This might be true on dictionary managed tablespaces and LMT Uniform size, but not so for LMT Autoallocate : SQL> create tablespace koert extent management local autoallocate datafile 'c:\d 1.dbf' size 10M, 'c:\d2.dbf' size 10M, 'c:\d3.dbf' size 10M, 'c:\d4.dbf' size 10 M ; Tablespace created. SQL> select file_id, file_name from dba_data_files where tablespace_name='KOERT' ; FILE_ID ---------- FILE_NAME ---------------------------------------------------------------------------- ---- 7 C:\D1.DBF 8 C:\D2.DBF 9 C:\D3.DBF 10 C:\D4.DBF SQL> create table t (n number) tablespace koert ; Table created. SQL> insert into t select object_id from dba_objects ; 44129 rows created. SQL> commit ; Commit complete. SQL> select file_id, extent_id from dba_extents where owner='SYS' and segment_name='T' ; FILE_ID EXTENT_ID ---------- ---------- 10 0 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 9 rows selected. cheers, Kurt At 11:59 6/10/2006 +0200, Christian Antognini wrote: >Alex > >> Suppose we have 4 datafiles in a tablespace, when we load data into >> this tablespace how will Oracle assign the space? I thought it would >> use round-robin like but it does not. > >Extents allocation is performed round-robin for a segment. Here an >example... > >SQL> create tablespace t > 2 datafile '/tmp/t1.dbf' size 10m, > 3 '/tmp/t2.dbf' size 10m, > 4 '/tmp/t3.dbf' size 10m, > 5 '/tmp/t4.dbf' size 10m > 6 extent management local uniform size 1m; > >SQL> select file_id, file_name > 2 from dba_data_files > 3 where tablespace_name = 'T'; > > FILE_ID FILE_NAME >---------- ---------------------------------------- > 5 /tmp/t1.dbf > 6 /tmp/t2.dbf > 7 /tmp/t3.dbf > 8 /tmp/t4.dbf > >SQL> create table t (n number) > 2 tablespace t > 3 storage (initial 20m); > >SQL> select file_id, extent_id > 2 from dba_extents > 3 where owner = user and segment_name = 'T' > 4 order by extent_id; > > FILE_ID EXTENT_ID >---------- ---------- > 6 0 > 7 1 > 8 2 > 5 3 > 6 4 > 7 5 > 8 6 > 5 7 > 6 8 > 7 9 > 8 10 > 5 11 > 6 12 > 7 13 > 8 14 > 5 15 > 6 16 > 7 17 > 8 18 > 5 19 > >SQL> drop tablespace t including contents and datafiles; > > > >HTH >Chris >-- >//www.freelists.org/webpage/oracle-l > > -- Kurt Van Meerbeeck kurtvm@xxxxxxxxxx kurt_van_meerbeeck@xxxxxx dude@xxxxxxxxxx http://www.ora600.org Imagination is more important than knowledge... (A.Einstein) You can have many different jobs and still be lazy... (H.Simpson) -- //www.freelists.org/webpage/oracle-l