Re: Problems Creating Rollback Segment

Smitty wrote:
> Hello. I am a newbie to the Oracle world, so it might just be
> something simple I am missing. I am trying to create rollback segment
> RBS0. Here is the script I am using:
>
> set echo on term on
> spool cr_RBS0_rollback.log
>
> CREATE ROLLBACK SEGMENT rbs0
> TABLESPACE RBS_64M
> STORAGE
> (INITIAL 64M
> NEXT 64M
> MINEXTENTS 2
> MAXEXTENTS 4096);
>
>
> spool off
>
>
> After the script runs successfully, I do a select on the
> dba_rollback_segs table to view the new segment, and the parameters are
> all wrong. They are not what I specified:
>
> SEGMENT_NAME OWNER
> ------------------------------ ------------------------------
> SEG FILE BLOCK
> TABLESPACE_NAME ID ID ID INITIAL_EXTENT
> NEXT_EXTENT
> ------------------------------ ---- ---- ------ --------------
> --------------
> MIN % REL
> EXT MAX_EXTENTS INC STATUS INSTANCE_NUM FNO
> ---- -------------- --- ---------- -------------------- ----
> RBS0 SYS
> RBS_64M 6 39 9 134,217,728
> 67,108,864
> 1 32,765 0 OFFLINE 39
>
>
> The initial_extent is double what it should be, and the minextent and
> maxextents are all wrong. Any ideas? Thanks a lot.

Version is extremely relevant with this kind of question. If you are on a newer release it could be that you are creating the rollback segment (or even may have to depending on other factors) in a locally managed tablespace. If so, your initial extent will be a minimum of two of the uniform extent size.

As such, you probably have created the RBS in a locally managed tablespace with a 64m uniform extent size. Two of those = 128M.

Having said that, and once again depending on the version, read up on undo_management at tahiti.oracle.com

Regards,

Steve Received on Fri Jun 02 2006 - 13:29:22 CDT