Re: Failure to Extend Rollback

A copy of this was sent to Kenneth C Stahl <BluesSax_at_Unforgettable.com> (if that email address didn't require changing) On Mon, 30 Aug 1999 08:15:59 -0400, you wrote:

>g.renfrew_at_acca.org.uk wrote:
>
>> Hi, quick question about rollback extents.
>>
>> I'm getting an ORA-1650 (rdbms 7.3.4.4/ solaris 2.7) on the RBS
>> tablespace. Next extent size is 1048567. However, the database is
>> unable to allocate this extent due to lack of contiguous free space.
>> However, it looks to me like there is enough space (see query below).
>> Why does an extent of 1048567 bytes not fit into the free space I've
>> got?
>>
>> SQL> select bytes, count(bytes)
>> 2 from dba_free_space
>> 3 where tablespace_name = 'RBS'
>> 4 group by bytes;
>>
>> BYTES COUNT(BYTES)
>> ---------- ------------
>> 940032 1
>> 1054720 63
>>
>> Many thanks.
>
>You might want to change your extent size to 1048576 vice 1048567 since
>the former is a multiple of 2 while the second is not.
>
>Only INITIAL extents require contiguous storage. NEXT extents can be
>non-contiguous.
>

All extents, whether they are initial or next, are contigous collections of blocks. All extents are contigous collections of stuff.

extents do not have to be contigous with each other but each extent must be contigous within itself (eg: cannot span files, cannot consist of blocks that do not 'touch' eachother).

>What it really looks like is that your data file is too small.
>

according to the above query though, they have at least 63 contigous free extents each of 1054720 bytes. They are asking for 1048567 bytes -- the appear to have enough free space (they are asking for 512 blocks and have 515 blocks free but what I think is happening is their rollback segment is not in that tablespace (RBS)... The 1048567 byte extent would fit there. I've tested this -- given the space above and the extent sizes -- the extent should fit.

>Ken

--
See http://govt.us.oracle.com/~tkyte/ for my columns 'Digging-in to Oracle8i'... Current article is "Part I of V, Autonomous Transactions" updated June 21'st  

Thomas Kyte                   tkyte_at_us.oracle.com
Oracle Service Industries     Reston, VA   USA

Opinions are mine and do not necessarily reflect those of Oracle Corporation Received on Mon Aug 30 1999 - 10:22:54 CDT