UNDO table space in oracle

Question

Hi,
Recently i have added one data file(2GB) to undo table space.Later i gog to know it is not recommend to extent the undo table space.In oracle 9i undo management is handle automatically.(in my init<SID>.ora file undo_management='AUTO')
I have 3 data file undo_1,undo_2,undo_3.
undo_2 is the datafile of 2Gb that i have added.
My question is ....is there any possibility to remove that data file from the DB(undo_2) if possible how can i dod that.
Pls help me.
roshantha

Answer 1

SQL> show parameter undo
NAME TYPE VALUE
undo_management string AUTO
undo_retention integer 900
undo_tablespace string UNDOTBS1
SQL>
SQL>
##FIRST : CREATE AN ANOTHER TEMPORARY UNDO TABLESPACE FOR YOUR DATABASE USERS.
SQL> create undo tablespace UNDOTBS_TEMP datafile 'c:\undotbs_temp1.dbf' size 2G;
Tablespace created.
SQL> show parameter undo
SQL> alter system set undo_tablespace=UNDOTBS_TEMP;
System altered.
SQL> show parameter undo
NAME TYPE VALUE
undo_management string AUTO
undo_retention integer 900
undo_tablespace string UNDOTBS_TEMP
##NOW DROP YOUR UNWANTED TABLESPACE INCLUDING DATAFILES
SQL> drop tablespace undotbs1;
Tablespace dropped.
SQL> drop tablespace undotbs2 including contents and datafiles;
Tablespace dropped.
##NOW RECREATE THE UNDOTBS and RUSE THE FILE YOU WANTED TO
SQL> create undo tablespace UNDOTBS1 datafile 'C:\ORACLE\PRODUCT\10.1.0\ORADATA\ORCL\UNDOTBS01.DBF' reuse;
Tablespace created.
SQL> alter system set undo_tablespace=UNDOTBS1;
System altered.
SQL> show parameter undo
NAME TYPE VALUE
undo_management string AUTO
undo_retention integer 900
undo_tablespace string UNDOTBS1
SQL>
hope it helps :-)
Thanks,
Z