SQL> show user USER is "SYS" SQL> select default_tablespace from dba_users where username='SYS'; DEFAULT_TABLESPACE ------------------------------ SYSTEM SQL> select sum(a.bytes) as "total_space", sum(b.bytes) as "free_space" from dba_data_files a, dba_free_space b 2 where a.file_id=b.file_id 3 and a.tablespace_name='SYSTEM'; total_space free_space ----------- ---------- 754974720 5308416 SQL> SQL> CREATE TABLE varchar2_test3 (col1 VARCHAR2(50)); Table created. SQL> SQL> select sum(a.bytes) as "total_space", sum(b.bytes) as "free_space" from dba_data_files a, dba_free_space b 2 where a.file_id=b.file_id 3 and a.tablespace_name='SYSTEM'; total_space free_space ----------- ---------- 377487360 5242880 SQL> SQL> select bytes from dba_segments where segment_name='VARCHAR2_TEST3'; BYTES ---------- 65536 SQL> SQL> SELECT col1, length(col1), dump(col1) "ASCII Dump" FROM varchar2_test3; no rows selected SQL> select 5308416-5242880 from dual; 5308416-5242880 --------------- 65536 SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> SELECT col1, length(col1), dump(col1) "ASCII Dump" FROM varchar2_test3; COL1 LENGTH(COL1) -------------------------------------------------- ------------ ASCII Dump -------------------------------------------------------------------------------- qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> INSERT INTO varchar2_test3 VALUES ('qwerty'); 1 row created. SQL> SELECT col1, length(col1), dump(col1) "ASCII Dump" FROM varchar2_test3; COL1 LENGTH(COL1) -------------------------------------------------- ------------ ASCII Dump -------------------------------------------------------------------------------- qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 COL1 LENGTH(COL1) -------------------------------------------------- ------------ ASCII Dump -------------------------------------------------------------------------------- qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 COL1 LENGTH(COL1) -------------------------------------------------- ------------ ASCII Dump -------------------------------------------------------------------------------- qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 COL1 LENGTH(COL1) -------------------------------------------------- ------------ ASCII Dump -------------------------------------------------------------------------------- qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 COL1 LENGTH(COL1) -------------------------------------------------- ------------ ASCII Dump -------------------------------------------------------------------------------- qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 COL1 LENGTH(COL1) -------------------------------------------------- ------------ ASCII Dump -------------------------------------------------------------------------------- qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 COL1 LENGTH(COL1) -------------------------------------------------- ------------ ASCII Dump -------------------------------------------------------------------------------- qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 COL1 LENGTH(COL1) -------------------------------------------------- ------------ ASCII Dump -------------------------------------------------------------------------------- qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 COL1 LENGTH(COL1) -------------------------------------------------- ------------ ASCII Dump -------------------------------------------------------------------------------- qwerty 6 Typ=1 Len=6: 113,119,101,114,116,121 25 rows selected. SQL> commit; Commit complete. SQL> select sum(a.bytes) as "total_space", sum(b.bytes) as "free_space" from dba_data_files a, dba_free_space b 2 where a.file_id=b.file_id 3 and a.tablespace_name='SYSTEM'; total_space free_space ----------- ---------- 377487360 5242880 SQL> SQL> select bytes from dba_segments where segment_name='VARCHAR2_TEST3' 2 ; BYTES ---------- 65536 SQL> CREATE TABLE varchar2_test4 (col1 VARCHAR2(500)); Table created. SQL> select bytes from dba_segments where segment_name='VARCHAR2_TEST4'; BYTES ---------- 65536 SQL> SQL> spool off