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[PATCH v29 6/6] Doc: Add Collation Versions section.
88+ messages / 1 participants
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* [PATCH v15 7/7] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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 20cdfabd7b..d4aa300c5a 100644
--- a/doc/src/sgml/charset.sgml
+++ b/doc/src/sgml/charset.sgml
@@ -936,6 +936,41 @@ CREATE COLLATION ignore_accents (provider = icu, locale = 'und-u-ks-level1-kc-tr
     </para>
    </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 reported
+    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


--bp/iNruPH9dso1Pn--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v14 7/7] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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 20cdfabd7b..d4aa300c5a 100644
--- a/doc/src/sgml/charset.sgml
+++ b/doc/src/sgml/charset.sgml
@@ -936,6 +936,41 @@ CREATE COLLATION ignore_accents (provider = icu, locale = 'und-u-ks-level1-kc-tr
     </para>
    </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 reported
+    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


--wRRV7LY7NUeQGEoC--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v19 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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 b6023fa459..a460cb5be8 100644
--- a/doc/src/sgml/charset.sgml
+++ b/doc/src/sgml/charset.sgml
@@ -946,6 +946,41 @@ 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 reported
+    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


--u65IjBhB3TIa72Vp--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v16 7/7] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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 20cdfabd7b..d4aa300c5a 100644
--- a/doc/src/sgml/charset.sgml
+++ b/doc/src/sgml/charset.sgml
@@ -936,6 +936,41 @@ CREATE COLLATION ignore_accents (provider = icu, locale = 'und-u-ks-level1-kc-tr
     </para>
    </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 reported
+    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


--sdtB3X0nJg68CQEu--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v17 7/7] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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 20cdfabd7b..d4aa300c5a 100644
--- a/doc/src/sgml/charset.sgml
+++ b/doc/src/sgml/charset.sgml
@@ -936,6 +936,41 @@ CREATE COLLATION ignore_accents (provider = icu, locale = 'und-u-ks-level1-kc-tr
     </para>
    </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 reported
+    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


--FCuugMFkClbJLl1L--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v23 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--MGYHOYXEY6WxJCY8--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v30 6/6] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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 2745b44417..9008d094bb 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


--vy36zrg552ym33jw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v29 6/6] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--9jxsPFA5p3P2qPhR--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v16 7/7] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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 20cdfabd7b..d4aa300c5a 100644
--- a/doc/src/sgml/charset.sgml
+++ b/doc/src/sgml/charset.sgml
@@ -936,6 +936,41 @@ CREATE COLLATION ignore_accents (provider = icu, locale = 'und-u-ks-level1-kc-tr
     </para>
    </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 reported
+    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


--fUYQa+Pmc3FrFX/N--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v28 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v25 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--lrZ03NoBR/3+SXJZ--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v27 5/5] Doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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


--o56keubw4jpehgac--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v20 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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 b6023fa459..a460cb5be8 100644
--- a/doc/src/sgml/charset.sgml
+++ b/doc/src/sgml/charset.sgml
@@ -946,6 +946,41 @@ 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 reported
+    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


--Q68bSM7Ycu6FN28Q--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

* [PATCH v24 5/5] doc: Add Collation Versions section.
@ 2020-03-11 02:01 Thomas Munro <[email protected]>
  0 siblings, 0 replies; 88+ 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
Reviewed-by: Julien Rouhaud
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..c537bdfc28 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 reported
+    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


--wac7ysb48OaltWcw--





^ permalink  raw  reply  [nested|flat] 88+ messages in thread

end of thread, other threads:[~2020-03-11 02:01 UTC | newest]

Thread overview: 88+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2020-03-11 02:01 [PATCH v15 7/7] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v14 7/7] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v19 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v16 7/7] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v17 7/7] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v23 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v30 6/6] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v29 6/6] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v16 7/7] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v28 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v25 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v27 5/5] Doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v20 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>
2020-03-11 02:01 [PATCH v24 5/5] doc: Add Collation Versions section. Thomas Munro <[email protected]>

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