Oracle FAQ | Your Portal to the Oracle Knowledge Grid |
Home -> Community -> Mailing Lists -> Oracle-L -> Re: DATAFILE??
On 10/18/05, oracle-l-bounce_at_freelists.org <oracle-l-bounce_at_freelists.org>
wrote:
>
> The best way to find out is to try it. You will probably find that it
> depends. If you use a LMT and do uniform extents then it will do it by
> concatenation. (fill up the first file then move on to the 2nd etc.).
> If you create an LMT and do automatic extents then it is different. It
> does it by striping. The first extent goes in the first file, the 2nd
> in the 2nd file...
>
> You can see this by setting up a small test.
> Jim
Unfortunately, if you run the test you'll find that your assertion isn't correct on 10gR1 :)
1 create tablespace demo
2 datafile 'c:\temp\demo01.dbf' size 10m,'c:\temp\demo02.dbf' size 10m
3* extent management local uniform size 128k
USER @ orcl>/
Tablespace created.
USER @ orcl>create table t1(c1 number);
create table t1(c1 number)
*
ERROR at line 1:
ORA-00955: name is already used by an existing object
USER @ orcl>create table demo(c1 number);
Table created.
USER @ orcl>drop table demo;
Table dropped.
USER @ orcl>create table demo(c1 number) 2 tablespace demo;
Table created.
USER @ orcl>alter table demo allocate extent;
Table altered.
USER @ orcl>alter table demo allocate extent;
Table altered.
USER @ orcl>alter table demo allocate extent;
Table altered.
USER @ orcl>alter table demo allocate extent;
Table altered.
USER @ orcl>alter table demo allocate extent;
Table altered.
USER@ orcl>alter table demo allocate extent;
Table altered.
USER @ orcl>select file_id,count(*)
2 from dba_extents
3 where segment_name='DEMO'
4 group by file_id;
FILE_ID COUNT(*)
---------- ----------
9 4
10 3
2 rows selected.
--
Niall Litchfield
Oracle DBA
http://www.niall.litchfield.dial.pipex.com
-- http://www.freelists.org/webpage/oracle-lReceived on Thu Oct 20 2005 - 05:32:32 CDT