In Oracle database 12c forward, by default, character set AL32UTF8 is installed. It takes 1 byte to store English character, but 3 bytes for a Chinese character.

For example:

select ename, length(ename), lengthb(ename), empno, length(empno),lengthb(empno)

from emp001;

ENAME     LENGTH(ENAME) LENGTHB(ENAME)      EMPNO LENGTH(EMPNO) LENGTHB(EMPNO)

-------------------- ------------- -------------- ---------- ------------- --------------

郭靖                             2              6        100             3              3

黃蓉                             2              6        200             3              3

裘千尺                           3              9        300             3              3

洪七公                           3              9        400             3              3

楊過                             2              6        600             3              3

梅超風(fēng)                           3              9        500             3              3

From storage point view, deciding to use Chinese characters in the table values, table or column names would cost 3 times more space 

usage than its English counterpart. When some applications, like bank, transportation, telecoms industry,

require to handle multi-languages, AL32UTF8 would be preferred character set, and storage consumption would be significant.