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* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
0 siblings, 0 replies; 3+ messages in thread
From: Thomas Munro @ 2020-03-11 02:01 UTC (permalink / raw)
Supply a brief introduction to collation version concepts.
Author: Thomas Munro <[email protected]>
Reviewed-by: Julien Rouhaud <[email protected]>
Discussion: https://postgr.es/m/CAEepm%3D0uEQCpfq_%2BLYFBdArCe4Ot98t1aR4eYiYTe%3DyavQygiQ%40mail.gmail.com
---
doc/src/sgml/charset.sgml | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/doc/src/sgml/charset.sgml b/doc/src/sgml/charset.sgml
index 4b4563c5b9..12a82ff18c 100644
--- a/doc/src/sgml/charset.sgml
+++ b/doc/src/sgml/charset.sgml
@@ -948,6 +948,41 @@ CREATE COLLATION ignore_accents (provider = icu, locale = 'und-u-ks-level1-kc-tr
</tip>
</sect3>
</sect2>
+
+ <sect2 id="collation-versions">
+ <title>Collation Versions</title>
+
+ <para>
+ The ordering defined by a collation is not necessarily fixed over time.
+ If a collation changes for any reason, persistent data structures such as
+ b-trees that depend on a stable ordering of text might be corrupted.
+ <productname>PostgreSQL</productname> defends against this by recording
+ the current version of each referenced collation for any index that
+ depends on it in the
+ <link linkend="catalog-pg-depend"><structname>pg_depend</structname></link>
+ catalog, if the collation provider makes it available. If the provider
+ later begins to report a different version, a warning will be issued
+ when the index is accessed, until either the <xref linkend="sql-reindex"/>
+ or the <xref linkend="sql-alterindex"/> command is used to update the
+ version.
+ </para>
+ <para>
+ Version information is available for collations from the
+ <literal>icu</literal> provider on all operating systems. For the
+ <literal>libc</literal> provider, versions are currently only available
+ on systems using the GNU C library (most Linux systems).
+ </para>
+
+ <note>
+ <para>
+ When using the GNU C library for collations, the C library's version
+ is used as a proxy for the collation version. Many Linux distributions
+ change collation definitions only when upgrading the C library, but this
+ approach is imperfect as maintainers are free to back-port newer
+ collation definitions to older C library releases.
+ </para>
+ </note>
+ </sect2>
</sect1>
<sect1 id="multibyte">
--
2.20.1
--gclmslubawp3yaq7--
^ permalink raw reply [nested|flat] 3+ messages in thread
* [Code Cleanup] : Small code cleanup in twophase.sql
@ 2023-09-26 13:01 Nishant Sharma <[email protected]>
2023-10-10 05:57 ` Re: [Code Cleanup] : Small code cleanup in twophase.sql Nishant Sharma <[email protected]>
0 siblings, 1 reply; 3+ messages in thread
From: Nishant Sharma @ 2023-09-26 13:01 UTC (permalink / raw)
To: pgsql-hackers
Hi,
PFA small code cleanup in twophase.sql. Which contains a drop table
statement for 'test_prepared_savepoint'. Which, to me, appears to be
missing in the cleanup section of that file.
To support it I have below points:-
1) Grepping this table 'test_prepared_savepoint' shows occurrences
only in twophase.out & twophase.sql files. This means that table is
local to that sql test file and not used in any other test file.
2) I don't see any comment on why this was not added in the cleanup
section of twophase.sql, but drop for other two test tables are done.
3) I ran "make check-world" with the patch and I don't see any failures.
Kindly correct, if I missed anything.
Regards,
Nishant (EDB).
Attachments:
[application/octet-stream] v1-0001-Small-code-cleanup-in-twophase.sql.patch (1.6K, ../../CADrsxdb0ueGV9nrC6s8zvXLkGUhnEjx7Ou_p5wo38TvmSvF83A@mail.gmail.com/3-v1-0001-Small-code-cleanup-in-twophase.sql.patch)
download | inline diff:
From 4af31a650c1a51f306c650f2fa6b67577ec39a96 Mon Sep 17 00:00:00 2001
From: Nishant Sharma <[email protected]>
Date: Tue, 26 Sep 2023 18:15:28 +0530
Subject: [PATCH v1] Small code cleanup in twophase.sql
---
contrib/test_decoding/expected/twophase.out | 1 +
contrib/test_decoding/sql/twophase.sql | 1 +
2 files changed, 2 insertions(+)
diff --git a/contrib/test_decoding/expected/twophase.out b/contrib/test_decoding/expected/twophase.out
index e89dc74..517f20b 100644
--- a/contrib/test_decoding/expected/twophase.out
+++ b/contrib/test_decoding/expected/twophase.out
@@ -209,6 +209,7 @@ SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'inc
-- cleanup and make sure results are also empty
DROP TABLE test_prepared1;
DROP TABLE test_prepared2;
+DROP TABLE test_prepared_savepoint;
-- show results. There should be nothing to show
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
data
diff --git a/contrib/test_decoding/sql/twophase.sql b/contrib/test_decoding/sql/twophase.sql
index aff5114..0244795 100644
--- a/contrib/test_decoding/sql/twophase.sql
+++ b/contrib/test_decoding/sql/twophase.sql
@@ -108,6 +108,7 @@ SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'inc
-- cleanup and make sure results are also empty
DROP TABLE test_prepared1;
DROP TABLE test_prepared2;
+DROP TABLE test_prepared_savepoint;
-- show results. There should be nothing to show
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
--
1.8.3.1
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: [Code Cleanup] : Small code cleanup in twophase.sql
2023-09-26 13:01 [Code Cleanup] : Small code cleanup in twophase.sql Nishant Sharma <[email protected]>
@ 2023-10-10 05:57 ` Nishant Sharma <[email protected]>
0 siblings, 0 replies; 3+ messages in thread
From: Nishant Sharma @ 2023-10-10 05:57 UTC (permalink / raw)
To: pgsql-hackers
Hi,
Any taker or rejector for above? -- It's a very small 'good to have' change
patch for cleanup.
Thanks,
Nishant (EDB).
On Tue, Sep 26, 2023 at 6:31 PM Nishant Sharma <
[email protected]> wrote:
> Hi,
>
>
> PFA small code cleanup in twophase.sql. Which contains a drop table
> statement for 'test_prepared_savepoint'. Which, to me, appears to be
> missing in the cleanup section of that file.
>
> To support it I have below points:-
>
> 1) Grepping this table 'test_prepared_savepoint' shows occurrences
> only in twophase.out & twophase.sql files. This means that table is
> local to that sql test file and not used in any other test file.
>
> 2) I don't see any comment on why this was not added in the cleanup
> section of twophase.sql, but drop for other two test tables are done.
>
> 3) I ran "make check-world" with the patch and I don't see any failures.
>
> Kindly correct, if I missed anything.
>
>
> Regards,
> Nishant (EDB).
>
^ permalink raw reply [nested|flat] 3+ messages in thread
end of thread, other threads:[~2023-10-10 05:57 UTC | newest]
Thread overview: 3+ messages (download: mbox mbox.gz follow: Atom feed)
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2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2023-09-26 13:01 [Code Cleanup] : Small code cleanup in twophase.sql Nishant Sharma <[email protected]>
2023-10-10 05:57 ` Re: [Code Cleanup] : Small code cleanup in twophase.sql Nishant Sharma <[email protected]>
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