Re: CREATE ROLLBACK SEGMENT

Actually minimum extent size is 5 blocks. Oracle can also increase it if it feels like it, it became pretty complex in 8.1. Anyway, it's funny to see initial, next and optimal sizes in K. Usually rollback segment is measured in megabytes.

In article <974394962.14591.0.nnrp-07.9e984b29_at_news.demon.co.uk>,   "Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote:
>
> PCTINCREASE is ignored in rollback segments.
>
> Have you got a minimum extent length (of 32K) defined
> for the rollback tablespace.
>
> select tablespace_name, min_extlen from dba_tablespaces;
>
> If so any extent you create in the tablespace will
> be forced into being a multiple of that size. So your
> 10K extents will actually turn into 32K (4 block)extents.
>
> --
>
> Jonathan Lewis
> Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk
>
> Practical Oracle 8i: Building Efficient Databases
>
> Publishers: Addison Wesley Longman
> Book bound date: 8th Dec 2000
> See a first review at:
> http://www.ixora.com.au/resources/index.htm#practical_8i
>
> David Fitzjarrell wrote in message <8v0sis$cuq$1_at_nnrp1.deja.com>...
> >In our last gripping episode diegolosi_at_my-deja.com wrote:
> >> I am using Oracle Version 8.1.5 on an NT server
> >> I have this problem:
> >> I want to create a rollback segment,
> >>
> >> create public rollback segment RB2
> >> tablespace RBS
> >> storage (
> >> initial 10 K next 10 K optimal 300 K
> >> minextents 20 maxextents 450);
> >>
> >> ORA-01593: rollback segment optimal size (38 blks) is smaller than the
> >> computed initial size (80 blks)
> >>
> >> The db_block_size is 8192. Is the initial size of the rollback segment
> >> 200K?
> >>
> >> Sent via Deja.com http://www.deja.com/
> >> Before you buy.
> >>
> >
> >It depends upon the PCTINCREASE parameter of the RBS tablespace. If
> >the PCTINCREASE is set to 0 (which it should be) then the initial size
> >of the rollback segment would be 200K. However that is not the case
> >since ORACLE is calculating that 20 extents will consume 80 8K blocks
> >or 640K. I would think that your PCTINCREASE is set at the default for
> >the tablespace, which is 50. Alter the PCTINCREASE value for the RBS
> >tablespace:
> >
> >ALTER TABLESPACE RBS
> >DEFAULT STORAGE(PCTINCREASE 0);
> >
> >and then create your rollback segment.
> >
> >--
> >David Fitzjarrell
> >Oracle Certified DBA
> >
> >
> >Sent via Deja.com http://www.deja.com/
> >Before you buy.
>
>

Sent via Deja.com http://www.deja.com/
Before you buy. Received on Thu Nov 16 2000 - 11:54:43 CST