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Home -> Community -> Usenet -> c.d.o.server -> Re: Minextents for rbsseg in LMT tablespace
True, Thomas, but try *modifying* minextents in LMT. You can't, because you
get the error message ORA25150 - Altering extent parameters not permitted.
So it is true that a storage clause specified at segment creation is honoured in its way, but you get one chance to get it right. After that, it's a drop and re-create job.
Regards
HJR
-- Resources for Oracle: http://www.hjrdba.com =============================== "Thomas Kyte" <tkyte_at_us.oracle.com> wrote in message news:9srd480g98_at_drn.newsguy.com...Received on Tue Nov 13 2001 - 12:52:58 CST
> In article <3bf0f837$0$214$edfadb0f_at_dspool01.news.tele.dk>, "Peter says...
> >
> >Hi,
> >
> >System: 8.1.6
> >I have a ora-1555 problem that i can solve by upping the minextents
> >parameter for my rollback segments in a dictionary managed tablespace.
> >However at some customers I have made the rbs tablespace LMT with uniform
> >size. It seemed like a good idea, but for a LMT you cant specify
minextents
> >or rather you can have a storage clause when creating a rollback segment
but
> >the clause but is is ignored.
> >
> >What to do?
> >Id rather not go back to dict managed rbs but do I have other choices?
> >
> >TIA
> >Peter Laursen
> >
> >
> >
> >
> >
>
>
>
> 1 select initial_extent, next_extent, extent_management
> 2* from dba_tablespaces where tablespace_name = 'USERS'
> ops$tkyte_at_ORA817DEV.US.ORACLE.COM> /
>
> INITIAL_EXTENT NEXT_EXTENT EXTENT_MAN
> -------------- ----------- ----------
> 524288 524288 LOCAL
>
>
> ops$tkyte_at_ORA817DEV.US.ORACLE.COM> create rollback segment foobar
> 2 storage ( minextents 25 ) tablespace users;
>
> Rollback segment created.
>
>
>
> ops$tkyte_at_ORA817DEV.US.ORACLE.COM> select segment_type, extent_id, blocks
> 2 from dba_extents where segment_name =
> 3 'FOOBAR';
>
> SEGMENT_TYPE EXTENT_ID BLOCKS
> ------------------ ---------- ----------
> ROLLBACK 0 64
> ROLLBACK 1 64
> ROLLBACK 2 64
> ROLLBACK 3 64
> ROLLBACK 4 64
> ROLLBACK 5 64
> ROLLBACK 6 64
> ROLLBACK 7 64
> ROLLBACK 8 64
> ROLLBACK 9 64
> ROLLBACK 10 64
> ROLLBACK 11 64
> ROLLBACK 12 64
> ROLLBACK 13 64
> ROLLBACK 14 64
> ROLLBACK 15 64
> ROLLBACK 16 64
> ROLLBACK 17 64
> ROLLBACK 18 64
> ROLLBACK 19 64
> ROLLBACK 20 64
> ROLLBACK 21 64
> ROLLBACK 22 64
> ROLLBACK 23 64
> ROLLBACK 24 64
>
> 25 rows selected.
>
> Minextents works just fine on LMTs....
>
> When you use a storage clause on an LMT, it is not accurate to say its
"ignored"
> perhaps - rather then it is used to conform to the rules
>
> what happens is the INITIAL, NEXT, MINEXTENTS -- etc are used to compute
how big
> the object would have allocated in a DMT -- then we divide by the size of
the
> extents in the LMT, round up and there we go -- thats how many extents
we'll
> allocate.
>
> For example:
>
> ops$tkyte_at_ORA817DEV.US.ORACLE.COM> drop rollback segment foobar;
> Rollback segment dropped.
>
> ops$tkyte_at_ORA817DEV.US.ORACLE.COM> create rollback segment foobar
> 2 storage ( initial 12800k ) tablespace users;
> Rollback segment created.
>
> ops$tkyte_at_ORA817DEV.US.ORACLE.COM> select count(*) from dba_extents where
> segment_name = 'FOOBAR';
>
> COUNT(*)
> ----------
> 26
>
>
> Using a big initial -- we got what we asked for -- just in separate
extents.
> Again:
>
> ops$tkyte_at_ORA817DEV.US.ORACLE.COM> drop rollback segment foobar;
>
> Rollback segment dropped.
>
> ops$tkyte_at_ORA817DEV.US.ORACLE.COM> create rollback segment foobar
> 2 storage ( initial 1m next 1m minextents 5 ) tablespace users;
>
> Rollback segment created.
>
> ops$tkyte_at_ORA817DEV.US.ORACLE.COM> select count(*) from dba_extents where
> segment_name = 'FOOBAR';
>
> COUNT(*)
> ----------
> 10
>
> we got what we asked for -- 5meg of rollback -- it just took 10 extents in
this
> LMT to do it.
>
> --
> Thomas Kyte (tkyte@us.oracle.com) http://asktom.oracle.com/
> Expert one on one Oracle, programming techniques and solutions for Oracle.
> http://www.amazon.com/exec/obidos/ASIN/1861004826/
> Opinions are mine and do not necessarily reflect those of Oracle Corp
>
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