Collations|V4.2.5| docs|Distributed Database

Collations

Last Updated：2025-11-19 10:08:12 Updated

The default collation of OceanBase Database is utf8mb4_general_ci.

The following table describes the collations supported by OceanBase Database.

Collation	Character set	Description
utf8mb4_general_ci	utf8mb4	A general collation.
utf8mb4_bin	utf8mb4	A binary collation.
utf8mb4_unicode_ci	utf8mb4	A collation that is based on Unicode Collation Algorithm (UCA).
utf8mb4_unicode_520_ci	utf8mb4	A collation that is based on Unicode 5.2.0. The collation sorts data based on their Unicode code points and is case-insensitive.
utf8mb4_general_ci	utf8mb4	A collation for Croatian. `utf8mb4_croatian_ci` is compatible with `utf8_croatian_ci`.
utf8mb4_czech_ci	utf8mb4	A collation for Czech.
utf8mb4_0900_ai_ci	utf8mb4	A collation that is based on Unicode 9.0.0. The collation is case-insensitive.
binary	binary	A binary collation.
gbk_chinese_ci	gbk	A collation for Chinese.
gbk_bin	gbk	A binary collation.
utf16_general_ci	utf16	A general collation.
utf16_bin	utf16	A binary collation.
utf16_unicode_ci	utf16	A collation that is based on UCA.
utf8mb4_german2_ci	utf16le	A collation for German.
utf8mb4_croatian_ci	utf16le	A collation for Croatian.
gb18030_chinese_ci	gb18030	A collation for Chinese.
gb18030_bin	gb18030	A binary collation.
latin1_swedish_ci	latin1	A collation for Swedish/Finnish.
latin1_bin	latin1	A binary collation.
gb18030_2022_bin	gb18030_2022	A binary collation.
gb18030_2022_chinese_ci	gb18030_2022	A collation that sorts data by Pinyin. The collation is case-insensitive. This is the default collation for this character set in MySQL mode.
gb18030_2022_chinese_cs	gb18030_2022	A collation that sorts data by Pinyin. The collation is case-sensitive.
gb18030_2022_radical_ci	gb18030_2022	A collation that sorts data by radicals. The collation is case-insensitive.
gb18030_2022_radical_cs	gb18030_2022	A collation that sorts data by radicals. The collation is case-sensitive.
gb18030_2022_stroke_ci	gb18030_2022	A collation that sorts data by strokes. The collation is case-insensitive.
gb18030_2022_stroke_cs	gb18030_2022	A collation that sorts data by strokes. The collation is case-sensitive.
ascii_bin	ascii	A binary collation that sorts data by binary digits. It uses characters as binary data for comparison and sorting.
ascii_general_ci	ascii	A collation that sorts data in alphabetical order. The collation is case-insensitive.
tis620_bin	tis620	A binary collation.
tis620_thai_ci	tis620	A collation for Thai. The collation is case-insensitive.
sjis_japanese_ci	sjis	A collation for Japanese.
dec8_swedish_ci	dec8	A collation for Swedish.

Note

For any Unicode character set, the operation is executed faster if the character set is sorted by a general collation xxx_general_ci instead of a Unicode collation xxx_unicode_ci.
You cannot modify the collations.

By default, you can execute the SHOW COLLATION statement to display all available collations.

obclient [(none)]> SHOW COLLATION;

The return result 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_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 |
+----------------------------+--------------+------+---------+----------+---------+
143 rows in set (0.013 sec)

General characteristics of collations are as follows:

Two different character sets cannot use the same collation.
Each character set uses a default collation. You can execute the SHOW CHARACTER SET statement to view the default collation of each character set. The execution result of the SHOW COLLATION statement has a column that indicates whether a collation is the default collation of its character set. If yes, the value is Yes. Otherwise, the value is empty.
The name of a collation starts with the name of the corresponding character set. In most cases, the name is followed by one or more suffix items that indicate other characteristics of the collation.