testing....
if the initial extent*min_extents is less than the optimal, yes you can
shrink below optimal.
if initial*minextents = optimal, you can execute an alter rollback
segment statement that lists a shrink size that is less than optimal
AND less than initial*minextents and it will not fail. But if you LOOK
at the size it shrinks to, it's initial*minextents.
so you can "kinda" shrink below optimal, the statement won't fail, but
Oracle will ignore the number you give it.
- "Johnston, Tim" <TJohnston_at_quallaby.com> wrote:
> You know what? I thought the same thing... But, the curious side of
> me
> decided to give it a try to be sure... And guess what... It works?
> Learn
> something new everyday...
>
> SQL> select segment_name,sum(bytes) from dba_segments where
> tablespace_name
> = 'RBS' and segment_name
> = 'RBS17' group by segment_name;
>
> SEGMENT_NAME SUM(BYTES)
> ------------------------ ----------
> RBS17 22364160
>
>
> SQL> select rs.optsize, rs.extents
> 2 from dba_rollback_segs drs,
> 3 v$rollstat rs
> 4 where drs.segment_name = 'RBS17'
> 5 and drs.segment_id = rs.usn;
>
> OPTSIZE EXTENTS
> ---------- ----------
> 22020096 21
>
> SQL> alter rollback segment RBS17 shrink to 10M;
>
> Rollback segment altered.
>
> SQL> select segment_name,sum(bytes) from dba_segments where
> tablespace_name
> = 'RBS' and segment_name
> = 'RBS17' group by segment_name;
>
> SEGMENT_NAME SUM(BYTES)
> ------------------------- ----------
> RBS17 10649600
>
>
> SQL> select rs.optsize, rs.extents
> 2 from dba_rollback_segs drs,
> 3 v$rollstat rs
> 4 where drs.segment_name = 'RBS17'
> 5 and drs.segment_id = rs.usn;
>
> OPTSIZE EXTENTS
> ---------- ----------
> 22020096 10
>
> SQL>
>
> 8.1.7.3 on Solaris 2.8
>
> Tim
>
> -----Original Message-----
> Sent: Wednesday, January 30, 2002 10:26 AM
> To: Multiple recipients of list ORACLE-L
>
>
> no, you can't shrink a rollback segment below the optimal value
>
> --- Sinard Xing <sinardyxing_at_bcs-ach.com.sg> wrote:
> > Hi,
> >
> >
> > Assume
> > INITIAL * MINEXTENT = 2M and also = OPTIMAL
> >
> > Do you think
> > ALTER ROLLBACK SEGMENT rbs SHRINK TO 1M;
> >
> > will work ?
> >
> >
> >
> > Thanks,
> >
> > Sinardy
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > --
> > Author: Sinard Xing
> > INET: sinardyxing_at_bcs-ach.com.sg
> >
> > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
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> __________________________________________________
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> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
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> INET: wisernet100_at_yahoo.com
>
> Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
> San Diego, California -- Public Internet access / Mailing
> Lists
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Do You Yahoo!?
Great stuff seeking new owners in Yahoo! Auctions!
http://auctions.yahoo.com
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Rachel Carmichael
INET: wisernet100_at_yahoo.com
Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
San Diego, California -- Public Internet access / Mailing Lists
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Received on Wed Jan 30 2002 - 13:19:17 CST