Rollback segment for index creation

Hi,
I want to assign a specific (big) rollback segment to the transactions used by InterMedia Text while creating the index.
However a 'SET TRANSACTION USE ROLLBACK SEGMENT create_index' directly before the 'CREATE INDEX ...' seems not to work, as I saw that the inserts performed by InterMedia Text (e.g. into the $i and $k tables) were done using other rollback segments (e.g. RBSxx).
Is there any way to InterMedia Text to tell which rollback segments it should use for its internal operation?
Cheers,
Johannes

we can't assign the rollback segment to particular user.
For better performance place different table
spaces in different disks.
by
ramana
null

Similar Messages

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.

Error:cannot use system rollback segment for non-system tablespace

Hi,
I have created a oracle database 10.2.0 on fedora 9 system. I have created a user and assigned the default tablespace SATYA and given the permissions. But when I create a table in the user I am getting the following error.
Can anyone help me in rectifying this error.
ORA-01552: cannot use system rollback segment for non-system tablespace 'SATYA'
thankyou
satya

Undo management is either AUTO or Manual, no local
http://download.oracle.com/docs/cd/B19306_01/server.102/b14231/undo.htm#sthref1469
Since you are using 10g, you are recommended to use Auto undo management
If you still plan to use manual undo management, make sure you have other non-system rollback segment in place.

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.

ORA-01552: cannot use system rollback segment for non-system tablespace

i try to create a table in new schema test1 and got the following error. please help.
SQL> create table employer1 as select * from a.employer;
create table employer1 as select * from a.employer
ERROR at line 1:
ORA-01552: cannot use system rollback segment for non-system tablespace 'TEST1'

Hi,
This is an example:
SQL>
CREATE UNDO TABLESPACE "UNDOTMP"
DATAFILE 'UNDOTMP.DBF01' SIZE 100M REUSE
AUTOEXTEND ON NEXT 51200K MAXSIZE 15000M
ALTER SYSTEM SET undo_tablespace=UNDOTMP SCOPE=BOTH;
Regards
David Duenas
Edited by: David Duenas on Jul 4, 2009 7:33 PM

Cannot use system rollback segment for non-system tablespace

I am getting the below error suddently
ORA-01552: cannot use system rollback segment for non-system tablespace 'USERS'

SQL> show parameter undo
Version : Oracle 10g
NAME TYPE VALUE
undo_management string AUTO
undo_retention integer 10800
undo_tablespace string UNDO
SQL>
SQL> select distinct tablespace_name, status from dba_rollback_segs
2 ;
TABLESPACE_NAME STATUS
SYSTEM ONLINE
UNDO OFFLINE
UNDO ONLINE

How can I avoid using rollback segment for batch updates.

I am currently trying to avoid associating a large amount of space for rollback segment as this gets filled up only during the nightly batch updates. All that space will never be used during the day. Hence want to know if there is any way of avoiding the use of rollback segment at the session level.
Rajesh

No, but what you can do is create a large rollback segment to use with your batch job, at the start of your batch job bring the segment online, then use set transaction to use that rollback segment, when the batch job is finished and committed, you can then bring the rollback segment offline.
If you are really pressed for space, as an alternate plan, you could actually create the large segment before the batch job and drop it after.

Best practice for index creation

Hello,
I am working on Oracle 10g and AIX.
I have one table with 9 columns.
The sql queries on this table are such that out of 10 column it always having 5 column in the where clause.
So ,we have concatenated index on these 5 columns.
Other columns 4 , can come in to where clause in any order and number , like of only 2 columns can be using in where clause or 3 columns
or non of these columns.
Is this better to create index on all 4 columns , it should be concatenated index or individual index on all 4 columns.
i do not have all sql statement , becasue as per developers there are 10 modules accessing this tables and each may have 100 sql statements on this table..
Any idea...what i can do in this scenario ..create concatenated index on all 4 columns or individual index or no index..

youre coming at it wrong. you could do more harm then good taking that approach, you need to isolate the individual sql statements hitting that table. system trace, tkprof, statspack, awr are your friends here
Once you identify the queries, get yourself a dev version of the table and start playing the indexes, get tkprof and explain plans for the queries. In general, only the predicates in the sql select are candidates for index usage.
if you have 5 cols and any one of the cols could be used in combination or individual, maybe start creating 5 different indexes and then with the combo indexes. but only after you tkprof / explain plan them before and after, youre just guessing otherwise.

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.

Big problem with ROLLBACK SEGMENT

I tried insert into DB Oracle 8i more than 23000 rows from .sql files.
This files contents:
-- START
delete from grls;
insert ..........
insert ..........
insert ..........
-- END
ORA-01562: failed to extend rollback segment ...
My configuration:
CREATE TABLESPACE rbs datafile '$ORACLE_BASE/oradata1/$ORACLE_SID/rbs01.dbf' SIZE 10M;
CREATE TABLESPACE rbs_02 datafile '$ORACLE_BASE/oradata1/$ORACLE_SID/rbs01_02.dbf' SIZE 300M;
CREATE ROLLBACK SEGMENT rbs01 storage (initial 20k next 20k minextents 3 maxextents 121) TABLESPACE rbs;
CREATE ROLLBACK SEGMENT rbs16 storage (initial 20k next 20k minextents 3 maxextents 121) TABLESPACE rbs;
CREATE ROLLBACK SEGMENT rbs_load01 storage (initial 30m next 30m minextents 3 maxextents 10) TABLESPACE rbs_02;
Please help me.

1.)Did you place the rollback segments online
after creation?
Alter rollback segment RBS01 online;
Alter rollback segment RBS16 online;
Alter rollback segment RBS_LOAD01 online;
2.)Did you set your init[sid].ora parameter
ROLLBACK_SEGMENTS = (RBS01, RBS16, RBS_LOAD01) so that they will automatically come on line on istance startup?
3.) You have set up only 304Meg of space for them cumulatively. Is this enough for the 23thousand rows you want to insert?
If not you may want to enable the autoextend option on your datafiles. Of course you will want to change your maxextents. Leaving that value out will give you a default of 505 maxextents.
4.) And finally you could throw in a commit during the insert procedure. This will commit the transaction at that point and clear out the rollback segments for use again.
Tom

Help me regarding Rollback Segment!! It is Very Very Urgent.

My Oracle Version is 8.1.5.0.0
I have created my Database with one Data File and after creating of the Database I have found that my Database is having one Tablespace and then name is "System" and I have also found that a Rollback Segment is also created by Default on The "System" Tablespace and the name of that Rollback Segment is also "System".
Then what I did, I did create another Tablespace name "HR" with the help of the following syntax:
CREATE TABLESPACE HR
DATAFILE 'E:\MANODATA\U5\HR01.DBF' SIZE 100M
EXTENT MANAGEMENT LOCAL UNIFORM SIZE 256K;
Then I tried to create a Rollback segment on the "HR" with the following syntax:
CREATE ROLLBACK SEGMENT HR_RS TABLESPACE HR;
Tablespace is not created but I am getting an error, which I am mentioning below:
Cannot Use System Rollback Segment For Non-System Tablespace 'HR'
Then what I did, I did create another Tablespace name "USERS" with the help of following syntax:
CREATE TABLESPACE USERS
DATAFILE 'E:\MANODATA\U4\USERS01.DBF' SIZE 10M
EXTENT MANAGEMENT DICTIONARY;
Then what I did, I did create a Rollback segment on the Tablespace "USERS" with the following syntax:
CREATE PUBLIC ROLLBACK SEGMENT USERS_RS
TABLESPACE USERS
STORAGE (
INITIAL 50K
NEXT 50K
OPTIMAL 750K
MINEXTENTS 15
MAXEXTENTS 100);
Then what I did, I again tried to create a Rollback segment on the "HR" with the following syntax that you provided:
CREATE ROLLBACK SEGMENT HR_RS TABLESPACE HR;
Now the Rollback Segment is created without any problem.
Now Please tell me why it is so happening. I am very much confused of all this. Can't I create any Rollback Segment on a Locally managed Tablespace unless and until I do not Create a Dictionary managed Tablespace and unless I don't create a Rollback Segment on that dictionary managed Tablespace? Is there any restriction in my Version of Oracle (8.1.5.0.0)?
Please help me in this matter as soon as possible.
Thanking You,
Manojit.

My Oracle Version is 8.1.5.0.0
I have created my Database with one Data File and after creating of the Database I have found that my Database is having one Tablespace and then name is "System" and I have also found that a Rollback Segment is also created by Default on The "System" Tablespace and the name of that Rollback Segment is also "System".
Then what I did, I did create another Tablespace name "HR" with the help of the following syntax:
CREATE TABLESPACE HR
DATAFILE 'E:\MANODATA\U5\HR01.DBF' SIZE 100M
EXTENT MANAGEMENT LOCAL UNIFORM SIZE 256K;
Then I tried to create a Rollback segment on the "HR" with the following syntax:
CREATE ROLLBACK SEGMENT HR_RS TABLESPACE HR;
Tablespace is not created but I am getting an error, which I am mentioning below:
Cannot Use System Rollback Segment For Non-System Tablespace 'HR'
Then what I did, I did create another Tablespace name "USERS" with the help of following syntax:
CREATE TABLESPACE USERS
DATAFILE 'E:\MANODATA\U4\USERS01.DBF' SIZE 10M
EXTENT MANAGEMENT DICTIONARY;
Then what I did, I did create a Rollback segment on the Tablespace "USERS" with the following syntax:
CREATE PUBLIC ROLLBACK SEGMENT USERS_RS
TABLESPACE USERS
STORAGE (
INITIAL 50K
NEXT 50K
OPTIMAL 750K
MINEXTENTS 15
MAXEXTENTS 100);
Then what I did, I again tried to create a Rollback segment on the "HR" with the following syntax that you provided:
CREATE ROLLBACK SEGMENT HR_RS TABLESPACE HR;
Now the Rollback Segment is created without any problem.
Now Please tell me why it is so happening. I am very much confused of all this. Can't I create any Rollback Segment on a Locally managed Tablespace unless and until I do not Create a Dictionary managed Tablespace and unless I don't create a Rollback Segment on that dictionary managed Tablespace? Is there any restriction in my Version of Oracle (8.1.5.0.0)?
Please help me in this matter as soon as possible.
Thanking You,
Manojit. Manojit -
Maybe too late but here goes anyways -
You need to have another SYSTEM Rollback segment before you begin the process you mention above. At this stage of developing your database, the SYSTEM tablespace will keep the one rollback segment for it's own use and you need another one to create rollback info in for other objects. Create another system rollback segment in the existing rollback tablespace, then create a separate rollback tablepace with extent management local, then create some rollback segments. You may even want to use the SET TRANSACTION USER ROLLBACK SEGMENT RBS2 for the creation of the new Rollback Tablespace. Then you can continue with the creation of other objects.
Hope this helps,
the Infamous,
Eric Cartman

Error while creating the rollback segment (Oracle 8i & OS Win NT)

hi
I am using Oracle 8i and when i am creating the new rollback segment for my database i have got following error message
ORA-01593 Rollback segment optimal size (30 blks) is smaller than the computed initial size (2560 blks)
CREATE ROLLBACK SEGMENT "RBS11" TABLESPACE "RBS1"
STORAGE ( INITIAL 120K NEXT
120K OPTIMAL
240K MINEXTENTS 2
MAXEXTENTS 100)
Note:- db_block size is 8k
Tablespace RBS1 is the Locally managed Tablespace having datafile of 50m and uniform size of 10m
But Given statement processed while i am using Tablespace RBS (winch is data dictionary managed)
Plz, suggest me to cause of that error and solution

You said 120K optimal and initial is 120K with minextents of 2. The optimal size then will be smaller than the initial allocation for the rbs.
ORA-01593: rollback segment optimal size (string blks) is smaller than the computed initial size (string blks)
Cause: Specified OPTIMAL size is smaller than the cumulative size of the initial extents during create rollback segment.
Action: Specify a larger OPTIMAL size.

Systemcopy using R3load - Index creation VERY slow

We exported a BW 7.0 system using R3load (newest tools and SMIGR_CREATE_DDL) and now importing it into the target system.
Source database size is ~ 800 GB.
The export was running a bit more than 20 hours using 16 parallel processes. The import is still running with the last R3load process. Checking the logs I found out that it's creating indexes on various tables:
(DB) INFO: /BI0/F0TCT_C02~150 created#20100423052851
(DB) INFO: /BIC/B0000530000KE created#20100423071501
(DB) INFO: /BI0/F0COPC_C08~01 created#20100423072742
(DB) INFO: /BI0/F0COPC_C08~04 created#20100423073954
(DB) INFO: /BI0/F0COPC_C08~05 created#20100423075156
(DB) INFO: /BI0/F0COPC_C08~06 created#20100423080436
(DB) INFO: /BI0/F0COPC_C08~07 created#20100423081948
(DB) INFO: /BI0/F0COPC_C08~08 created#20100423083258
(DB) INFO: /BIC/B0000533000KE created#20100423101009
(DB) INFO: /BIC/AODS_FA00~010 created#20100423121754
As one can see on the timestamps the creation of one index can take an hour or more.
x_cons is showing constant CrIndex reading in parallel, however, the througput is not more than 1 - 2 MB/sec. Those index creation processes are running now since over two days (> 48 hours) and since the .TSK files don't mentioned those indexes any more I wonder how many of them are to be created and how long this will take.
The whole import was started at "2010-04-20 12:19:08" (according to import_monitor.log) so running now since more than three days with four parallel processes. Target machine has 4 CPUs and 16 GB RAM (CACHE_SIZE is 10 GB). The machine is idling though with 98 - 99 %.
I have three questions:
- why does index creation take such a long time? I'm aware of the fact, that the cache may not be big enough to take all the data but that speed is far from being acceptable. Doing a Unicode migration, even in parallel, will lead to a downtime that may not be acceptable by the business.
- why are the indexes not created first and then filled with the data? Each savepoint may take longer but I don't think that it will take that long.
- how to find out which indexes are still to be created and how to estimate the avg. runtime of that?
Markus

i Peter,
I would suggest creating an SAP ticket for this, because these kind of problems are quite difficult to analyze.
But let me describe the index creation within MaxDB. If only one index creation process is active, MaxDB can use multiple Server Tasks (one for each Data Volume) to possibly increase the I/O throughput. This means the more Data Volumes you have configured, the faster the parallel index creation process should be. However, this hugely depends on your I/O system being able to handle an increasing amount of read/write requests in parallel. If one index creation process is running using parallel Server tasks, all further indexes to be created at that time can only utilize one single User Task for the I/O.
The R3load import process assumes that the indexes can be created fast, if all necessary base table data is still present in the Data Cache. This mostly applies to small tables up to table sizes that take up a certain amount of the Data Cache. All indexes for these tables are created right after the table has been imported to make use of the fact, that all the needed data for index creation is still in the cache. Many idexes may be created simultaneously here, but only one index at a time can use parallel Server Tasks.
If a table is too large in relation to the total database size, then its indexes are being queued for serial index creation to be started when all tables were imported. The idea is that the needed base table data would likely have been flushed out of the Data Cache already and so there is additional I/O necessary rereading that table for index creation. And this additional I/O would greatly benefit from parallel Server Tasks accessing the Data Volumes. For this reason, the indexes that are to be created at the end are queued and serialized to ensure that only one index creation process is active at a time.
Now you mentioned that the index creation process takes a lot of time. I would suggest (besides opening an OSS ticket) to start the MaxDB tool 'Database Analyzer' with an interval of 60 seconds configured during the whole import. In addition, you should activate the 'time measurement' to get a reading on the I/O times. Plus, ensure that you have many Data Volumes configured and that your I/O system can handle that additional loag. E.g. it would make no sense to have 25 Server Tasks all writing to a single local disk, I would assume that the disk would become a bottle neck...
Hope my reply was not too confusing,
Thorsten

How to Create Exclusive Rollback Segment

How can we create exclsive rollback segment for a particular
session,
Even setting "set transaction use rollback segment
rollack_segment"
still other session can step on newly created rollback segment

Hi Santanu,
The steps that you mentioned are in sequence. You also need to check if user exist for this requirement.
sap help can give u a good deal of information.

Error rollback segment - urgent

hi
i have created locally managed tablesspace and in init.ora file i have sent unto management as manual as our application needs to specify rollback segments
when i created rollback segments and attached to a locally managed tablespace i am getting ora-01552 error
i have also speecified names of rollback segment in init.ora file
ERROR at line 1:
ORA-01552: cannot use system rollback segment for non-system tablespace 'ROLLTBLS'
can i not specify a rollback segment to locally managed tablespace
regards
Kedar

the database is in open mode and the undo_management is set to manual. after i created the locally managed tablespace i ran the script for rollback segment refering to one of the above locally managed tablespace
what other checks do i have to make for creating rollback segment.

Rollback segment for index creation

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