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Oracle内部错误ORA-600:[1112]

2009/07/06 by admin Leave a Comment

以下为ORA-600[1112]内部错误的相关诊断信息:

ERROR:
ORA-600 [1112] [a] [b] [c] [d] [e]

VERSIONS:
versions 7.3 to 9.2

DESCRIPTION:

ORA-600 [1112] is getting raised while trying to add a
row cache enqueue to a transaction state object during
lookup of the default tablespace number during table
creation.

FUNCTIONALITY:
STATE OBJECT MANAGEMENT

IMPACT:
PROCESS FAILURE
NON CORRUPTIVE - No underlying data corruption.


Bug 2489130 - OERI:1112 can occur while dumping PROCESSSTATE informatio (Doc ID 2489130.8)
Bug 4126973: ORA-600[504] AND ORA-600[1112] OCCURED WHEN GETTING "ERRORSTACK"
Base Bug 2489130
Bug 3954753: ORA-600 [1112] AND SESSION CRASH

The cause for the ORA-00600 [1112] appears due to Bug 2489130
This error can occur on dumping of process state which is what occurred here.
The primary issue is the WAITED TOO LONG FOR A ROW CACHE ENQUEUE LOCK!
This then triggers a system state and process state to be dumped due to nature of the problem.
The ORA-00600 [1112] gets dumped out when process state is done.

Stack for trace very similar to Bug 2489130 and this is only known bug on 9.2 like this with a fix.

A fix for bug 2489130 is included in the 9.2.0.7 patchset.
Recommend applying 9.2.0.8 patchset to have this and other bug fixes.
This would only prevent the ORA-00600 [1112] from occurring on state dumps.
The primary row cache issue still to be investigated by performance team.

Filed Under: Oracle, Oracle Bug Tagged With: ora-00600, row cache

How many LMS processes for Oracle Rac 9i?

2009/07/06 by admin Leave a Comment

Question:

How many LMS processes for Oracle 9i Rac?

Can you check if you have increased the CPU in the machine during the upgrade.
Also please let me know if you have changed any underscore parameter.

Do you have some formula for calculate LMS processes and Num of CPU ?? Let say 2 CPU for 1 LMS process ??

Answer:

This can go dynamically as and when required and the # of startup of lms is also controlled by
_lm_lms,_lm_max_lms _lm_min_lms , later 2 seems to be for dynamic control of this numbers.
These parameters should not be set manually.
Also the no. of lms process should be one less than the number of CPU on the node.

Filed Under: Oracle, Oracle RAC Tagged With: lms, RAC

Tune Very Large Hash Join

2009/07/02 by admin Leave a Comment

set timing on;
alter session set workarea_size_policy=MANUAL;
alter session set workarea_size_policy=MANUAL;

alter session set db_file_multiblock_read_count=512;
alter session set db_file_multiblock_read_count=512;

alter session set events '10351 trace name context forever, level 128';

alter session set hash_area_size=524288000;
alter session set hash_area_size=524288000;

alter session set "_hash_multiblock_io_count"=128;
alter session set "_hash_multiblock_io_count"=128;

alter session enable parallel query;

select /*+   pq_distribute(a hash,hash) parallel(a) parallel(b) */ column1,column2....
  from source_tab a, driving_tab b
 where  condition
 ;



--PQ_DISTRIBUTE(tab,out,in) How to distribute rows from tab in a PQ
--(out/in may be HASH/NONE/BROADCAST/PARTITION)

Filed Under: Oracle, Oracle SQL性能调优, Oracle脚本script Tagged With: hash join, Oracle脚本script, SQL tuning, Very Large

unique index vs non-unique index

2009/06/30 by admin Leave a Comment

Question:

What is between between “unique index vs non-unique index”. Which one is faster. The customer using non-unique and sql is getting delay If we change tp non-unique. Is it work ?

Answer:

Indexes can be unique or non-unique. Unique indexes guarantee that no two rows of a table have duplicate values in the key column (or columns). Non-unique indexes do not impose this restriction on the column values.

Oracle recommends that unique indexes be created explicitly, using CREATE UNIQUE INDEX. Creating unique indexes through a primary key or unique constraint is not guaranteed to create a new index, and the index they create is not guaranteed to be a unique index.

It is just that in a unique index, the rowid is not considered “part of the key” and in a non-unique index “the rowid is considered part of the key”.

From Performance point of view:

The optimizer can look at an index that is unique and check, if you use “where x =:x and y = :y and ….” I’m going to get ONE row back, I can cost that much better”

If the index is non-unique, the optimizer will perform , index range scan, he is going to get 0..N rows back” and it’ll cost it differently.

So, a unique index will affect the generated plan — it is more information for the optimizer to grab onto.

If the data must be UNIQUE, you should use a UNIQUE constraint – not an index. We will take care of the index for you. If the constraint is not deferrable, we’ll create a unique index for you. If the constraint is deferrable — we’ll use a non-unique index.
Non-Unique indexes have various “overheads” when compared to Unique Indexes

Will examine two key differences today:

Extra byte required per index row entry
Index requires additional consistent reads and latch gets

Reading a Non-Unique Index is more expensive in terms of consistent reads and latches.

Filed Under: Oracle, Oracle SQL性能调优 Tagged With: Oracle索引index, unique

Know about RAC Clusterware Process OPROCD

2009/06/28 by admin 1 Comment

OPROCD introduced in 10.2.0.4 Linux and other Unix platform.

Fencing
- Cluster handling of nodes that should not have access to shared resources
- STONITH – Power cycle the node
- PCW – nodes fence themselves through the reboot(8) command
- Fabric Fencing from Polyserve
  - Healthy nodes send SNMP msgs to Fabric switch to disable SAN access from unhealthy nodes [ fence them out ]
  - Server is left in up state to view logs etc.

Oracle’s Cluster I/O Fencing solution
Only started on Unix platforms when vendor Clusterware is not running
Does not run on Windows and Linux!
Takes 2 parameters
- Timeout value [ length of time between executions ]
- Margin [ leeway for dispatches ]
- Oproc.debug –t 1000 –m 500
In fatal mode node will get reboot’ed
In non-fatal mode error messages will be logged

OPROCD – This process is spawned in any non-vendor clusterware environment, except
on Windows where Oracle uses a kernel driver to perform the same actions and Linux
prior to version 10.2.0.4. If oprocd detects problems, it will kill a node via C
code. It is spawned in init.cssd and runs as root. This daemon is used to detect
hardware and driver freezes on the machine. If a machine were frozen for long enough
that the other nodes evicted it from the cluster, it needs to kill itself to prevent
any IO from getting reissued to the disk after the rest of the cluster has remastered
locks.”

*** Oprocd log locations:
In /etc/oracle/oprocd or /var/opt/oracle/oprocd depending on version/platform.

Note that oprocd only runs when no vendor clusterware is running or on Linux > 10.2.0.4

COMMON CAUSES OF OPROCD REBOOTS

– A problem detected by the OPROCD process. This can be caused by 4 things:1) An OS scheduler problem.
2) The OS is getting locked up in a driver or hardware.
3) Excessive amounts of load on the machine, thus preventing the scheduler from
behaving reasonably.
4) An Oracle bug.OPROCD Bugs Known to Cause Reboots:

Bug 5015469 – OPROCD may reboot the node whenever the system date is moved
backwards.
Fixed in 10.2.0.3+

Bug 4206159 – Oprocd is prone to time regression due to current API used (AIX only)
Fixed in 10.1.0.3 + One off patch for Bug 4206159.

Diagnostic Fixes (VERY NECESSARY IN MOST CASES):

Bug 5137401 – Oprocd logfile is cleared after a reboot
Fixed in 10.2.0.4+

Bug 5037858 – Increase the warning levels if a reboot is approaching
Fixed in 10.2.0.3+

FILES TO REVIEW AND GATHER FOR OPROCD REBOOTS

If logging a service request, please provide ALL of the following files to Oracle
Support if possible:

– Oprocd logs in /etc/oracle/oprocd or /var/opt/oracle/oprocd depending on version/platform.

– All the files in the following directories from all nodes.

For 10.2 and above, all files under:

<CRS_HOME>/log

Recommended method for gathering these for each node would be to run the
diagcollection.pl script.

For 10.1:

<CRS_HOME>/crs/log
<CRS_HOME>/crs/init
<CRS_HOME>/css/log
<CRS_HOME>/css/init
<CRS_HOME>/evm/log
<CRS_HOME>/evm/init
<CRS_HOME>/srvm/log

Recommended method for gathering these for each node:

cd <CRS_HOME>
tar cf crs.tar crs/init crs/log css/init css/log evm/init evm/log srvm/log

– Messages or Syslog from all nodes from the time of the problem:

Sun: /var/adm/messages
HP-UX: /var/adm/syslog/syslog.log
Tru64: /var/adm/messages
Linux: /var/log/messages
IBM: /bin/errpt -a > messages.out

– ‘opatch lsinventory -detail’ output for the CRS home

– It would also be useful to get the following from each node leading up to the time
of the reboot:

– netstat -is (or equivelant)
– iostat -x (or equivelant)
– vmstat (or equivelant)

There is a tool called “OS Watcher” that helps gather this information. This tool
will dump netstat, vmstat, iostat, and other output at an inverval and save x number
of hours of archived data. For more information about this tool see Note 301137.1.

The OPROCD executable sets a signal handler for the SIGALRM handler and sets the interval timer based on the to-millisec parameter provided. The alarm handler gets the current time and checks it against the time that the alarm handler was last entered. If the difference exceeds (to-millisec + margin-millisec), it will fail; the production version will cause a node reboot.

In fatal mode, OPROCD will reboot the node if it detects excessive wait. In Non Fatal mode, it will write an error message out to the file .oprocd.log in one of the following directories.

Oracle clusterware has the following three daemons which may be responsible for panicing the node. It is possible that some other external entity may have rebooted the node. In the context of this discussion, we will assume that the reboot/panic was done by an Oracle clusterware daemon.

* Oprocd – Cluster fencing module
* Cssd – Cluster sychronization module which manages node membership
* Oclsomon – Cssd monitor which will monitor for cssd hangs

OPROCD This is a daemon that only gets activated when there is no vendor clusterware present on the OS.This daemon is also not activated to run on Windows/Linux. This daemon runs a tight loop and if it is not scheduled for 1.5 seconds, will reboot the node.
CSSD This daemon pings the other members of the cluster over the private network and Voting disk. If this does not get a response for Misscount seconds and Disktimeout seconds respectively, it will reboot the node.
Oclsomon This daemon monitors the CSSD to ensure that CSSD is scheduled by the OS, if it detects any problems it will reboot the node.

A sample log looks like
May 11 18:13:15.528 | INF | monitoring started with timeout(1000), margin(500)
May 11 18:13:15.548 | INF | normal startup, setting process to fatal mode
May 12 11:43:00.899 | INF | shutting down from client request
May 12 11:43:00.899 | INF | exiting current process in NORMAL mode
May 12 12:10:43.984 | INF | monitoring started with timeout(1000), margin(500)
May 13 11:29:37.528 | INF | shutting down from client request
May 13 11:29:37.528 | INF | exiting current process in NORMAL mode

When fatal mode is disabled, OPROCD will write the following to the log file and exit:
May 10 18:01:40.668 | INF | monitoring started with timeout(1000), margin(500)
May 10 18:23:02.490 | ERR | AlarmHandler:? timeout(1739751316) exceeds interval(1000000000)+margin(500000000)

[root@rh2 ~]# ps -ef|grep oprocd|grep -v grep
root     19763     1  0 Jun27 ?        00:00:00 oprocd start

[root@rh2 oprocd]# cd /etc/oracle/oprocd

[root@rh2 oprocd]# ls -l
total 20
drwxrwx--- 2 root oinstall 4096 Jun 27 23:52 check
drwxrwx--- 2 root oinstall 4096 Mar 29 22:37 fatal
-rwxr--r-- 1 root root      512 Jun 27 23:52 rh2.oprocd.lgl
-rw-r--r-- 1 root root      171 Jun 27 23:52 rh2.oprocd.log
drwxrwx--- 2 root oinstall 4096 Jun 27 23:52 stop

[root@rh2 oprocd]# cat rh2.oprocd.log
Jun 27 23:52:47.861 | INF | monitoring started with timeout(1000), margin(500), skewTimeout(125)
Jun 27 23:52:47.864 | INF | normal startup, setting process to fatal mode

[root@rh2 oprocd]# oprocd

usage:  oprocd [start | startInstall | stop | check | enableFatal| help | -?]

        run [ -t | -m | -g | -f  | -e]   foreground startup
              -t           timeout in ms
              -m            timout margin in ms
              -e           clock skew epsilon in ms
              -g         group name to enable fatal
              -f                    fatal startup

        start  [-t | -m  | -e]           starts the daemon
                -t         timeout in ms
                -m          timout margin in ms
                 -e         clock skew epsilon in ms

        startInstall [ -t | -m | -g  | - e] start process in install mode
                       -t    timeout in ms
                       -m     timout margin in ms
                       -e    clock skew epsilon in ms
                       -g  group name to enable fatal

        enableFatal  [ -t ]             force install mode process to fatal
                       -t    timeout for response in ms
        stop         [ -t ]             stops running daemon
                       -t    timeout for response in ms
        check        [ -t ]           checks status of daemon
                       -t    timeout for response in ms
        help                          this help information
        -?                            same as help above

[root@rh2 oprocd]# oprocd stop
Jun 28 00:17:36.604 | INF | daemon shutting down

Oracle ClusterwareProcess Monitor (OPROCD) From Julian Dyke

Process Monitor Daemon
Provides Cluster I/O Fencing

Implemented on Unix systems
Not required with third-party clusterware
Implemented in Linux in 10.2.0.4 and above
In 10.2.0.3 and below hangcheck timer module is used

Provides hangcheck timer functionality to maintain cluster integrity
Behaviour similar to hangcheck timer
Runs as root
Locked in memory
Failure causes reboot of system
See /etc/init.d/init.cssd for operating system reboot commands

OPROCD takes two parameters
-t  - Timeout value
Length of time between executions (milliseconds)
Normally defaults to 1000
-m - Margin
Acceptable margin before rebooting (milliseconds)
Normally defaults to 500

Parameters are specified in /etc/init.d/init.cssd
OPROCD_DEFAULT_TIMEOUT=1000
OPROCD_DEFAULT_MARGIN=500

Contact Oracle Support before changing these values

/etc/init.d/init.cssd can increase OPROCD_DEFAULT_MARGIN based on two CSS variables
reboottime (mandatory)
diagwait (optional)
Values can for these be obtained using

[root@server3]# crsctl get css reboottime
[root@server3]# crsctl get css diagwait

Both values are reported in seconds
The algorithm is

If diagwait > reboottime then
OPROCD_DEFAULT_MARGIN := (diagwait - reboottime) * 1000

Therefore increasing diagwait will reduce frequency of reboots e.g

[root@server3]# crsctl set css diagwait 13

Filed Under: Oracle, Oracle RAC Tagged With: Clusterware, oprocd, RAC

Active Session History (ASH) performed an emergency flush

2009/06/21 by admin Leave a Comment

Active Session History (ASH) performed an emergency flush. This may mean that ASH is undersized. If emergency flushes are a recurring issue, you may consider increasing ASH size by setting the value of _ASH_SIZE to a sufficiently large value. Currently, ASH size is 4194304 bytes. Both ASH size and the total number of emergency flushes since instance startup can be monitored by running the following query:


SQL> select total_size,awr_flush_emergency_count from v$ash_info;

TOTAL_SIZE AWR_FLUSH_EMERGENCY_COUNT
---------- -------------------------
   4194304                         1

SQL> select * from v$ash_info;

TOTAL_SIZE FIXED_SIZE SAMPLING_INTERVAL OLDEST_SAMPLE_ID OLDEST_SAMPLE_TIME                                                          LATEST_SAMPLE_ID
---------- ---------- ----------------- ---------------- --------------------------------------------------------------------------- ----------------
LATEST_SAMPLE_TIME                                                          SAMPLE_COUNT SAMPLED_BYTES SAMPLER_ELAPSED_TIME DISK_FILTER_RATIO
--------------------------------------------------------------------------- ------------ ------------- -------------------- -----------------
AWR_FLUSH_BYTES AWR_FLUSH_ELAPSED_TIME AWR_FLUSH_COUNT AWR_FLUSH_EMERGENCY_COUNT
--------------- ---------------------- --------------- -------------------------
   4194304    4194304              1000          1168516 18-JUN-11 05.06.33.163000000 AM                                                      1490473
21-JUN-11 10.40.34.688000000 PM                                                     9257       3104088              2883663                10
        2764680                 557774               1                         1

This issue can be ignored.

Filed Under: Oracle, Oracle 11g新特性 Tagged With: ash, Oracle 11g新特性

RAC Deadlock For Example

2009/06/21 by admin 1 Comment

Single resource deadlock: blocking enqueue which blocks itself, f 0

Single resource deadlock: blocking enqueue which blocks itself, f 0
Granted global enqueue 0xd8578490
----------enqueue 0xd8578490------------------------
lock version     : 1
Owner inst       : 2
grant_level      : KJUSERCW
req_level        : KJUSERPW
bast_level       : KJUSERNL
notify_func      : 0x4fe4b6e
resp             : 0xd9c7ad50
procp            : 0xd9971780
pid              : 0
proc version     : 0
oprocp           : (nil)
opid             : 0
group lock owner : (nil)
xid              : 0000-0000-00000000
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     :
Convert options  : KJUSERGETVALUE
History          : 0xd7d8d7da
Msg_Seq          : 0x60005
res_seq          : 2
valblk           : 0x00000000000000000000000000000000 .
DUMP LOCAL BLOCKER/HOLDER: block level 4 res [0x1451c][0x0],[TM][ext 0x0,0x0]
----------resource 0xd9c7ad50----------------------
resname       : [0x1451c][0x0],[TM][ext 0x0,0x0]
hash mask     : x3
Local inst    : 1
dir_inst      : 1
master_inst   : 1
hv idx        : 112
hv last r.inc : 56
current inc   : 56
hv status     : 0
hv master     : 0
open options  : dd cached
grant_bits    : KJUSERCW
grant mode    : KJUSERNL  KJUSERCR  KJUSERCW  KJUSERPR  KJUSERPW  KJUSEREX
count         : 0         0         2         0         0         0
val_state     : KJUSERVS_NOVALUE
valblk        : 0x00000000000000000000000000000000 .
access_inst   : 1
vbreq_state   : 0
state         : x0
resp          : 0xd9c7ad50
On Scan_q?    : N
Total accesses: 150
Imm.  accesses: 143
Granted_locks : 1
Cvting_locks  : 1
value_block:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
GRANTED_Q :
lp 0xd876ab70 gl KJUSERCW rp 0xd9c7ad50 [0x1451c][0x0],[TM][ext 0x0,0x0]
  master 1 gl owner 0xda7233c0 possible pid 1993 xid 2B000-0001-000000B5 bast 0 rseq 1 mseq 0 history 0x49a51495
  open opt KJUSERDEADLOCK
CONVERT_Q:
lp 0xd8578490 gl KJUSERCW rl KJUSERPW rp 0xd9c7ad50 [0x1451c][0x0],[TM][ext 0x0,0x0]
  master 1 owner 2  bast 1 rseq 2 mseq 0x60005 history 0xd7d8d7da
  convert opt KJUSERGETVALUE
----------enqueue 0xd876ab70------------------------
lock version     : 2071
Owner inst       : 1
grant_level      : KJUSERCW
req_level        : KJUSERPW
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9c7ad50
procp            : 0xd9979b08
pid              : 1993
proc version     : 81
oprocp           : (nil)
opid             : 1993
group lock owner : 0xda7233c0
possible pid     : 1993
xid              : 2B000-0001-000000B5
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : CONVERTING
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERGETVALUE
History          : 0x49a51495
Msg_Seq          : 0x0
res_seq          : 1
valblk           : 0x00000000000000000000000000000000 .
user session for deadlock lock 0xd876ab70
  sid: 416 ser: 217 audsid: 2301258 user: 95/SPOT
    flags: (0x10041) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40008) -/-
  pid: 43 O/S info: user: oracle, term: UNKNOWN, ospid: 1993
    image: oracle@rh2.oracle.com (J000)
  client details:
    O/S info: user: oracle, term: UNKNOWN, ospid: 1993
    machine: rh2.oracle.com program: oracle@rh2.oracle.com (J000)
    application name: DBMS_SCHEDULER, hash value=2478762354
    action name: QUEST_PPCM_JOB_PM_1, hash value=3637730750
  current SQL:
  DELETE FROM QUEST_PPCM_SNAPSHOT WHERE SNAPSHOT_TYPE = :B2 AND INSTANCE_ID > 0
  AND SNAPSHOT_TIMESTAMP < TRUNC (SYSDATE) - :B1  

----------enqueue 0xd8578490------------------------
lock version     : 1
Owner inst       : 2
grant_level      : KJUSERCW
req_level        : KJUSERPW
bast_level       : KJUSERNL
notify_func      : 0x4fe4b6e
resp             : 0xd9c7ad50
procp            : 0xd9971780
pid              : 0
proc version     : 0
oprocp           : (nil)
opid             : 0
group lock owner : (nil)
xid              : 0000-0000-00000000
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     :
Convert options  : KJUSERGETVALUE
History          : 0xd7d8d7da
Msg_Seq          : 0x60005
res_seq          : 2
valblk           : 0x03000000000000000100000000000000 . 

Requesting global enqueue 0xd876ab70 

----------enqueue 0xd876ab70------------------------
lock version     : 2071
Owner inst       : 1
grant_level      : KJUSERCW
req_level        : KJUSERPW
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9c7ad50
procp            : 0xd9979b08
pid              : 1993
proc version     : 81
oprocp           : (nil)
opid             : 1993
group lock owner : 0xda7233c0
possible pid     : 1993
xid              : 2B000-0001-000000B5
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : CONVERTING
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERGETVALUE
History          : 0x49a51495
Msg_Seq          : 0x0
res_seq          : 1
valblk           : 0x00000000000000000000000000000000 . u
ser session for deadlock lock 0xd876ab70
sid: 416 ser: 217 audsid: 2301258 user: 95/SPOT
flags: (0x10041) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
flags2: (0x40008) -/-
pid: 43 O/S info: user: oracle, term: UNKNOWN, ospid: 1993
image: oracle@rh2.oracle.com (J000)
client details:     O/S info: user: oracle, term: UNKNOWN, ospid: 1993
machine: rh2.oracle.com program: oracle@rh2.oracle.com (J000)
application name: DBMS_SCHEDULER, hash value=2478762354
action name: QUEST_PPCM_JOB_PM_1, hash value=3637730750
current SQL:
DELETE FROM QUEST_PPCM_SNAPSHOT WHERE SNAPSHOT_TYPE = :B2 AND INSTANCE_ID > 0 AND SNAPSHOT_TIMESTAMP < TRUNC (SYSDATE) - :B1
----------resource 0xd9c7ad50----------------------
resname       : [0x1451c][0x0],[TM][ext 0x0,0x0]
hash mask     : x3
Local inst    : 1
dir_inst      : 1
master_inst   : 1
hv idx        : 112
hv last r.inc : 56
current inc   : 56
hv status     : 0
hv master     : 0
open options  : dd cached
grant_bits    : KJUSERCW
grant mode    : KJUSERNL  KJUSERCR  KJUSERCW  KJUSERPR  KJUSERPW  KJUSEREX
count         : 0         0         2         0         0         0
val_state     : KJUSERVS_NOVALUE
valblk        : 0x00000000000000000000000000000000 .
access_inst   : 1
vbreq_state   : 0
state         : x0
resp          : 0xd9c7ad50
On Scan_q?    : N
Total accesses: 150
Imm.  accesses: 143
Granted_locks : 1
Cvting_locks  : 1
value_block:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
GRANTED_Q :
lp 0xd876ab70 gl KJUSERCW rp 0xd9c7ad50 [0x1451c][0x0],[TM][ext 0x0,0x0]
  master 1 gl owner 0xda7233c0 possible pid 1993 xid 2B000-0001-000000B5 bast 0 rseq 1 mseq 0 history 0x49a51495
  open opt KJUSERDEADLOCK
CONVERT_Q:
lp 0xd8578490 gl KJUSERCW rl KJUSERPW rp 0xd9c7ad50 [0x1451c][0x0],[TM][ext 0x0,0x0]
  master 1 owner 2  bast 1 rseq 2 mseq 0x60005 history 0xd7d8d7da
  convert opt KJUSERGETVALUE
-------------------------------------------------------------------------------
Trace Bucket Dump Begin: default bucket for process 43 (osid: 1993, J000)
TIME(*=approx):SEQ:COMPONENT:FILE@LINE:FUNCTION:SECT/DUMP: [EVENT#:PID:SID] DATA

TM DEADLOCK IN RAC:

* End DRM for pkey remastering request(s) (locally requested)
ENQUEUE DUMP REQUEST: from 2 spnum 12 on [0x1475a][0x0],[TM][ext 0x0,0x0] for reason 3 mtype 0

*** 2011-06-21 21:57:42.212
DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0x1475a][0x0],[TM][ext 0x0,0x0]
----------resource 0xd9e62b48----------------------
resname       : [0x1475a][0x0],[TM][ext 0x0,0x0]
hash mask     : x3
Local inst    : 1
dir_inst      : 1
master_inst   : 1
hv idx        : 46
hv last r.inc : 56
current inc   : 56
hv status     : 0
hv master     : 0
open options  : dd cached
grant_bits    : KJUSERNL KJUSEREX
grant mode    : KJUSERNL  KJUSERCR  KJUSERCW  KJUSERPR  KJUSERPW  KJUSEREX
count         : 1         0         0         0         0         1
val_state     : KJUSERVS_NOVALUE
valblk        : 0x00000000000000000000000000000000 .
access_inst   : 1
vbreq_state   : 0
state         : x0
resp          : 0xd9e62b48
On Scan_q?    : N
Total accesses: 30
Imm.  accesses: 25
Granted_locks : 1
Cvting_locks  : 1
value_block:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
GRANTED_Q :
lp 0xd87530a8 gl KJUSEREX rp 0xd9e62b48 [0x1475a][0x0],[TM][ext 0x0,0x0]
  master 1 gl owner 0xda7233c0 possible pid 26255 xid 2B000-0001-00000576 bast 0 rseq 3 mseq 0 history 0x9a514495
  open opt KJUSERDEADLOCK
CONVERT_Q:
lp 0xd85b60e0 gl KJUSERNL rl KJUSEREX rp 0xd9e62b48 [0x1475a][0x0],[TM][ext 0x0,0x0]
  master 1 owner 2  bast 0 rseq 12 mseq 0x1 history 0x97ad
  convert opt KJUSERGETVALUE
----------enqueue 0xd87530a8------------------------
lock version     : 10199
Owner inst       : 1
grant_level      : KJUSEREX
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9e62b48
procp            : 0xd99750b0
pid              : 26255
proc version     : 229
oprocp           : (nil)
opid             : 26255
group lock owner : 0xda7233c0
possible pid     : 26255
xid              : 2B000-0001-00000576
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERGETVALUE
History          : 0x9a514495
Msg_Seq          : 0x0
res_seq          : 3
valblk           : 0x00000000000000000000000000000000 .
user session for deadlock lock 0xd87530a8
  sid: 416 ser: 1053 audsid: 4294967295 user: 0/SYS
    flags: (0x41) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40008) -/-
  pid: 43 O/S info: user: oracle, term: UNKNOWN, ospid: 26255
    image: oracle@rh2.oracle.com (TNS V1-V3)
  client details:
    O/S info: user: oracle, term: pts/3, ospid: 26254
    machine: rh2.oracle.com program: sqlplus@rh2.oracle.com (TNS V1-V3)
    application name: sqlplus@rh2.oracle.com (TNS V1-V3), hash value=3660119738
  current SQL:
  lock table lock2 in exclusive mode
DUMP LOCAL BLOCKER: initiate state dump for DEADLOCK
  possible owner[43.26255] on resource TM-0001475A-00000000

*** 2011-06-21 21:57:42.215
Submitting asynchronized dump request [28]. summary=[ges process stack dump (kjdglblkrdm1)].
----------enqueue 0xd85b60e0------------------------
lock version     : 1
Owner inst       : 2
grant_level      : KJUSERNL
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9e62b48
procp            : 0xd9971780
pid              : 0
proc version     : 0
oprocp           : (nil)
opid             : 0
group lock owner : (nil)
xid              : 0000-0000-00000000
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     :  KJUSERNO_XID
Convert options  : KJUSERGETVALUE
History          : 0x97ad
Msg_Seq          : 0x1
res_seq          : 12
valblk           : 0xe0720660ff7f000020700660ff7f0000 .r` p`
Global blockers dump start:---------------------------------
DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0x1485a][0x0],[TM][ext 0x0,0x0]
----------resource 0xd9c5a7c8----------------------
resname       : [0x1485a][0x0],[TM][ext 0x0,0x0]
hash mask     : x3
Local inst    : 1
dir_inst      : 1
master_inst   : 1
hv idx        : 46
hv last r.inc : 56
current inc   : 56
hv status     : 0
hv master     : 0
open options  : dd cached
grant_bits    : KJUSERNL KJUSEREX
grant mode    : KJUSERNL  KJUSERCR  KJUSERCW  KJUSERPR  KJUSERPW  KJUSEREX
count         : 1         0         0         0         0         1
val_state     : KJUSERVS_NOVALUE
valblk        : 0x000000000a0000000a00000001000000 .
access_inst   : 2
vbreq_state   : 0
state         : x0
resp          : 0xd9c5a7c8
On Scan_q?    : N
Total accesses: 29
Imm.  accesses: 20
Granted_locks : 1
Cvting_locks  : 1
value_block:  00 00 00 00 0a 00 00 00 0a 00 00 00 01 00 00 00
GRANTED_Q :
lp 0xd85b5f20 gl KJUSEREX rp 0xd9c5a7c8 [0x1485a][0x0],[TM][ext 0x0,0x0]
  master 1 owner 2  bast 0 rseq 15 mseq 0x2 history 0x977d8d
  open opt  KJUSERNO_XID
CONVERT_Q:
lp 0xd8757ff8 gl KJUSERNL rl KJUSEREX rp 0xd9c5a7c8 [0x1485a][0x0],[TM][ext 0x0,0x0]
  master 1 gl owner 0xda7233c0 possible pid 26255 xid 2B000-0001-00000576 bast 0 rseq 2 mseq 0 history 0xda51449a
  convert opt KJUSERGETVALUE
----------enqueue 0xd85b5f20------------------------
lock version     : 1
Owner inst       : 2
grant_level      : KJUSEREX
req_level        : KJUSEREX
bast_level       : KJUSEREX
notify_func      : (nil)
resp             : 0xd9c5a7c8
procp            : 0xd9971780
pid              : 0
proc version     : 0
oprocp           : (nil)
opid             : 0
group lock owner : (nil)
xid              : 0000-0000-00000000
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     :  KJUSERNO_XID
Convert options  : KJUSERGETVALUE
History          : 0x977d8d
Msg_Seq          : 0x2
res_seq          : 15
valblk           : 0x00000000000000000000000000000000 .
----------enqueue 0xd8757ff8------------------------
lock version     : 10261
Owner inst       : 1
grant_level      : KJUSERNL
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9c5a7c8
procp            : 0xd99750b0
pid              : 26255
proc version     : 229
oprocp           : (nil)
opid             : 26255
group lock owner : 0xda7233c0
possible pid     : 26255
xid              : 2B000-0001-00000576
dd_time          : 10.0 secs
dd_count         : 1
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : Y
lock_state       : OPENING CONVERTING
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERGETVALUE
History          : 0xda51449a
Msg_Seq          : 0x0
res_seq          : 2
valblk           : 0x00000000000000000000000000000000 .
user session for deadlock lock 0xd8757ff8
  sid: 416 ser: 1053 audsid: 4294967295 user: 0/SYS
    flags: (0x41) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40008) -/-
  pid: 43 O/S info: user: oracle, term: UNKNOWN, ospid: 26255
    image: oracle@rh2.oracle.com (TNS V1-V3)
  client details:
    O/S info: user: oracle, term: pts/3, ospid: 26254
    machine: rh2.oracle.com program: sqlplus@rh2.oracle.com (TNS V1-V3)
    application name: sqlplus@rh2.oracle.com (TNS V1-V3), hash value=3660119738
  current SQL:
  lock table lock2 in exclusive mode
DUMP LOCAL BLOCKER: initiate state dump for DEADLOCK
  possible owner[43.26255] on resource TM-0001485A-00000000

*** 2011-06-21 21:57:42.219
Submitting asynchronized dump request [28]. summary=[ges process stack dump (kjdglblkrdm1)].
DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0x1475a][0x0],[TM][ext 0x0,0x0]
----------resource 0xd9e62b48----------------------
resname       : [0x1475a][0x0],[TM][ext 0x0,0x0]
hash mask     : x3
Local inst    : 1
dir_inst      : 1
master_inst   : 1
hv idx        : 46
hv last r.inc : 56
current inc   : 56
hv status     : 0
hv master     : 0
open options  : dd cached
grant_bits    : KJUSERNL KJUSEREX
grant mode    : KJUSERNL  KJUSERCR  KJUSERCW  KJUSERPR  KJUSERPW  KJUSEREX
count         : 1         0         0         0         0         1
val_state     : KJUSERVS_NOVALUE
valblk        : 0x7c5b5c0900000000806a0660ff7f0000 |[\j`
access_inst   : 1
vbreq_state   : 0
state         : x0
resp          : 0xd9e62b48
On Scan_q?    : N
Total accesses: 32
Imm.  accesses: 26
Granted_locks : 1
Cvting_locks  : 1
value_block:  7c 5b 5c 09 00 00 00 00 80 6a 06 60 ff 7f 00 00
GRANTED_Q :
lp 0xd87530a8 gl KJUSEREX rp 0xd9e62b48 [0x1475a][0x0],[TM][ext 0x0,0x0]
  master 1 gl owner 0xda7233c0 possible pid 26255 xid 2B000-0001-00000576 bast 0 rseq 3 mseq 0 history 0x9a514495
  open opt KJUSERDEADLOCK
CONVERT_Q:
lp 0xd85b60e0 gl KJUSERNL rl KJUSEREX rp 0xd9e62b48 [0x1475a][0x0],[TM][ext 0x0,0x0]
  master 1 owner 2  bast 0 rseq 12 mseq 0x1 history 0x97ad
  convert opt KJUSERGETVALUE
----------enqueue 0xd87530a8------------------------
lock version     : 10199
Owner inst       : 1
grant_level      : KJUSEREX
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9e62b48
procp            : 0xd99750b0
pid              : 26255
proc version     : 229
oprocp           : (nil)
opid             : 26255
group lock owner : 0xda7233c0
possible pid     : 26255
xid              : 2B000-0001-00000576
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERGETVALUE
History          : 0x9a514495
Msg_Seq          : 0x0
res_seq          : 3
valblk           : 0x00000000ff7f000031000502ff7f0000 .1
user session for deadlock lock 0xd87530a8
  sid: 416 ser: 1053 audsid: 4294967295 user: 0/SYS
    flags: (0x41) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40008) -/-
  pid: 43 O/S info: user: oracle, term: UNKNOWN, ospid: 26255
    image: oracle@rh2.oracle.com (TNS V1-V3)
  client details:
    O/S info: user: oracle, term: pts/3, ospid: 26254
    machine: rh2.oracle.com program: sqlplus@rh2.oracle.com (TNS V1-V3)
    application name: sqlplus@rh2.oracle.com (TNS V1-V3), hash value=3660119738
  current SQL:
  lock table lock2 in exclusive mode
DUMP LOCAL BLOCKER: initiate state dump for DEADLOCK
  possible owner[43.26255] on resource TM-0001475A-00000000

*** 2011-06-21 21:57:42.220
Submitting asynchronized dump request [28]. summary=[ges process stack dump (kjdglblkrdm1)].
----------enqueue 0xd85b60e0------------------------
lock version     : 1
Owner inst       : 2
grant_level      : KJUSERNL
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9e62b48
procp            : 0xd9971780
pid              : 0
proc version     : 0
oprocp           : (nil)
opid             : 0
group lock owner : (nil)
xid              : 0000-0000-00000000
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     :  KJUSERNO_XID
Convert options  : KJUSERGETVALUE
History          : 0x97ad
Msg_Seq          : 0x1
res_seq          : 12
valblk           : 0x406f0660ff7f0000806c0660ff7f0000 @o`l`
Global blockers dump end:-----------------------------------
Global Wait-For-Graph(WFG) at ddTS[0.1] :
BLOCKED 0xd8757ff8 5 wq 2 cvtops x1 TM 0x1485a.0x0(ext 0x0,0x0)[2B000-0001-00000576] inst 1
BLOCKER 0xd87520d0 5 wq 1 cvtops x1 TM 0x1485a.0x0(ext 0x0,0x0)[22000-0002-000010C6] inst 2
BLOCKED 0xd8766338 5 wq 2 cvtops x1 TM 0x1475a.0x0(ext 0x0,0x0)[22000-0002-000010C6] inst 2
BLOCKER 0xd87530a8 5 wq 1 cvtops x1 TM 0x1475a.0x0(ext 0x0,0x0)[2B000-0001-00000576] inst 1

TX DEADLOCK in RAC:

ENQUEUE DUMP REQUEST: from 2 spnum 12 on [0x10001][0x7b3],[TX][ext 0x2,0x0] for reason 3 mtype 0
DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0x10001][0x7b3],[TX][ext 0x2,0x0]
----------resource 0xd9c5a6a0----------------------
resname       : [0x10001][0x7b3],[TX][ext 0x2,0x0]
hash mask     : x3
Local inst    : 1
dir_inst      : 1
master_inst   : 1
hv idx        : 8
hv last r.inc : 56
current inc   : 56
hv status     : 0
hv master     : 0
open options  : dd
grant_bits    : KJUSERNL KJUSEREX
grant mode    : KJUSERNL  KJUSERCR  KJUSERCW  KJUSERPR  KJUSERPW  KJUSEREX
count         : 1         0         0         0         0         1
val_state     : KJUSERVS_NOVALUE
valblk        : 0x00000000000000000000000000000000 .
access_inst   : 1
vbreq_state   : 0
state         : x0
resp          : 0xd9c5a6a0
On Scan_q?    : N
Total accesses: 54
Imm.  accesses: 44
Granted_locks : 1
Cvting_locks  : 1
value_block:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
GRANTED_Q :
lp 0xd85b62a0 gl KJUSEREX rp 0xd9c5a6a0 [0x10001][0x7b3],[TX][ext 0x2,0x0]
  master 1 gl owner 0xda7233c0 possible pid 26287 xid 2B000-0001-00000578 bast 0 rseq 8 mseq 0 history 0x95
  open opt KJUSERDEADLOCK
CONVERT_Q:
lp 0xd85b6460 gl KJUSERNL rl KJUSEREX rp 0xd9c5a6a0 [0x10001][0x7b3],[TX][ext 0x2,0x0]
  master 1 owner 2  bast 0 rseq 22 mseq 0x1 history 0x97ad
  convert opt KJUSERGETVALUE
----------enqueue 0xd85b62a0------------------------
lock version     : 1
Owner inst       : 1
grant_level      : KJUSEREX
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9c5a6a0
procp            : 0xd996b090
pid              : 22148
proc version     : 0
oprocp           : (nil)
opid             : 22148
group lock owner : 0xda7233c0
possible pid     : 26287
xid              : 2B000-0001-00000578
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERNOQUEUE KJUSERNODEADLOCKWAIT
History          : 0x95
Msg_Seq          : 0x0
res_seq          : 8
valblk           : 0x00000000000000000000000000000000 .
user session for deadlock lock 0xd85b62a0
  sid: 416 ser: 1055 audsid: 4294967295 user: 0/SYS
    flags: (0x41) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40008) -/-
  pid: 43 O/S info: user: oracle, term: UNKNOWN, ospid: 26287
    image: oracle@rh2.oracle.com (TNS V1-V3)
  client details:
    O/S info: user: oracle, term: pts/3, ospid: 26286
    machine: rh2.oracle.com program: sqlplus@rh2.oracle.com (TNS V1-V3)
    application name: sqlplus@rh2.oracle.com (TNS V1-V3), hash value=3660119738
  current SQL:
  update lock1 set t1=t1+10 where t1=2
DUMP LOCAL BLOCKER: initiate state dump for DEADLOCK
  possible owner[43.26287] on resource TX-00010001-000007B3

*** 2011-06-21 22:08:18.048
Submitting asynchronized dump request [28]. summary=[ges process stack dump (kjdglblkrdm1)].
----------enqueue 0xd85b6460------------------------
lock version     : 1
Owner inst       : 2
grant_level      : KJUSERNL
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9c5a6a0
procp            : 0xd9971780
pid              : 0
proc version     : 0
oprocp           : (nil)
opid             : 0
group lock owner : (nil)
xid              : 0000-0000-00000000
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     :  KJUSERNO_XID
Convert options  : KJUSERGETVALUE
History          : 0x97ad
Msg_Seq          : 0x1
res_seq          : 22
valblk           : 0xe0720660ff7f000020700660ff7f0000 .r` p`
Global blockers dump start:---------------------------------
DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0xb0000][0xc8],[TX][ext 0x5,0x0]
----------resource 0xd9e626a8----------------------
resname       : [0xb0000][0xc8],[TX][ext 0x5,0x0]
hash mask     : x3
Local inst    : 1
dir_inst      : 2
master_inst   : 2
hv idx        : 28
hv last r.inc : 56
current inc   : 56
hv status     : 0
hv master     : 0
open options  : dd
Held mode     : KJUSERNL
Cvt mode      : KJUSEREX
Next Cvt mode : KJUSERNL
msg_seq       : 0x1
res_seq       : 2
grant_bits    : KJUSERNL
grant mode    : KJUSERNL  KJUSERCR  KJUSERCW  KJUSERPR  KJUSERPW  KJUSEREX
count         : 1         0         0         0         0         0
val_state     : KJUSERVS_NOVALUE
valblk        : 0x000000000a0000000a00000001000000 .
access_inst   : 2
vbreq_state   : 0
state         : x8
resp          : 0xd9e626a8
On Scan_q?    : N
Total accesses: 24
Imm.  accesses: 15
Granted_locks : 0
Cvting_locks  : 1
value_block:  00 00 00 00 0a 00 00 00 0a 00 00 00 01 00 00 00
GRANTED_Q :
CONVERT_Q:
lp 0xd8757ff8 gl KJUSERNL rl KJUSEREX rp 0xd9e626a8 [0xb0000][0xc8],[TX][ext 0x5,0x0]
  master 2 gl owner 0xda7233c0 possible pid 26287 xid 2B000-0001-00000578 bast 0 rseq 2 mseq 0 history 0x495149da
  convert opt KJUSERGETVALUE
----------enqueue 0xd8757ff8------------------------
lock version     : 11019
Owner inst       : 1
grant_level      : KJUSERNL
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9e626a8
procp            : 0xd99750b0
pid              : 26287
proc version     : 230
oprocp           : (nil)
opid             : 26287
group lock owner : 0xda7233c0
possible pid     : 26287
xid              : 2B000-0001-00000578
dd_time          : 10.0 secs
dd_count         : 1
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : Y
lock_state       : OPENING CONVERTING
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERGETVALUE
History          : 0x495149da
Msg_Seq          : 0x0
res_seq          : 2
valblk           : 0x00000000000000000000000000000000 .
user session for deadlock lock 0xd8757ff8
  sid: 416 ser: 1055 audsid: 4294967295 user: 0/SYS
    flags: (0x41) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40008) -/-
  pid: 43 O/S info: user: oracle, term: UNKNOWN, ospid: 26287
    image: oracle@rh2.oracle.com (TNS V1-V3)
  client details:
    O/S info: user: oracle, term: pts/3, ospid: 26286
    machine: rh2.oracle.com program: sqlplus@rh2.oracle.com (TNS V1-V3)
    application name: sqlplus@rh2.oracle.com (TNS V1-V3), hash value=3660119738
  current SQL:
  update lock1 set t1=t1+10 where t1=2
DUMP LOCAL BLOCKER: initiate state dump for DEADLOCK
  possible owner[43.26287] on resource TX-000B0000-000000C8

*** 2011-06-21 22:08:18.051
Submitting asynchronized dump request [28]. summary=[ges process stack dump (kjdglblkrdm1)].
DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0x10001][0x7b3],[TX][ext 0x2,0x0]
----------resource 0xd9c5a6a0----------------------
resname       : [0x10001][0x7b3],[TX][ext 0x2,0x0]
hash mask     : x3
Local inst    : 1
dir_inst      : 1
master_inst   : 1
hv idx        : 8
hv last r.inc : 56
current inc   : 56
hv status     : 0
hv master     : 0
open options  : dd
grant_bits    : KJUSERNL KJUSEREX
grant mode    : KJUSERNL  KJUSERCR  KJUSERCW  KJUSERPR  KJUSERPW  KJUSEREX
count         : 1         0         0         0         0         1
val_state     : KJUSERVS_NOVALUE
valblk        : 0x7c5b5c0900000000806a0660ff7f0000 |[\j`
access_inst   : 1
vbreq_state   : 0
state         : x0
resp          : 0xd9c5a6a0
On Scan_q?    : N
Total accesses: 56
Imm.  accesses: 45
Granted_locks : 1
Cvting_locks  : 1
value_block:  7c 5b 5c 09 00 00 00 00 80 6a 06 60 ff 7f 00 00
GRANTED_Q :
lp 0xd85b62a0 gl KJUSEREX rp 0xd9c5a6a0 [0x10001][0x7b3],[TX][ext 0x2,0x0]
  master 1 gl owner 0xda7233c0 possible pid 26287 xid 2B000-0001-00000578 bast 0 rseq 8 mseq 0 history 0x95
  open opt KJUSERDEADLOCK
CONVERT_Q:
lp 0xd85b6460 gl KJUSERNL rl KJUSEREX rp 0xd9c5a6a0 [0x10001][0x7b3],[TX][ext 0x2,0x0]
  master 1 owner 2  bast 0 rseq 22 mseq 0x1 history 0x97ad
  convert opt KJUSERGETVALUE
----------enqueue 0xd85b62a0------------------------
lock version     : 1
Owner inst       : 1
grant_level      : KJUSEREX
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9c5a6a0
procp            : 0xd996b090
pid              : 22148
proc version     : 0
oprocp           : (nil)
opid             : 22148
group lock owner : 0xda7233c0
possible pid     : 26287
xid              : 2B000-0001-00000578
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERNOQUEUE KJUSERNODEADLOCKWAIT
History          : 0x95
Msg_Seq          : 0x0
res_seq          : 8
valblk           : 0x00000000ff7f000031000502ff7f0000 .1
user session for deadlock lock 0xd85b62a0
  sid: 416 ser: 1055 audsid: 4294967295 user: 0/SYS
    flags: (0x41) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40008) -/-
  pid: 43 O/S info: user: oracle, term: UNKNOWN, ospid: 26287
    image: oracle@rh2.oracle.com (TNS V1-V3)
  client details:
    O/S info: user: oracle, term: pts/3, ospid: 26286
    machine: rh2.oracle.com program: sqlplus@rh2.oracle.com (TNS V1-V3)
    application name: sqlplus@rh2.oracle.com (TNS V1-V3), hash value=3660119738
  current SQL:
  update lock1 set t1=t1+10 where t1=2
DUMP LOCAL BLOCKER: initiate state dump for DEADLOCK
  possible owner[43.26287] on resource TX-00010001-000007B3

*** 2011-06-21 22:08:18.053
Submitting asynchronized dump request [28]. summary=[ges process stack dump (kjdglblkrdm1)].
----------enqueue 0xd85b6460------------------------
lock version     : 1
Owner inst       : 2
grant_level      : KJUSERNL
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9c5a6a0
procp            : 0xd9971780
pid              : 0
proc version     : 0
oprocp           : (nil)
opid             : 0
group lock owner : (nil)
xid              : 0000-0000-00000000
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     :  KJUSERNO_XID
Convert options  : KJUSERGETVALUE
History          : 0x97ad
Msg_Seq          : 0x1
res_seq          : 22
valblk           : 0x406f0660ff7f0000806c0660ff7f0000 @o`l`
Global blockers dump end:-----------------------------------
Global Wait-For-Graph(WFG) at ddTS[0.6] :
BLOCKED 0xd8757ff8 5 wq 2 cvtops x1 TX 0xb0000.0xc8(ext 0x5,0x0)[2B000-0001-00000578] inst 1
BLOCKER 0xd8561ee0 5 wq 1 cvtops x28 TX 0xb0000.0xc8(ext 0x5,0x0)[22000-0002-000010C6] inst 2
BLOCKED 0xd8766338 5 wq 2 cvtops x1 TX 0x10001.0x7b3(ext 0x2,0x0)[22000-0002-000010C6] inst 2
BLOCKER 0xd85b62a0 5 wq 1 cvtops x28 TX 0x10001.0x7b3(ext 0x2,0x0)[2B000-0001-00000578] inst 1 

*** 2011-06-21 22:08:19.059
* Cancel deadlock victim lockp 0xd8757ff8

TX DEADLOCK LOCAL only:

*** 2011-06-21 22:27:00.022
DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0x70015][0x81e],[TX][ext 0x2,0x0]
----------resource 0xd9e62330----------------------
resname       : [0x70015][0x81e],[TX][ext 0x2,0x0]
hash mask     : x3
Local inst    : 1
dir_inst      : 1
master_inst   : 1
hv idx        : 7
hv last r.inc : 42
current inc   : 56
hv status     : 0
hv master     : 1
open options  : dd
grant_bits    : KJUSERNL KJUSEREX
grant mode    : KJUSERNL  KJUSERCR  KJUSERCW  KJUSERPR  KJUSERPW  KJUSEREX
count         : 1         0         0         0         0         1
val_state     : KJUSERVS_NOVALUE
valblk        : 0x506b0660ff7f00006d6cf50400000000 Pk`ml
access_inst   : 1
vbreq_state   : 0
state         : x0
resp          : 0xd9e62330
On Scan_q?    : N
Total accesses: 23
Imm.  accesses: 15
Granted_locks : 1
Cvting_locks  : 1
value_block:  50 6b 06 60 ff 7f 00 00 6d 6c f5 04 00 00 00 00
GRANTED_Q :
lp 0xd8767a10 gl KJUSEREX rp 0xd9e62330 [0x70015][0x81e],[TX][ext 0x2,0x0]
  master 1 gl owner 0xda2cff40 possible pid 26847 xid 2E000-0001-00000347 bast 0 rseq 1 mseq 0 history 0x14951495
  open opt KJUSERDEADLOCK
CONVERT_Q:
lp 0xd876a630 gl KJUSERNL rl KJUSEREX rp 0xd9e62330 [0x70015][0x81e],[TX][ext 0x2,0x0]
  master 1 gl owner 0xda7233c0 possible pid 26843 xid 2B000-0001-0000057A bast 0 rseq 1 mseq 0 history 0x1495149a
  convert opt KJUSERGETVALUE
----------enqueue 0xd8767a10------------------------
lock version     : 8523
Owner inst       : 1
grant_level      : KJUSEREX
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9e62330
procp            : 0xd99750b0
pid              : 26843
proc version     : 231
oprocp           : (nil)
opid             : 26843
group lock owner : 0xda2cff40
possible pid     : 26847
xid              : 2E000-0001-00000347
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERNOQUEUE KJUSERNODEADLOCKWAIT
History          : 0x14951495
Msg_Seq          : 0x0
res_seq          : 1
valblk           : 0x00000000000000000000000000000000 .
user session for deadlock lock 0xd8767a10
  sid: 16 ser: 851 audsid: 4294967295 user: 0/SYS
    flags: (0x41) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40008) -/-
  pid: 46 O/S info: user: oracle, term: UNKNOWN, ospid: 26847
    image: oracle@rh2.oracle.com (TNS V1-V3)
  client details:
    O/S info: user: oracle, term: pts/3, ospid: 26846
    machine: rh2.oracle.com program: sqlplus@rh2.oracle.com (TNS V1-V3)
    application name: sqlplus@rh2.oracle.com (TNS V1-V3), hash value=3660119738
  current SQL:
   update lock1 set t1=t1+10 where t1=11
DUMP LOCAL BLOCKER: initiate state dump for DEADLOCK
  possible owner[46.26847] on resource TX-00070015-0000081E

*** 2011-06-21 22:27:00.024
Submitting asynchronized dump request [28]. summary=[ges process stack dump (kjdglblkrdm1)].
----------enqueue 0xd876a630------------------------
lock version     : 9399
Owner inst       : 1
grant_level      : KJUSERNL
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9e62330
procp            : 0xd99750b0
pid              : 26843
proc version     : 231
oprocp           : (nil)
opid             : 26843
group lock owner : 0xda7233c0
possible pid     : 26843
xid              : 2B000-0001-0000057A
dd_time          : 10.0 secs
dd_count         : 1
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : Y
lock_state       : OPENING CONVERTING
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERGETVALUE
History          : 0x1495149a
Msg_Seq          : 0x0
res_seq          : 1
valblk           : 0xa06e0660ff7f0000e06b0660ff7f0000 .n`k`
user session for deadlock lock 0xd876a630
  sid: 416 ser: 1057 audsid: 4294967295 user: 0/SYS
    flags: (0x41) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40008) -/-
  pid: 43 O/S info: user: oracle, term: UNKNOWN, ospid: 26843
    image: oracle@rh2.oracle.com (TNS V1-V3)
  client details:
    O/S info: user: oracle, term: pts/4, ospid: 26842
    machine: rh2.oracle.com program: sqlplus@rh2.oracle.com (TNS V1-V3)
    application name: sqlplus@rh2.oracle.com (TNS V1-V3), hash value=3660119738
  current SQL:
  update lock1 set t1=t1+10 where t1=12
DUMP LOCAL BLOCKER: initiate state dump for DEADLOCK
  possible owner[43.26843] on resource TX-00070015-0000081E

*** 2011-06-21 22:27:00.025
Submitting asynchronized dump request [28]. summary=[ges process stack dump (kjdglblkrdm1)].
DUMP LOCAL BLOCKER/HOLDER: block level 5 res [0x40008][0x7d9],[TX][ext 0x2,0x0]
----------resource 0xd9e62208----------------------
resname       : [0x40008][0x7d9],[TX][ext 0x2,0x0]
hash mask     : x3
Local inst    : 1
dir_inst      : 1
master_inst   : 1
hv idx        : 53
hv last r.inc : 42
current inc   : 56
hv status     : 0
hv master     : 1
open options  : dd
grant_bits    : KJUSERNL KJUSEREX
grant mode    : KJUSERNL  KJUSERCR  KJUSERCW  KJUSERPR  KJUSERPW  KJUSEREX
count         : 1         0         0         0         0         1
val_state     : KJUSERVS_NOVALUE
valblk        : 0x7c5b5c0900000000e0690660ff7f0000 |[\i`
access_inst   : 1
vbreq_state   : 0
state         : x0
resp          : 0xd9e62208
On Scan_q?    : N
Total accesses: 92
Imm.  accesses: 82
Granted_locks : 1
Cvting_locks  : 1
value_block:  7c 5b 5c 09 00 00 00 00 e0 69 06 60 ff 7f 00 00
GRANTED_Q :
lp 0xd876a7f0 gl KJUSEREX rp 0xd9e62208 [0x40008][0x7d9],[TX][ext 0x2,0x0]
  master 1 gl owner 0xda7233c0 possible pid 26843 xid 2B000-0001-0000057A bast 0 rseq 6 mseq 0 history 0x14951495
  open opt KJUSERDEADLOCK
CONVERT_Q:
lp 0xd876ab70 gl KJUSERNL rl KJUSEREX rp 0xd9e62208 [0x40008][0x7d9],[TX][ext 0x2,0x0]
  master 1 gl owner 0xda2cff40 possible pid 26847 xid 2E000-0001-00000347 bast 0 rseq 6 mseq 0 history 0x1495149a
  convert opt KJUSERGETVALUE
----------enqueue 0xd876a7f0------------------------
lock version     : 6107
Owner inst       : 1
grant_level      : KJUSEREX
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9e62208
procp            : 0xd9978428
pid              : 26847
proc version     : 238
oprocp           : (nil)
opid             : 26847
group lock owner : 0xda7233c0
possible pid     : 26843
xid              : 2B000-0001-0000057A
dd_time          : 0.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : N
lock_state       : GRANTED
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERNOQUEUE KJUSERNODEADLOCKWAIT
History          : 0x14951495
Msg_Seq          : 0x0
res_seq          : 6
valblk           : 0x00000000ff7f000031000502ff7f0000 .1
user session for deadlock lock 0xd876a7f0
  sid: 416 ser: 1057 audsid: 4294967295 user: 0/SYS
    flags: (0x41) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40008) -/-
  pid: 43 O/S info: user: oracle, term: UNKNOWN, ospid: 26843
    image: oracle@rh2.oracle.com (TNS V1-V3)
  client details:
    O/S info: user: oracle, term: pts/4, ospid: 26842
    machine: rh2.oracle.com program: sqlplus@rh2.oracle.com (TNS V1-V3)
    application name: sqlplus@rh2.oracle.com (TNS V1-V3), hash value=3660119738
  current SQL:
  update lock1 set t1=t1+10 where t1=12
DUMP LOCAL BLOCKER: initiate state dump for DEADLOCK
  possible owner[43.26843] on resource TX-00040008-000007D9

*** 2011-06-21 22:27:00.029
Submitting asynchronized dump request [28]. summary=[ges process stack dump (kjdglblkrdm1)].
----------enqueue 0xd876ab70------------------------
lock version     : 3827
Owner inst       : 1
grant_level      : KJUSERNL
req_level        : KJUSEREX
bast_level       : KJUSERNL
notify_func      : (nil)
resp             : 0xd9e62208
procp            : 0xd9978428
pid              : 26847
proc version     : 238
oprocp           : (nil)
opid             : 26847
group lock owner : 0xda2cff40
possible pid     : 26847
xid              : 2E000-0001-00000347
dd_time          : 5.0 secs
dd_count         : 0
timeout          : 0.0 secs
On_timer_q?      : N
On_dd_q?         : Y
lock_state       : OPENING CONVERTING
ast_flag         : 0x0
Open Options     : KJUSERDEADLOCK
Convert options  : KJUSERGETVALUE
History          : 0x1495149a
Msg_Seq          : 0x0
res_seq          : 6
valblk           : 0xa06e0660ff7f0000e06b0660ff7f0000 .n`k`
user session for deadlock lock 0xd876ab70
  sid: 16 ser: 851 audsid: 4294967295 user: 0/SYS
    flags: (0x41) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40008) -/-
  pid: 46 O/S info: user: oracle, term: UNKNOWN, ospid: 26847
    image: oracle@rh2.oracle.com (TNS V1-V3)
  client details:
    O/S info: user: oracle, term: pts/3, ospid: 26846
    machine: rh2.oracle.com program: sqlplus@rh2.oracle.com (TNS V1-V3)
    application name: sqlplus@rh2.oracle.com (TNS V1-V3), hash value=3660119738
  current SQL:
   update lock1 set t1=t1+10 where t1=11
DUMP LOCAL BLOCKER: initiate state dump for DEADLOCK
  possible owner[46.26847] on resource TX-00040008-000007D9

*** 2011-06-21 22:27:00.031
Submitting asynchronized dump request [28]. summary=[ges process stack dump (kjdglblkrdm1)].
Global blockers dump end:-----------------------------------
Global Wait-For-Graph(WFG) at ddTS[0.db] :
BLOCKED 0xd876a630 5 wq 2 cvtops x1 TX 0x70015.0x81e(ext 0x2,0x0)[2B000-0001-0000057A] inst 1
BLOCKER 0xd8767a10 5 wq 1 cvtops x28 TX 0x70015.0x81e(ext 0x2,0x0)[2E000-0001-00000347] inst 1
BLOCKED 0xd876ab70 5 wq 2 cvtops x1 TX 0x40008.0x7d9(ext 0x2,0x0)[2E000-0001-00000347] inst 1
BLOCKER 0xd876a7f0 5 wq 1 cvtops x28 TX 0x40008.0x7d9(ext 0x2,0x0)[2B000-0001-0000057A] inst 1

Summary Of Bugs Which Could Cause Deadlock In RAC Environment

Applies to:
Oracle Server - Enterprise Edition - Version: 9.2.0.4 to 11.1
 Information in this document applies to any platform.
Purpose
The purpose of this Note is to explain various bugs filed specifically
for the Dead lock errors in a RAC environment  against specific Oracle
database versions (This Note covers bugs reported versions  above  9.2.0.4),
and explain the symptoms of each bug, workarounds if any and  references the patch
availability at the time this article was written.
Scope
This article is a consolidated effort to summarisze top bugs reported
specifically for the Dead lock  error in RAC environment 
(This Note  covers bugs reported versions above 9.2.0.4) which have been fixed.
It  is directed towards Oracle Support Analysts and Oracle Customers to have
an overview of various bugs logged for the same error .
Summary Of Bugs Which Could Cause  Deadlock In RAC Environment
Bugs Fixed in Version 9.2.0.5 

Note 2941738.8 Bug 2941738   SMON processes may deadlock in RAC
Note 2902030.8 Bug 2902030   Deadlocks in RAC not logged in alert log

Bugs Fixed in Version 9.2.0.6 10.1.0.4 10.2.0.1

Note 3268802.8 Bug 3268802 Additional diagnostics for deadlock in RAC environment
Note.3646162.8 Bug 3646162 False deadlock (ORA-60) in a RAC environment / TM lock mode change
Note.3627263.8 Bug 3627263 DEADLOCK OPS STARTUP Deadlock / hang during RAC instance startup




Bugs Fixed in Version 9.2.0.7 10.2.0.1 

Note.3992847.8 Bug 3992847 Deadlocks are not detected in rac when one node rebooted more recently than the rest
 Note 3641819.8 Bug 3641819  Undetected deadlock possible in RAC
 Note 3777178.8 Bug 3777178   TA / US enqueue deadlock during transaction recovery in RAC
 Note 4220161.8 Bug 4220161 OPS Deadlock between SMON processes on different instances


Bug Fixed in Version  9.2.0.8 10.2.0.1

Note 4371923.8 Bug 4371923 SMON may deadlock on TX enqueue waits for updates to COL_USAGE$ in RAC

Bug Fixed in  Version 10.2.0.2

 Note 4579381.8 Bug 4579381  Deadlock on DC_USERS in RAC (ORA-4020) 


Bug Fixed in Version 10.2.0.3

Note 5012368.8 Bug 5012368 Undetected deadlock in RAC 
 Note 4913415.8 Bug 4913415 Global deadlock not reported in RAC 


Bug Fixed in Version 10.2.0.4

 Note 5470095.8 Bug 5470095  Self deadlock should provide more targeted diagnostics
 Note 5454831.8 Bug 5454831  deadlock possible on working set latches
 Note 5334733.8 Bug 5334733  Deadlock resolution can be slow in RAC 
 Note 4441119.8 Bug 4441119 Not enough information dumped when RAC detects a deadlock 
 Note 5883112.8 Bug 5883112 False deadlock in RAC

Bug Fixed in Version 10.2.0.5

Note 6145177.8 Bug 6145177 Single resource deadlock with a zero DID
 For summary of bugs which could cause deadlock in single instance see Note 554616.1

Filed Under: Oracle, Oracle RAC Tagged With: block, deadlock, ENQUEUE, RAC

SCN may jump in a distributed transaction with dblink

2009/06/21 by admin 1 Comment

在分布式事务环境中数据库的SCN可能瞬间暴增，这种行为被称作SCN jump in distributed transaction，注意这种现象是正常的。在发生分布式事务的2个数据库中，SCN较低的DB会将SCN和较高的那个数据库同步，这有时候会造成我们的一些误解认为可能是Hot backup等操作引起了SCN的猛增。

我们来具体看一下这种现象:

SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
PL/SQL Release 11.2.0.1.0 - Production
CORE    11.2.0.1.0      Production
TNS for 32-bit Windows: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production

SQL> select * from global_name;

GLOBAL_NAME
--------------------------------------------------------------------------------
www.askmac.cn

SQL> select current_scn from v$database;

CURRENT_SCN
-----------
    5072553

SQL> select current_scn from v$database@PROD;

CURRENT_SCN
-----------
    7798262

SQL> insert into testlink@PROD values(1);

1 row created.

SQL> select current_scn from v$database;

CURRENT_SCN
-----------
    7798282

由于这种SCN跳跃可能引起ORA-600 [2252]内部错误，相关的bug case.

Filed Under: Oracle Tagged With: dblink, distributed transaction, system change number

Know more about redo log buffer and latches

2009/06/19 by admin Leave a Comment

1.
The Total size of the log buffer is determined by LOG_BUFFER parameter.

2.
Only Server process may pin a data block in exclusive mode.

3.
LGWR writes to the redo log files when:

The redo log buffer is 1/3 full.
1 MB of data have been written to the redo log buffer.
A 3-second time-out occurs.
commit!
before dbwr write out dirty buffers
A thread is closed

4.
the correct sequence for the LGWR algorithm is :

Acquire the redo writing and redo allocation latches
determine the buffer to write out
Release the redo allocation latch
determine how many writes are required

5.
In Oracle8i, the redo copy latch is always acquired regardless of the redo size.

Because the parameter LOG_SMALL_ENTRY_MAX_SIZE is obsolete, a redo copy latch is always acquired.

6.
Three most relevant redo events under normal operations:

Log file parallel write
Log buffer space
Log file sync

7.
relevant redo statistics and their purpose

REDO writes === Number of times the log buffer is written
redo blocks written === Number of times the log buffer is written
redo write time === Total time required to write all the redos to disk
redo buffer allocation retires === Total number of retries necessary to allocate space in the redo buffer

8.
Log buffer contention is typically indicated by Redo buffer allocation retries .

The buffer allocation retries indicates that a process has to continually try to allocate buffers that are not available

9.
Redo buffer allocation retries can be gathered by querying the name and value columns from V$ dynamic views:
V$sesstat
V$sysstat

10.
Stripe the redo log files across physical disks will help flush the redo buffer faster.

The redo log file write batch is 128K, so striping the redo logs across 8 disks with a stripe size of 16K could improve the write time by as much as 75%.

11.
The number of redo copy latches can be defined by setting _Log_simultaneous_copies .

The parameter begins with an underscore because in 8i it is a hidden parameter.

12.
The purpose of the redo writing latch is to: Prevent multiple processes from posting
LGWR when there is no space in the buffer .
The redo writing latch frees space in log buffer and does not want
processes writing to the buffer while space is being freed

13.
_log_io_size is set to reduce contention for the redo writing latch.

But notice that it is a hidden parameter. This is the number of used redo blocks that will automatically initiate a log write.

14.
A standby database must be refreshed following a nologging operation.

When nologging occurs, the redo logs of the standby database are not written to.

15.
log_small_entry_max_size is used to determine if a redo copy latch is required based upon the redo entry size,

however, this parameter is obsolete in Oracle8i, as a copy latch is always acquired.

_log_simultaneous_copies determines the number of redo copy latches to allocate.

Note that this is a hidden parameter in Oracle8i because it is not recommended to have more than one copy latch.

log_checkpoint_interval determines the need for a checkpoint.

Filed Under: Oracle, Oracle Internal Research内部原理研究 Tagged With: internal, latch, redo log buffer

如何设计分区索引

2009/06/18 by admin Leave a Comment

通过下图定义的规则，可确定分区索引类型:

Hash Global分区索引介绍
HASH-Partitioned Global索引是Oracle 10g开始提供的新特性。而在以前的版本中
，Oracle只支持Range-Partitioned Global索引。HASH-Partitioned Global索引的好处如下：
比Range-Partitioned Global索引易于实施。HASH-Partitioned Global索引是根据
索引字段值，通过Oracle内部的HASH算法自动均匀散列到定义的分区中。而
Range-Partitioned Global索引需要根据索引字段值的范围进行分区，因此实施和
维护的难度都大。
HASH-Partitioned Global索引适合于在并发量、吞吐量很大的交易系统（OLTP）
中，对某些字段的访问冲突。尤其是sequence字段值。
HASH-Partitioned Global索引适合于大批量的数据查询。HASH-Partitioned Global索引不仅可以提供分区之间的并行查询，
而且在分区内也可进行并行查询的处理。
建立分区索引必须指定表空间，并且指定的表空间要与数据表空间分开，
这样便于管理，同时尽可能分开索引和数据的IO访问，提高效率

Filed Under: Oracle Tagged With: image, index partition