Alter rollback segment command giving error.

Hi all ,
i am novice to Oracle 9i i am altering rollback segment but getting following error messages.
ORA-30021: Operation not allowed on Undo Tablespace
ORA-25150:Altering of extent parameters not permitted
(in this i am trying to alter maxextents parameter of rollback segment )

Apparently you are using undo segments, as opposed to rollback segments.
You should use undo segments, and they are located in a separate undo tablespace (see the first error message)
Oracle manages the undo tablespace. You can't do anything about it.
However, Oracle is still using 'rollback segment' and 'undo segment' interchangeably.
Likely, your rollback segment is an undo segment, and you can not change it, nor do you need to.
Sybrand Bakker
Senior Oracle DBA

Similar Messages

Alter rollback segment

I am trying to issue the statement :
ALTER ROLLBACK SEGMENT "SYSTEM" STORAGE ( MAXEXTENTS UNLIMITED);
But I get a message saying that
ORA-01681: Parameter unlimited_rollback_segments must be set TRUE for this operation
ORA-02226: invalid maxextents value (max allowed : 505)
how could i make it to unlimited

404045, why are you trying to change the system rollback segment? It should only be used by Oracle to support internal operations.
Allocate non-system rollback segments in their own tablespace (or use undo tablespace) and leave the system segment alone!
The error messages are pretty clear. You have to set an init.ora parameter to make use of the unlimited value with rollback segments. At least for the version of Oracle you are using.
HTH -- Mark D Powell --

MDM Lock command giving error MDMClientError:71 on Mavericks

I registred OSx 10.9 to my MDM server and installed MDM profiles successfully and when i send a lock command to the device it is not locking the device and i could see the below error in system.log file:
*** ERROR *** [Agent:501] ### Errors while processing: DeviceLock ###
*** ERROR *** [Agent:501] <MDMClientError:71> Command received for: <User: 503> but restricted to: <Device> <MDMClientError:71>
The same command is working fine in OSx 10.7/10.8 and iOS devices. I tried on different 10.9 systems but failing on all the devices with same error.
Not sure what went wrong, does mavericks need any configurations/settings tobe changed? Anyone faced this issue any time??
Any suggestions will be highly appreciated.

below is the correct error log :
*** ERROR *** [Agent:501] ### Errors while processing: DeviceLock ###
*** ERROR *** [Agent:501] <MDMClientError:71> Command received for: <User: 501> but restricted to: <Device> <MDMClientError:71>

ROLLBACK SEGMENT NEEDS RECOVERY AND HOW TO RESOLVE IT

제품 : ORACLE SERVER
작성날짜 : 1995-02-06
Subject :
This article discusses what it means when a rollback segment needs
recovery and how to resolve it.
OVERVIEW
This bulletin discusses why a rollback segment is the status of
"needs recovery", what the status means, and how to resolve it.
INTRODUCTION
Rollback segments can be monitored through the data dictionary view,
dba_rollback_segments. There is a status column that describes what state
the rollback segment is currently in. Normal states are either online or offline.
Occasionally, the status of "needs recovery" will appear.
This is considered to be a corrupted rollback segment.
When a rollback segment is in this state, bringing the rollback segment
offline or online either through the alter rollback segment command or
removing it from the rollback segments parameter in the init.ora usually has no effect.
UNDERSTANDING
A rollback segment falls into this status of needs recovery whenever
Oracle tries to roll back an uncommitted transaction in its transaction
table and fails.
Here are some examples of why a transaction may need to rollback:
1-A user may do a dml transaction and decides to issue rollback
2-A shutdown abort occurs and the database needs to do an instance recovery
in which case, Oracle has to roll back all uncommitted transactions.
When a rollback of a transaction occurs, undo must be applied to the
data block the modified row/s are in. If for whatever reason, that data
block is unavailable, the undo cannot be applied. The result is a
'corrupted' rollback segment with the status of needs recovery.
What could be some reasons a datablock is unaccessible for undo?
1-If a tablespace or a datafile is offline or missing.
2-If the object the datablock belongs to is corrupted.
3-If the datablock that is corrupt is actually in the rollback segment
itself rather than the object.
HOW TO RESOLVE IT
1-MAKE sure that all tablespaces are online and all datafiles are
online. This can be checked through dba_data_files under the
status column. For tablespaces, look in dba_tablespaces.
If that still does not resolve the problem then
2-PUT the following in the init.ora-
event = "10015 trace name context forever, level 10"
Setting this event will generate a trace file that will reveal the
necessary information about the transaction Oracle is trying to roll
back and mostimportantly, what object Oracle is trying to apply
the undo to.
3-TAKE the corrupted rollback segment out of the rollback_segments parameter in the init.ora
4-SHUTDOWN the database (if normal does not work, immediate, if that does
not work, abort) and bring it back up.
Note: An ora-1545 may be encountered, or other errors, that is ok.
5-CHECK in the directory that is specified by the user_dump_dest parameter
(in the init.ora or show parameter command) for a trace file that was
generated at startup time.
6-IN the trace file, there should be a message similiar to-
error recovery tx(#,#) object #.
TX(#,#) refers to transaction information.
The object # is the same as the object_id in sys.dba_objects.
7-USE the following query to find out what object Oracle is trying to
perform recovery on.
select owner, object_name, object_type, status
from dba_objects where object_id = <object #>;
8-THIS object must be dropped so the undo can be released. An export or
relying on a backup may be necessary to restore the object after the corrupted
rollback segment goes away.
9-AFTER dropping the object, put the rollback segment back in the init.ora
parameter rollback_segments, removed the event, and shutdown and startup
the database.
In most cases, the above steps will resolve the problematic rollback segment.
If this still does not resolve the problem, it may be likely that the corruption is
in the actual rollback segment.
At this point, if the problem has not been resolved, please contact
customer support.

Yes we were having the performance issues when it is getting locked? in this what i want to know
why it happens suddenly?
or what package this piece of code is calling?
or is there any possiblity of system will degrade the performance like sys user etc...?
where exactly i found the root cause for further analysis?
so that next time onwards if particular objects is locking we come to know why it happens is there any logical false or how do we eliminate this issue last time?
coz in our environment sometimes most of lockings are from the same table?
pls let me know where i have to concentrate for debug and how to troubloshoot and reslove this
sorry for the inconvience.. i m expecting the answer from here. if anybody wants some more info i ll let him know.
as of till now i got some docs i start to read this.
Regards
M.Murali..
Note: will system/sys degrade the performance ?if so how ?

Cannot use system rollback segment for non-system tablespace 'TEMP

Hi everyone!
I encountered this error: "Cannot use system rollback segment for non-system tablespace 'TEMP"
So this is what I did to check if the undo stuffs are online.
SQL> select tablespace_name,status from dba_tablespaces;
TABLESPACE_NAME                STATUS
SYSTEM                         ONLINE
UNDO                           ONLINE
SYSAUX                         ONLINE
TEMP                           ONLINE
LARGEDATA                      ONLINE
LARGEINDEXES                   ONLINE
MEDIUMDATA                     ONLINE
MEDIUMINDEXES                  ONLINE
SMALLDATA                      ONLINE
SMALLINDEXES                   ONLINE
XSMALLDATA                     ONLINE
TABLESPACE_NAME                STATUS
XSMALLINDEXES                  ONLINE
XXSMALLTABS                    ONLINE
USERS                          ONLINE
CONVTABLES                     ONLINE
UNDO_02                        ONLINE
16 rows selected.
SQL> SELECT tablespace_name, sum((bytes/1024)/1024) free FROM DBA_FREE_SPACE gr
oup by tablespace_name;
TABLESPACE_NAME                      FREE
LARGEDATA                      18.3105469
SMALLDATA                        10.46875
SYSAUX                           106.5625
UNDO_02                            67.125
XXSMALLTABS                    13.0078125
CONVTABLES                     170.039063
MEDIUMDATA                             22
USERS                           37.265625
SYSTEM                             55.875
LARGEINDEXES                   30.5175781
XSMALLINDEXES                    17.34375
TABLESPACE_NAME                      FREE
UNDO                             546.9375
MEDIUMINDEXES                       33.25
SMALLINDEXES                    31.015625
XSMALLDATA                     23.6328125
15 rows selected.
SQL> select file#,status from v$datafile;
     FILE# STATUS
         1 SYSTEM
         2 ONLINE
         3 ONLINE
         4 ONLINE
         5 ONLINE
         6 ONLINE
         7 ONLINE
         8 ONLINE
         9 ONLINE
        10 ONLINE
        11 ONLINE
     FILE# STATUS
        12 ONLINE
        13 ONLINE
        14 ONLINE
        15 ONLINE
15 rows selected.
SQL> select segment_name, tablespace_name, initial_extent,status
2 from dba_rollback_segs;
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
SYSTEM                         SYSTEM                                 102400
ONLINE
_SYSSMU1$                      UNDO                                   131072
OFFLINE
_SYSSMU2$                      UNDO                                   131072
OFFLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU3$                      UNDO                                   131072
OFFLINE
_SYSSMU4$                      UNDO                                   131072
OFFLINE
_SYSSMU5$                      UNDO                                   131072
OFFLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU6$                      UNDO                                   131072
OFFLINE
_SYSSMU7$                      UNDO                                   131072
OFFLINE
_SYSSMU8$                      UNDO                                   131072
OFFLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU9$                      UNDO                                   131072
OFFLINE
_SYSSMU10$                     UNDO                                   131072
OFFLINE
_SYSSMU11$                     UNDO_02                                131072
OFFLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU12$                     UNDO_02                                131072
OFFLINE
_SYSSMU13$                     UNDO_02                                131072
OFFLINE
_SYSSMU14$                     UNDO_02                                131072
OFFLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU15$                     UNDO_02                                131072
OFFLINE
_SYSSMU16$                     UNDO_02                                131072
OFFLINE
_SYSSMU17$                     UNDO_02                                131072
OFFLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU18$                     UNDO_02                                131072
OFFLINE
_SYSSMU19$                     UNDO_02                                131072
OFFLINE
_SYSSMU20$                     UNDO_02                                131072
OFFLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU21$                     UNDO_02                                131072
OFFLINE
22 rows selected.How should I be bringing them online?
I tried this but didn't work for me.
SQL> alter rollback segment _SYSSMU1$ online;
alter rollback segment _SYSSMU1$ online
ERROR at line 1:
ORA-00911: invalid character
SQL> alter rollback segment '_SYSSMU1$' online;
alter rollback segment '_SYSSMU1$' online
ERROR at line 1:
ORA-02245: invalid ROLLBACK SEGMENT name
SQL> alter rollback segment _SYSSMU21$ online;
alter rollback segment _SYSSMU21$ online
ERROR at line 1:
ORA-00911: invalid character
SQL> alter rollback segment SYSSMU21$ online;
alter rollback segment SYSSMU21$ online
ERROR at line 1:
ORA-01534: rollback segment 'SYSSMU21$' doesn't exist
SQL> alter rollback segment '_SYSSMU21$' online;
alter rollback segment '_SYSSMU21$' online
ERROR at line 1:
ORA-02245: invalid ROLLBACK SEGMENT name
SQL> alter rollback segment "_SYSSMU21$" online;
alter rollback segment "_SYSSMU21$" online
ERROR at line 1:
ORA-30017: segment '_SYSSMU21$' is not supported in MANUAL Undo Management mode
SQL> ALTER SYSTEM SET UNDO_MANAGEMENT=AUTO SCOPE=SPFILE;
System altered.Should I be bringing every segment online separately? Please guide me.
Nith
Edited by: user645399 on Feb 23, 2011 2:52 PM

SQL> select segment_name, tablespace_name, initial_extent,status
2 from dba_rollback_segs;
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
SYSTEM                         SYSTEM                                 102400
ONLINE
_SYSSMU1$                      UNDO                                   131072
ONLINE
_SYSSMU2$                      UNDO                                   131072
ONLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU3$                      UNDO                                   131072
ONLINE
_SYSSMU4$                      UNDO                                   131072
ONLINE
_SYSSMU5$                      UNDO                                   131072
ONLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU6$                      UNDO                                   131072
ONLINE
_SYSSMU7$                      UNDO                                   131072
ONLINE
_SYSSMU8$                      UNDO                                   131072
ONLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU9$                      UNDO                                   131072
ONLINE
_SYSSMU10$                     UNDO                                   131072
ONLINE
_SYSSMU11$                     UNDO_02                                131072
OFFLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU12$                     UNDO_02                                131072
OFFLINE
_SYSSMU13$                     UNDO_02                                131072
OFFLINE
_SYSSMU14$                     UNDO_02                                131072
OFFLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU15$                     UNDO_02                                131072
OFFLINE
_SYSSMU16$                     UNDO_02                                131072
OFFLINE
_SYSSMU17$                     UNDO_02                                131072
OFFLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU18$                     UNDO_02                                131072
OFFLINE
_SYSSMU19$                     UNDO_02                                131072
OFFLINE
_SYSSMU20$                     UNDO_02                                131072
OFFLINE
SEGMENT_NAME                   TABLESPACE_NAME                INITIAL_EXTENT
STATUS
_SYSSMU21$                     UNDO_02                                131072
OFFLINEStill undo_02's segments are offline.

Failed to extend Rollback Segment

Version of the database is
Oracle8i Enterprise Edition Release 8.1.7.0.0 - Production
I have a rollback tablespace that is 99%used and wen I am tryng to use DML statements to the database it is throwing the following error.
ORA-01562:FAILED TO EXTEND ROLLBACK SEGMENT 2
ORA-01650:UNABLE TO EXTEND ROLLBACK SEGMENT RBS01 BY 128 IN TABLESPACE
R
May I know how do I proceed now? Do I have to extend the tablespace or add a new datafile to the tablespace?

PK wrote:
Version of the database is
Oracle8i Enterprise Edition Release 8.1.7.0.0 - Production
I have a rollback tablespace that is 99%used and wen I am tryng to use DML statements to the database it is throwing the following error.
ORA-01562:FAILED TO EXTEND ROLLBACK SEGMENT 2
ORA-01650:UNABLE TO EXTEND ROLLBACK SEGMENT RBS01 BY 128 IN TABLESPACE
R
May I know how do I proceed now? Do I have to extend the tablespace or add a new datafile to the tablespace?
01562, 00000, "failed to extend rollback segment number %s"
// *Cause: Failure occurred when trying to extend rollback segment
// *Action: This is normally followed by another error message that caused
//        the failure. You may take the rollback segment offline to perform
//         maintainence. Use the alter rollback segment offline command
//         to take the rollback segment offline.
bcm@bcm-laptop:~$ oerr ora 1650
01650, 00000, "unable to extend rollback segment %s by %s in tablespace %s"
// *Cause: Failed to allocate an extent of the required number of blocks for
//          a rollback segment in the tablespace.
// *Action: Use ALTER TABLESPACE ADD DATAFILE statement to add one or more
//          files to the tablespace indicated.

Trying to understand rollback segments - offline tblspaces for backup

Using Oracle 8i, on Windows platform - The question - receive an error ORA-01556 when performing a
sql "ALTER TABLESPACE MY_TBS_LT OFFLINE IMMEDIATE";
=============================================
First off I created a tablespace and table on an 8i database.
create tablespace my_tbs_lt_tbs_lt
datafile '&&2\oradata\&&1\my_tbs_lt_guitest1.dbf'
size 10M
AUTOEXTEND ON NEXT 1280k EXTENT MANAGEMENT LOCAL UNIFORM SIZE 128K; <===== Is this right for use with rollback segments?
CREATE ROLLBACK SEGMENT rbgui1t2 STORAGE(INITIAL 50K NEXT 250K)
tablespace my_tbs_lt;
CREATE ROLLBACK SEGMENT rbgui2t2 STORAGE(INITIAL 50K NEXT 250K)
tablespace my_tbs_lt;
CREATE ROLLBACK SEGMENT rbgui3t2 STORAGE(INITIAL 50K NEXT 250K)
tablespace my_tbs_lt;
CREATE ROLLBACK SEGMENT rbgui4t2 STORAGE(INITIAL 50K NEXT 250K)
tablespace my_tbs_lt;
-- Bring new rollback segments online
ALTER ROLLBACK SEGMENT rbgui1t2 ONLINE;
ALTER ROLLBACK SEGMENT rbgui2t2 ONLINE;
ALTER ROLLBACK SEGMENT rbgui3t2 ONLINE;
ALTER ROLLBACK SEGMENT rbgui4t2 ONLINE;
CREATE TABLE guitester.guitester_t2
( employee_id NUMBER(6)
, first_name VARCHAR2(20)
, last_name VARCHAR2(25)
CONSTRAINT emp_last_name_nn_demo NOT NULL
, email VARCHAR2(25)
CONSTRAINT emp_email_nn_demo NOT NULL
, phone_number VARCHAR2(20)
, hire_date DATE DEFAULT SYSDATE
CONSTRAINT emp_hire_date_nn_demo NOT NULL
, job_id VARCHAR2(10)
CONSTRAINT emp_job_nn_demo NOT NULL
, salary NUMBER(8,2)
CONSTRAINT emp_salary_nn_demo NOT NULL
, commission_pct NUMBER(2,2)
, manager_id NUMBER(6)
, department_id NUMBER(4)
, dn VARCHAR2(300)
, CONSTRAINT emp_salary_min_demo
CHECK (salary > 0)
tablespace my_tbs_lt;
=======================================
I changed the initSID.ora file to have
Rollback_segments=( rbgui1t2, rbgui2t2, rbgui3t2, rbgui4t2)
=======================================
restarted everything
========================================
did a backup of the tablespace my_tbs_lt;
========================================
added some data to the table in the tablespace
========================================
ran a restore/recover - Get the error
========================================
It makes sense that I get the error because it is the tablespace that I have been working with, adding data. Is my logic correct? How does one restore a tablespace if it has rollback segments active? Can someone look to make sure I am declaring the rollback segments appropriately?

Thank you for the link - very helpful.
So would a more appropriate scheme be:
Create a tablespace
Create rollback segments
Put them online
enter their names in the ROLLBACK_SEGMENTS= segment(s)
I havent read everything, so you may say go look at the link again, but a second question. If you are managing the extent locally, does it not use a rollback segments, or is it using system, or is it actually creating rollback segments for itself within the context of the local management?
In my above scenario, I would have to take my rollback segment offline as well as the tablespace.

ROLLBACK SEGMENTS OPERATION

Hello Everyone
This is the first time I am a forum member and I'm figuring out how it works because I have a very big problem
Look, I'm a support engineer and, as you know, the code of the application is not own by me.
Three weeks ago I received a report which is related with the Rollback operation.
There's a process which delete old data from my database and, normally, this process has three parts, as shown in the alert_dbinstance.log:
Wed May 17 03:00:08 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE
Wed May 17 03:00:08 2000
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE
Wed May 17 04:52:25 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 SHRINK
Wed May 17 04:52:26 2000
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 SHRINK
Wed May 17 04:52:26 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 OFFLINE
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 OFFLINE
But, one day, the server crashed and this process didn't finish:
Sat May 20 03:00:03 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE
Sat May 20 03:00:03 2000
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE
Sat May 20 04:39:09 2000
the next messages about this process are these:
Sun May 21 03:00:04 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE
Sun May 21 03:00:04 2000
ORA-1636 signalled during: alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE...
Sun May 21 03:10:10 2000
Thread 1 advanced to log sequence 303
Current log# 1 seq# 303 mem# 0: /usr/users/fraude/dblinks/redo_db/dbfraude_log0.dbf
Sun May 21 03:11:48 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 SHRINK
Sun May 21 03:11:49 2000
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 SHRINK
Sun May 21 03:11:49 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 OFFLINE
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 OFFLINE
Since this day, the delete process sends this message:
--- Fault (4) Notify (3) : 2000-06-01 03:00:01 ---
Message (400020): Database Operation Failed
Partition: 0
Module (13000): Daily Cleanup
Description: ORA-00955: name is already used by an existing object
My question here is : Is there a way, using oracle, to identify this object? Can I find the objects with a failure register in a table? in a log file?
thanks for your comments and your efforts. I'll be very thankful.
null

It seems you should look here:
ORA-1636 signalled during: alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE...
Looks like you have ORA-01636 error:
rollback segment 'string' is already online
I suggest you check Oracle documentation about this error. Seems to me your process try to access rollback segment that is already in use.
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by German Garcia Ibarra ([email protected]):
[b]Hello Everyone
This is the first time I am a forum member and I'm figuring out how it works because I have a very big problem
Look, I'm a support engineer and, as you know, the code of the application is not own by me.
Three weeks ago I received a report which is related with the Rollback operation.
There's a process which delete old data from my database and, normally, this process has three parts, as shown in the alert_dbinstance.log:
Wed May 17 03:00:08 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE
Wed May 17 03:00:08 2000
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE
Wed May 17 04:52:25 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 SHRINK
Wed May 17 04:52:26 2000
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 SHRINK
Wed May 17 04:52:26 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 OFFLINE
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 OFFLINE
But, one day, the server crashed and this process didn't finish:
Sat May 20 03:00:03 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE
Sat May 20 03:00:03 2000
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE
Sat May 20 04:39:09 2000
the next messages about this process are these:
Sun May 21 03:00:04 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE
Sun May 21 03:00:04 2000
ORA-1636 signalled during: alter ROLLBACK SEGMENT CLEANUP_RS0 ONLINE...
Sun May 21 03:10:10 2000
Thread 1 advanced to log sequence 303
Current log# 1 seq# 303 mem# 0: /usr/users/fraude/dblinks/redo_db/dbfraude_log0.dbf
Sun May 21 03:11:48 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 SHRINK
Sun May 21 03:11:49 2000
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 SHRINK
Sun May 21 03:11:49 2000
alter ROLLBACK SEGMENT CLEANUP_RS0 OFFLINE
Completed: alter ROLLBACK SEGMENT CLEANUP_RS0 OFFLINE
Since this day, the delete process sends this message:
--- Fault (4) Notify (3) : 2000-06-01 03:00:01 ---
Message (400020): Database Operation Failed
Partition: 0
Module (13000): Daily Cleanup
Description: ORA-00955: name is already used by an existing object
My question here is : Is there a way, using oracle, to identify this object? Can I find the objects with a failure register in a table? in a log file?
thanks for your comments and your efforts. I'll be very thankful.
<HR></BLOCKQUOTE>
null

Rollback Segment

I have a UNIX script through which i call a procedure. In that procedure i have two statements
EXECUTE IMMEDIATE 'ALTER ROLLBACK SEGMENT R01 SHRINK';
EXECUTE IMMEDIATE 'SET TRANSACTION USE ROLLBACK SEGMENT R01';
The procedure gives me the error insufficent insufficent privileges. But when i execute these statements in SQL*Plus (with same username password) they are running fine.
Any Help ??

Which is the exact Oracle message error do you have ?
What is your Oracle version ?
if you get
"ORA-01650 unable to extend rollback segment ... by ... in tablespace ...", you could extend one of your rollback segment tablespace datafile with:
ALTER DATABASE DATAFILE .... RESIZE ... or add a new datafile to the tablespace:
ORA-01650 unable to extend rollback segment string by string in tablespace string
Cause: Failed to allocate an extent for rollback segment in tablespace.
Action: Use ALTER TABLESPACE ADD DATAFILE statement to add one or more files to the tablespace indicated.
Message was edited by:
Pierre Forstmann

Rollback segment for set transaction

there is way that i can setup a rollback segment for a spacific user or specific transction.
ALTER ROLLBACK SEGMENT big_rbs ONLINE;
SET TRANSACTION USE ROLLBACK SEGMENT big_rbs;
sql .....
commit;
ALTER ROLLBACK SEGMENT big_rbs OFFLINE;
the sql is going for about hour, i was woundering during that time can some else use this rollback segment. i just want this rbs to this user, how i can do that.
thanks

I guess i didn't clearify well. let say i created a rbs for specific tranction. before this transaction is start it will turn on this rbs and once this transaction is completed, it issue the command commit, and bring it back to this rbs offline. the question is durning this transaction does any other transaction can come and use this rbs instead of we have lot of other rbs.
I hope that you get my point.

Transaction taking default rollback segment

Dear al,
10.2.0.4. on solaris 10
transaction taking default rollback segment
set transaction use rollback segment rbs2;
structure of rbs2:
Create rollback segment rbs2 tablespace tempt storage (initial 1M next 1M minextents 2 maxextents 1024);
alter ROLLBACK SEGMENT RBS2 STORAGE
(MINEXTENTS 20
MAXEXTENTS UNLIMITED );
set transaction use rollback segment rbs2;
when am running the query , am getting the below error :
ERROR at line 3:
ORA-01555: snapshot too old: rollback segment number 8 with name "_SYSSMU8$"
too small
why still the transaction is referring to system rollback segment "_SYSSMU8$" where I've explicitly set the rollback segment for the transactiom ?
ANy idea ?
KAI

Thanks robert and
Now, after setting
undo_retention integer
2700
It failed with the below and now it took 20 minutes..
ERROR at line 4:
ORA-01555: snapshot too old: rollback segment number 9 with name "_SYSSMU9$"
too small
ORA-02063: preceding line from TABS2CALLS
Elapsed: 00:20:11.40
Please advise
Kai

SYSTEM Rollback Segment bad

I ported a database over to a new server.
It seems there may be transactions pending...which I don't care about.
I can log as SYS and run queries, but I cannot run DML or DDL statements.
I have narrowed down the problem to the SYSTEM rollback segment.
I am running in Automatic Undo mode.
How do I clear transactions from a rollback segment?
I don't think I can alter or create a new SYSTEM rollback segment.

There is no error message.
When I issue any DML/DDL statement Oracle just hangs forever...and never issues an error message.
Here is the latest printout from the alert.log file:
Tue Jul 11 14:33:03 2006
LGWR: Primary database is in CLUSTER CONSISTENT mode
Tue Jul 11 14:33:03 2006
ARCH: Evaluating archive log 3 thread 1 sequence 14697
ARCH: Beginning to archive log 3 thread 1 sequence 14697
Creating archive destination LOG_ARCHIVE_DEST_1: 'D:\ORA92\RDBMS\ARC14697.001'
ARCH: Completed archiving log 3 thread 1 sequence 14697
Tue Jul 11 14:33:05 2006
LGWR: Primary database is in CLUSTER CONSISTENT mode
Thread 1 advanced to log sequence 14700
Thread 1 opened at log sequence 14700
Current log# 3 seq# 14700 mem# 0: D:\ORADATA\9.2\ICDB\LOG\LOG3A.ORA
Successful open of redo thread 1
Tue Jul 11 14:33:06 2006
SMON: enabling cache recovery
Tue Jul 11 14:33:06 2006
Successfully onlined Undo Tablespace 1.
Tue Jul 11 14:33:06 2006
SMON: enabling tx recovery
Tue Jul 11 14:33:06 2006
Database Characterset is WE8MSWIN1252
replication_dependency_tracking turned off (no async multimaster replication found)
Completed: alter database open
Tue Jul 11 14:33:53 2006
SMON: Parallel transaction recovery tried
Tue Jul 11 14:34:45 2006
create rollback segment system
tablespace system
storage (
initial 112K
minextents 1
maxextents 1
Tue Jul 11 14:34:45 2006
ORA-1535 signalled during: create rollback segment system
tablespace system
s...
Tue Jul 11 14:35:02 2006
Thread 1 cannot allocate new log, sequence 14701
All online logs needed archiving
Current log# 3 seq# 14700 mem# 0: D:\ORADATA\9.2\ICDB\LOG\LOG3A.ORA
Tue Jul 11 14:35:12 2006
drop rollback segment system
Tue Jul 11 14:35:12 2006
ORA-1544 signalled during: drop rollback segment system...
Tue Jul 11 14:41:33 2006
alter rollback segment system offline
Tue Jul 11 14:41:33 2006
ORA-30019 signalled during: alter rollback segment system offline...

ROLLBACK SEGMENT의 MINEXTENTS를 20 이상으로 하면 좋은 이유

제품 : ORACLE SERVER
작성날짜 : 2003-06-19
ROLLBACK SEGMENT의 MINEXTENTS를 20 이상으로 하면 좋은 이유
=========================================================
PURPOSE
이 자료는 다음과 같은 주제에 대하여 소개하는 자료이다.
이 문서는 database application의 요구 사항을 충족시키기 위해 고려되어
져야 할 rollback segment tablespace 구성에 관한 내용을 담고 있다.
Creating, Optimizing, and Understanding Rollback Segments
-Rollback Segment 구성과 기록 방식
-Transaction에 Rollback Segment를 할당하는 Oracle 내부 메커니즘
-Rollback Segment 크기와 갯수
-Rollback Segment의 크기와 갯수 결정을 위한 테스트
-Rollback Segment extent의 크기와 갯수
-Rollback Segment의 minextents를 20 이상으로 하면 좋은 이유?
-Rollback Segment의 Optimal storage parameter와 Shrink
Explanation
Rollback Segment 구성과 기록 방식
Rollback segment는 extent라 불리는 연속적인 여러 개의 block으로 구성된다.
Rollback segment는 ordered circular 방식으로 extent를 쓰게 되는데,
current extent가 full이 되면 next extent로 옮겨 가며 사용하게 된다.
Transaction은 rollback segment 내의 current location에 record를 쓴 다음,
record의 size 만큼 current pointer를 옮겨 간다.
Rollback segment에 현재 record가 쓰여지고 있는 위치를 "Head"라고 한다.
또한, "Tail"이란 용어는 rollback segment에서 가장 오래된 active
transaction record의 시작 위치가 되는 부분을 말한다.
Transaction에 Rollback Segment를 할당하는 Oracle 내부 메커니즘
새로운 transaction이 rollback segment 를 요청하면, 각 rollback segment
를 이용하고 있는 active transaction 갯수를 확인하여 가장 적은 갯수의
active transaction 을 가진 rollback segment를 할당하게 된다.
Rollback segment는 transaction load를 처리하기에 충분한 크기를 가져야
하고, 필요한 만큼의 rollback segment를 사용할 수 있도록 적당한 갯수의
rollback segment를 가져야 한다.
1. 한 transaction은 단 하나의 rollback segment만을 사용할 수 있다.
2. 같은 extent에 여러 transaction이 기록할 수 있다.
3. Rollback segment의 Head는 Tail에 의해 현재 사용 중인 extent를
침범하지 않는다.
4. 링 형태로 구성되어 있는 rollback segment의 extent들은 다음 extent를
찾을 때 절대 건너 뛰는 일이 없으며, 순서를 뒤바꾸어 사용하지도 않는다.
5. Head가 next extent를 찾지 못하면, 새로운 extent를 추가로 할당하고,
그 extent를 링 안에 포함시킨다.
위와 같은 원리를 감안할 때, transaction size 뿐만 아니라 transaction
time도 상당히 중요한 고려 사항이라는 것을 알 수 있다.
Rollback Segment 크기와 갯수
Rollback segment size가 충분한지 판단하는 기준은 transaction activity에
직접적으로 영향을 받는다. 주로 일어나는 transaction activity에 근거하여
rollback segment size를 결정하여야 하고, 잘 일어나지 않는 특수한 경우의
큰 transaction이 문제라면 별도의 rollback segment로 관리되어야 한다.
Transaction 발생 중 Head가 너무 빨리 wrap around 시켜서 tail을 catch하
지 않도록 하여야 하며, 자주 변경되는 data에 대해 long-running query가
수행되었을 경우 read-consistency가 유지될 수 있도록 rollback segment
가 wrap around되지 않아야 한다.
Rollback segment 갯수를 적당히 잡아야 하는 이유는 process들 간에
contention을 방지하기 위함이고, V$WAITSTAT, V$ROLLSTAT, V$ROLLNAME
view를 통해서 contention을 확인할 수 있으며, 조회문은 다음과 같다.
sqlplus system/manager
select rn.name, (rs.waits/rs.gets) rbs_header_wait_ratio
from v$rollstat rs, v$rollname rn
where rs.usn = rn.usn
order by 1;
위의 query에 의해 조회된 rbs_header_wait_ratio 가 0.01 보다 크면,
rollback segment 갯수를 추가한다.
Rollback Segment의 크기와 갯수 결정을 위한 테스트
1. Rollback segment tablespace 생성
2. 테스트하기 위해 생성할 Rollback segment 갯수 결정
3. 같은 크기의 extent로 rollback segment 생성
extent 갯수는 최대 확장 시 10 - 30 개 정도가 되도록 extent 크기를 결정
4. Rollback segment의 minextents는 2이다.
5. 테스트할 rollback segment와 system rollback segment만 online 상태로 한다.
6. Transaction을 수행하고, 필요하면 application을 load한다.
7. Rollback segment contention을 확인한다.
8. Rollback segment가 최대 얼마까지 확장하는지 모니터링한다.
Rollback Segment extent의 크기와 갯수
Rollback segment가 자라나는 최대 사이즈를 알 수 있는데, 이 수치를
"minimum coverage size"라 한다. 만약, contention이 발생한다면 rollback
segment 갯수를 늘려 가면 테스트를 반복한다. 또한, extent 갯수가 10개
미만이나 30개 이상이 될 필요가 있다면 extent 크기를 늘리거나 줄이면서
테스트를 반복해 나가면 된다.
Rollback segment의 extent 크기를 정할 때, 각 extent는 모두 같은 크기로
생성할 것을 recommend한다.
Rollback tablespace의 크기는 extent size의 배수로 지정한다.
최적의 성능을 위한 rollback segment의 minextents는 20 이상이어야 한다.
Rollback Segment의 minextents를 20 이상으로 하면 좋은 이유?
Rollback segment는 dynamic하게 allocate되고, 더 이상 필요 없게 되었을 때
(만약, Optimal parameter가 셋팅되어 있으면) 모두 commit된 extent에
대해서는 optimal size 만큼만 남기고 release(deallocate)된다.
Rollback segment가 적은 수의 extent를 가질 수록, space 할당/해제 시
extent 수가 많을 때보다 큰 사이즈의 space가 할당되고, 해제된다.
다음과 같은 예를 들어 보자.
200M 정도의 rollback segment가 있는데, 100M 짜리 2개의 extent로 이루어져
있다고 가정해보자. 이 rollback segment에 추가로 space를 할당해야 할 일이
생겼을 때, 모든 rollback segment extent는 같은 크기를 가져야 한다는 점을
감안할 때, 100M 짜리 extent를 하나 더 할당해야 할 것이다.
이 결과 직전의 rollback segment 크기에 비하여 50% 만큼의 크기 증가분이
생겨나게 된 것인데, 실제 필요로 하는 space보다 더 많은 space가 할당되었을
것이다.
이와 반대로, 10M 짜리 extent 20개로 구성된 200M 짜리 rollback segment를
생각해보자.
여기에 추가로 space를 할당해야 할 일이 생겼을 때, 10M 짜리 extent 하나만
추가되면 되는 것이다.
Rollback segment가 20개 또는 그 이상의 extent로 구성되어 있다면 extent가
하나 더 증가할 경우가 생겼을 때, rollback segment의 전체 크기가 5% 이상은
늘어나지 않는다는 것이다.
즉, space의 할당과 해제 작업이 보다 유연하고 쉽게 일어날 수 있다.
요약하면, rollback segment의 extent 갯수를 20 이상으로 잡으면 space
할당과 해제가 "보다" 수월해진다.
실제로 extent 갯수를 20 이상으로 잡았을 때, 처리 속도가 훨씬 빨라진다는
사실이 많은 테스트 결과 밝혀졌다.
한가지 확실한 사실은, space를 할당하고 해제하는 작업은 cost가 적게 드는
작업이 아니라는 사실이다.
실제로 extent가 할당/해제되는 작업이 일어날 때, performance가 저하되는
일이 발생한다는 것이다.
Extent 하나에 대한 cost는 별 문제가 안 된다고 할지라도, rollback segment
는 끊임없이 space를 할당하고 해제하는 작업을 반복하기 때문에 작은 크기의
extent를 갖는 것이 cost 측면에서 훨씬 효율적이라는 결론이다.
Rollback Segment의 Optimal storage parameter와 Shrink
Optimal은 deallocate 시에 rollback segment 내에 optimal size 만큼의
extents를 유지하기 위해 사용하는 rollback segment storage parameter이다.
다음과 같은 명령으로 사용한다.
alter rollback segment r01 storage (optimal 1m);Optimal size는 storage 절 안에서 기술되어야 한다.
Optimal size 이상이 되면, 모두 commit된 extent에 대해서는 optimal size
만큼만 남기고 release된다.
즉, optimal에서 지정한 크기 만큼만 rollback segment를 유지하겠다는
뜻이며, 일정한 크기로 늘어났다가 다음번 tx이 해당 rbs를 취할 경우
optimal size만큼 resize하는 option이다.
rbs의 가장 최근에 사용된 extent가 다 차서 다른 extent를 요구할 때
이 optimal size와 rbs size를 비교하게 되며, 만약 rbs size가 더 크다면
active tx에 관여하지 않는 tail extent에 대하여 deallocation이 이루어진다.
특정 rollback segment가 너무 큰 space를 차지해서 다른 rollback segment가
extent를 발생할 수 있는 여유 공간을 부족하게 만들기 때문에 이를 극복하기
위해서 optimal size를 지정할 필요가 있다.
즉, optimal parameter를 지정하면 space availability 측면에서 효율적이다.
다음과 같이 shrink 명령을 수행하는데, size를 지정하지 않으면 optimal
size 만큼 shrink된다.
alter rollback segment [rbs_name] shrink to [size];Shrink 명령 수행 후, 바로 줄어들지 않는 경우가 있는데,
transaction이 있는 경우는 줄어들지 않고, transaction이 종료되면 줄어든다.
Optimal이 적용되는 시간은 session이 빠져 나가고 약 5~10 분 정도 걸린다.
적당한 OPTIMAL SIZE?
=> 20 ~ 30 extents 정도가 적당한데, batch job의 성격에 따라 size는 달라
지며 각 optimal의 합이 datafile의 size를 넘어도 전혀 상관없다.
Optimal size를 initial, next와 같게 주면 extent가 발생하는 매번 shrink가
일어나므로 좋지 않다.
RBS들의 평균 크기를 구하여 이것을 optimal 크기로 지정하여 사용하는 것을
권한다.
다음의 query를 이용하여 peak time에 rollback segment들의 평균 크기를 구한다.
select initial_extent + next_extent * (extents-1) "Rollback_size", extents
from dba_segments
where segment_type ='ROLLBACK';
이 크기의 평균값(bytes)을 rollback segment들의 optimal size로 사용할 수
있다.
주의할 사항은 너무 자주 shrink된다거나 optimal 값을 너무 작게 주면
ora-1555 : snapshot too old error가 발생할 확률이 높아지므로,
사용하지 않는 것이 좋을 수도 있고, 되도록 큰 값으로 셋팅해야 한다.
Rollback segment의 optimal size를 확인할 수 있는 view는 V$ROLLSTAT
이라는 dynamic view로서 OPTSIZE column에서 확인이 가능하다.
Example
none
Reference Documents
<Note:69464.1>

Quick Cleanup of Temporary Segments and also for Rollback Segment

Do you know a tip allowe to do a quick
Cleanup of Temporary Segments and also for Rollback Segment; same time we
need to wait about 2 hours to cleanup these tablespaces.
we have to take action immediately to prevent other sessions to fail as well
and we cannot bounce the Oracle instance. So, how do we get rid of this
temporary segment as quickly as possible?
Rq: the shrink commande same time not cleanup Rollback Segment, i don't know why (Ex:Alter rollback segment R01 shrink; )
Thank you

According to my knowledge the rollback tablespace can not be cleanup as you want because in the rollback segments are the transactions without commit and because of that you can not do that. The Rollback tablespace cleans up itself when pending transactions make commit.
[email protected]
Joel P�rez

Rollback segment problem

Hello:
I'm using oracle 8 database and I have a process that generates small transactions (and they're really small), usually this process is executed from 2 or 3 different workstations at the same time, but they don't use the same data sets. The frequency of execution of the small transaction is 10 or 12 a second for each workstation. Each time the process is executed I can count near 6000 transactions, and I always have 2 o 3 of them arising "ORA-01562: failed to extend rollback segment number n" error. Since the transaction uses a small space of the rollback segment I can't find an explanation to this behavior. Is this related to the time between transaction and the freeing of the unused rollback segment ? I would really appreciate if somebody could help me!!!
Thanks in advance, Javier Petrozzi

It appears to me that some of the transactions remain open for quite some time and the new transactions are not able to obtain an extent for the rollback segment.
The following query gives some useful information.
1 select s.sid, s.username, r.name "SEGMENT NAME"
2 from v$session s, v$transaction t, v$rollname r
3 where s.taddr=t.addr
4* and t.xidusn = r.usn
SQL> /
SID USERNAME SEGMENT NAME
16 SCOTT _SYSSMU7$You may have to commit your changes sooner.

Alter rollback segment command giving error.

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