I use below command to increase the size of table/file .
SQL> select FILE_NAME from dba_data_files where TABLESPACE_NAME='RCA_CFM_PROP_DATA';


alter database datafile '/gxsdb/database/oradata4/RCA/RCA_REF_CFM_PROP_DATA.dbf' resize 1M;

After this , I want to reduce back the size of the table/file again in order to save the space ???
It is already alter for a while/period of time .
How can I fall back ???
Any suggestion ??