Home » RDBMS Server » Server Administration » Rollback segments
Rollback segments [message #117599] Thu, 28 April 2005 08:35 Go to next message
j_potucek
Messages: 6
Registered: April 2005
Junior Member

Oracle 9i. Can you dynamically change the size of rollback segments?

Also, can you dynamically change the size of a datafile in a tablespace? have some performance issues !!!

Report message to a moderator

Re: Rollback segments [message #117600 is a reply to message #117599] Thu, 28 April 2005 08:43 Go to previous messageGo to next message
Mahesh Rajendran
Messages: 10708
Registered: March 2002
Location: oracleDocoVille
Senior Member
Account Moderator
>>Oracle 9i. Can you dynamically change the size of rollback segments?

Use of RBS in 9i is not recomended.

You can extend the datafile.
if you need to shrink the datafile, you shrink to point where it is max utilized.

Report message to a moderator

Re: Rollback segments [message #117607 is a reply to message #117600] Thu, 28 April 2005 09:11 Go to previous messageGo to next message
j_potucek
Messages: 6
Registered: April 2005
Junior Member

Is it recommended to add a datafile to a tablespace and then take the original file offline rather than increase the size of an existing datafile? or does it matter. I have a two datafiles that are in question. One is the Temp_tablespace datafile and one is a regular_tablespace datafile. both consistantly run at 99% and neither are set to autogrow. Both datafiles are of size 2084000. Can I just expand the size of each in EM? what can I change it to ?

Report message to a moderator

Re: Rollback segments [message #117610 is a reply to message #117607] Thu, 28 April 2005 09:21 Go to previous messageGo to next message
Mahesh Rajendran
Messages: 10708
Registered: March 2002
Location: oracleDocoVille
Senior Member
Account Moderator
>>Is it recommended to add a datafile to a tablespace and then take the original file offline rather than increase the size of an existing datafile?

In case of datafiles used for storage, you need to transfer the contents to new datafiles before you drop the old ones.
so,
just adding a newdatafile to tablespace would be easy.
In case of a tempfile, it is very common that the usage is 99% full. It is the way it works.
If you want to have bigger tempfile/temp tablespace,
create a new temp tablespace with a bigger size
set it as defualt temp tablespace database wide.
drop the old temp tablespace.

Report message to a moderator

Re: Rollback segments [message #117648 is a reply to message #117610] Thu, 28 April 2005 14:19 Go to previous messageGo to next message
j_potucek
Messages: 6
Registered: April 2005
Junior Member

just some clarification please??!!!

If I have a tablespace with ONE datafile and the datafile is pegged 99% utilization - won't that adversly affect performance??? Should I add a datafile to the tablespace, put it online and then take the old datafile offline before dropping it??

Report message to a moderator

Re: Rollback segments [message #117651 is a reply to message #117648] Thu, 28 April 2005 14:24 Go to previous messageGo to next message
Mahesh Rajendran
Messages: 10708
Registered: March 2002
Location: oracleDocoVille
Senior Member
Account Moderator
add a datafile to the existing tablespace.
or
Make the existing datfile much bigger.

Do not drop the datafile without backing up.
when you add a new datafile to an existing tablespace, it doesnt mean that you can drop the old datafile (unless you do a complete re-org).

and try it first on a test machine.
then do in a production database.




99% utilization of tablespace used for storage would NOT effect performance. You may be running out of space real soon. So all you need to do is, allocate more space.~!

(messed with my keyboard. Added the crucial NOT).

[Updated on: Thu, 28 April 2005 14:42]

Report message to a moderator

Re: Rollback segments [message #117656 is a reply to message #117651] Thu, 28 April 2005 14:40 Go to previous messageGo to next message
j_potucek
Messages: 6
Registered: April 2005
Junior Member

Thank you so much.. ans for your patience too. The datafile I want to expand is currently 2048000 bytes. Do I need to expand in any specific increments??? In other words, can I go into EM and change the size to say 2548000 on the fly?

Report message to a moderator

Re: Rollback segments [message #117659 is a reply to message #117656] Thu, 28 April 2005 14:49 Go to previous messageGo to next message
Mahesh Rajendran
Messages: 10708
Registered: March 2002
Location: oracleDocoVille
Senior Member
Account Moderator
>>2048000 bytes

less than 2m?

http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96521/dfiles.htm#8165


http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96521/dfiles.htm#7459

[Updated on: Thu, 28 April 2005 14:50]

Report message to a moderator

Re: Rollback segments [message #117661 is a reply to message #117659] Thu, 28 April 2005 14:53 Go to previous messageGo to next message
j_potucek
Messages: 6
Registered: April 2005
Junior Member

2048000 kbytes

Report message to a moderator

Re: Rollback segments [message #117702 is a reply to message #117661] Fri, 29 April 2005 01:23 Go to previous message
girish.rohini
Messages: 744
Registered: April 2005
Location: Delhi (India)
Senior Member
>>The datafile I want to expand is currently 2048000 bytes. Do I need to expand in any specific increments??? In other words, can I go into EM and change the size to say 2548000 on the fly?

yes u can do that, but a better way would be to enable autoextend in the storage clause and specify a maximum size for the file.

Report message to a moderator

Previous Topic: automatic database startup on Unix
Next Topic: How to install Oracle9i from command line interface
Goto Forum:
  

[ Syndicate this forum (XML) ] [ RSS ]

Current Time: Sun Jan 26 04:38:25 CST 2025
.:: Forum Home :: Blogger Home :: Wiki Home :: Contact :: Privacy ::.