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f69319f2f1
The builtin C.UTF-8 locale has similar semantics to the libc locale of the same name. That is, code point sort order (fast, memcmp-based) combined with Unicode semantics for character operations such as pattern matching, regular expressions, and LOWER()/INITCAP()/UPPER(). The character semantics are based on Unicode simple case mappings. The builtin provider's C.UTF-8 offers several important advantages over libc: * faster sorting -- benefits from additional optimizations such as abbreviated keys and varstrfastcmp_c * faster case conversion, e.g. LOWER(), at least compared with some libc implementations * available on all platforms with identical semantics, and the semantics are stable, testable, and documentable within a given Postgres major version Being based on memcmp, the builtin C.UTF-8 locale does not offer natural language sort order. But it is an improvement for most use cases that might otherwise use libc's "C.UTF-8" locale, as well as many use cases that use libc's "C" locale. Discussion: https://postgr.es/m/ff4c2f2f9c8fc7ca27c1c24ae37ecaeaeaff6b53.camel%40j-davis.com Reviewed-by: Daniel Vérité, Peter Eisentraut, Jeremy Schneider
68 lines
1.9 KiB
SQL
68 lines
1.9 KiB
SQL
/*
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* This test is for collations and character operations when using the
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* builtin provider with the C.UTF-8 locale.
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*/
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/* skip test if not UTF8 server encoding */
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SELECT getdatabaseencoding() <> 'UTF8' AS skip_test \gset
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\if :skip_test
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\quit
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\endif
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SET client_encoding TO UTF8;
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--
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-- Test PG_C_UTF8
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--
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CREATE COLLATION regress_pg_c_utf8 (
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provider = builtin, locale = 'C_UTF8'); -- fails
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CREATE COLLATION regress_pg_c_utf8 (
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provider = builtin, locale = 'C.UTF8');
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DROP COLLATION regress_pg_c_utf8;
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CREATE COLLATION regress_pg_c_utf8 (
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provider = builtin, locale = 'C.UTF-8');
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CREATE TABLE test_pg_c_utf8 (
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t TEXT COLLATE PG_C_UTF8
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);
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INSERT INTO test_pg_c_utf8 VALUES
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('abc DEF 123abc'),
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('ábc sßs ßss DÉF'),
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('DŽxxDŽ džxxDž Džxxdž'),
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('ȺȺȺ'),
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('ⱥⱥⱥ'),
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('ⱥȺ');
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SELECT
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t, lower(t), initcap(t), upper(t),
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length(convert_to(t, 'UTF8')) AS t_bytes,
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length(convert_to(lower(t), 'UTF8')) AS lower_t_bytes,
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length(convert_to(initcap(t), 'UTF8')) AS initcap_t_bytes,
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length(convert_to(upper(t), 'UTF8')) AS upper_t_bytes
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FROM test_pg_c_utf8;
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DROP TABLE test_pg_c_utf8;
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-- negative test: Final_Sigma not used for builtin locale C.UTF-8
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SELECT lower('ΑΣ' COLLATE PG_C_UTF8);
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SELECT lower('ΑͺΣͺ' COLLATE PG_C_UTF8);
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SELECT lower('Α΄Σ΄' COLLATE PG_C_UTF8);
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-- properties
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SELECT 'xyz' ~ '[[:alnum:]]' COLLATE PG_C_UTF8;
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SELECT 'xyz' !~ '[[:upper:]]' COLLATE PG_C_UTF8;
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SELECT '@' !~ '[[:alnum:]]' COLLATE PG_C_UTF8;
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SELECT '=' ~ '[[:punct:]]' COLLATE PG_C_UTF8; -- symbols are punctuation in posix
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SELECT 'a8a' ~ '[[:digit:]]' COLLATE PG_C_UTF8;
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SELECT '൧' !~ '\d' COLLATE PG_C_UTF8; -- only 0-9 considered digits in posix
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-- case mapping
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SELECT 'xYz' ~* 'XyZ' COLLATE PG_C_UTF8;
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SELECT 'xAb' ~* '[W-Y]' COLLATE PG_C_UTF8;
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SELECT 'xAb' !~* '[c-d]' COLLATE PG_C_UTF8;
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SELECT 'Δ' ~* '[γ-λ]' COLLATE PG_C_UTF8;
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SELECT 'δ' ~* '[Γ-Λ]' COLLATE PG_C_UTF8; -- same as above with cases reversed
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