, file 1 block 721
Running generated file "@dict.ddl" to unload the dictionary tables
. unloading table                      OBJ$
DUL: Warning: Recreating file "OBJ.ctl"
   50806 rows unloaded
. unloading table                      TAB$
DUL: Warning: Recreating file "TAB.ctl"
    1560 rows unloaded
. unloading table                      COL$
DUL: Warning: Recreating file "COL.ctl"
   54822 rows unloaded
. unloading table                     USER$
DUL: Warning: Recreating file "USER.ctl"
      57 rows unloaded
. unloading table                  TABPART$      72 rows unloaded
. unloading table                  INDPART$      80 rows unloaded
. unloading table               TABCOMPART$       0 rows unloaded
. unloading table               INDCOMPART$       0 rows unloaded
. unloading table               TABSUBPART$       0 rows unloaded
. unloading table               INDSUBPART$       0 rows unloaded
. unloading table                      IND$    2213 rows unloaded
. unloading table                     ICOL$    3618 rows unloaded
. unloading table                      LOB$     528 rows unloaded
. unloading table                  COLTYPE$    1688 rows unloaded
. unloading table                     TYPE$    1885 rows unloaded
. unloading table               COLLECTION$     551 rows unloaded
. unloading table                ATTRIBUTE$    7051 rows unloaded
. unloading table                  LOBFRAG$       1 row  unloaded
. unloading table              LOBCOMPPART$       0 rows unloaded
. unloading table                     UNDO$      21 rows unloaded
. unloading table                       TS$       7 rows unloaded
. unloading table                    PROPS$      27 rows unloaded
Reading USER.dat 57 entries loaded
Reading OBJ.dat 50806 entries loaded and sorted 50806 entries
Reading TAB.dat 1560 entries loaded
Reading COL.dat 54822 entries loaded and sorted 54822 entries
Reading TABPART.dat 72 entries loaded and sorted 72 entries
Reading TABCOMPART.dat 0 entries loaded and sorted 0 entries
Reading TABSUBPART.dat 0 entries loaded and sorted 0 entries
Reading INDPART.dat 80 entries loaded and sorted 80 entries
Reading INDCOMPART.dat 0 entries loaded and sorted 0 entries
Reading INDSUBPART.dat 0 entries loaded and sorted 0 entries
Reading IND.dat 2213 entries loaded
Reading LOB.dat 528 entries loaded
Reading ICOL.dat 3618 entries loaded
Reading COLTYPE.dat 1688 entries loaded
Reading TYPE.dat 1885 entries loaded
Reading ATTRIBUTE.dat 7051 entries loaded
Reading COLLECTION.dat 551 entries loaded
Reading BOOTSTRAP.dat 57 entries loaded
Reading LOBFRAG.dat 1 entries loaded and sorted 1 entries
Reading LOBCOMPPART.dat 0 entries loaded and sorted 0 entries
Reading UNDO.dat 21 entries loaded
Reading TS.dat 7 entries loaded
Reading PROPS.dat 27 entries loaded
Database character set is ZHS16GBK
Database national character set is AL16UTF16

--恢复表
DUL> unload table chf.t_xifenfei;
. unloading table                T_XIFENFEI       9 rows unloaded

验证恢复数据库

[oracle@xifenfei dul]$ ll CHF_T_XIFENFEI*
-rw-r--r-- 1 oracle oinstall  269 Jun 22 00:26 CHF_T_XIFENFEI.ctl
-rw-r--r-- 1 oracle oinstall  134 Jun 22 00:26 CHF_T_XIFENFEI.dat
[oracle@xifenfei dul]$ more CHF_T_XIFENFEI.ctl 
load data
CHARACTERSET UTF8
infile 'CHF_T_XIFENFEI.dat'
insert
into table "CHF"."T_XIFENFEI"
fields terminated by whitespace
(
  "OBJECT_ID"                        CHAR(2) enclosed by X'22'       
 ,"OBJECT_NAME"                      CHAR(16) enclosed by X'22'      
)
[oracle@xifenfei dul]$ more CHF_T_XIFENFEI.dat
"20" "ICOL$"
"44" "I_USER1"
"28" "CON$"
"15" "UNDO$"
"29" "C_COBJ#"
"3" "I_OBJ#"
"25" "PROXY_ROLE_DATA$"
"39" "I_IND1"
"51" "I_CDEF2"
发表在 非常规恢复 | 标签为 , , | 评论关闭