RE: help for rollback segments..

From: Suhen Pather <Suhen.Pather_at_strandbags.com.au>
Date: Fri, 08 Jun 2001 00:38:10 -0700
Message-ID: <F001.00321AF9.20010607235053@fatcity.com>

<FONT color=#0000ff face=Arial

size=2>Saurabh,
 
<FONT

color=#0000ff>First of all no
rollback segment should be in the SYSTEM tablespace except SYSTEM rollback segment.
<FONT

color=#0000ff>This cause serious
performance problems.
<SPAN

class=520275306-08062001> 
<SPAN

class=520275306-08062001>You would need to drop all the other rollback segments that are in the SYSTEM tablespace and recreate them in

<SPAN

class=520275306-08062001>a
ROLLBACK tablespace.
<SPAN

class=520275306-08062001> 
<FONT

color=#0000ff>To drop rollback
segment make sure no transactiosn are
running.
<FONT

color=#0000ff>alter rollback
segment SEGMENT_NAME offline;
<SPAN

class=520275306-08062001> 
<FONT

color=#0000ff>drop rollback
segment SEGMENT_NAME;
<SPAN

class=520275306-08062001> 
<FONT

color=#0000ff>For each rollback
segment and then recreate in the ROLLBACK tablespace.
<SPAN

class=520275306-08062001>After creation the rollback segments will be offline. You would need to set them online
individually.
<SPAN

class=520275306-08062001> 
<FONT

color=#0000ff>The reason why the
rollback segments are offline is probably because they are not included in your

<FONT

color=#0000ff>init.ora
file.  Add all rollback segments to this file and restart instance.
<SPAN

class=520275306-08062001> 
<FONT

color=#0000ff>You do not need to
create the rollback segments as public rollback segments.  I think public Rollback
<FONT

color=#0000ff>segments are used
mostly for OPS.
<SPAN

class=520275306-08062001> 
<SPAN

class=520275306-08062001>Regards
<FONT

color=#0000ff><SPAN
class=520275306-08062001>Suhen

  HI ALL,
   
  i've some confusion regarding
  rollback segments. could anyone explain this information from my   database.
   
  select * from
  dba_rollback_segs  revealed following stats..    
  SEGMENT_NAME  OWNER 
  TABLESPACE INITIAL_EX NEXT_EXTEN MIN_EXTENT MAX_EXTENT PCT_INCREA

  STATUS------------- ------ ---------- ---------- ---------- ---------- 
  ---------- ---------- 
  -------SYSTEM        

  SYS   

  SYSTEM          
  57344      
  57344          
  2        
  505          0 

  ONLINESYSROL       
  SYS    SYSTEM        

  106496     
  106496          
  2        
  505          0 

  OFFLINERB0          
  PUBLIC RBS           

  106496     
  262144          
  2        
  121          0 

  ONLINERB1          
  PUBLIC RBS           

  106496     
  262144          
  2        
  121          0 

  ONLINERB_TEMP       SYS   

  SYSTEM         
  106496     
  106496          
  2        
  121          0 

  OFFLINERB2          
  PUBLIC SYSTEM         

  57344     
  262144          
  2        
  121          0 

  ONLINERB3          
  PUBLIC SYSTEM         

  57344     
  262144          
  2        
  121          0 

  ONLINERB4          
  PUBLIC SYSTEM         

  57344     
  262144          
  2        
  121          0 

  ONLINERB5          
  PUBLIC SYSTEM         

  57344     
  262144          
  2        
  121          0 

  ONLINERB6          
  PUBLIC SYSTEM         

  57344     
  262144          
  2        
  121          0 

  ONLINERB7          
  PUBLIC SYSTEM         

  57344     
  262144          
  2        
  121          0 

  ONLINERB8          
  PUBLIC SYSTEM         

  57344     
  262144          
  2        
  121          0 

  ONLINERB9          
  PUBLIC SYSTEM         

  57344     
  262144          
  2        
  121          0 

  ONLINERB10          PUBLIC

  SYSTEM          
  57344     
  262144          
  2        
  121          0 

  ONLINERB11          PUBLIC

  SYSTEM          
  57344     
  262144          
  2        
  121          0 

  ONLINERB12          PUBLIC

  SYSTEM          
  57344     
  262144          
  2        
  121          0 

  ONLINERB13          PUBLIC

  SYSTEM          
  57344     
  262144          
  2        
  121          0 

  ONLINERB14          PUBLIC

  SYSTEM          
  57344     
  262144          
  2        
  121          0 

  OFFLINERB15          PUBLIC

  SYSTEM          
  57344     
  262144          
  2        
  121          0 

  OFFLINERB16          PUBLIC

  SYSTEM          
  57344     
  262144          
  2        
  121          0 

   
  can anybody explain, why i get
  some status as offline. will this extent allocation and other parameters ok. i   've oracle 8.1.5 on NT, these stats are from my test database.   why are they in system
  tablespace. i've two rollback tablespace of size 15 and 20 mb   resp.
  should they be in system or in
  rollback.
  if yes, how to change their
  default tablespace.
   
  pls help me in deciding
  that.
   
  thanks in advance.
   
  saurabh
   
    Received on Fri Jun 08 2001 - 02:38:10 CDT