Oracle FAQ Your Portal to the Oracle Knowledge Grid

Home -> Community -> Mailing Lists -> Oracle-L -> RE: Your opinion please...RBS

RE: Your opinion please...RBS

From: aaaa wwwwww <>
Date: Fri, 15 Dec 2000 21:43:11 -0800
Message-Id: <>

Dear Gurus

It is advisable to have more Rollback Segs with lesser size

But too many -- We experienced a funny problem in 7.3.3 that database not opened ora-704 error signalled

What Oracle Support guys opined that some rollback segments in init.ora are non-existant .It is not true

We had 26 RBSs I scaled them down to 16 means 10 of them are offlined

For the past 2 weeks we haven't faced any problem

Of course ! there is no relation - still



On Tue, 12 Dec 2000 10:06:38  
 Koivu, Lisa wrote:

>Yes, the rule of thumb is if you have any waits, you have too few rbs's.
>But more than 26? That's more than I've seen in my tenure as a dba, and
>I've worked on databases and applications larger (and busier) than this.
>My gut feel is that it's harmless to add some more rbs's and increase sizes.
>Aw, what the heck. I already had my death scare for the day and my heart
>just stopped pounding about 10 minutes ago. <whew>
>Lisa Rutland Koivu
>Oracle Database Administrator
>4850 North State Road 7
>Suite G104
>Fort Lauderdale, FL 33319
>V: 954.484.3191, x174
>F: 954.484.2933
>C: 954.658.5849
>"The information contained herein does not express the opinion or position
>of and cannot be attributed to or made binding upon"
>-----Original Message-----
>Sent: Tuesday, December 12, 2000 11:44 AM
>To: Multiple recipients of list ORACLE-L
>Dear Lisa
>I think your problem is having too few rollback segments .
>As you know Oracle shares transactions between rolback segments acc to their
>active transaction count.In your case
>you have only one rollback segment so all transactions must share it. You
>can make it bigger and bigger, but you should
>also think about transaction table of it, there may be congestion on the
>transaction table of rbs.
>Therefore you should create more rbs Oracle says that rbs count should be
>transaction count / 4 but I think because you know your system requirements
>you can calculate as you wish.
>Good luck
>Please see the official ORACLE-L FAQ:
>Author: Emine ATES
>Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
>San Diego, California -- Public Internet access / Mailing Lists
>To REMOVE yourself from this mailing list, send an E-Mail message
>to: (note EXACT spelling of 'ListGuru') and in
>the message BODY, include a line containing: UNSUB ORACLE-L
>(or the name of mailing list you want to be removed from). You may
>also send the HELP command for other information (like subscribing).
Get FREE Email/Voicemail with 15MB at Lycos Communications at
Received on Fri Dec 15 2000 - 23:43:11 CST

Original text of this message