1969 Supported Character Sets and Collations •For replication, if character sets that support supplementary characters are to be used on the source, all replicas must understand them as well. Also, keep in mind the general principle that if a table has different definitions on the source and replica, this can lead to unexpected results. For example, the differences in maximum index key length make it risky to use  utf8mb3  on the source and  utf8mb4  on the replica. If you have converted to  utf8mb4 ,  utf16 ,  utf16le , or  utf32 , and then decide to convert back to utf8mb3  or  ucs2  (for example, to downgrade to an older version of MySQL), these considerations apply: • utf8mb3  and  ucs2  data should present no problems. •The server must be recent enough to recognize definitions referring to the character set from which you are converting. •For object definitions that refer to the  utf8mb4  character set, you can dump them with  mysqldump  prior to downgrading, edit the dump file to change instances of  utf8mb4  to  utf8 , and reload the file in the older server, as long as there are no 4-byte characters in the data. The older server sees  utf8  in the dump file object definitions and create new objects that use the (3-byte)  utf8  character set. 10.10 Supported Character Sets and Collations This section indicates which character sets MySQL supports. There is one subsection for each group of related character sets. For each character set, the permissible collations are listed. To list the available character sets and their default collations, use the  SHOW CHARACTER SET  statement or query the  INFORMATION_SCHEMA CHARACTER_SETS  table. For example: mysql>  SHOW CHARACTER SET; +----------+---------------------------------+---------------------+--------+ | Charset | Description | Default collation | Maxlen | +----------+---------------------------------+---------------------+--------+ | armscii8 | ARMSCII-8 Armenian | armscii8_general_ci | 1 | | ascii | US ASCII | ascii_general_ci | 1 | | big5 | Big5 Traditional Chinese | big5_chinese_ci | 2 | | binary | Binary pseudo charset | binary | 1 | | cp1250 | Windows Central European | cp1250_general_ci | 1 | | cp1251 | Windows Cyrillic | cp1251_general_ci | 1 | | cp1256 | Windows Arabic | cp1256_general_ci | 1 | | cp1257 | Windows Baltic | cp1257_general_ci | 1 | | cp850 | DOS West European | cp850_general_ci | 1 | | cp852 | DOS Central European | cp852_general_ci | 1 | | cp866 | DOS Russian | cp866_general_ci | 1 | | cp932 | SJIS for Windows Japanese | cp932_japanese_ci | 2 | | dec8 | DEC West European | dec8_swedish_ci | 1 | | eucjpms | UJIS for Windows Japanese | eucjpms_japanese_ci | 3 | | euckr | EUC-KR Korean | euckr_korean_ci | 2 | | gb18030 | China National Standard GB18030 | gb18030_chinese_ci | 4 | | gb2312 | GB2312 Simplified Chinese | gb2312_chinese_ci | 2 | | gbk | GBK Simplified Chinese | gbk_chinese_ci | 2 | | geostd8 | GEOSTD8 Georgian | geostd8_general_ci | 1 | | greek | ISO 8859-7 Greek | greek_general_ci | 1 | | hebrew | ISO 8859-8 Hebrew | hebrew_general_ci | 1 | | hp8 | HP West European | hp8_english_ci | 1 | | keybcs2 | DOS Kamenicky Czech-Slovak | keybcs2_general_ci | 1 | | koi8r | KOI8-R Relcom Russian | koi8r_general_ci | 1 | | koi8u | KOI8-U Ukrainian | koi8u_general_ci | 1 | | latin1 | cp1252 West European | latin1_swedish_ci | 1 | | latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 | | latin5 | ISO 8859-9 Turkish | latin5_turkish_ci | 1 | | latin7 | ISO 8859-13 Baltic | latin7_general_ci | 1 | | macce | Mac Central European | macce_general_ci | 1 |