MDEV-36213 Doubled memory usage (11.4.4 <-> 11.4.5)

Fixing the code adding MySQL _0900_ collations as _uca1400_ aliases not to perform deep initialization of the corresponding _uca1400_ collations. Only basic initialization is now performed which allows to watch these collations (both _0900_ and _uca1400_) in queries to INFORMATION_SCHEMA tables COLLATIONS and COLLATION_CHARACTER_SET_APPLICABILITY, as well as in SHOW COLLATION statements. Deep initialization is now performed only when a collation (either the _0900_ alias or the corresponding _uca1400_ collation) is used for the very first time after the server startup. Refactoring was done to maintain the code easier: - most of the _uca1400_ code was moved from ctype-uca.c to a new file ctype-uca1400.c - most of the _0900_ code was moved from type-uca.c to a new file ctype-uca0900.c Change details: - The original function add_alias_for_collation() added by the patch for "MDEV-20912 Add support for utf8mb4_0900_* collations in MariaDB Server" was removed from mysys/charset.c, as it had two two problems: a. it forced deep initialization of the _uca1400_ collations when adding _0900_ aliases for them at the server startup (the main reported problem) b. the collation initialization code in add_alias_for_collation() was related more to collations rather than to memory management, so /strings should be a better place for it than /mysys. The code from add_alias_for_collation() was split into separate functions. Cyclic dependency was removed. `#include <my_sys.h>` was removed from /strings/ctype-uca.c. Collations are now added using a callback function MY_CHARSET_LOADED::add_collation, like it is done for user collations defined in Index.xml. The code in /mysys sets MY_CHARSET_LOADED::add_collation to add_compiled_collation(). - The function compare_collations() was removed. A new virtual function was added into my_collation_handler_st instead: my_bool (*eq_collation)(CHARSET_INFO *self, CHARSET_INFO *other); because it is the collation handler who knows how to detect equal collations by comparing only some of CHARSET_INFO members without their deep initialization. Three implementations were added: - my_ci_eq_collation_uca() for UCA collations, it compares _0900_ collations as equal to their corresponding _uca1400_ collations. - my_ci_eq_collation_utf8mb4_bin(), it compares utf8mb4_nopad_bin and utf8mb4_0900_bin as equal. - my_ci_eq_collation_generic() - the default implementation, which compares all collations as not equal. A C++ wrapper CHARSET_INFO::eq_collations() was added. The code in /sql was changes to use the wrapper instead of the former calls for the removed function compare_collations(). - A part of add_alias_for_collation() was moved into a new function my_ci_alloc(). It allocates a memory for a new charset_info_st instance together with the collation name and the comment using a single MY_CHARSET_LOADER::once_alloc call, which points to my_once_alloc() in the server. - A part of add_alias_for_collation() was moved into a new function my_ci_make_comment_for_alias(). It makes an "Alias for xxx" string, e.g. "Alias for utf8mb4_uca1400_swedish_ai_ci" in case of utf8mb4_sv_0900_ai_ci. - A part of the code in create_tailoring() was moved to a new function my_uca1400_collation_get_initialized_shared_uca(), to reuse the code between _uca1400_ and _0900_ collations. - A new function my_collation_id_is_mysql_uca0900() was added in addition to my_collation_id_is_mysql_uca1400(). - Functions to build collation names were added: my_uca0900_collation_build_name() my_uca1400_collation_build_name() - A shared function function was added: my_bool my_uca1400_collation_alloc_and_init(MY_CHARSET_LOADER *loader, LEX_CSTRING name, LEX_CSTRING comment, const uca_collation_def_param_t *param, uint id) It's reused to add _uca1400_ and _0900_ collations, with basic initialization (without deep initialization). - The function add_compiled_collation() changed its return type from void to int, to make it compatible with MY_CHARSET_LOADER::add_collation. - Functions mysql_uca0900_collation_definition_add(), mysql_uca0900_utf8mb4_collation_definitions_add(), mysql_utf8mb4_0900_bin_add() were added into ctype-uca0900.c. They get MY_CHARSET_LOADER as a parameter. - Functions my_uca1400_collation_definition_add(), my_uca1400_collation_definitions_add() were moved from charset-def.c to strings/ctype-uca1400.c. The latter now accepts MY_CHARSET_LOADER as the first parameter instead of initializing a MY_CHARSET_LOADER inside. - init_compiled_charsets() now initializes a MY_CHARSET_LOADER variable and passes it to all functions adding collations: - mysql_utf8mb4_0900_collation_definitions_add() - mysql_uca0900_utf8mb4_collation_definitions_add() - mysql_utf8mb4_0900_bin_add() - A new structure was added into ctype-uca.h: typedef struct uca_collation_def_param { my_cs_encoding_t cs_id; uint tailoring_id; uint nopad_flags; uint level_flags; } uca_collation_def_param_t; It simplifies reusing the code for _uca1400_ and _0900_ collations. - The definition of MY_UCA1400_COLLATION_DEFINITION was moved from ctype-uca.c to ctype-uca1400.h, to reuse the code for _uca1400_ and _0900_ collations. - The definitions of "MY_UCA_INFO my_uca_v1400" and "MY_UCA_INFO my_uca1400_info_tailored[][]" were moved from ctype-uca.c to ctype-uca1400.c. - The definitions/declarations of: - mysql_0900_collation_start, - struct mysql_0900_to_mariadb_1400_mapping - mysql_0900_to_mariadb_1400_mapping - mysql_utf8mb4_0900_collation_definitions_add() were moved from ctype-uca.c to ctype-uca0900.c - Functions my_uca1400_make_builtin_collation_id() my_uca1400_collation_definition_init() my_uca1400_collation_id_uca400_compat() my_ci_get_collation_name_uca1400_context() were moved from ctype-uca.c to ctype-uca1400.c and ctype-uca1400.h - A part of my_uca1400_collation_definition_init() was moved into my_uca0520_builtin_collation_by_id(), to make functions smaller.
2025-08-07 00:04:31 +03:00 · 2025-03-22 12:45:13 +04:00
parent 0dad1458e7
commit 10c063f9f0
38 changed files with 1498 additions and 646 deletions
--- a/strings/CMakeLists.txt
+++ b/strings/CMakeLists.txt
@@ -20,7 +20,8 @@ ${CMAKE_BINARY_DIR}/strings

 SET(STRINGS_SOURCES bchange.c bmove_upp.c ctype-big5.c ctype-bin.c ctype-cp932.c
                ctype-czech.c ctype-euc_kr.c ctype-eucjpms.c ctype-extra.c ctype-gb2312.c ctype-gbk.c
-                ctype-latin1.c ctype-mb.c ctype-simple.c ctype-sjis.c ctype-tis620.c ctype-uca.c
+                ctype-latin1.c ctype-mb.c ctype-simple.c ctype-sjis.c ctype-tis620.c
+                ctype-uca.c ctype-uca0900.c ctype-uca1400.c
                ctype-ucs2.c ctype-ujis.c ctype-utf8.c ctype-win1250ch.c ctype.c decimal.c dtoa.c int2str.c
                ctype-unidata.c
                is_prefix.c llstr.c longlong2str.c my_strtoll10.c my_vsnprintf.c
--- a/strings/ctype-big5.c
+++ b/strings/ctype-big5.c
@@ -6730,7 +6730,8 @@ static MY_COLLATION_HANDLER my_collation_handler_big5_chinese_ci=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -6751,7 +6752,8 @@ static MY_COLLATION_HANDLER my_collation_handler_big5_bin=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -6772,7 +6774,8 @@ static MY_COLLATION_HANDLER my_collation_handler_big5_chinese_nopad_ci=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -6793,7 +6796,8 @@ static MY_COLLATION_HANDLER my_collation_handler_big5_nopad_bin=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


--- a/strings/ctype-bin.c
+++ b/strings/ctype-bin.c
@@ -529,7 +529,8 @@ MY_COLLATION_HANDLER my_collation_8bit_bin_handler =
  my_min_str_8bit_simple,
  my_max_str_8bit_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -550,7 +551,8 @@ MY_COLLATION_HANDLER my_collation_8bit_nopad_bin_handler =
  my_min_str_8bit_simple_nopad,
  my_max_str_8bit_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -571,7 +573,8 @@ static MY_COLLATION_HANDLER my_collation_binary_handler =
  my_min_str_8bit_simple_nopad,
  my_max_str_8bit_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


--- a/strings/ctype-cp932.c
+++ b/strings/ctype-cp932.c
@@ -34687,7 +34687,8 @@ static MY_COLLATION_HANDLER my_collation_handler_cp932_japanese_ci=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -34708,7 +34709,8 @@ static MY_COLLATION_HANDLER my_collation_handler_cp932_bin=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -34729,7 +34731,8 @@ static MY_COLLATION_HANDLER my_collation_handler_cp932_japanese_nopad_ci=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -34750,7 +34753,8 @@ static MY_COLLATION_HANDLER my_collation_handler_cp932_nopad_bin=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


--- a/strings/ctype-czech.c
+++ b/strings/ctype-czech.c
@@ -598,7 +598,8 @@ static MY_COLLATION_HANDLER my_collation_latin2_czech_cs_handler =
  my_min_str_8bit_simple,
  my_max_str_8bit_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };

 struct charset_info_st my_charset_latin2_czech_cs =
--- a/strings/ctype-euc_kr.c
+++ b/strings/ctype-euc_kr.c
@@ -9977,7 +9977,8 @@ static MY_COLLATION_HANDLER my_collation_handler_euckr_korean_ci=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -9998,7 +9999,8 @@ static MY_COLLATION_HANDLER my_collation_handler_euckr_bin=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -10019,7 +10021,8 @@ static MY_COLLATION_HANDLER my_collation_handler_euckr_korean_nopad_ci=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -10040,7 +10043,8 @@ static MY_COLLATION_HANDLER my_collation_handler_euckr_nopad_bin=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


--- a/strings/ctype-eucjpms.c
+++ b/strings/ctype-eucjpms.c
@@ -67515,7 +67515,8 @@ static MY_COLLATION_HANDLER my_collation_eucjpms_japanese_ci_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -67536,7 +67537,8 @@ static MY_COLLATION_HANDLER my_collation_eucjpms_bin_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -67557,7 +67559,8 @@ static MY_COLLATION_HANDLER my_collation_eucjpms_japanese_nopad_ci_handler =
    my_min_str_mb_simple_nopad,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -67578,7 +67581,8 @@ static MY_COLLATION_HANDLER my_collation_eucjpms_nopad_bin_handler =
    my_min_str_mb_simple_nopad,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


--- a/strings/ctype-gb2312.c
+++ b/strings/ctype-gb2312.c
@@ -6381,7 +6381,8 @@ static MY_COLLATION_HANDLER my_collation_handler_gb2312_chinese_ci=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -6402,7 +6403,8 @@ static MY_COLLATION_HANDLER my_collation_handler_gb2312_bin=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -6423,7 +6425,8 @@ static MY_COLLATION_HANDLER my_collation_handler_gb2312_chinese_nopad_ci=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -6444,7 +6447,8 @@ static MY_COLLATION_HANDLER my_collation_handler_gb2312_nopad_bin=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


--- a/strings/ctype-gbk.c
+++ b/strings/ctype-gbk.c
@@ -10663,7 +10663,8 @@ static MY_COLLATION_HANDLER my_collation_handler_gbk_chinese_ci=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -10684,7 +10685,8 @@ static MY_COLLATION_HANDLER my_collation_handler_gbk_bin=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -10705,7 +10707,8 @@ static MY_COLLATION_HANDLER my_collation_handler_gbk_chinese_nopad_ci=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -10726,7 +10729,8 @@ static MY_COLLATION_HANDLER my_collation_handler_gbk_nopad_bin=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };

 static MY_CHARSET_HANDLER my_charset_handler=
--- a/strings/ctype-latin1.c
+++ b/strings/ctype-latin1.c
@@ -742,7 +742,8 @@ static MY_COLLATION_HANDLER my_collation_german2_ci_handler=
  my_min_str_8bit_simple,
  my_max_str_8bit_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


--- a/strings/ctype-simple.c
+++ b/strings/ctype-simple.c
@@ -2192,7 +2192,8 @@ MY_COLLATION_HANDLER my_collation_8bit_simple_ci_handler =
    my_min_str_8bit_simple,
    my_max_str_8bit_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -2213,5 +2214,6 @@ MY_COLLATION_HANDLER my_collation_8bit_simple_nopad_ci_handler =
    my_min_str_8bit_simple_nopad,
    my_max_str_8bit_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };
--- a/strings/ctype-sjis.c
+++ b/strings/ctype-sjis.c
@@ -34075,7 +34075,8 @@ static MY_COLLATION_HANDLER my_collation_handler_sjis_japanese_ci=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -34096,7 +34097,8 @@ static MY_COLLATION_HANDLER my_collation_handler_sjis_bin=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -34117,7 +34119,8 @@ static MY_COLLATION_HANDLER my_collation_handler_sjis_japanese_nopad_ci=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -34138,7 +34141,8 @@ static MY_COLLATION_HANDLER my_collation_handler_sjis_nopad_bin=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


--- a/strings/ctype-tis620.c
+++ b/strings/ctype-tis620.c
@@ -881,7 +881,8 @@ static MY_COLLATION_HANDLER my_collation_ci_handler =
    my_min_str_8bit_simple,
    my_max_str_8bit_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };

 static MY_COLLATION_HANDLER my_collation_nopad_ci_handler =
@@ -901,7 +902,8 @@ static MY_COLLATION_HANDLER my_collation_nopad_ci_handler =
    my_min_str_8bit_simple_nopad,
    my_max_str_8bit_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };

 static MY_CHARSET_HANDLER my_charset_handler=
--- a/strings/ctype-uca.c
+++ b/strings/ctype-uca.c
@@ -34,8 +34,8 @@

 #include "strings_def.h"
 #include <m_ctype.h>
-#include <my_sys.h>
 #include "ctype-uca.h"
+#include "ctype-uca0520.h"
 #include "ctype-unidata.h"
 #include "my_bit.h"

@@ -30214,78 +30214,6 @@ MY_UCA_INFO my_uca_v520=
 };


-#include "ctype-uca1400data.h"
-
-static MY_UCA_INFO my_uca_v1400=
-{
-  {
-    {
-      0x10FFFF,      /* maxchar           */
-      (uchar *) uca1400_length,
-      (uint16 **) uca1400_weight,
-      {              /* Contractions:     */
-        array_elements(uca1400_contractions), /* nitems */
-        uca1400_contractions,                 /* item   */
-        NULL         /*   flags           */
-      },
-      0,             /* levelno */
-      {0},           /* contraction_hash   */
-      NULL           /* booster            */
-    },
-
-    {
-      0x10FFFF,      /* maxchar */
-      (uchar *) uca1400_length_secondary,
-      (uint16 **) uca1400_weight_secondary,
-      {              /* Contractions: */
-        array_elements(uca1400_contractions_secondary), /* nitems */
-        uca1400_contractions_secondary,                 /* item   */
-        NULL         /*   flags */
-      },
-      1,             /* levelno */
-      {0},           /* contraction_hash   */
-      NULL           /* booster            */
-    },
-
-    {
-      0x10FFFF,      /* maxchar */
-      (uchar *) uca1400_length_tertiary,
-      (uint16 **) uca1400_weight_tertiary,
-      {              /* Contractions: */
-        array_elements(uca1400_contractions_tertiary), /* nitems */
-        uca1400_contractions_tertiary,                 /* item   */
-        NULL         /*   flags */
-      },
-      2,             /* levelno */
-      {0},           /* contraction_hash   */
-      NULL           /* booster            */
-    }
-
-  },
-
-  uca1400_non_ignorable_first,
-  uca1400_non_ignorable_last,
-
-  uca1400_primary_ignorable_first,
-  uca1400_primary_ignorable_last,
-
-  uca1400_secondary_ignorable_first,
-  uca1400_secondary_ignorable_last,
-
-  uca1400_tertiary_ignorable_first,
-  uca1400_tertiary_ignorable_last,
-
-  0x0000,    /* first_trailing */
-  0x0000,    /* last_trailing  */
-
-  uca1400_variable_first,
-  uca1400_variable_last,
-
-  /* Misc */
-  uca1400_version
-};
-
-
 /******************************************************/

 /*
@@ -31247,25 +31175,12 @@ static const char myanmar[]= "[shift-after-method expand]"
 ;


-typedef struct my_uca1400_collation_definition_st
-{
-  const char * tailoring;
-  const char * name;
-  uint16 id_utf8mb3;
-  uint16 id_utf8mb4;
-  uint16 id_ucs2;
-  uint16 id_utf16;
-  uint16 id_utf32;
-} MY_UCA1400_COLLATION_DEFINITION;
-
-
-
 /*
  UCA1400 collation definitions in the order of their UCA400 counterparts,
  with IDs of their closest UCA1400 counterparts, for character sets
  utf8mb3, utf8mb4, ucs2, utf16, utf32.
 */
-static MY_UCA1400_COLLATION_DEFINITION
+MY_UCA1400_COLLATION_DEFINITION
 my_uca1400_collation_definitions[MY_UCA1400_COLLATION_DEFINITION_COUNT]=
 {
 #define COLDEF(tl,name,id_utf8mb3,id_utf8mb4,id_ucs2,id_utf16,id_utf32) \
@@ -31309,9 +31224,17 @@ my_uca1400_collation_definitions[MY_UCA1400_COLLATION_DEFINITION_COUNT]=
 };


-static MY_UCA_INFO
-my_uca1400_info_tailored[MY_CS_ENCODING_LAST+1]
-                        [MY_UCA1400_COLLATION_DEFINITION_COUNT];
+static my_bool
+my_ci_eq_collation_uca(CHARSET_INFO *a, CHARSET_INFO *b)
+{
+  return a->cset == b->cset &&
+         a->coll == b->coll &&
+         a->uca == b->uca &&
+         a->casefold == b->casefold &&
+         (a->state & MY_CS_NOPAD) == (b->state & MY_CS_NOPAD) &&
+         a->levels_for_order == b->levels_for_order &&
+         a->tailoring == b->tailoring;
+}


 typedef struct my_uca_scanner_param_st
@@ -34722,6 +34645,30 @@ my_uca_info_init(MY_CHARSET_LOADER *loader,
 }


+/*
+  Initialize (if needed) an element of the array my_uca1400_info_tailored[].
+  UCA1400 collations with equal character set and tailoring
+  (but with different level flags) share the same MY_UCA_INFO.
+*/
+static MY_UCA_INFO *
+my_uca1400_collation_get_initialized_shared_uca(MY_CHARSET_LOADER *loader,
+                                                struct charset_info_st *cs,
+                                                MY_COLL_RULES *rules,
+                                                const MY_UCA_INFO *src_uca,
+                                                uint id)
+{
+  my_cs_encoding_t enc= my_uca1400_collation_id_to_charset_id(id);
+  uint tailoring= my_uca1400_collation_id_to_tailoring_id(id);
+  MY_UCA_INFO *dst_uca= &my_uca1400_info_tailored[enc][tailoring];
+  DBUG_ASSERT(my_collation_id_is_uca1400(id));
+  if (!dst_uca->level[0].weights/*Check if already initialized*/ &&
+     (my_uca_info_init(loader, dst_uca, rules, cs, src_uca,
+                       (1<<MY_UCA_WEIGHT_LEVELS)-1)))
+    return NULL; /* EOM or an error in rules */
+  return dst_uca;
+}
+
+
 /*
  This function copies an UCS2 collation from
  the default Unicode Collation Algorithm (UCA)
@@ -34789,20 +34736,23 @@ create_tailoring(struct charset_info_st *cs,
    my_ci_set_strength(cs, 1);


-  if (my_collation_id_is_uca1400(cs->number))
+  if (my_collation_id_is_mysql_uca0900(cs->number))
  {
-    /*
-      UCA1400 collations with equal character set and tailoring
-      (but with different level flags) share the same MY_UCA_INFO.
-    */
-    my_cs_encoding_t enc= my_uca1400_collation_id_to_charset_id(cs->number);
-    uint tailoring= my_uca1400_collation_id_to_tailoring_id(cs->number);
-    MY_UCA_INFO *dst_uca= &my_uca1400_info_tailored[enc][tailoring];
-    if (!dst_uca->level[0].weights &&
-       (rc= my_uca_info_init(loader, dst_uca, &rules, cs, src_uca,
-                             (1<<MY_UCA_WEIGHT_LEVELS)-1)))
-        goto ex;
-    cs->uca= dst_uca;
+    uint id1400= mysql_0900_mapping[cs->number - mysql_0900_collation_start].
+                                                                collation_id;
+    if (!(cs->uca= my_uca1400_collation_get_initialized_shared_uca(loader, cs,
+                                                                   &rules,
+                                                                   src_uca,
+                                                                   id1400)))
+      goto ex;
+  }
+  else if (my_collation_id_is_uca1400(cs->number))
+  {
+    if (!(cs->uca= my_uca1400_collation_get_initialized_shared_uca(loader, cs,
+                                                                   &rules,
+                                                                   src_uca,
+                                                                   cs->number)))
+      goto ex;
  }
  else
  {
@@ -39397,122 +39347,6 @@ struct charset_info_st my_charset_utf16_unicode_520_nopad_ci=
 #endif /* HAVE_CHARSET_utf16 */


-uint
-my_uca1400_make_builtin_collation_id(my_cs_encoding_t charset_id,
-                                     uint tailoring_id,
-                                     my_bool nopad,
-                                     my_bool secondary_level,
-                                     my_bool tertiary_level)
-{
-  if (!my_uca1400_collation_definitions[tailoring_id].tailoring)
-    return 0;
-  return MY_UCA1400_COLLATION_ID_POSSIBLE_MIN +
-         (charset_id << 8) +
-         (tailoring_id << 3) +
-         (nopad << 2) +
-         (secondary_level << 1) +
-         (tertiary_level << 0);
-}
-
-
-my_bool
-my_uca1400_collation_definition_init(MY_CHARSET_LOADER *loader,
-                                     struct charset_info_st *dst,
-                                     uint id)
-{
-  my_cs_encoding_t cs_id= my_uca1400_collation_id_to_charset_id(id);
-  uint tailoring_id=       my_uca1400_collation_id_to_tailoring_id(id);
-  my_bool nopad=           my_uca1400_collation_id_to_nopad_flag(id);
-  my_bool secondary_level= my_uca1400_collation_id_to_secondary_level_flag(id);
-  my_bool tertiary_level=  my_uca1400_collation_id_to_tertiary_level_flag(id);
-  const MY_UCA1400_COLLATION_DEFINITION *def=
-    &my_uca1400_collation_definitions[tailoring_id];
-  char tmp[128], *coll_name;
-  size_t length;
-
-  switch (cs_id) {
-  case MY_CS_ENCODING_UTF8MB3:
-    *dst= nopad ? my_charset_utf8mb3_unicode_520_nopad_ci :
-                  my_charset_utf8mb3_unicode_520_ci;
-    break;
-  case MY_CS_ENCODING_UTF8MB4:
-    *dst= nopad ? my_charset_utf8mb4_unicode_520_nopad_ci :
-                  my_charset_utf8mb4_unicode_520_ci;
-    break;
-#ifdef HAVE_CHARSET_ucs2
-  case MY_CS_ENCODING_UCS2:
-    *dst= nopad ? my_charset_ucs2_unicode_520_nopad_ci :
-                  my_charset_ucs2_unicode_520_ci;
-    break;
-#endif
-#ifdef HAVE_CHARSET_utf16
-  case MY_CS_ENCODING_UTF16:
-    *dst= nopad ? my_charset_utf16_unicode_520_nopad_ci :
-                  my_charset_utf16_unicode_520_ci;
-    break;
-#endif
-#ifdef HAVE_CHARSET_utf32
-  case MY_CS_ENCODING_UTF32:
-    *dst= nopad ? my_charset_utf32_unicode_520_nopad_ci :
-                  my_charset_utf32_unicode_520_ci;
-    break;
-#endif
-  }
-
-  dst->number= id;
-  dst->uca= &my_uca_v1400;
-  dst->tailoring= def->tailoring;
-  if (def->tailoring == turkish)
-    dst->casefold= &my_casefold_unicode1400tr;
-  else
-    dst->casefold= &my_casefold_unicode1400;
-  if (nopad)
-    dst->state|= MY_CS_NOPAD;
-  my_ci_set_level_flags(dst, (1 << MY_CS_LEVEL_BIT_PRIMARY) |
-                             (secondary_level ?
-                              1 << MY_CS_LEVEL_BIT_SECONDARY : 0) |
-                             (tertiary_level  ?
-                              1 << MY_CS_LEVEL_BIT_TERTIARY  : 0));
-
-  length= my_snprintf(tmp, sizeof(tmp), "%.*s_uca1400%s%s%s%s%s",
-                      (int) dst->cs_name.length, dst->cs_name.str,
-                      def->name[0] ? "_" : "",
-                      def->name,
-                      nopad ? "_nopad" : "",
-                      secondary_level ? "_as" : "_ai",
-                      tertiary_level ? "_cs" : "_ci");
-  if (!(coll_name= loader->once_alloc(length + 1)))
-    return TRUE;
-  strcpy(coll_name, tmp);
-  dst->coll_name.str= coll_name;
-  dst->coll_name.length= length;
-  return FALSE;
-}
-
-
-/*
-  Return UCA-4.0.0 compatible ID, e.g. for use in the protocol
-  with the old clients.
-*/
-static uint my_uca1400_collation_id_uca400_compat(uint id)
-{
-  uint tlid= my_uca1400_collation_id_to_tailoring_id(id);
-  my_cs_encoding_t csid= my_uca1400_collation_id_to_charset_id(id);
-  MY_UCA1400_COLLATION_DEFINITION *def;
-  DBUG_ASSERT(my_collation_id_is_uca1400(id));
-  if (!(def= &my_uca1400_collation_definitions[tlid])->name)
-    return id;
-  switch (csid) {
-  case MY_CS_ENCODING_UTF8MB3: return def->id_utf8mb3;
-  case MY_CS_ENCODING_UTF8MB4: return def->id_utf8mb4;
-  case MY_CS_ENCODING_UCS2:    return def->id_ucs2;
-  case MY_CS_ENCODING_UTF16:   return def->id_utf16;
-  case MY_CS_ENCODING_UTF32:   return def->id_utf32;
-  }
-  return id;
-}
-
-
 uint my_ci_get_id_uca(CHARSET_INFO *cs, my_collation_id_type_t type)
 {
  switch (type)
@@ -39532,23 +39366,6 @@ uint my_ci_get_id_uca(CHARSET_INFO *cs, my_collation_id_type_t type)
 }


-LEX_CSTRING my_ci_get_collation_name_uca1400_context(CHARSET_INFO *cs)
-{
-  LEX_CSTRING res;
-  DBUG_ASSERT(my_collation_id_is_uca1400(cs->number));
-
-  if (cs->coll_name.length <= cs->cs_name.length ||
-      cs->coll_name.str[cs->cs_name.length] != '_')
-  {
-    DBUG_ASSERT(0);
-    return cs->coll_name;
-  }
-  res.str= cs->coll_name.str + cs->cs_name.length + 1;
-  res.length= cs->coll_name.length - cs->cs_name.length - 1;
-  return res;
-}
-
-
 LEX_CSTRING my_ci_get_collation_name_uca(CHARSET_INFO *cs,
                                         my_collation_name_mode_t mode)
 {
@@ -39565,137 +39382,4 @@ LEX_CSTRING my_ci_get_collation_name_uca(CHARSET_INFO *cs,
  return cs->coll_name;
 }

-
-/*
-  Add support for MySQL 8.0 utf8mb4_0900_.. collations
-
-  The collation id's where collected from fprintf() in add_alias_for_collation()
-*/
-
-#define mysql_0900_collation_start 255
-
-struct mysql_0900_to_mariadb_1400_mapping
-{
-  const char *mysql_col_name, *mariadb_col_name, *case_sensitivity;
-  uint collation_id;
-};
-
-struct mysql_0900_to_mariadb_1400_mapping mysql_0900_mapping[]=
-{
-  /* 255 Ascent insensitive, Case insensitive 'ai_ci' */
-  {"", "", "ai_ci", 2308},
-  {"de_pb", "german2", "ai_ci", 2468},
-  {"is", "icelandic", "ai_ci", 2316},
-  {"lv", "latvian", "ai_ci", 2324},
-  {"ro", "romanian", "ai_ci", 2332},
-  {"sl", "slovenian", "ai_ci", 2340},
-  {"pl", "polish", "ai_ci", 2348},
-  {"et", "estonian", "ai_ci", 2356},
-  {"es", "spanish", "ai_ci", 2364},
-  {"sv", "swedish", "ai_ci", 2372},
-  {"tr", "turkish", "ai_ci", 2380},
-  {"cs", "czech", "ai_ci", 2388},
-  {"da", "danish", "ai_ci", 2396},
-  {"lt", "lithuanian", "ai_ci", 2404},
-  {"sk", "slovak", "ai_ci", 2412},
-  {"es_trad", "spanish2", "ai_ci", 2420},
-  {"la", "roman", "ai_ci", 2428},
-  {"fa", NullS, "ai_ci", 0},                          // Disabled in MySQL
-  {"eo", "esperanto", "ai_ci", 2444},
-  {"hu", "hungarian", "ai_ci", 2452},
-  {"hr", "croatian", "ai_ci", 2500},
-  {"si", NullS, "ai_ci", 0},                          // Disabled in MySQL
-  {"vi", "vietnamese", "ai_ci", 2492},
-
-  /* 278 Ascent sensitive, Case sensitive 'as_cs' */
-  {"","", "as_cs", 2311},
-  {"de_pb", "german2", "as_cs", 2471},
-  {"is", "icelandic", "as_cs", 2319},
-  {"lv", "latvian", "as_cs", 2327},
-  {"ro", "romanian", "as_cs", 2335},
-  {"sl", "slovenian", "as_cs", 2343},
-  {"pl", "polish", "as_cs", 2351},
-  {"et", "estonian", "as_cs", 2359},
-  {"es", "spanish", "as_cs", 2367},
-  {"sv", "swedish", "as_cs", 2375},
-  {"tr", "turkish", "as_cs", 2383},
-  {"cs", "czech", "as_cs", 2391},
-  {"da", "danish", "as_cs", 2399},
-  {"lt", "lithuanian", "as_cs", 2407},
-  {"sk", "slovak", "as_cs", 2415},
-  {"es_trad", "spanish2", "as_cs", 2423},
-  {"la", "roman", "as_cs", 2431},
-  {"fa", NullS, "as_cs", 0},                          // Disabled in MySQL
-  {"eo", "esperanto", "as_cs", 2447},
-  {"hu", "hungarian", "as_cs", 2455},
-  {"hr", "croatian", "as_cs", 2503},
-  {"si", NullS, "as_cs", 0},                          // Disabled in MySQL
-  {"vi", "vietnamese", "as_cs", 2495},
-
-  {"", NullS, "as_cs", 0},                            // Missing
-  {"", NullS, "as_cs", 0},                            // Missing
-  {"_ja_0900_as_cs", NullS, "as_cs", 0},              // Not supported
-  {"_ja_0900_as_cs_ks", NullS, "as_cs", 0},           // Not supported
-
-  /* 305 Ascent-sensitive, Case insensitive 'as_ci' */
-  {"","", "as_ci", 2310},
-  {"ru", NullS, "ai_ci", 0},                          // Not supported
-  {"ru", NullS, "as_cs", 0},                          // Not supported
-  {"zh", NullS, "as_cs", 0},                          // Not supported
-  {NullS, NullS, "", 0}
-};
-
-
-static LEX_CSTRING
-  mysql_utf8mb4_0900_bin= {STRING_WITH_LEN("utf8mb4_0900_bin")},
-  mariadb_utf8mb4_nopad_bin= {STRING_WITH_LEN("utf8mb4_nopad_bin")};
-
-/*
-  Map mysql character sets to MariaDB using the same definition but with
-  with the MySQL collation name and id.
-*/
-
-my_bool mysql_utf8mb4_0900_collation_definitions_add()
-{
-  uint id= mysql_0900_collation_start;
-  struct mysql_0900_to_mariadb_1400_mapping *map;
-
-  for (map= mysql_0900_mapping; map->mysql_col_name ; map++, id++)
-  {
-    if (map->mariadb_col_name)               /* Supported collation */
-    {
-      size_t org_length, ali_length;
-      char original[64], alias[64];
-      LEX_CSTRING org_name, alias_name;
-
-      org_length= (strxnmov(original, sizeof(original)-1,
-                            "utf8mb4_uca1400_",
-                            map->mariadb_col_name,
-                            (map->mariadb_col_name[0] ? "_" : ""),
-                            "nopad_",
-                            map->case_sensitivity,
-                            NullS) - original);
-      ali_length= (strxnmov(alias, sizeof(alias)-1,
-                            "utf8mb4_", map->mysql_col_name,
-                            (map->mysql_col_name[0] ? "_" : ""),
-                            "0900_",
-                            map->case_sensitivity,
-                            NullS) - alias);
-      org_name.str=      original;
-      org_name.length=   org_length;
-      alias_name.str=    alias;
-      alias_name.length= ali_length;
-
-      if (add_alias_for_collation(&org_name, map->collation_id, &alias_name,
-                                  id))
-        return 1;
-    }
-  }
-
-  if (add_alias_for_collation(&mariadb_utf8mb4_nopad_bin, 1070,
-                              &mysql_utf8mb4_0900_bin, 309))
-    return 1;
-  return 0;
-}
-
 #endif /* HAVE_UCA_COLLATIONS */
--- a/strings/ctype-uca.h
+++ b/strings/ctype-uca.h
@@ -118,9 +118,18 @@ typedef enum my_cs_encoding_enum
 #define MY_CS_ENCODING_LAST MY_CS_ENCODING_UTF32


-#include "ctype-uca1400.h"
+typedef struct uca_collation_def_param
+{
+  my_cs_encoding_t cs_id;
+  uint tailoring_id;
+  uint nopad_flags;
+  uint level_flags;
+} uca_collation_def_param_t;


+#include "ctype-uca1400.h"
+#include "ctype-uca0900.h"
+
 static inline MY_UCA_IMPLICIT_WEIGHT
 my_uca_implicit_weight_primary(uint version, my_wc_t code)
 {
--- a/strings/ctype-uca.inl
+++ b/strings/ctype-uca.inl
@@ -963,7 +963,8 @@ MY_COLLATION_HANDLER MY_FUNCTION_NAME(collation_handler)=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_uca,
-  my_ci_get_collation_name_uca
+  my_ci_get_collation_name_uca,
+  my_ci_eq_collation_uca
 };


@@ -989,7 +990,8 @@ MY_COLLATION_HANDLER MY_FUNCTION_NAME(collation_handler_nopad)=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_uca,
-  my_ci_get_collation_name_uca
+  my_ci_get_collation_name_uca,
+  my_ci_eq_collation_uca
 };


@@ -1013,7 +1015,8 @@ MY_COLLATION_HANDLER MY_FUNCTION_NAME(collation_handler_multilevel)=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_uca,
-  my_ci_get_collation_name_uca
+  my_ci_get_collation_name_uca,
+  my_ci_eq_collation_uca
 };


@@ -1037,7 +1040,8 @@ MY_COLLATION_HANDLER MY_FUNCTION_NAME(collation_handler_nopad_multilevel)=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_uca,
-  my_ci_get_collation_name_uca
+  my_ci_get_collation_name_uca,
+  my_ci_eq_collation_uca
 };


--- a/strings/ctype-uca0520.h
+++ b/strings/ctype-uca0520.h
@@ -0,0 +1,69 @@
+#ifndef CTYPE_UCA_0520_H
+#define CTYPE_UCA_0520_H
+/* Copyright (c) 2025, MariaDB Corporation
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License as published by the Free Software Foundation; version 2
+   of the License.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+   MA 02110-1335  USA */
+
+
+extern struct charset_info_st my_charset_utf8mb3_unicode_520_nopad_ci;
+extern struct charset_info_st my_charset_utf8mb3_unicode_520_ci;
+extern struct charset_info_st my_charset_utf8mb4_unicode_520_nopad_ci;
+extern struct charset_info_st my_charset_utf8mb4_unicode_520_ci;
+extern struct charset_info_st my_charset_ucs2_unicode_520_nopad_ci;
+extern struct charset_info_st my_charset_ucs2_unicode_520_ci;
+extern struct charset_info_st my_charset_utf16_unicode_520_nopad_ci;
+extern struct charset_info_st my_charset_utf16_unicode_520_ci;
+extern struct charset_info_st my_charset_utf32_unicode_520_nopad_ci;
+extern struct charset_info_st my_charset_utf32_unicode_520_ci;
+extern struct charset_info_st my_charset_utf8mb4_turkish_uca_ci;
+
+
+/*
+  Get a UCA-5.2.0 CHARSET_INFO using its character set ID and PAD flags.
+  Used to initialize UCA-14.0.0 collations.
+*/
+static inline
+CHARSET_INFO *my_uca0520_builtin_collation_by_id(my_cs_encoding_t cs_id,
+                                                 uint nopad_flags)
+{
+  switch (cs_id) {
+  case MY_CS_ENCODING_UTF8MB3:
+    return nopad_flags ? &my_charset_utf8mb3_unicode_520_nopad_ci :
+                         &my_charset_utf8mb3_unicode_520_ci;
+  case MY_CS_ENCODING_UTF8MB4:
+    return nopad_flags ? &my_charset_utf8mb4_unicode_520_nopad_ci :
+                         &my_charset_utf8mb4_unicode_520_ci;
+#ifdef HAVE_CHARSET_ucs2
+  case MY_CS_ENCODING_UCS2:
+    return nopad_flags ? &my_charset_ucs2_unicode_520_nopad_ci :
+                         &my_charset_ucs2_unicode_520_ci;
+#endif
+#ifdef HAVE_CHARSET_utf16
+  case MY_CS_ENCODING_UTF16:
+    return nopad_flags ? &my_charset_utf16_unicode_520_nopad_ci :
+                         &my_charset_utf16_unicode_520_ci;
+#endif
+#ifdef HAVE_CHARSET_utf32
+  case MY_CS_ENCODING_UTF32:
+    return nopad_flags ? &my_charset_utf32_unicode_520_nopad_ci :
+                         &my_charset_utf32_unicode_520_ci;
+#endif
+  }
+  return NULL;
+}
+
+
+#endif /* CTYPE_UCA_0520_H */
--- a/strings/ctype-uca0900.c
+++ b/strings/ctype-uca0900.c
@@ -0,0 +1,221 @@
+/* Copyright (c) 2025, MariaDB Corporation
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License as published by the Free Software Foundation; version 2
+   of the License.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+   MA 02110-1335  USA */
+
+#include "my_global.h"
+#include "strings_def.h"
+#include "ctype-uca.h"
+
+struct mysql_0900_to_mariadb_1400_mapping
+         mysql_0900_mapping[mysql_0900_collation_num]=
+{
+  /* 255 Ascent insensitive, Case insensitive 'ai_ci' */
+  {"", "", "ai_ci", 2308},
+  {"de_pb", "german2", "ai_ci", 2468},
+  {"is", "icelandic", "ai_ci", 2316},
+  {"lv", "latvian", "ai_ci", 2324},
+  {"ro", "romanian", "ai_ci", 2332},
+  {"sl", "slovenian", "ai_ci", 2340},
+  {"pl", "polish", "ai_ci", 2348},
+  {"et", "estonian", "ai_ci", 2356},
+  {"es", "spanish", "ai_ci", 2364},
+  {"sv", "swedish", "ai_ci", 2372},
+  {"tr", "turkish", "ai_ci", 2380},
+  {"cs", "czech", "ai_ci", 2388},
+  {"da", "danish", "ai_ci", 2396},
+  {"lt", "lithuanian", "ai_ci", 2404},
+  {"sk", "slovak", "ai_ci", 2412},
+  {"es_trad", "spanish2", "ai_ci", 2420},
+  {"la", "roman", "ai_ci", 2428},
+  {"fa", NullS, "ai_ci", 0},                          // Disabled in MySQL
+  {"eo", "esperanto", "ai_ci", 2444},
+  {"hu", "hungarian", "ai_ci", 2452},
+  {"hr", "croatian", "ai_ci", 2500},
+  {"si", NullS, "ai_ci", 0},                          // Disabled in MySQL
+  {"vi", "vietnamese", "ai_ci", 2492},
+
+  /* 278 Ascent sensitive, Case sensitive 'as_cs' */
+  {"","", "as_cs", 2311},
+  {"de_pb", "german2", "as_cs", 2471},
+  {"is", "icelandic", "as_cs", 2319},
+  {"lv", "latvian", "as_cs", 2327},
+  {"ro", "romanian", "as_cs", 2335},
+  {"sl", "slovenian", "as_cs", 2343},
+  {"pl", "polish", "as_cs", 2351},
+  {"et", "estonian", "as_cs", 2359},
+  {"es", "spanish", "as_cs", 2367},
+  {"sv", "swedish", "as_cs", 2375},
+  {"tr", "turkish", "as_cs", 2383},
+  {"cs", "czech", "as_cs", 2391},
+  {"da", "danish", "as_cs", 2399},
+  {"lt", "lithuanian", "as_cs", 2407},
+  {"sk", "slovak", "as_cs", 2415},
+  {"es_trad", "spanish2", "as_cs", 2423},
+  {"la", "roman", "as_cs", 2431},
+  {"fa", NullS, "as_cs", 0},                          // Disabled in MySQL
+  {"eo", "esperanto", "as_cs", 2447},
+  {"hu", "hungarian", "as_cs", 2455},
+  {"hr", "croatian", "as_cs", 2503},
+  {"si", NullS, "as_cs", 0},                          // Disabled in MySQL
+  {"vi", "vietnamese", "as_cs", 2495},
+
+  {"", NullS, "as_cs", 0},                            // Missing
+  {"", NullS, "as_cs", 0},                            // Missing
+  {"_ja_0900_as_cs", NullS, "as_cs", 0},              // Not supported
+  {"_ja_0900_as_cs_ks", NullS, "as_cs", 0},           // Not supported
+
+  /* 305 Ascent-sensitive, Case insensitive 'as_ci' */
+  {"","", "as_ci", 2310},
+  {"ru", NullS, "ai_ci", 0},                          // Not supported
+  {"ru", NullS, "as_cs", 0},                          // Not supported
+  {"zh", NullS, "as_cs", 0},                          // Not supported
+  {NullS, NullS, "", 0}
+};
+
+
+static LEX_CSTRING
+my_uca0900_collation_build_name(char *buffer, size_t buffer_size,
+                                const char *cs_name,
+                                const char *tailoring_name,
+                                const char *sensitivity_suffix)
+{
+  LEX_CSTRING res;
+  DBUG_ASSERT(buffer_size > 1);
+  res.str= buffer;
+  res.length= (strxnmov(buffer, buffer_size - 1,
+                        cs_name, "_", tailoring_name,
+                        (tailoring_name[0] ? "_" : ""),
+                        "0900_",
+                        sensitivity_suffix,
+                        NullS) - buffer);
+  return res;
+}
+
+
+static LEX_CSTRING
+my_ci_make_comment_for_alias(char *buffer, size_t buffer_size,
+                             const char *srcname)
+{
+  LEX_CSTRING res= {buffer, 0};
+  DBUG_ASSERT(buffer_size > 0);
+  res.length= strxnmov(buffer, buffer_size - 1, "Alias for ", srcname, NullS) -
+              buffer;
+  return res;
+}
+
+
+/*
+  Add a MySQL UCA-0900 collation as an alias for a MariaDB UCA-1400 collation.
+*/
+static my_bool
+mysql_uca0900_collation_definition_add(MY_CHARSET_LOADER *loader,
+                                       const struct
+                                       mysql_0900_to_mariadb_1400_mapping *map,
+                                       uint alias_id)
+{
+  char comment_buffer[MY_CS_COLLATION_NAME_SIZE + 15];
+  char alias_buffer[MY_CS_COLLATION_NAME_SIZE + 1];
+  char name1400_buffer[MY_CS_COLLATION_NAME_SIZE + 1];
+  LEX_CSTRING comment= {comment_buffer, 0};
+  LEX_CSTRING alias_name= {alias_buffer, 0};
+  LEX_CSTRING name1400= {name1400_buffer, 0};
+  LEX_CSTRING utf8mb4= {STRING_WITH_LEN("utf8mb4")};
+  uint id1400= map->collation_id;
+  uca_collation_def_param_t param= my_uca1400_collation_param_by_id(id1400);
+  const MY_UCA1400_COLLATION_DEFINITION *def1400=
+    &my_uca1400_collation_definitions[param.tailoring_id];
+
+  DBUG_ASSERT(my_collation_id_is_mysql_uca0900(alias_id));
+
+  alias_name= my_uca0900_collation_build_name(alias_buffer,
+                                              sizeof(alias_buffer),
+                                              "utf8mb4",
+                                              map->mysql_col_name,
+                                              map->case_sensitivity);
+
+  name1400= my_uca1400_collation_build_name(name1400_buffer,
+                                            sizeof(name1400_buffer),
+                                            &utf8mb4, def1400->name, &param);
+  comment= my_ci_make_comment_for_alias(comment_buffer, sizeof(comment_buffer),
+                                        name1400.str);
+
+#ifdef DEBUG_PRINT_ALIAS
+  fprintf(stderr, "alias[%u] %-26s -> [%u] %s\n",
+          id, alias_name.str, id1400, name1400.str);
+#endif
+
+  return my_uca1400_collation_alloc_and_init(loader, alias_name,
+                                             comment, &param, alias_id);
+}
+
+
+/*
+  Add support for MySQL 8.0 utf8mb4_0900_.. UCA collations.
+
+  The collation id's were collected from fprintf()
+  in mysql_uca0900_collation_definition_add().
+
+  Map mysql character sets to MariaDB using the same definition but
+  with the MySQL collation name and id.
+*/
+
+my_bool
+mysql_uca0900_utf8mb4_collation_definitions_add(MY_CHARSET_LOADER *loader)
+{
+  uint alias_id= mysql_0900_collation_start;
+  struct mysql_0900_to_mariadb_1400_mapping *map;
+
+  for (map= mysql_0900_mapping; map->mysql_col_name ; map++, alias_id++)
+  {
+    if (map->mariadb_col_name)               /* Supported collation */
+    {
+      if (mysql_uca0900_collation_definition_add(loader, map, alias_id))
+        return TRUE;
+    }
+  }
+
+  return FALSE;
+}
+
+
+/*
+  Add MySQL utf8mb4_0900_bin collation as
+  an alias for MariaDB utf8mb4_nopad_bin.
+*/
+my_bool mysql_utf8mb4_0900_bin_add(MY_CHARSET_LOADER *loader)
+{
+  CHARSET_INFO *src= &my_charset_utf8mb4_nopad_bin;
+  LEX_CSTRING alias_name= {STRING_WITH_LEN("utf8mb4_0900_bin")};
+  uint alias_id= 309;
+  char comment_buffer[MY_CS_COLLATION_NAME_SIZE+15];
+  LEX_CSTRING comment= my_ci_make_comment_for_alias(comment_buffer,
+                                                    sizeof(comment_buffer),
+                                                    src->coll_name.str);
+  struct charset_info_st *dst= my_ci_alloc(loader, alias_name, &alias_name,
+                                           comment, &comment);
+  if (!dst)
+    return TRUE;
+
+  *dst= *src;
+
+  dst->number= alias_id;
+  dst->coll_name= alias_name;
+  dst->comment= comment.str;
+
+  (loader->add_collation)(dst);
+
+  return FALSE;
+}
--- a/strings/ctype-uca0900.h
+++ b/strings/ctype-uca0900.h
@@ -0,0 +1,47 @@
+#ifndef CTYPE_UCA_0900_H
+#define CTYPE_UCA_0900_H
+/* Copyright (c) 2025, MariaDB Corporation
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License as published by the Free Software Foundation; version 2
+   of the License.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+   MA 02110-1335  USA */
+
+
+#define mysql_0900_collation_start 255
+#define mysql_0900_collation_end 308
+#define mysql_0900_collation_num \
+ (mysql_0900_collation_end - mysql_0900_collation_start + 1 + 1/*End marker*/)
+
+struct mysql_0900_to_mariadb_1400_mapping
+{
+  const char *mysql_col_name, *mariadb_col_name, *case_sensitivity;
+  uint collation_id;
+};
+
+extern struct mysql_0900_to_mariadb_1400_mapping
+  mysql_0900_mapping[mysql_0900_collation_num];
+
+
+static inline
+my_bool my_collation_id_is_mysql_uca0900(uint id)
+{
+  return id >= mysql_0900_collation_start &&
+         id <= mysql_0900_collation_end;
+}
+
+my_bool mysql_uca0900_utf8mb4_collation_definitions_add(MY_CHARSET_LOADER *ld);
+
+my_bool mysql_utf8mb4_0900_bin_add(MY_CHARSET_LOADER *loader);
+
+#endif /* CTYPE_UCA_0900_H */
--- a/strings/ctype-uca1400.c
+++ b/strings/ctype-uca1400.c
@@ -0,0 +1,363 @@
+/* Copyright (c) 2025, MariaDB Corporation
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License as published by the Free Software Foundation; version 2
+   of the License.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+   MA 02110-1335  USA */
+
+#include "strings_def.h"
+#include "m_ctype.h"
+#include "ctype-uca.h"
+#include "ctype-uca0520.h"
+#include "ctype-unidata.h"
+#include "ctype-uca1400data.h"
+
+/*
+  Return UCA-4.0.0 compatible ID (known since MySQL-4.1),
+  e.g. for use in the protocol with the old clients.
+*/
+uint my_uca1400_collation_id_uca400_compat(uint id)
+{
+  uint tlid= my_uca1400_collation_id_to_tailoring_id(id);
+  my_cs_encoding_t csid= my_uca1400_collation_id_to_charset_id(id);
+  const MY_UCA1400_COLLATION_DEFINITION *def;
+  DBUG_ASSERT(my_collation_id_is_uca1400(id));
+  if (!(def= &my_uca1400_collation_definitions[tlid])->name)
+    return id;
+  switch (csid) {
+  case MY_CS_ENCODING_UTF8MB3: return def->id_utf8mb3;
+  case MY_CS_ENCODING_UTF8MB4: return def->id_utf8mb4;
+  case MY_CS_ENCODING_UCS2:    return def->id_ucs2;
+  case MY_CS_ENCODING_UTF16:   return def->id_utf16;
+  case MY_CS_ENCODING_UTF32:   return def->id_utf32;
+  }
+  return id;
+}
+
+
+/*
+  Get a short (without the character set prefix) collation name
+  of a UCA-14.0.0 collation, e.g.
+    utf8mb4_uca1400_swedish_ai_ci -> uca1400_swedish_ai_ci
+*/
+LEX_CSTRING my_ci_get_collation_name_uca1400_context(CHARSET_INFO *cs)
+{
+  LEX_CSTRING res;
+  DBUG_ASSERT(my_collation_id_is_uca1400(cs->number));
+
+  if (cs->coll_name.length <= cs->cs_name.length ||
+      cs->coll_name.str[cs->cs_name.length] != '_')
+  {
+    DBUG_ASSERT(0);
+    return cs->coll_name; /* Something went wrong, return the full name. */
+  }
+  res.str= cs->coll_name.str + cs->cs_name.length + 1;
+  res.length= cs->coll_name.length - cs->cs_name.length - 1;
+  return res;
+}
+
+
+/*
+  A preliminary initialized data for a UCA-14.0.0 collation.
+  The goal is to have the "logical position" members initialized (see below).
+  Weight tables are initialized later, at create_tailoring() time.
+*/
+MY_UCA_INFO my_uca_v1400=
+{
+  {
+    {
+      0x10FFFF,      /* maxchar           */
+      (uchar *) uca1400_length,
+      (uint16 **) uca1400_weight,
+      {              /* Contractions:     */
+        array_elements(uca1400_contractions), /* nitems */
+        uca1400_contractions,                 /* item   */
+        NULL         /*   flags           */
+      },
+      0,             /* levelno */
+      {0},           /* contraction_hash   */
+      NULL           /* booster            */
+    },
+
+    {
+      0x10FFFF,      /* maxchar */
+      (uchar *) uca1400_length_secondary,
+      (uint16 **) uca1400_weight_secondary,
+      {              /* Contractions: */
+        array_elements(uca1400_contractions_secondary), /* nitems */
+        uca1400_contractions_secondary,                 /* item   */
+        NULL         /*   flags */
+      },
+      1,             /* levelno */
+      {0},           /* contraction_hash   */
+      NULL           /* booster            */
+    },
+
+    {
+      0x10FFFF,      /* maxchar */
+      (uchar *) uca1400_length_tertiary,
+      (uint16 **) uca1400_weight_tertiary,
+      {              /* Contractions: */
+        array_elements(uca1400_contractions_tertiary), /* nitems */
+        uca1400_contractions_tertiary,                 /* item   */
+        NULL         /*   flags */
+      },
+      2,             /* levelno */
+      {0},           /* contraction_hash   */
+      NULL           /* booster            */
+    }
+
+  },
+
+  /* Logical positions */
+  uca1400_non_ignorable_first,
+  uca1400_non_ignorable_last,
+
+  uca1400_primary_ignorable_first,
+  uca1400_primary_ignorable_last,
+
+  uca1400_secondary_ignorable_first,
+  uca1400_secondary_ignorable_last,
+
+  uca1400_tertiary_ignorable_first,
+  uca1400_tertiary_ignorable_last,
+
+  0x0000,    /* first_trailing */
+  0x0000,    /* last_trailing  */
+
+  uca1400_variable_first,
+  uca1400_variable_last,
+
+  /* Misc */
+  uca1400_version
+};
+
+
+/*
+  An array of MY_UCA_INFO (sorting tables).
+  Collations having the same character set and tailoring
+  (but different pad and accent/case sensitivity flags)
+  share the same array element. Also, aliases for MySQL-8.0
+  UCA-9.0.0 collations share the same array element with the
+  corresponding UCA-14.0.0 MariaDB collations.
+
+  For example, all these collation share one element of the array:
+  - utf8mb4_uca1400_swedish_ai_ci
+  - utf8mb4_uca1400_swedish_ai_cs
+  - utf8mb4_uca1400_swedish_as_ci
+  - utf8mb4_uca1400_swedish_as_cs
+  - utf8mb4_uca1400_swedish_nopad_ai_ci
+  - utf8mb4_uca1400_swedish_nopad_ai_cs
+  - utf8mb4_uca1400_swedish_nopad_as_ci
+  - utf8mb4_uca1400_swedish_nopad_as_cs
+  - utf8mb4_sv_0900_ai_ci
+  - utf8mb4_sv_0900_as_cs
+*/
+MY_UCA_INFO
+my_uca1400_info_tailored[MY_CS_ENCODING_LAST+1]
+                        [MY_UCA1400_COLLATION_DEFINITION_COUNT];
+
+
+/*
+  Make an UCA-14.0.0 collation ID using its properties.
+*/
+uint my_uca1400_make_builtin_collation_id(my_cs_encoding_t charset_id,
+                                          uint tailoring_id,
+                                          my_bool nopad,
+                                          my_bool secondary_level,
+                                          my_bool tertiary_level)
+{
+  if (!my_uca1400_collation_definitions[tailoring_id].tailoring)
+    return 0;
+  return MY_UCA1400_COLLATION_ID_POSSIBLE_MIN +
+         (charset_id << 8) +
+         (tailoring_id << 3) +
+         (nopad << 2) +
+         (secondary_level << 1) +
+         (tertiary_level << 0);
+}
+
+
+/*
+  Make an UCA-14.0.0 full collation name as a concatenation of its
+  - Character set name
+  - UCA version
+  - Language rules (tailoring)
+  - pad characteristics
+  - accent sensitivity
+  - case sensitivity
+  e.g.:  "utf8mb4" + "_uca1400" + "_swedish" + "_as" + "_ci"
+*/
+LEX_CSTRING
+my_uca1400_collation_build_name(char *buffer, size_t buffer_size,
+                                const LEX_CSTRING *cs_name,
+                                const char *tailoring_name,
+                                const uca_collation_def_param_t *prm)
+{
+  LEX_CSTRING res;
+  res.str= buffer;
+  res.length=
+    my_snprintf(buffer, buffer_size, "%.*s_uca1400%s%s%s%s%s",
+         (int) cs_name->length, cs_name->str,
+         tailoring_name[0] ? "_" : "",
+         tailoring_name,
+         prm->nopad_flags ? "_nopad" : "",
+         prm->level_flags & (1<<MY_CS_LEVEL_BIT_SECONDARY) ? "_as" : "_ai",
+         prm->level_flags & (1<<MY_CS_LEVEL_BIT_TERTIARY) ? "_cs" : "_ci");
+  return res;
+}
+
+
+/*
+  For extra safety let's define and check a set of flags
+  which are not expected for UCA 1400 collations.
+*/
+static inline uint
+uca1400_unexpected_flags()
+{
+  return  MY_CS_BINSORT|
+          MY_CS_PRIMARY|
+          MY_CS_PUREASCII|
+          MY_CS_LOWER_SORT;
+}
+
+
+/*
+  Perform a preliminary initialization of a charset_info_st instance.
+  It's enough for SHOW and INFORMATION_SCHEMA queries.
+  Deep initialization will be done later, when the collation is
+  used for the first time. See create_tailoring().
+*/
+static void
+my_uca1400_collation_definition_init(MY_CHARSET_LOADER *loader,
+                                     struct charset_info_st *dst,
+                                     const uca_collation_def_param_t *param)
+{
+  const MY_UCA1400_COLLATION_DEFINITION *def=
+    &my_uca1400_collation_definitions[param->tailoring_id];
+
+  /* Copy the entire charset_info_st from an in-compiled one. */
+  *dst= *my_uca0520_builtin_collation_by_id(param->cs_id, param->nopad_flags);
+
+  /* Now replace some members according to param */
+  DBUG_ASSERT((dst->state & uca1400_unexpected_flags()) == 0);
+  dst->uca= &my_uca_v1400;
+  dst->tailoring= def->tailoring;
+  if (def->tailoring == my_charset_utf8mb4_turkish_uca_ci.tailoring)
+    dst->casefold= &my_casefold_unicode1400tr;
+  else
+    dst->casefold= &my_casefold_unicode1400;
+
+  dst->state|= param->nopad_flags;
+  my_ci_set_level_flags(dst, param->level_flags);
+}
+
+
+/*
+  Allocate memory for a new charset_info_st instance together
+  with its name and comment.
+  Perform preliminary initialization, then add to the list
+  of available collations using MY_CHARSET_LOADER::add_collation.
+*/
+my_bool
+my_uca1400_collation_alloc_and_init(MY_CHARSET_LOADER *loader,
+                                    LEX_CSTRING name,
+                                    LEX_CSTRING comment,
+                                    const uca_collation_def_param_t *param,
+                                    uint id)
+{
+  struct charset_info_st *dst;
+
+  if (!(dst= my_ci_alloc(loader, name, &name, comment, &comment)))
+    return TRUE;
+
+  my_uca1400_collation_definition_init(loader, dst, param);
+
+  dst->number= id;
+  dst->coll_name= name;
+  dst->comment= comment.str;
+
+  return (loader->add_collation)(dst) != 0;
+}
+
+
+/*
+  Make an UCA-14.0.0 full collation name using its id,
+  then allocate and add the collation.
+*/
+static
+my_bool my_uca1400_collation_definition_add(MY_CHARSET_LOADER *loader, uint id)
+{
+  char coll_name_buffer[MY_CS_COLLATION_NAME_SIZE + 1];
+  LEX_CSTRING coll_name;
+  LEX_CSTRING comment= {"",0};
+  uca_collation_def_param_t param= my_uca1400_collation_param_by_id(id);
+  CHARSET_INFO *src= my_uca0520_builtin_collation_by_id(param.cs_id,
+                                                        param.nopad_flags);
+  const MY_UCA1400_COLLATION_DEFINITION *def=
+    &my_uca1400_collation_definitions[param.tailoring_id];
+
+  coll_name= my_uca1400_collation_build_name(coll_name_buffer,
+                                             sizeof(coll_name_buffer),
+                                             &src->cs_name,
+                                             def->name,
+                                             &param);
+
+  return my_uca1400_collation_alloc_and_init(loader, coll_name, comment,
+                                             &param, id);
+}
+
+
+/*
+  Add UCA-14.0.0 collations for all combinations of:
+  - Unicode character sets (utf8mb3, utf8mb4, ucs2, utf16, utf32)
+  - language rules (tailorings)
+  - pad properties
+  - accent sensitivity
+  - case sensitivity
+*/
+my_bool my_uca1400_collation_definitions_add(MY_CHARSET_LOADER *loader)
+{
+  my_cs_encoding_t charset_id;
+  for (charset_id= (my_cs_encoding_t) 0;
+       charset_id <= (my_cs_encoding_t) MY_CS_ENCODING_LAST;
+       charset_id++)
+  {
+    uint tailoring_id;
+    for (tailoring_id= 0 ;
+         tailoring_id < MY_UCA1400_COLLATION_DEFINITION_COUNT;
+         tailoring_id++)
+    {
+      my_bool nopad; /* PAD / NOPAD */
+      for (nopad= 0; nopad < 2; nopad++)
+      {
+        my_bool secondary_level; /* ai / as */
+        for (secondary_level= 0; secondary_level < 2; secondary_level++)
+        {
+          my_bool tertiary_level; /* ci / cs */
+          for (tertiary_level= 0; tertiary_level < 2; tertiary_level++)
+          {
+            uint id= my_uca1400_make_builtin_collation_id(charset_id,
+                                                          tailoring_id,
+                                                          nopad,
+                                                          secondary_level,
+                                                          tertiary_level);
+            if (id && my_uca1400_collation_definition_add(loader, id))
+              return TRUE;
+          }
+        }
+      }
+    }
+  }
+  return FALSE;
+}
--- a/strings/ctype-uca1400.h
+++ b/strings/ctype-uca1400.h
@@ -187,6 +187,19 @@ my_collation_id_is_uca1400(uint id)
                    id <= MY_UCA1400_COLLATION_ID_POSSIBLE_MAX);
 }

+
+typedef struct my_uca1400_collation_definition_st
+{
+  const char * tailoring;
+  const char * name;
+  uint16 id_utf8mb3;
+  uint16 id_utf8mb4;
+  uint16 id_ucs2;
+  uint16 id_utf16;
+  uint16 id_utf32;
+} MY_UCA1400_COLLATION_DEFINITION;
+
+
 /*
  UCA1400 collation ID:

@@ -204,6 +217,7 @@ my_collation_id_is_uca1400(uint id)
 static inline my_cs_encoding_t
 my_uca1400_collation_id_to_charset_id(uint id)
 {
+  DBUG_ASSERT(id);
  return (my_cs_encoding_t) ((id >> 8) & 0x07);
 }

@@ -211,6 +225,7 @@ my_uca1400_collation_id_to_charset_id(uint id)
 static inline uint
 my_uca1400_collation_id_to_tailoring_id(uint id)
 {
+  DBUG_ASSERT(id);
  return (id >> 3) & 0x1F;
 }

@@ -218,21 +233,52 @@ my_uca1400_collation_id_to_tailoring_id(uint id)
 static inline my_bool
 my_uca1400_collation_id_to_nopad_flag(uint id)
 {
+  DBUG_ASSERT(id);
  return (my_bool) ((id >> 2) & 0x01);
 }

 static inline my_bool
 my_uca1400_collation_id_to_secondary_level_flag(uint id)
 {
+  DBUG_ASSERT(id);
  return (my_bool) ((id >> 1) & 0x01);
 }

 static inline my_bool
 my_uca1400_collation_id_to_tertiary_level_flag(uint id)
 {
+  DBUG_ASSERT(id);
  return (my_bool) ((id >> 0) & 0x01);
 }

+static inline uint
+my_uca1400_collation_id_to_level_flags(uint id)
+{
+  my_bool secondary_level, tertiary_level;
+  DBUG_ASSERT(id);
+  secondary_level= my_uca1400_collation_id_to_secondary_level_flag(id);
+  tertiary_level=  my_uca1400_collation_id_to_tertiary_level_flag(id);
+  return (1 << MY_CS_LEVEL_BIT_PRIMARY) |
+         (secondary_level ? 1 << MY_CS_LEVEL_BIT_SECONDARY : 0) |
+         (tertiary_level  ? 1 << MY_CS_LEVEL_BIT_TERTIARY  : 0);
+}
+
+
+/*
+  Return an UCA-14.0.0 collation properties using its ID.
+*/
+static inline uca_collation_def_param_t
+my_uca1400_collation_param_by_id(uint id)
+{
+  uca_collation_def_param_t res;
+  DBUG_ASSERT(id);
+  res.cs_id= my_uca1400_collation_id_to_charset_id(id);
+  res.tailoring_id= my_uca1400_collation_id_to_tailoring_id(id);
+  res.nopad_flags= my_uca1400_collation_id_to_nopad_flag(id);
+  res.level_flags= my_uca1400_collation_id_to_level_flags(id);
+  return res;
+}
+

 uint
 my_uca1400_make_builtin_collation_id(my_cs_encoding_t charset_id,
@@ -241,13 +287,36 @@ my_uca1400_make_builtin_collation_id(my_cs_encoding_t charset_id,
                                     my_bool secondary_level,
                                     my_bool tertiary_level);

-my_bool
-my_uca1400_collation_definition_init(MY_CHARSET_LOADER *loader,
-                                     struct charset_info_st *dst,
-                                     uint collation_id);
+LEX_CSTRING
+my_uca1400_collation_build_name(char *buffer, size_t buffer_size,
+                                const LEX_CSTRING *cs_name,
+                                const char *tailoring_name,
+                                const uca_collation_def_param_t *prm);

+my_bool
+my_uca1400_collation_alloc_and_init(MY_CHARSET_LOADER *loader,
+                                    LEX_CSTRING name,
+                                    LEX_CSTRING comment,
+                                    const uca_collation_def_param_t *param,
+                                    uint id);
+
+LEX_CSTRING my_ci_get_collation_name_uca1400_context(CHARSET_INFO *cs);
+
+uint my_uca1400_collation_id_uca400_compat(uint id);
+
+my_bool my_uca1400_collation_definitions_add(MY_CHARSET_LOADER *loader);
+
+
+/* Exported data */
 #define MY_UCA1400_COLLATION_DEFINITION_COUNT 26

-my_bool mysql_utf8mb4_0900_collation_definitions_add();
+extern MY_UCA1400_COLLATION_DEFINITION
+my_uca1400_collation_definitions[MY_UCA1400_COLLATION_DEFINITION_COUNT];
+
+extern MY_UCA_INFO my_uca_v1400;
+
+
+extern MY_UCA_INFO my_uca1400_info_tailored[MY_CS_ENCODING_LAST+1]
+                                      [MY_UCA1400_COLLATION_DEFINITION_COUNT];

 #endif /* CTYPE_UCA_1400_H */
--- a/strings/ctype-ucs2.c
+++ b/strings/ctype-ucs2.c
@@ -1505,7 +1505,8 @@ static MY_COLLATION_HANDLER my_collation_utf16_general_ci_handler =
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -1526,7 +1527,8 @@ static MY_COLLATION_HANDLER my_collation_utf16_bin_handler =
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -1547,7 +1549,8 @@ static MY_COLLATION_HANDLER my_collation_utf16_general_nopad_ci_handler =
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -1568,7 +1571,8 @@ static MY_COLLATION_HANDLER my_collation_utf16_nopad_bin_handler =
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -1858,7 +1862,8 @@ static MY_COLLATION_HANDLER my_collation_utf16le_general_ci_handler =
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -1879,7 +1884,8 @@ static MY_COLLATION_HANDLER my_collation_utf16le_bin_handler =
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -1900,7 +1906,8 @@ static MY_COLLATION_HANDLER my_collation_utf16le_general_nopad_ci_handler =
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -1921,7 +1928,8 @@ static MY_COLLATION_HANDLER my_collation_utf16le_nopad_bin_handler =
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -2663,7 +2671,8 @@ static MY_COLLATION_HANDLER my_collation_utf32_general_ci_handler =
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -2684,7 +2693,8 @@ static MY_COLLATION_HANDLER my_collation_utf32_bin_handler =
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -2705,7 +2715,8 @@ static MY_COLLATION_HANDLER my_collation_utf32_general_nopad_ci_handler =
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -2726,7 +2737,8 @@ static MY_COLLATION_HANDLER my_collation_utf32_nopad_bin_handler =
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -3263,7 +3275,8 @@ static MY_COLLATION_HANDLER my_collation_ucs2_general_ci_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -3284,7 +3297,8 @@ static MY_COLLATION_HANDLER my_collation_ucs2_general_mysql500_ci_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -3305,7 +3319,8 @@ static MY_COLLATION_HANDLER my_collation_ucs2_bin_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -3326,7 +3341,8 @@ static MY_COLLATION_HANDLER my_collation_ucs2_general_nopad_ci_handler =
    my_min_str_mb_simple_nopad,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -3347,7 +3363,8 @@ static MY_COLLATION_HANDLER my_collation_ucs2_nopad_bin_handler =
    my_min_str_mb_simple_nopad,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


--- a/strings/ctype-ujis.c
+++ b/strings/ctype-ujis.c
@@ -67261,7 +67261,8 @@ static MY_COLLATION_HANDLER my_collation_ujis_japanese_ci_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -67282,7 +67283,8 @@ static MY_COLLATION_HANDLER my_collation_ujis_bin_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -67303,7 +67305,8 @@ static MY_COLLATION_HANDLER my_collation_ujis_japanese_nopad_ci_handler =
    my_min_str_mb_simple_nopad,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -67324,7 +67327,8 @@ static MY_COLLATION_HANDLER my_collation_ujis_nopad_bin_handler =
    my_min_str_mb_simple_nopad,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


--- a/strings/ctype-utf8.c
+++ b/strings/ctype-utf8.c
@@ -1119,7 +1119,8 @@ static MY_COLLATION_HANDLER my_collation_utf8mb3_general_ci_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -1140,7 +1141,8 @@ static MY_COLLATION_HANDLER my_collation_utf8mb3_general_mysql500_ci_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -1161,7 +1163,8 @@ static MY_COLLATION_HANDLER my_collation_utf8mb3_bin_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };


@@ -1182,7 +1185,8 @@ static MY_COLLATION_HANDLER my_collation_utf8mb3_general_nopad_ci_handler =
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -1203,7 +1207,8 @@ static MY_COLLATION_HANDLER my_collation_utf8mb3_nopad_bin_handler =
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -1529,7 +1534,8 @@ static MY_COLLATION_HANDLER my_collation_cs_handler =
    my_hash_sort_utf8mb3,
    my_propagate_simple,
    my_min_str_mb_simple,
-    my_max_str_mb_simple
+    my_max_str_mb_simple,
+    my_ci_eq_collation_generic
 };

 struct charset_info_st my_charset_utf8mb3_general_cs=
@@ -2848,7 +2854,8 @@ static MY_COLLATION_HANDLER my_collation_filename_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_generic
 };

 static MY_CHARSET_HANDLER my_charset_filename_handler=
@@ -3393,6 +3400,19 @@ my_charlen_utf8mb4(CHARSET_INFO *cs __attribute__((unused)),
 }


+static my_bool
+my_ci_eq_collation_utf8mb4_bin(CHARSET_INFO *a, CHARSET_INFO *b)
+{
+  return a->cset == b->cset &&
+         a->coll == b->coll &&
+         a->uca == b->uca && a->uca == NULL &&
+         a->casefold == b->casefold &&
+         (a->state & MY_CS_NOPAD) == (b->state & MY_CS_NOPAD) &&
+         a->levels_for_order == b->levels_for_order &&
+         a->tailoring == b->tailoring && a->tailoring == NULL;
+}
+
+
 #define MY_FUNCTION_NAME(x)       my_ ## x ## _utf8mb4
 #define CHARLEN(cs,str,end)       my_charlen_utf8mb4(cs,str,end)
 #define DEFINE_WELL_FORMED_CHAR_LENGTH_USING_CHARLEN
@@ -3475,7 +3495,8 @@ static MY_COLLATION_HANDLER my_collation_utf8mb4_general_ci_handler=
  my_min_str_mb_simple,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -3496,7 +3517,8 @@ static MY_COLLATION_HANDLER my_collation_utf8mb4_bin_handler =
    my_min_str_mb_simple,
    my_max_str_mb_simple,
    my_ci_get_id_generic,
-    my_ci_get_collation_name_generic
+    my_ci_get_collation_name_generic,
+    my_ci_eq_collation_utf8mb4_bin
 };


@@ -3517,7 +3539,8 @@ static MY_COLLATION_HANDLER my_collation_utf8mb4_general_nopad_ci_handler=
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


@@ -3538,7 +3561,8 @@ static MY_COLLATION_HANDLER my_collation_utf8mb4_nopad_bin_handler =
  my_min_str_mb_simple_nopad,
  my_max_str_mb_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_utf8mb4_bin
 };


--- a/strings/ctype-win1250ch.c
+++ b/strings/ctype-win1250ch.c
@@ -690,7 +690,8 @@ static MY_COLLATION_HANDLER my_collation_czech_cs_handler =
  my_min_str_8bit_simple,
  my_max_str_8bit_simple,
  my_ci_get_id_generic,
-  my_ci_get_collation_name_generic
+  my_ci_get_collation_name_generic,
+  my_ci_eq_collation_generic
 };


--- a/strings/ctype.c
+++ b/strings/ctype.c
@@ -1413,3 +1413,41 @@ uint my_casefold_multiply_2(CHARSET_INFO *cs)
 {
  return 2;
 }
+
+
+my_bool my_ci_eq_collation_generic(CHARSET_INFO *self, CHARSET_INFO *other)
+{
+  return FALSE;
+}
+
+
+/*
+  Allocate a memory block for a new charset_info_st together with
+  its name and its comment in a single once_alloc() call.
+  Copy the name and the comment into the new block.
+*/
+struct charset_info_st *my_ci_alloc(MY_CHARSET_LOADER *loader,
+                                    const LEX_CSTRING name,
+                                    LEX_CSTRING *out_name,
+                                    const LEX_CSTRING comment,
+                                    LEX_CSTRING *out_comment)
+{
+  size_t nbytes= sizeof(struct charset_info_st) +
+                 name.length + comment.length + 2;
+  struct charset_info_st *csinfo;
+  char *dst;
+  if (!(csinfo= (struct charset_info_st*) (loader->once_alloc)(nbytes)))
+    return NULL;
+  dst= ((char*) csinfo) + sizeof(struct charset_info_st);
+
+  memcpy(dst, name.str, name.length + 1);
+  out_name->str= dst;
+  out_name->length= name.length;
+  dst+= name.length + 1;
+
+  memcpy(dst, comment.str, comment.length + 1);
+  out_comment->str= dst;
+  out_comment->length= comment.length;
+
+  return csinfo;
+}
--- a/strings/strings_def.h
+++ b/strings/strings_def.h
@@ -20,6 +20,7 @@
 #undef DBUG_ASSERT_AS_PRINTF
 #include <my_global.h>		/* Define standard vars */
 #include "m_string.h"		/* Exernal definitions of string functions */
+#include "m_ctype.h"

 /*
  We can't use the original DBUG_ASSERT() (which includes _db_flush())
@@ -148,6 +149,13 @@ void my_ci_set_level_flags(struct charset_info_st *cs, uint flags);
 uint my_casefold_multiply_1(CHARSET_INFO *cs);
 uint my_casefold_multiply_2(CHARSET_INFO *cs);

+my_bool my_ci_eq_collation_generic(CHARSET_INFO *self, CHARSET_INFO *other);
+
+struct charset_info_st *my_ci_alloc(MY_CHARSET_LOADER *loader,
+                                    const LEX_CSTRING name,
+                                    LEX_CSTRING *out_name,
+                                    const LEX_CSTRING comment,
+                                    LEX_CSTRING *out_comment);

 /* Some common character set names */
 extern const char charset_name_latin2[];