1. Manually change the data file size
SQL> conn/as sysdba
SQL> Createtablespace exampletb Datafile 'e: \ examp01.dbf' size 10 M;
SQL> alter database datafile 'e: \ examp01.dbf' resize 20 m;
SQL> alter database datafile 'e: \ examp01.dbf' resize 9 m;
2. Add data files to the tablespace
SQL> alter tablespace exampletb add datafile 'e: \ examp02.dbf' size 10 M;
3. delete data files from tablespace
SQL> alter tablespace exampletb drop datafile 'e: \ examp02.dbf ';
4. Set the tablespace to read-only and read-write modes.
SQL> CREATETABLE scott. student (id NUMBER (5), name VARCHAR2 (10) TABLESPACE exampletb;
SQL> insertinto scott. student (id, name) values (1, 'Lucy ');
SQL> alter tablespace exampletb read only;
SQL> insertinto scott. student (id, name) values (2, 'lily ');
SQL> select * from scott. student;
SQL> alter tablespace exampletb read write;
SQL> insertinto scott. student (id, name) values (2, 'lily ');
5. Set the tablespace to online or offline.
SQL> alter tablespace exampletb offline;
SQL> select * from scott. student;
SQL> alter tablespace exampletb online;
SQL> select * from scott. student;
6. query table space and data files
SQL> select * from v $ tablespace;
SQL> select * from dba_tablespaces;
SQL> select * from v $ datafile;
SQL> select * from dba_data_files;