Drop a datafile

Question

Hello, I was adding data files to a tablespace and I added one that I did not want so I did an "alter database datafile... offline drop'. The file is still there. Is there a way to get rid of it, hopefully without bringing down the database. Thank you,
David

Answer 1

Even if this is dirty to have an unused referenced file... and if you haven't any extent into this datafile it should work :
Connected to:
Oracle9i Enterprise Edition Release 9.2.0.8.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.8.0 - Production
SQL> create tablespace test datafile 'E:\oracle\oradata\DEMO92\TEST01.DBF' size 10M;
Tablespace created.
SQL> create table emp tablespace test as select * from scott.emp;
Table created.
SQL> select tablespace_name from user_tables where table_name = 'EMP'
SQL> /
TABLESPACE_NAME
TEST
SQL> alter tablespace test add datafile 'E:\oracle\oradata\DEMO92\TEST02.DBF' size 10M
SQL> /
Tablespace altered.
SQL> select file_name,bytes from dba_data_files where tablespace_name = 'TEST'
SQL> /
FILE_NAME                                  BYTES
E:\ORACLE\ORADATA\DEMO92\TEST01.DBF     10485760
E:\ORACLE\ORADATA\DEMO92\TEST02.DBF     10485760
SQL> alter database datafile 'E:\ORACLE\ORADATA\DEMO92\TEST02.DBF' offline drop;
Database altered.
SQL> select file_name,bytes from dba_data_files where tablespace_name = 'TEST'
  2  /
FILE_NAME                                  BYTES
E:\ORACLE\ORADATA\DEMO92\TEST01.DBF     10485760
E:\ORACLE\ORADATA\DEMO92\TEST02.DBF    
SQL> select count(*) from emp;
  COUNT(*)
        14
SQL> select tablespace_name from user_tables where table_name = 'EMP'
  2  /
TABLESPACE_NAME
TEST
SQL> select file_name,bytes, status from dba_data_files where tablespace_name = 'TEST';
FILE_NAME                                  BYTES STATUS
E:\ORACLE\ORADATA\DEMO92\TEST01.DBF     10485760 AVAILABLE
E:\ORACLE\ORADATA\DEMO92\TEST02.DBF              AVAILABLE
SQL> begin
  2  for i in 1..10 loop
  3   insert into emp select * from emp;
  4  end loop;
  5* end;
SQL> /
PL/SQL procedure successfully completed.
SQL> commit;
Commit complete.
SQL> select count(*) from emp;
  COUNT(*)
     14336
SQL> select sum(bytes) from user_extents where segment_name='EMP';
SUM(BYTES)
   9437184
SQL> insert into emp select * from emp;
insert
ERROR at line 1:
ORA-01653: unable to extend table SYSTEM.EMP by 128 in tablespace TEST
ORA-06512: at line 1
SQL> alter tablespace test add datafile 'E:\oracle\oradata\DEMO92\TEST03.DBF' size 10M;
Tablespace altered.
SQL> insert into emp select * from emp;
14336 rows created.
SQL> select count(*) from emp;
  COUNT(*)
     28672
SQL> select sum(bytes) from user_extents where segment_name='EMP';
SUM(BYTES)
  18874368
SQL> select file_name,bytes, status from dba_data_files where tablespace_name = 'TEST';
FILE_NAME                                  BYTES STATUS
E:\ORACLE\ORADATA\DEMO92\TEST01.DBF     10485760 AVAILABLE
E:\ORACLE\ORADATA\DEMO92\TEST02.DBF              AVAILABLE
E:\ORACLE\ORADATA\DEMO92\TEST03.DBF     10485760 AVAILABLE
--here I drop the file from the disk
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.
Total System Global Area  135339604 bytes
Fixed Size                   454228 bytes
Variable Size             109051904 bytes
Database Buffers           25165824 bytes
Redo Buffers                 667648 bytes
Database mounted.
Database opened.
SQL> select file_name, status from dba_data_files where tablespace_name='TEST'
FILE_NAME                               STATUS
E:\ORACLE\ORADATA\DEMO92\TEST01.DBF     AVAILABLE
E:\ORACLE\ORADATA\DEMO92\TEST02.DBF     AVAILABLE
E:\ORACLE\ORADATA\DEMO92\TEST03.DBF     AVAILABLE
SQL> drop tablespace test including contents and datafiles;
Tablespace dropped.
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.
Total System Global Area  135339604 bytes
Fixed Size                   454228 bytes
Variable Size             109051904 bytes
Database Buffers           25165824 bytes
Redo Buffers                 667648 bytes
Database mounted.
Database opened.
SQL>Nicolas.