Character sets|V4.2.5| docs|Distributed Database

Character sets

Last Updated：2026-02-11 07:43:39 Updated

The default character set of OceanBase Database is utf8mb4_general_ci.

OceanBase Database supports the character sets listed in the following table.

Character set	Collation	Description
utf8mb4_general_ci	utf8mb4	Uses the general collation rule.
utf8mb4_bin	utf8mb4	Uses the binary collation rule.
utf8mb4_unicode_ci	utf8mb4	Uses the Unicode Collation Algorithm (UCA) collation rule.
utf8mb4_unicode_520_ci	utf8mb4	Uses the collation rule of Unicode 5.2.0. It follows the Unicode code point collation and ignores the case sensitivity.
utf8mb4_croatian_ci	utf8mb4	Uses the Croatian collation rule. `utf8mb4_croatian_ci` is compatible with `utf8_croatian_ci`.
utf8mb4_czech_ci	utf8mb4	Uses the Czech collation rule.
utf8mb4_0900_ai_ci	utf8mb4	Uses the collation rule of Unicode 9.0.0. It ignores the case sensitivity and treats uppercase and lowercase letters as the same character.
binary	binary	Uses the binary collation rule.
gbk_chinese_ci	gbk	Uses the Chinese collation rule.
gbk_bin	gbk	Uses the binary collation rule.
utf16_general_ci	utf16	Uses the general collation rule.
utf16_bin	utf16	Uses the binary collation rule.
utf16_unicode_ci	utf16	Uses the Unicode Collation Algorithm (UCA) collation rule.
utf8mb4_german2_ci	utf16le	Uses the German collation rule.
utf8mb4_croatian_ci	utf16le	Uses the Croatian collation rule.
gb18030_chinese_ci	gb18030	Uses the Chinese collation rule.
gb18030_bin	gb18030	Uses the binary collation rule.
latin1_swedish_ci	latin1	Uses the Swedish/Finnish collation rule.
latin1_german1_ci	latin1	The collation rule for the Latin1 character set in the German language environment. Note For OceanBase Database V4.2.5, this collation is supported starting from V4.2.5 BP1.
latin1_danish_ci	latin1	The collation rule for the Latin1 character set in the Danish language environment. Note For OceanBase Database V4.2.5, this collation is supported starting from V4.2.5 BP1.
latin1_german2_ci	latin1	The collation rule for the German language environment, suitable for applications that require character comparison based on dictionary order. Note For OceanBase Database V4.2.5, this collation is supported starting from V4.2.5 BP1.
latin1_general_ci	latin1	The collation rule for scenarios that require case-insensitive comparison and support for accents, such as in the design of certain European language databases. Note For OceanBase Database V4.2.5, this collation is supported starting from V4.2.5 BP1.
latin1_general_cs	latin1	The case-sensitive general collation rule, supporting multiple languages (such as Western European languages). Note For OceanBase Database V4.2.5, this collation is supported starting from V4.2.5 BP1.
latin1_spanish_ci	latin1	The collation rule for the Spanish language environment. Note For OceanBase Database V4.2.5, this collation is supported starting from V4.2.5 BP1.
latin1_bin	latin1	The Latin1 character set uses the binary collation rule.
gb18030_2022_bin	gb18030_2022	Uses the binary collation rule.
gb18030_2022_chinese_ci	gb18030_2022	Uses the pinyin collation rule. Case-insensitive. The default collation for this character set in MySQL mode.
gb18030_2022_chinese_cs	gb18030_2022	Uses the pinyin collation rule. Case-sensitive.
gb18030_2022_radical_ci	gb18030_2022	Uses the radical-stroke collation rule. Case-insensitive.
gb18030_2022_radical_cs	gb18030_2022	Uses the radical-stroke collation rule. Case-sensitive.
gb18030_2022_stroke_ci	gb18030_2022	Uses the stroke collation rule. Case-insensitive.
gb18030_2022_stroke_cs	gb18030_2022	Uses the stroke collation rule. Case-sensitive.
ascii_bin	ascii	The collation rule is based on binary bit comparison. It compares and sorts characters as binary data.
ascii_general_ci	ascii	The collation rule is based on case-insensitive letter sorting. It ignores the case sensitivity and treats uppercase and lowercase letters as the same character.
tis620_bin	tis620	Uses the binary collation rule.
tis620_thai_ci	tis620	Uses the Thai collation rule, case-insensitive.
sjis_japanese_ci	sjis	Uses the Japanese collation rule.
dec8_swedish_ci	dec8	Uses the Swedish collation rule.

Note

For any Unicode character set, operations performed using the xxx_general_ci collation are faster than those performed using the xxx_unicode_ci collation.
Character set collations cannot be modified.

By default, the SHOW COLLATION statement displays all available collations.

obclient [(none)]> SHOW COLLATION;

The result set is as follows:

+----------------------------+--------------+------+---------+----------+---------+
| Collation                  | Charset      | Id   | Default | Compiled | Sortlen |
+----------------------------+--------------+------+---------+----------+---------+
| utf8mb4_general_ci         | utf8mb4      |   45 | Yes     | Yes      |       1 |
| utf8mb4_bin                | utf8mb4      |   46 |         | Yes      |       1 |
| binary                     | binary       |   63 | Yes     | Yes      |       1 |
| gbk_chinese_ci             | gbk          |   28 | Yes     | Yes      |       1 |
| gbk_bin                    | gbk          |   87 |         | Yes      |       1 |
| utf16_general_ci           | utf16        |   54 | Yes     | Yes      |       1 |
| utf16_bin                  | utf16        |   55 |         | Yes      |       1 |
| gb18030_chinese_ci         | gb18030      |  248 | Yes     | Yes      |       2 |
| gb18030_bin                | gb18030      |  249 |         | Yes      |       1 |
| latin1_swedish_ci          | latin1       |    8 | Yes     | Yes      |       1 |
| latin1_german1_ci          | latin1       |    5 |         | Yes      |       1 |
| latin1_danish_ci           | latin1       |   15 |         | Yes      |       1 |
| latin1_german2_ci          | latin1       |   31 |         | Yes      |       1 |
| latin1_general_ci          | latin1       |   48 |         | Yes      |       1 |
| latin1_general_cs          | latin1       |   49 |         | Yes      |       1 |
| latin1_spanish_ci          | latin1       |   94 |         | Yes      |       1 |
| latin1_bin                 | latin1       |   47 |         | Yes      |       1 |
| gb18030_2022_bin           | gb18030_2022 |  216 |         | Yes      |       1 |
| gb18030_2022_chinese_ci    | gb18030_2022 |  217 | Yes     | Yes      |       1 |
| gb18030_2022_chinese_cs    | gb18030_2022 |  218 |         | Yes      |       1 |
| gb18030_2022_radical_ci    | gb18030_2022 |  219 |         | Yes      |       1 |
| gb18030_2022_radical_cs    | gb18030_2022 |  220 |         | Yes      |       1 |
| gb18030_2022_stroke_ci     | gb18030_2022 |  221 |         | Yes      |       1 |
| gb18030_2022_stroke_cs     | gb18030_2022 |  222 |         | Yes      |       1 |
| ascii_general_ci           | ascii        |   11 | Yes     | Yes      |       1 |
| ascii_bin                  | ascii        |   65 |         | Yes      |       1 |
| tis620_thai_ci             | tis620       |   18 | Yes     | Yes      |       1 |
| tis620_bin                 | tis620       |   89 |         | Yes      |       1 |
| utf16le_general_ci         | utf16le      |   56 | Yes     | Yes      |       1 |
| utf16le_bin                | utf16le      |   62 |         | Yes      |       1 |
| sjis_japanese_ci           | sjis         |   13 | Yes     | Yes      |       1 |
| sjis_bin                   | sjis         |   88 |         | Yes      |       1 |
| big5_chinese_ci            | big5         |    1 | Yes     | Yes      |       1 |
| big5_bin                   | big5         |   84 |         | Yes      |       1 |
| hkscs_bin                  | hkscs        |  152 | Yes     | Yes      |       1 |
| hkscs31_bin                | hkscs31      |  153 | Yes     | Yes      |       1 |
| utf16_unicode_ci           | utf16        |  101 |         | Yes      |       8 |
| utf16_icelandic_ci         | utf16        |  102 |         | Yes      |       8 |
| utf16_latvian_ci           | utf16        |  103 |         | Yes      |       8 |
| utf16_romanian_ci          | utf16        |  104 |         | Yes      |       8 |
| utf16_slovenian_ci         | utf16        |  105 |         | Yes      |       8 |
| utf16_polish_ci            | utf16        |  106 |         | Yes      |       8 |
| utf16_estonian_ci          | utf16        |  107 |         | Yes      |       8 |
| utf16_spanish_ci           | utf16        |  108 |         | Yes      |       8 |
| utf16_swedish_ci           | utf16        |  109 |         | Yes      |       8 |
| utf16_turkish_ci           | utf16        |  110 |         | Yes      |       8 |
| utf16_czech_ci             | utf16        |  111 |         | Yes      |       8 |
| utf16_danish_ci            | utf16        |  112 |         | Yes      |       8 |
| utf16_lithuanian_ci        | utf16        |  113 |         | Yes      |       8 |
| utf16_slovak_ci            | utf16        |  114 |         | Yes      |       8 |
| utf16_spanish2_ci          | utf16        |  115 |         | Yes      |       8 |
| utf16_roman_ci             | utf16        |  116 |         | Yes      |       8 |
| utf16_persian_ci           | utf16        |  117 |         | Yes      |       8 |
| utf16_esperanto_ci         | utf16        |  118 |         | Yes      |       8 |
| utf16_hungarian_ci         | utf16        |  119 |         | Yes      |       8 |
| utf16_sinhala_ci           | utf16        |  120 |         | Yes      |       8 |
| utf16_german2_ci           | utf16        |  121 |         | Yes      |       8 |
| utf16_croatian_ci          | utf16        |  122 |         | Yes      |       8 |
| utf16_unicode_520_ci       | utf16        |  123 |         | Yes      |       8 |
| utf16_vietnamese_ci        | utf16        |  124 |         | Yes      |       8 |
| utf8mb4_unicode_ci         | utf8mb4      |  224 |         | Yes      |       8 |
| utf8mb4_icelandic_ci       | utf8mb4      |  225 |         | Yes      |       8 |
| utf8mb4_latvian_ci         | utf8mb4      |  226 |         | Yes      |       8 |
| utf8mb4_romanian_ci        | utf8mb4      |  227 |         | Yes      |       8 |
| utf8mb4_slovenian_ci       | utf8mb4      |  228 |         | Yes      |       8 |
| utf8mb4_polish_ci          | utf8mb4      |  229 |         | Yes      |       8 |
| utf8mb4_estonian_ci        | utf8mb4      |  230 |         | Yes      |       8 |
| utf8mb4_spanish_ci         | utf8mb4      |  231 |         | Yes      |       8 |
| utf8mb4_swedish_ci         | utf8mb4      |  232 |         | Yes      |       8 |
| utf8mb4_turkish_ci         | utf8mb4      |  233 |         | Yes      |       8 |
| utf8mb4_czech_ci           | utf8mb4      |  234 |         | Yes      |       8 |
| utf8mb4_danish_ci          | utf8mb4      |  235 |         | Yes      |       8 |
| utf8mb4_lithuanian_ci      | utf8mb4      |  236 |         | Yes      |       8 |
| utf8mb4_slovak_ci          | utf8mb4      |  237 |         | Yes      |       8 |
| utf8mb4_spanish2_ci        | utf8mb4      |  238 |         | Yes      |       8 |
| utf8mb4_roman_ci           | utf8mb4      |  239 |         | Yes      |       8 |
| utf8mb4_persian_ci         | utf8mb4      |  240 |         | Yes      |       8 |
| utf8mb4_esperanto_ci       | utf8mb4      |  241 |         | Yes      |       8 |
| utf8mb4_hungarian_ci       | utf8mb4      |  242 |         | Yes      |       8 |
| utf8mb4_sinhala_ci         | utf8mb4      |  243 |         | Yes      |       8 |
| utf8mb4_german2_ci         | utf8mb4      |  244 |         | Yes      |       8 |
| utf8mb4_croatian_ci        | utf8mb4      |  245 |         | Yes      |       8 |
| utf8mb4_unicode_520_ci     | utf8mb4      |  246 |         | Yes      |       8 |
| utf8mb4_vietnamese_ci      | utf8mb4      |  247 |         | Yes      |       8 |
| dec8_swedish_ci            | dec8         |    3 | Yes     | Yes      |       8 |
| dec8_bin                   | dec8         |   69 |         | Yes      |       8 |
| utf8mb4_0900_ai_ci         | utf8mb4      |  255 |         | Yes      |       0 |
| utf8mb4_de_pb_0900_ai_ci   | utf8mb4      |  256 |         | Yes      |       0 |
| utf8mb4_is_0900_ai_ci      | utf8mb4      |  257 |         | Yes      |       0 |
| utf8mb4_lv_0900_ai_ci      | utf8mb4      |  258 |         | Yes      |       0 |
| utf8mb4_ro_0900_ai_ci      | utf8mb4      |  259 |         | Yes      |       0 |
| utf8mb4_sl_0900_ai_ci      | utf8mb4      |  260 |         | Yes      |       0 |
| utf8mb4_pl_0900_ai_ci      | utf8mb4      |  261 |         | Yes      |       0 |
| utf8mb4_et_0900_ai_ci      | utf8mb4      |  262 |         | Yes      |       0 |
| utf8mb4_es_0900_ai_ci      | utf8mb4      |  263 |         | Yes      |       0 |
| utf8mb4_sv_0900_ai_ci      | utf8mb4      |  264 |         | Yes      |       0 |
| utf8mb4_tr_0900_ai_ci      | utf8mb4      |  265 |         | Yes      |       0 |
| utf8mb4_cs_0900_ai_ci      | utf8mb4      |  266 |         | Yes      |       0 |
| utf8mb4_da_0900_ai_ci      | utf8mb4      |  267 |         | Yes      |       0 |
| utf8mb4_lt_0900_ai_ci      | utf8mb4      |  268 |         | Yes      |       0 |
| utf8mb4_sk_0900_ai_ci      | utf8mb4      |  269 |         | Yes      |       0 |
| utf8mb4_es_trad_0900_ai_ci | utf8mb4      |  270 |         | Yes      |       0 |
| utf8mb4_la_0900_ai_ci      | utf8mb4      |  271 |         | Yes      |       0 |
| utf8mb4_eo_0900_ai_ci      | utf8mb4      |  273 |         | Yes      |       0 |
| utf8mb4_hu_0900_ai_ci      | utf8mb4      |  274 |         | Yes      |       0 |
| utf8mb4_hr_0900_ai_ci      | utf8mb4      |  275 |         | Yes      |       0 |
| utf8mb4_vi_0900_ai_ci      | utf8mb4      |  277 |         | Yes      |       0 |
| utf8mb4_0900_as_cs         | utf8mb4      |  278 |         | Yes      |       0 |
| utf8mb4_de_pb_0900_as_cs   | utf8mb4      |  279 |         | Yes      |       0 |
| utf8mb4_is_0900_as_cs      | utf8mb4      |  280 |         | Yes      |       0 |
| utf8mb4_lv_0900_as_cs      | utf8mb4      |  281 |         | Yes      |       0 |
| utf8mb4_ro_0900_as_cs      | utf8mb4      |  282 |         | Yes      |       0 |
| utf8mb4_sl_0900_as_cs      | utf8mb4      |  283 |         | Yes      |       0 |
| utf8mb4_pl_0900_as_cs      | utf8mb4      |  284 |         | Yes      |       0 |
| utf8mb4_et_0900_as_cs      | utf8mb4      |  285 |         | Yes      |       0 |
| utf8mb4_es_0900_as_cs      | utf8mb4      |  286 |         | Yes      |       0 |
| utf8mb4_sv_0900_as_cs      | utf8mb4      |  287 |         | Yes      |       0 |
| utf8mb4_tr_0900_as_cs      | utf8mb4      |  288 |         | Yes      |       0 |
| utf8mb4_cs_0900_as_cs      | utf8mb4      |  289 |         | Yes      |       0 |
| utf8mb4_da_0900_as_cs      | utf8mb4      |  290 |         | Yes      |       0 |
| utf8mb4_lt_0900_as_cs      | utf8mb4      |  291 |         | Yes      |       0 |
| utf8mb4_sk_0900_as_cs      | utf8mb4      |  292 |         | Yes      |       0 |
| utf8mb4_es_trad_0900_as_cs | utf8mb4      |  293 |         | Yes      |       0 |
| utf8mb4_la_0900_as_cs      | utf8mb4      |  294 |         | Yes      |       0 |
| utf8mb4_eo_0900_as_cs      | utf8mb4      |  296 |         | Yes      |       0 |
| utf8mb4_hu_0900_as_cs      | utf8mb4      |  297 |         | Yes      |       0 |
| utf8mb4_hr_0900_as_cs      | utf8mb4      |  298 |         | Yes      |       0 |
| utf8mb4_vi_0900_as_cs      | utf8mb4      |  300 |         | Yes      |       0 |
| utf8mb4_ja_0900_as_cs      | utf8mb4      |  303 |         | Yes      |       0 |
| utf8mb4_ja_0900_as_cs_ks   | utf8mb4      |  304 |         | Yes      |      24 |
| utf8mb4_0900_as_ci         | utf8mb4      |  305 |         | Yes      |       0 |
| utf8mb4_ru_0900_ai_ci      | utf8mb4      |  306 |         | Yes      |       0 |
| utf8mb4_ru_0900_as_cs      | utf8mb4      |  307 |         | Yes      |       0 |
| utf8mb4_zh_0900_as_cs      | utf8mb4      |  308 |         | Yes      |       0 |
| utf8mb4_0900_bin           | utf8mb4      |  309 |         | Yes      |       1 |
| utf8mb4_nb_0900_ai_ci      | utf8mb4      |  310 |         | Yes      |       0 |
| utf8mb4_nb_0900_as_cs      | utf8mb4      |  311 |         | Yes      |       0 |
| utf8mb4_nn_0900_ai_ci      | utf8mb4      |  312 |         | Yes      |       0 |
| utf8mb4_nn_0900_as_cs      | utf8mb4      |  313 |         | Yes      |       0 |
| utf8mb4_sr_latn_0900_ai_ci | utf8mb4      |  314 |         | Yes      |       0 |
| utf8mb4_sr_latn_0900_as_cs | utf8mb4      |  315 |         | Yes      |       0 |
| utf8mb4_bs_0900_ai_ci      | utf8mb4      |  316 |         | Yes      |       0 |
| utf8mb4_bs_0900_as_cs      | utf8mb4      |  317 |         | Yes      |       0 |
| utf8mb4_bg_0900_ai_ci      | utf8mb4      |  318 |         | Yes      |       0 |
| utf8mb4_bg_0900_as_cs      | utf8mb4      |  319 |         | Yes      |       0 |
| utf8mb4_gl_0900_ai_ci      | utf8mb4      |  320 |         | Yes      |       0 |
| utf8mb4_gl_0900_as_cs      | utf8mb4      |  321 |         | Yes      |       0 |
| utf8mb4_mn_cyrl_0900_ai_ci | utf8mb4      |  322 |         | Yes      |       0 |
| utf8mb4_mn_cyrl_0900_as_cs | utf8mb4      |  323 |         | Yes      |       0 |
+----------------------------+--------------+------+---------+----------+---------+
149 rows in set

Character set collations have the following general characteristics:

Two different character sets cannot have the same collation.
Each character set has a default collation. The SHOW CHARACTER SET statement indicates the default collation for each character set. The SHOW COLLATION statement has a column that indicates whether a collation is the default for its character set (Yes if it is, otherwise empty).
The name of a collation starts with the name of the character set to which it is associated, and is usually followed by one or more suffixes that indicate other collation characteristics.