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Re: Window Function "Run Conditions" 18+ messages / 5 participants [nested] [flat]
* Re: Window Function "Run Conditions" @ 2022-03-15 21:23 Greg Stark <[email protected]> 0 siblings, 2 replies; 18+ messages in thread From: Greg Stark @ 2022-03-15 21:23 UTC (permalink / raw) To: Andy Fan <[email protected]>; +Cc: David Rowley <[email protected]>; Zhihong Yu <[email protected]>; PostgreSQL Developers <[email protected]> This looks like an awesome addition. I have one technical questions... Is it possible to actually transform the row_number case into a LIMIT clause or make the planner support for this case equivalent to it (in which case we can replace the LIMIT clause planning to transform into a window function)? The reason I ask is because the Limit plan node is actually quite a bit more optimized than the general window function plan node. It calculates cost estimates based on the limit and can support Top-N sort nodes. But the bigger question is whether this patch is ready for a committer to look at? Were you able to resolve Andy Fan's bug report? Did you resolve the two questions in the original email? ^ permalink raw reply [nested|flat] 18+ messages in thread
* Re: Window Function "Run Conditions" @ 2022-03-17 04:04 Corey Huinker <[email protected]> parent: Greg Stark <[email protected]> 1 sibling, 1 reply; 18+ messages in thread From: Corey Huinker @ 2022-03-17 04:04 UTC (permalink / raw) To: Greg Stark <[email protected]>; +Cc: Andy Fan <[email protected]>; David Rowley <[email protected]>; Zhihong Yu <[email protected]>; PostgreSQL Developers <[email protected]> On Tue, Mar 15, 2022 at 5:24 PM Greg Stark <[email protected]> wrote: > This looks like an awesome addition. > > I have one technical questions... > > Is it possible to actually transform the row_number case into a LIMIT > clause or make the planner support for this case equivalent to it (in > which case we can replace the LIMIT clause planning to transform into > a window function)? > > The reason I ask is because the Limit plan node is actually quite a > bit more optimized than the general window function plan node. It > calculates cost estimates based on the limit and can support Top-N > sort nodes. > > But the bigger question is whether this patch is ready for a committer > to look at? Were you able to resolve Andy Fan's bug report? Did you > resolve the two questions in the original email? > +1 to all this It seems like this effort would aid in implementing what some other databases implement via the QUALIFY clause, which is to window functions what HAVING is to aggregate functions. example: https://cloud.google.com/bigquery/docs/reference/standard-sql/query-syntax#qualify_clause ^ permalink raw reply [nested|flat] 18+ messages in thread
* Re: Window Function "Run Conditions" @ 2022-03-22 22:35 David Rowley <[email protected]> parent: Greg Stark <[email protected]> 1 sibling, 0 replies; 18+ messages in thread From: David Rowley @ 2022-03-22 22:35 UTC (permalink / raw) To: Greg Stark <[email protected]>; +Cc: Andy Fan <[email protected]>; Zhihong Yu <[email protected]>; PostgreSQL Developers <[email protected]> On Wed, 16 Mar 2022 at 10:24, Greg Stark <[email protected]> wrote: > > This looks like an awesome addition. Thanks > I have one technical questions... > > Is it possible to actually transform the row_number case into a LIMIT > clause or make the planner support for this case equivalent to it (in > which case we can replace the LIMIT clause planning to transform into > a window function)? Currently, I have only coded it to support monotonically increasing and decreasing functions. Putting a <= <const> type condition on a row_number() function with no PARTITION BY clause I think is logically the same as a LIMIT clause, but that's not the case for rank() and dense_rank(). There may be multiple peer rows with the same rank in those cases. We'd have no way to know what the LIMIT should be set to. I don't really want to just do this for row_number(). > The reason I ask is because the Limit plan node is actually quite a > bit more optimized than the general window function plan node. It > calculates cost estimates based on the limit and can support Top-N > sort nodes. This is true. There's perhaps no reason why an additional property could not be added to allow the prosupport function to optionally set *exactly* the maximum number of rows that could match the condition. e.g. for select * from (select *,row_number() over (order by c) rn from ..) w where rn <= 10; that could be set to 10, and if we used rank() instead of row_number(), it could just be left unset. I think this is probably worth thinking about at some future date. I don't really want to make it part of this effort. I also don't think I'm doing anything here that would need to be undone to make that work. David ^ permalink raw reply [nested|flat] 18+ messages in thread
* Re: Window Function "Run Conditions" @ 2022-03-22 22:39 David Rowley <[email protected]> parent: Corey Huinker <[email protected]> 0 siblings, 1 reply; 18+ messages in thread From: David Rowley @ 2022-03-22 22:39 UTC (permalink / raw) To: Corey Huinker <[email protected]>; +Cc: Greg Stark <[email protected]>; Andy Fan <[email protected]>; Zhihong Yu <[email protected]>; PostgreSQL Developers <[email protected]> On Thu, 17 Mar 2022 at 17:04, Corey Huinker <[email protected]> wrote: > It seems like this effort would aid in implementing what some other databases implement via the QUALIFY clause, which is to window functions what HAVING is to aggregate functions. > example: https://cloud.google.com/bigquery/docs/reference/standard-sql/query-syntax#qualify_clause Isn't that just syntactic sugar? You could get the same from adding a subquery where a WHERE clause to filter rows evaluated after the window clause. David ^ permalink raw reply [nested|flat] 18+ messages in thread
* Re: Window Function "Run Conditions" @ 2022-03-23 05:09 David G. Johnston <[email protected]> parent: David Rowley <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: David G. Johnston @ 2022-03-23 05:09 UTC (permalink / raw) To: David Rowley <[email protected]>; +Cc: Corey Huinker <[email protected]>; Greg Stark <[email protected]>; Andy Fan <[email protected]>; Zhihong Yu <[email protected]>; PostgreSQL Developers <[email protected]> On Tue, Mar 22, 2022 at 3:39 PM David Rowley <[email protected]> wrote: > On Thu, 17 Mar 2022 at 17:04, Corey Huinker <[email protected]> > wrote: > > It seems like this effort would aid in implementing what some other > databases implement via the QUALIFY clause, which is to window functions > what HAVING is to aggregate functions. > > example: > https://cloud.google.com/bigquery/docs/reference/standard-sql/query-syntax#qualify_clause > > Isn't that just syntactic sugar? You could get the same from adding a > subquery where a WHERE clause to filter rows evaluated after the > window clause. > > I'd like some of that syntactic sugar please. It goes nicely with my HAVING syntactic coffee. David J. ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v15 6/7] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 206 ++++++++++-------- 1 file changed, 110 insertions(+), 96 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index 7064307d9e..7ed50a3b52 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,52 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know to make use of the archive module. The + return value needs to be of server lifetime, which is typically achieved by + defining it as a <literal>static const</literal> variable in global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,91 +72,98 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has any state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has any state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - </sect2> + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. + </para> + </sect3> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> - - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has any state, this callback should - free it to avoid leaks. + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> + + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has any state, this callback + should free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --k+w/mQv8wyuph6w0 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v15-0007-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v12 5/6] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 207 ++++++++++-------- 1 file changed, 111 insertions(+), 96 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index 7cf44e82e2..f30ee591e7 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,53 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know how to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know how to make use of the archive module. + The return value needs to be of server lifetime, which is typically + achieved by defining it as a <literal>static const</literal> variable in + global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,91 +73,98 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has a state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - </sect2> + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. + </para> + </sect3> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> - - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has a state, this callback should - free it to avoid leaks. + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> + + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has state, this callback should + free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --YiEDa0DAkWCtVeE4 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v12-0006-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v13 6/7] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 207 ++++++++++-------- 1 file changed, 111 insertions(+), 96 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index 7cf44e82e2..f30ee591e7 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,53 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know how to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know how to make use of the archive module. + The return value needs to be of server lifetime, which is typically + achieved by defining it as a <literal>static const</literal> variable in + global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,91 +73,98 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has a state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - </sect2> + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. + </para> + </sect3> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> - - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has a state, this callback should - free it to avoid leaks. + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> + + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has state, this callback should + free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --5vNYLRcllDrimb99 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v13-0007-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v14 6/7] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 207 ++++++++++-------- 1 file changed, 111 insertions(+), 96 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index 7cf44e82e2..f30ee591e7 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,53 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know how to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know how to make use of the archive module. + The return value needs to be of server lifetime, which is typically + achieved by defining it as a <literal>static const</literal> variable in + global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,91 +73,98 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has a state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - </sect2> + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. + </para> + </sect3> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> - - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has a state, this callback should - free it to avoid leaks. + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> + + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has state, this callback should + free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --IS0zKkzwUGydFO0o Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v14-0007-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v18 4/5] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 226 ++++++++++-------- 1 file changed, 120 insertions(+), 106 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index cf7438a759..a52d15082d 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,52 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know to make use of the archive module. The + return value needs to be of server lifetime, which is typically achieved by + defining it as a <literal>static const</literal> variable in global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,103 +72,110 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has any state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has any state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - - <note> - <para> - When returning <literal>false</literal>, it may be useful to append some - additional information to the generic warning message. To do that, provide - a message to the <function>arch_module_check_errdetail</function> macro - before returning <literal>false</literal>. Like - <function>errdetail()</function>, this macro accepts a format string - followed by an optional list of arguments. The resulting string will be - emitted as the <literal>DETAIL</literal> line of the warning message. + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. </para> - </note> - </sect2> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <note> + <para> + When returning <literal>false</literal>, it may be useful to append some + additional information to the generic warning message. To do that, + provide a message to the <function>arch_module_check_errdetail</function> + macro before returning <literal>false</literal>. Like + <function>errdetail()</function>, this macro accepts a format string + followed by an optional list of arguments. The resulting string will be + emitted as the <literal>DETAIL</literal> line of the warning message. + </para> + </note> + </sect3> + + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has any state, this callback should - free it to avoid leaks. + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has any state, this callback + should free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --IJpNTDwzlM2Ie8A6 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v18-0005-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v19 4/5] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 226 ++++++++++-------- 1 file changed, 120 insertions(+), 106 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index cf7438a759..a52d15082d 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,52 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know to make use of the archive module. The + return value needs to be of server lifetime, which is typically achieved by + defining it as a <literal>static const</literal> variable in global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,103 +72,110 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has any state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has any state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - - <note> - <para> - When returning <literal>false</literal>, it may be useful to append some - additional information to the generic warning message. To do that, provide - a message to the <function>arch_module_check_errdetail</function> macro - before returning <literal>false</literal>. Like - <function>errdetail()</function>, this macro accepts a format string - followed by an optional list of arguments. The resulting string will be - emitted as the <literal>DETAIL</literal> line of the warning message. + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. </para> - </note> - </sect2> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <note> + <para> + When returning <literal>false</literal>, it may be useful to append some + additional information to the generic warning message. To do that, + provide a message to the <function>arch_module_check_errdetail</function> + macro before returning <literal>false</literal>. Like + <function>errdetail()</function>, this macro accepts a format string + followed by an optional list of arguments. The resulting string will be + emitted as the <literal>DETAIL</literal> line of the warning message. + </para> + </note> + </sect3> + + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has any state, this callback should - free it to avoid leaks. + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has any state, this callback + should free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --oyUTqETQ0mS9luUI Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v19-0005-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v18 4/5] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 226 ++++++++++-------- 1 file changed, 120 insertions(+), 106 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index cf7438a759..a52d15082d 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,52 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know to make use of the archive module. The + return value needs to be of server lifetime, which is typically achieved by + defining it as a <literal>static const</literal> variable in global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,103 +72,110 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has any state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has any state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - - <note> - <para> - When returning <literal>false</literal>, it may be useful to append some - additional information to the generic warning message. To do that, provide - a message to the <function>arch_module_check_errdetail</function> macro - before returning <literal>false</literal>. Like - <function>errdetail()</function>, this macro accepts a format string - followed by an optional list of arguments. The resulting string will be - emitted as the <literal>DETAIL</literal> line of the warning message. + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. </para> - </note> - </sect2> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <note> + <para> + When returning <literal>false</literal>, it may be useful to append some + additional information to the generic warning message. To do that, + provide a message to the <function>arch_module_check_errdetail</function> + macro before returning <literal>false</literal>. Like + <function>errdetail()</function>, this macro accepts a format string + followed by an optional list of arguments. The resulting string will be + emitted as the <literal>DETAIL</literal> line of the warning message. + </para> + </note> + </sect3> + + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has any state, this callback should - free it to avoid leaks. + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has any state, this callback + should free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --IJpNTDwzlM2Ie8A6 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v18-0005-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v19 4/5] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 226 ++++++++++-------- 1 file changed, 120 insertions(+), 106 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index cf7438a759..a52d15082d 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,52 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know to make use of the archive module. The + return value needs to be of server lifetime, which is typically achieved by + defining it as a <literal>static const</literal> variable in global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,103 +72,110 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has any state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has any state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - - <note> - <para> - When returning <literal>false</literal>, it may be useful to append some - additional information to the generic warning message. To do that, provide - a message to the <function>arch_module_check_errdetail</function> macro - before returning <literal>false</literal>. Like - <function>errdetail()</function>, this macro accepts a format string - followed by an optional list of arguments. The resulting string will be - emitted as the <literal>DETAIL</literal> line of the warning message. + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. </para> - </note> - </sect2> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <note> + <para> + When returning <literal>false</literal>, it may be useful to append some + additional information to the generic warning message. To do that, + provide a message to the <function>arch_module_check_errdetail</function> + macro before returning <literal>false</literal>. Like + <function>errdetail()</function>, this macro accepts a format string + followed by an optional list of arguments. The resulting string will be + emitted as the <literal>DETAIL</literal> line of the warning message. + </para> + </note> + </sect3> + + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has any state, this callback should - free it to avoid leaks. + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has any state, this callback + should free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --oyUTqETQ0mS9luUI Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v19-0005-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v20 4/5] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 226 ++++++++++-------- 1 file changed, 120 insertions(+), 106 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index cf7438a759..a52d15082d 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,52 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know to make use of the archive module. The + return value needs to be of server lifetime, which is typically achieved by + defining it as a <literal>static const</literal> variable in global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,103 +72,110 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has any state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has any state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - - <note> - <para> - When returning <literal>false</literal>, it may be useful to append some - additional information to the generic warning message. To do that, provide - a message to the <function>arch_module_check_errdetail</function> macro - before returning <literal>false</literal>. Like - <function>errdetail()</function>, this macro accepts a format string - followed by an optional list of arguments. The resulting string will be - emitted as the <literal>DETAIL</literal> line of the warning message. + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. </para> - </note> - </sect2> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <note> + <para> + When returning <literal>false</literal>, it may be useful to append some + additional information to the generic warning message. To do that, + provide a message to the <function>arch_module_check_errdetail</function> + macro before returning <literal>false</literal>. Like + <function>errdetail()</function>, this macro accepts a format string + followed by an optional list of arguments. The resulting string will be + emitted as the <literal>DETAIL</literal> line of the warning message. + </para> + </note> + </sect3> + + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has any state, this callback should - free it to avoid leaks. + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has any state, this callback + should free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --3V7upXqbjpZ4EhLz Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v20-0005-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v16 4/5] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 206 ++++++++++-------- 1 file changed, 110 insertions(+), 96 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index 7064307d9e..7ed50a3b52 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,52 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know to make use of the archive module. The + return value needs to be of server lifetime, which is typically achieved by + defining it as a <literal>static const</literal> variable in global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,91 +72,98 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has any state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has any state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - </sect2> + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. + </para> + </sect3> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> - - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has any state, this callback should - free it to avoid leaks. + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> + + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has any state, this callback + should free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --SLDf9lqlvOQaIe6s Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v16-0005-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v18 4/5] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 226 ++++++++++-------- 1 file changed, 120 insertions(+), 106 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index cf7438a759..a52d15082d 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,52 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know to make use of the archive module. The + return value needs to be of server lifetime, which is typically achieved by + defining it as a <literal>static const</literal> variable in global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,103 +72,110 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has any state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has any state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - - <note> - <para> - When returning <literal>false</literal>, it may be useful to append some - additional information to the generic warning message. To do that, provide - a message to the <function>arch_module_check_errdetail</function> macro - before returning <literal>false</literal>. Like - <function>errdetail()</function>, this macro accepts a format string - followed by an optional list of arguments. The resulting string will be - emitted as the <literal>DETAIL</literal> line of the warning message. + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. </para> - </note> - </sect2> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <note> + <para> + When returning <literal>false</literal>, it may be useful to append some + additional information to the generic warning message. To do that, + provide a message to the <function>arch_module_check_errdetail</function> + macro before returning <literal>false</literal>. Like + <function>errdetail()</function>, this macro accepts a format string + followed by an optional list of arguments. The resulting string will be + emitted as the <literal>DETAIL</literal> line of the warning message. + </para> + </note> + </sect3> + + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has any state, this callback should - free it to avoid leaks. + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has any state, this callback + should free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --IJpNTDwzlM2Ie8A6 Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v18-0005-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v19 4/5] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 226 ++++++++++-------- 1 file changed, 120 insertions(+), 106 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index cf7438a759..a52d15082d 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,52 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know to make use of the archive module. The + return value needs to be of server lifetime, which is typically achieved by + defining it as a <literal>static const</literal> variable in global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,103 +72,110 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has any state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has any state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - - <note> - <para> - When returning <literal>false</literal>, it may be useful to append some - additional information to the generic warning message. To do that, provide - a message to the <function>arch_module_check_errdetail</function> macro - before returning <literal>false</literal>. Like - <function>errdetail()</function>, this macro accepts a format string - followed by an optional list of arguments. The resulting string will be - emitted as the <literal>DETAIL</literal> line of the warning message. + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. </para> - </note> - </sect2> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <note> + <para> + When returning <literal>false</literal>, it may be useful to append some + additional information to the generic warning message. To do that, + provide a message to the <function>arch_module_check_errdetail</function> + macro before returning <literal>false</literal>. Like + <function>errdetail()</function>, this macro accepts a format string + followed by an optional list of arguments. The resulting string will be + emitted as the <literal>DETAIL</literal> line of the warning message. + </para> + </note> + </sect3> + + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has any state, this callback should - free it to avoid leaks. + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has any state, this callback + should free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --oyUTqETQ0mS9luUI Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v19-0005-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
* [PATCH v20 4/5] restructure archive modules docs in preparation for restore modules @ 2023-02-15 22:48 Nathan Bossart <[email protected]> 0 siblings, 0 replies; 18+ messages in thread From: Nathan Bossart @ 2023-02-15 22:48 UTC (permalink / raw) --- doc/src/sgml/archive-and-restore-modules.sgml | 226 ++++++++++-------- 1 file changed, 120 insertions(+), 106 deletions(-) diff --git a/doc/src/sgml/archive-and-restore-modules.sgml b/doc/src/sgml/archive-and-restore-modules.sgml index cf7438a759..a52d15082d 100644 --- a/doc/src/sgml/archive-and-restore-modules.sgml +++ b/doc/src/sgml/archive-and-restore-modules.sgml @@ -1,9 +1,9 @@ -<!-- doc/src/sgml/archive-modules.sgml --> +<!-- doc/src/sgml/archive-and-restore-modules.sgml --> -<chapter id="archive-modules"> - <title>Archive Modules</title> - <indexterm zone="archive-modules"> - <primary>Archive Modules</primary> +<chapter id="archive-and-restore-modules"> + <title>Archive and Restore Modules</title> + <indexterm zone="archive-and-restore-modules"> + <primary>Archive and Restore Modules</primary> </indexterm> <para> @@ -14,45 +14,52 @@ performant. </para> - <para> - When a custom <xref linkend="guc-archive-library"/> is configured, PostgreSQL - will submit completed WAL files to the module, and the server will avoid - recycling or removing these WAL files until the module indicates that the files - were successfully archived. It is ultimately up to the module to decide what - to do with each WAL file, but many recommendations are listed at - <xref linkend="backup-archiving-wal"/>. - </para> - - <para> - Archiving modules must at least consist of an initialization function (see - <xref linkend="archive-module-init"/>) and the required callbacks (see - <xref linkend="archive-module-callbacks"/>). However, archive modules are - also permitted to do much more (e.g., declare GUCs and register background - workers). - </para> - <para> The <filename>contrib/basic_archive</filename> module contains a working example, which demonstrates some useful techniques. </para> - <sect1 id="archive-module-init"> - <title>Initialization Functions</title> - <indexterm zone="archive-module-init"> - <primary>_PG_archive_module_init</primary> + <sect1 id="archive-modules"> + <title>Archive Modules</title> + <indexterm zone="archive-modules"> + <primary>Archive Modules</primary> </indexterm> + + <para> + When a custom <xref linkend="guc-archive-library"/> is configured, + PostgreSQL will submit completed WAL files to the module, and the server + will avoid recycling or removing these WAL files until the module indicates + that the files were successfully archived. It is ultimately up to the + module to decide what to do with each WAL file, but many recommendations are + listed at <xref linkend="backup-archiving-wal"/>. + </para> + <para> - An archive library is loaded by dynamically loading a shared library with the - <xref linkend="guc-archive-library"/>'s name as the library base name. The - normal library search path is used to locate the library. To provide the - required archive module callbacks and to indicate that the library is - actually an archive module, it needs to provide a function named - <function>_PG_archive_module_init</function>. The result of the function - must be a pointer to a struct of type - <structname>ArchiveModuleCallbacks</structname>, which contains everything - that the core code needs to know to make use of the archive module. The - return value needs to be of server lifetime, which is typically achieved by - defining it as a <literal>static const</literal> variable in global scope. + Archiving modules must at least consist of an initialization function (see + <xref linkend="archive-module-init"/>) and the required callbacks (see + <xref linkend="archive-module-callbacks"/>). However, archive modules are + also permitted to do much more (e.g., declare GUCs and register background + workers). + </para> + + <sect2 id="archive-module-init"> + <title>Initialization Functions</title> + <indexterm zone="archive-module-init"> + <primary>_PG_archive_module_init</primary> + </indexterm> + + <para> + An archive library is loaded by dynamically loading a shared library with + the <xref linkend="guc-archive-library"/>'s name as the library base name. + The normal library search path is used to locate the library. To provide + the required archive module callbacks and to indicate that the library is + actually an archive module, it needs to provide a function named + <function>_PG_archive_module_init</function>. The result of the function + must be a pointer to a struct of type + <structname>ArchiveModuleCallbacks</structname>, which contains everything + that the core code needs to know to make use of the archive module. The + return value needs to be of server lifetime, which is typically achieved by + defining it as a <literal>static const</literal> variable in global scope. <programlisting> typedef struct ArchiveModuleCallbacks @@ -65,103 +72,110 @@ typedef struct ArchiveModuleCallbacks typedef const ArchiveModuleCallbacks *(*ArchiveModuleInit) (void); </programlisting> - Only the <function>archive_file_cb</function> callback is required. The - others are optional. - </para> - </sect1> + Only the <function>archive_file_cb</function> callback is required. The + others are optional. + </para> + </sect2> - <sect1 id="archive-module-callbacks"> - <title>Archive Module Callbacks</title> - <para> - The archive callbacks define the actual archiving behavior of the module. - The server will call them as required to process each individual WAL file. - </para> + <sect2 id="archive-module-callbacks"> + <title>Archive Module Callbacks</title> - <sect2 id="archive-module-startup"> - <title>Startup Callback</title> <para> - The <function>startup_cb</function> callback is called shortly after the - module is loaded. This callback can be used to perform any additional - initialization required. If the archive module has any state, it can use - <structfield>state->private_data</structfield> to store it. + The archive callbacks define the actual archiving behavior of the module. + The server will call them as required to process each individual WAL file. + </para> + + <sect3 id="archive-module-startup"> + <title>Startup Callback</title> + + <para> + The <function>startup_cb</function> callback is called shortly after the + module is loaded. This callback can be used to perform any additional + initialization required. If the archive module has any state, it can use + <structfield>state->private_data</structfield> to store it. <programlisting> typedef void (*ArchiveStartupCB) (ArchiveModuleState *state); </programlisting> - </para> - </sect2> + </para> + </sect3> - <sect2 id="archive-module-check"> - <title>Check Callback</title> - <para> - The <function>check_configured_cb</function> callback is called to determine - whether the module is fully configured and ready to accept WAL files (e.g., - its configuration parameters are set to valid values). If no - <function>check_configured_cb</function> is defined, the server always - assumes the module is configured. + <sect3 id="archive-module-check"> + <title>Check Callback</title> + + <para> + The <function>check_configured_cb</function> callback is called to + determine whether the module is fully configured and ready to accept WAL + files (e.g., its configuration parameters are set to valid values). If no + <function>check_configured_cb</function> is defined, the server always + assumes the module is configured. <programlisting> typedef bool (*ArchiveCheckConfiguredCB) (ArchiveModuleState *state); </programlisting> - If <literal>true</literal> is returned, the server will proceed with - archiving the file by calling the <function>archive_file_cb</function> - callback. If <literal>false</literal> is returned, archiving will not - proceed, and the archiver will emit the following message to the server log: + If <literal>true</literal> is returned, the server will proceed with + archiving the file by calling the <function>archive_file_cb</function> + callback. If <literal>false</literal> is returned, archiving will not + proceed, and the archiver will emit the following message to the server + log: <screen> WARNING: archive_mode enabled, yet archiving is not configured </screen> - In the latter case, the server will periodically call this function, and - archiving will proceed only when it returns <literal>true</literal>. - </para> - - <note> - <para> - When returning <literal>false</literal>, it may be useful to append some - additional information to the generic warning message. To do that, provide - a message to the <function>arch_module_check_errdetail</function> macro - before returning <literal>false</literal>. Like - <function>errdetail()</function>, this macro accepts a format string - followed by an optional list of arguments. The resulting string will be - emitted as the <literal>DETAIL</literal> line of the warning message. + In the latter case, the server will periodically call this function, and + archiving will proceed only when it returns <literal>true</literal>. </para> - </note> - </sect2> - <sect2 id="archive-module-archive"> - <title>Archive Callback</title> - <para> - The <function>archive_file_cb</function> callback is called to archive a - single WAL file. + <note> + <para> + When returning <literal>false</literal>, it may be useful to append some + additional information to the generic warning message. To do that, + provide a message to the <function>arch_module_check_errdetail</function> + macro before returning <literal>false</literal>. Like + <function>errdetail()</function>, this macro accepts a format string + followed by an optional list of arguments. The resulting string will be + emitted as the <literal>DETAIL</literal> line of the warning message. + </para> + </note> + </sect3> + + <sect3 id="archive-module-archive"> + <title>Archive Callback</title> + + <para> + The <function>archive_file_cb</function> callback is called to archive a + single WAL file. <programlisting> typedef bool (*ArchiveFileCB) (ArchiveModuleState *state, const char *file, const char *path); </programlisting> - If <literal>true</literal> is returned, the server proceeds as if the file - was successfully archived, which may include recycling or removing the - original WAL file. If <literal>false</literal> is returned, the server will - keep the original WAL file and retry archiving later. - <replaceable>file</replaceable> will contain just the file name of the WAL - file to archive, while <replaceable>path</replaceable> contains the full - path of the WAL file (including the file name). - </para> - </sect2> + If <literal>true</literal> is returned, the server proceeds as if the file + was successfully archived, which may include recycling or removing the + original WAL file. If <literal>false</literal> is returned, the server + will keep the original WAL file and retry archiving later. + <replaceable>file</replaceable> will contain just the file name of the WAL + file to archive, while <replaceable>path</replaceable> contains the full + path of the WAL file (including the file name). + </para> + </sect3> - <sect2 id="archive-module-shutdown"> - <title>Shutdown Callback</title> - <para> - The <function>shutdown_cb</function> callback is called when the archiver - process exits (e.g., after an error) or the value of - <xref linkend="guc-archive-library"/> changes. If no - <function>shutdown_cb</function> is defined, no special action is taken in - these situations. If the archive module has any state, this callback should - free it to avoid leaks. + <sect3 id="archive-module-shutdown"> + <title>Shutdown Callback</title> + + <para> + The <function>shutdown_cb</function> callback is called when the archiver + process exits (e.g., after an error) or the value of + <xref linkend="guc-archive-library"/> changes. If no + <function>shutdown_cb</function> is defined, no special action is taken in + these situations. If the archive module has any state, this callback + should free it to avoid leaks. <programlisting> typedef void (*ArchiveShutdownCB) (ArchiveModuleState *state); </programlisting> - </para> + </para> + </sect3> </sect2> </sect1> </chapter> -- 2.25.1 --3V7upXqbjpZ4EhLz Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v20-0005-introduce-restore_library.patch" ^ permalink raw reply [nested|flat] 18+ messages in thread
end of thread, other threads:[~2023-02-15 22:48 UTC | newest] Thread overview: 18+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2022-03-15 21:23 Re: Window Function "Run Conditions" Greg Stark <[email protected]> 2022-03-17 04:04 ` Corey Huinker <[email protected]> 2022-03-22 22:39 ` David Rowley <[email protected]> 2022-03-23 05:09 ` David G. Johnston <[email protected]> 2022-03-22 22:35 ` David Rowley <[email protected]> 2023-02-15 22:48 [PATCH v19 4/5] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v18 4/5] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v12 5/6] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v18 4/5] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v19 4/5] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v13 6/7] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v18 4/5] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v14 6/7] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v20 4/5] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v15 6/7] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v19 4/5] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v20 4/5] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]> 2023-02-15 22:48 [PATCH v16 4/5] restructure archive modules docs in preparation for restore modules Nathan Bossart <[email protected]>
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