From d3d0983169130a9b81e3fe48d5c2ca4931480956 Mon Sep 17 00:00:00 2001 From: Jeff Davis Date: Fri, 17 Jan 2025 15:56:30 -0800 Subject: Support PG_UNICODE_FAST locale in the builtin collation provider. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The PG_UNICODE_FAST locale uses code point sort order (fast, memcmp-based) combined with Unicode character semantics. The character semantics are based on Unicode full case mapping. Full case mapping can map a single codepoint to multiple codepoints, such as "ß" uppercasing to "SS". Additionally, it handles context-sensitive mappings like the "final sigma", and it uses titlecase mappings such as "Dž" when titlecasing (rather than plain uppercase mappings). Importantly, the uppercasing of "ß" as "SS" is specifically mentioned by the SQL standard. In Postgres, UCS_BASIC uses plain ASCII semantics for case mapping and pattern matching, so if we changed it to use the PG_UNICODE_FAST locale, it would offer better compliance with the standard. For now, though, do not change the behavior of UCS_BASIC. Discussion: https://postgr.es/m/ddfd67928818f138f51635712529bc5e1d25e4e7.camel@j-davis.com Discussion: https://postgr.es/m/27bb0e52-801d-4f73-a0a4-02cfdd4a9ada@eisentraut.org Reviewed-by: Peter Eisentraut, Daniel Verite --- src/backend/utils/adt/pg_locale_builtin.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'src/backend/utils/adt/pg_locale_builtin.c') diff --git a/src/backend/utils/adt/pg_locale_builtin.c b/src/backend/utils/adt/pg_locale_builtin.c index fef5b6e6d38..436e32c0ca0 100644 --- a/src/backend/utils/adt/pg_locale_builtin.c +++ b/src/backend/utils/adt/pg_locale_builtin.c @@ -78,7 +78,8 @@ size_t strlower_builtin(char *dest, size_t destsize, const char *src, ssize_t srclen, pg_locale_t locale) { - return unicode_strlower(dest, destsize, src, srclen, false); + return unicode_strlower(dest, destsize, src, srclen, + locale->info.builtin.casemap_full); } size_t @@ -93,7 +94,8 @@ strtitle_builtin(char *dest, size_t destsize, const char *src, ssize_t srclen, .prev_alnum = false, }; - return unicode_strtitle(dest, destsize, src, srclen, false, + return unicode_strtitle(dest, destsize, src, srclen, + locale->info.builtin.casemap_full, initcap_wbnext, &wbstate); } @@ -101,7 +103,8 @@ size_t strupper_builtin(char *dest, size_t destsize, const char *src, ssize_t srclen, pg_locale_t locale) { - return unicode_strupper(dest, destsize, src, srclen, false); + return unicode_strupper(dest, destsize, src, srclen, + locale->info.builtin.casemap_full); } pg_locale_t @@ -142,6 +145,7 @@ create_pg_locale_builtin(Oid collid, MemoryContext context) result = MemoryContextAllocZero(context, sizeof(struct pg_locale_struct)); result->info.builtin.locale = MemoryContextStrdup(context, locstr); + result->info.builtin.casemap_full = (strcmp(locstr, "PG_UNICODE_FAST") == 0); result->provider = COLLPROVIDER_BUILTIN; result->deterministic = true; result->collate_is_c = true; @@ -164,6 +168,8 @@ get_collation_actual_version_builtin(const char *collcollate) return "1"; else if (strcmp(collcollate, "C.UTF-8") == 0) return "1"; + else if (strcmp(collcollate, "PG_UNICODE_FAST") == 0) + return "1"; else ereport(ERROR, (errcode(ERRCODE_WRONG_OBJECT_TYPE), -- cgit v1.2.3