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2023-07-17Remove db_user_namespace.Nathan Bossart
This feature was intended to be a temporary measure to support per-database user names. A better one hasn't materialized in the ~21 years since it was added, and nobody claims to be using it, so let's just remove it. Reviewed-by: Michael Paquier, Magnus Hagander Discussion: https://postgr.es/m/20230630200509.GA2830328%40nathanxps13 Discussion: https://postgr.es/m/20230630215608.GD2941194%40nathanxps13
2023-07-12Rename session_auth_is_superuser to current_role_is_superuser.Nathan Bossart
This variable might've been accurately named when it was added in ea886339b8, but the name hasn't been accurate since at least the introduction of SET ROLE in e5d6b91220. The corresponding documentation was fixed in eedb068c0a. This commit renames the variable accordingly. Suggested-by: Joseph Koshakow Discussion: https://postgr.es/m/CAAvxfHc-HHzONQ2oXdvhFF9ayRnidPwK%2BfVBhRzaBWYYLVQL-g%40mail.gmail.com
2023-07-10Message wording improvementsPeter Eisentraut
2023-07-06Add GUC parameter "huge_pages_status"Michael Paquier
This is useful to show the allocation state of huge pages when setting up a server with "huge_pages = try", where allocating huge pages would be attempted but the server would continue its startup sequence even if the allocation fails. The effective status of huge pages is not easily visible without OS-level tools (or for instance, a lookup at /proc/N/smaps), and the environments where Postgres runs may not authorize that. Like the other GUCs related to huge pages, this works for Linux and Windows. This GUC can report as values: - "on", if huge pages were allocated. - "off", if huge pages were not allocated. - "unknown", a special state that could only be seen when using for example postgres -C because it is only possible to know if the shared memory allocation worked after we can check for the GUC values, even if checking a runtime-computed GUC. This value should never be seen when querying for the GUC on a running server. An assertion is added to check that. The discussion has also turned around having a new function to grab this status, but this would have required more tricks for -DEXEC_BACKEND, something that GUCs already handle. Noriyoshi Shinoda has initiated the thread that has led to the result of this commit. Author: Justin Pryzby Reviewed-by: Nathan Bossart, Kyotaro Horiguchi, Michael Paquier Discussion: https://postgr.es/m/TU4PR8401MB1152EBB0D271F827E2E37A01EECC9@TU4PR8401MB1152.NAMPRD84.PROD.OUTLOOK.COM
2023-07-03Add macro for maximum statistics targetPeter Eisentraut
The number of places where 10000 was hardcoded had grown a bit beyond the comfort level. Introduce a macro MAX_STATISTICS_TARGET instead. Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com> Discussion: https://www.postgresql.org/message-id/flat/d6069765-5971-04d3-c10d-e4f7b2e9c459%40eisentraut.org
2023-06-15Replace GUC_UNIT_MEMORY|GUC_UNIT_TIME with GUC_UNIT.Masahiko Sawada
We used (GUC_UNIT_MEMORY | GUC_UNIT_TIME) instead of GUC_UNIT some places but we already define it in guc.h. This commit replaces them with GUC_UNIT for better consistency with their surrounding code. Author: Japin Li Reviewed-by: Richard Guo, Michael Paquier, Masahiko Sawada Discussion: https://postgr.es/m/MEYP282MB1669EC0FED922F7A151673ACB65AA@MEYP282MB1669.AUSP282.PROD.OUTLOOK.COM
2023-06-12Remove a few unused global variables and declarations.Heikki Linnakangas
- Commit 3eb77eba5a, which moved the pending ops queue from md.c to sync.c, introduced a duplicate, unused 'pendingOpsCxt' variable. (I'm surprised none of the compilers or static analysis tools have complained about that.) - Commit c2fe139c20 moved the 'synchronize_seqscans' variable and introduced an extern declaration in tableam.h, making the one in guc_tables.c unnecessary. - Commit 6f0cf87872 removed the 'pgstat_temp_directory' GUC, but forgot to remove the corresponding global variable. - Commit 1b4e729eaa removed the 'pg_krb_realm' GUC, and its global variable, but forgot the declaration in auth.h. Spotted all these by reading the code.
2023-06-07Remove read-only server settings lc_collate and lc_ctypePeter Eisentraut
The GUC settings lc_collate and lc_ctype are from a time when those locale settings were cluster-global. When those locale settings were made per-database (PG 8.4), the settings were kept as read-only. As of PG 15, you can use ICU as the per-database locale provider, so examining these settings is already less meaningful and possibly confusing, since you need to look into pg_database to find out what is really happening, and they would likely become fully obsolete in the future anyway. Reviewed-by: Jeff Davis <pgsql@j-davis.com> Discussion: https://www.postgresql.org/message-id/696054d1-bc88-b6ab-129a-18b8bce6a6f0@enterprisedb.com
2023-05-23Use lower case for icu_validation_level valuesPeter Eisentraut
Similar to client_min_messages etc.
2023-05-23Punctuation improvement in postgresql.conf.samplePeter Eisentraut
2023-05-20Fix remaining references to gss_accept_deleg.Nathan Bossart
These were missed in 9c0a0e2ed9. Discussion: https://postgr.es/m/20230521031757.GA3835667%40nathanxps13
2023-05-20rename "gss_accept_deleg" to "gss_accept_delegation".Bruce Momjian
This is more consistent with existing GUC spelling. Discussion: https://postgr.es/m/ZGdnEsGtNj7+fZoa@momjian.us
2023-05-19Pre-beta mechanical code beautification.Tom Lane
Run pgindent, pgperltidy, and reformat-dat-files. This set of diffs is a bit larger than typical. We've updated to pg_bsd_indent 2.1.2, which properly indents variable declarations that have multi-line initialization expressions (the continuation lines are now indented one tab stop). We've also updated to perltidy version 20230309 and changed some of its settings, which reduces its desire to add whitespace to lines to make assignments etc. line up. Going forward, that should make for fewer random-seeming changes to existing code. Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
2023-05-17Reduce icu_validation_level default to WARNING.Jeff Davis
Discussion: https://postgr.es/m/daa9f060aa2349ebc84444515efece49e7b32c5d.camel@j-davis.com
2023-05-17Revert "Add USER SET parameter values for pg_db_role_setting"Alexander Korotkov
This reverts commit 096dd80f3ccc and its fixups beecbe8e5001, afdd9f7f0e00, 529da086ba, db93e739ac61. Catversion is bumped. Discussion: https://postgr.es/m/d46f9265-ff3c-6743-2278-6772598233c2%40pgmasters.net
2023-05-15Fix wal_writer_flush_after initializer value.Thomas Munro
Commit a73952b7956 (new in 16) required default values in guc_table.c and C variable initializers to match. This one only matched when XLOG_BLCKSZ == 8kB. Fix by using the same expression in both places with a new DEFAULT_XXX macro, as done for other GUCs. Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CA+hUKGLNmLV=VrT==5MqnbARgx2ifRSFtdd8ofdfrdSLL3yv5A@mail.gmail.com
2023-05-15Rename io_direct to debug_io_direct.Thomas Munro
Give the new GUC introduced by d4e71df6 a name that is clearly not intended for mainstream use quite yet. Future proposals would drop the prefix only after adding infrastructure to make it efficient. Having the switch in the tree sooner is good because it might lead to new discoveries about the hazards awaiting us on a wide range of systems, but that name was too enticing and could lead to cross-version confusion in future, per complaints from Noah and Justin. Suggested-by: Noah Misch <noah@leadboat.com> Reviewed-by: Noah Misch <noah@leadboat.com> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> (the idea, not the patch) Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> (ditto) Discussion: https://postgr.es/m/20230430041106.GA2268796%40rfd.leadboat.com
2023-05-10Fix assertion failure when updating stats_fetch_consistency in a transactionMichael Paquier
An update of the GUC stats_fetch_consistency in a transaction would be able to trigger an assertion when doing cache->snapshot. In this case, when retrieving a pgstat entry after the switch, a new snapshot would be rebuilt, confusing pgstat_build_snapshot() because a snapshot is already cached with an unexpected mode ("cache"). In order to fix this problem, this commit adds a flag to force a snapshot clear each time this GUC is changed. Some tests are added to check, while on it. Some optimizations in avoiding the snapshot clear should be possible depending on what is cached and the current GUC value, I guess, but this solution is simple, and ensures that the state of the cache is updated each time a new pgstat entry is fetched, hence being consistent with the level wanted by the client that has set the GUC. Note that cache->none and snapshot->none would not cause issues, as fetching a pgstat entry would be retrieved from shared memory on the second attempt, however a snapshot would still be cached. Similarly, none->snapshot and none->cache would build a new snapshot on the second fetch attempt. Finally, snapshot->cache would cache a new snapshot on the second attempt. Reported-by: Alexander Lakhin Author: Kyotaro Horiguchi Discussion: https://postgr.es/m/17804-2a118cd046f2d0e5@postgresql.org backpatch-through: 15
2023-05-10Document values of stats_fetch_consistency in postgresql.conf.sampleMichael Paquier
Issue noted while looking at a patch related to that. Discussion: https://postgr.es/m/ZE9LiFc7JdNHokz/@paquier.xyz
2023-04-28Add unit to vacuum_buffer_usage_limit value in postgresql.conf.sample.Masahiko Sawada
Also adjust the indentation of the comment to the surrounding parameters. Author: Masahiko Sawada Reviewed-by: David Rowley, Daniel Gustafsson, Melanie Plageman Discussion: https://postgr.es/m/CAD21AoCBSqmqOKVH4Q256DeCC_UE50gu1sgixcjLFZGLEbABVA@mail.gmail.com
2023-04-27Fix wrong construct_array_builtin() call in GUCArrayDelete()Alexander Korotkov
The current code unintentionally uses the wrong datum to construct an array. The bug was introduced by 096dd80f3c, so no backpatching is needed. Reported-by: David Steele Discussion: https://postgr.es/m/d46f9265-ff3c-6743-2278-6772598233c2%40pgmasters.net Author: Nathan Bossart Reviewed-by: David Steele, Tom Lane
2023-04-24Remove vacuum_defer_cleanup_ageAndres Freund
vacuum_defer_cleanup_age was introduced before hot_standby_feedback and replication slots existed. It is hard to use reasonably - commonly it will either be set too low (not preventing recovery conflicts, while still causing some bloat), or too high (causing a lot of bloat). The alternatives do not have that issue. That on its own might not be sufficient reason to remove vacuum_defer_cleanup_age, but it also complicates computation of xid horizons. See e.g. the bug fixed in be504a3e974. It also is untested. This commit removes TransactionIdRetreatSafely(), as there are no users anymore. There might be potential future users, hence noting that here. Reviewed-by: Daniel Gustafsson <daniel@yesql.se> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20230317230930.nhsgk3qfk7f4axls@awork3.anarazel.de
2023-04-18Fix various typosDavid Rowley
This fixes many spelling mistakes in comments, but a few references to invalid parameter names, function names and option names too in comments and also some in string constants Also, fix an #undef that was undefining the incorrect definition Author: Alexander Lakhin Reviewed-by: Justin Pryzby Discussion: https://postgr.es/m/d5f68d19-c0fc-91a9-118d-7c6a5a3f5fad@gmail.com
2023-04-14Remove old GUC name mapping for "force_parallel_mode"David Rowley
This GUC was renamed to debug_parallel_query in 5352ca22e. That commit added an entry into map_old_guc_names[] to allow the old name still to work. That was done to allow a transition time where the buildfarm configs could be swapped over to use debug_parallel_query instead. That work is now complete. Here we remove the old name with the intention of breaking any user code which is using force_parallel_query. As mentioned in the commit message for 5352ca22e, it appeared many users were misled into thinking that setting this GUC was doing something useful for them to make queries run more quickly. Discussion: https://postgr.es/m/CAApHDvoR7EOz7Tvyzrd18FO-Dw2Cp4Uyq25TEWguK+XyCJtzOw@mail.gmail.com
2023-04-13De-Revert "Add support for Kerberos credential delegation"Stephen Frost
This reverts commit 3d03b24c3 (Revert Add support for Kerberos credential delegation) which was committed on the grounds of concern about portability, but on further review and discussion, it's clear that we are better off explicitly requiring MIT Kerberos as that appears to be the only GSSAPI library currently that's under proper maintenance and ongoing development. The API used for storing credentials was added to MIT Kerberos over a decade ago while for the other libraries which appear to be mainly based on Heimdal, which exists explicitly to be a re-implementation of MIT Kerberos, the API never made it to a released version (even though it was added to the Heimdal git repo over 5 years ago..). This post-feature-freeze change was approved by the RMT. Discussion: https://postgr.es/m/ZDDO6jaESKaBgej0%40tamriel.snowman.net
2023-04-08Revert "Add support for Kerberos credential delegation"Stephen Frost
This reverts commit 3d4fa227bce4294ce1cc214b4a9d3b7caa3f0454. Per discussion and buildfarm, this depends on APIs that seem to not be available on at least one platform (NetBSD). Should be certainly possible to rework to be optional on that platform if necessary but bit late for that at this point. Discussion: https://postgr.es/m/3286097.1680922218@sss.pgh.pa.us
2023-04-08Add io_direct setting (developer-only).Thomas Munro
Provide a way to ask the kernel to use O_DIRECT (or local equivalent) where available for data and WAL files, to avoid or minimize kernel caching. This hurts performance currently and is not intended for end users yet. Later proposed work would introduce our own I/O clustering, read-ahead, etc to replace the facilities the kernel disables with this option. The only user-visible change, if the developer-only GUC is not used, is that this commit also removes the obscure logic that would activate O_DIRECT for the WAL when wal_sync_method=open_[data]sync and wal_level=minimal (which also requires max_wal_senders=0). Those are non-default and unlikely settings, and this behavior wasn't (correctly) documented. The same effect can be achieved with io_direct=wal. Author: Thomas Munro <thomas.munro@gmail.com> Author: Andres Freund <andres@anarazel.de> Author: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> Discussion: https://postgr.es/m/CA%2BhUKGK1X532hYqJ_MzFWt0n1zt8trz980D79WbjwnT-yYLZpg%40mail.gmail.com
2023-04-07Add support for Kerberos credential delegationStephen Frost
Support GSSAPI/Kerberos credentials being delegated to the server by a client. With this, a user authenticating to PostgreSQL using Kerberos (GSSAPI) credentials can choose to delegate their credentials to the PostgreSQL server (which can choose to accept them, or not), allowing the server to then use those delegated credentials to connect to another service, such as with postgres_fdw or dblink or theoretically any other service which is able to be authenticated using Kerberos. Both postgres_fdw and dblink are changed to allow non-superuser password-less connections but only when GSSAPI credentials have been delegated to the server by the client and GSSAPI is used to authenticate to the remote system. Authors: Stephen Frost, Peifeng Qiu Reviewed-By: David Christensen Discussion: https://postgr.es/m/CO1PR05MB8023CC2CB575E0FAAD7DF4F8A8E29@CO1PR05MB8023.namprd05.prod.outlook.com
2023-04-07Doc: improve descriptions of max_[pred_]locks_per_transaction GUCs.Tom Lane
The old wording described these as being multiplied by max_connections plus max_prepared_transactions, which hasn't been exactly right for some time thanks to the addition of various auxiliary processes. Moreover, exactness here is a bit pointless given that the lock tables can expand into the initially-unallocated "slop" space in shared memory. Rather than trying to track exactly what the code is doing, let's just use the term "server processes". Likewise adjust these GUCs' description strings in guc_tables.c. Wang Wei, reviewed by Nathan Bossart and myself Discussion: https://postgr.es/m/OS3PR01MB6275BDD09C9B875C65FCC5AB9EA39@OS3PR01MB6275.jpnprd01.prod.outlook.com
2023-04-07Add VACUUM/ANALYZE BUFFER_USAGE_LIMIT optionDavid Rowley
Add new options to the VACUUM and ANALYZE commands called BUFFER_USAGE_LIMIT to allow users more control over how large to make the buffer access strategy that is used to limit the usage of buffers in shared buffers. Larger rings can allow VACUUM to run more quickly but have the drawback of VACUUM possibly evicting more buffers from shared buffers that might be useful for other queries running on the database. Here we also add a new GUC named vacuum_buffer_usage_limit which controls how large to make the access strategy when it's not specified in the VACUUM/ANALYZE command. This defaults to 256KB, which is the same size as the access strategy was prior to this change. This setting also controls how large to make the buffer access strategy for autovacuum. Per idea by Andres Freund. Author: Melanie Plageman Reviewed-by: David Rowley Reviewed-by: Andres Freund Reviewed-by: Justin Pryzby Reviewed-by: Bharath Rupireddy Discussion: https://postgr.es/m/20230111182720.ejifsclfwymw2reb@awork3.anarazel.de
2023-03-28Validate ICU locales.Jeff Davis
For ICU collations, ensure that the locale's language exists in ICU, and that the locale can be opened. Basic validation helps avoid minor mistakes and misspellings, which often fall back to the root locale instead of the intended locale. It's even more important to avoid such mistakes in ICU versions 54 and earlier, where the same (misspelled) locale string could fall back to different locales depending on the environment. Discussion: https://postgr.es/m/11b1eeb7e7667fdd4178497aeb796c48d26e69b9.camel@j-davis.com Discussion: https://postgr.es/m/df2efad0cae7c65180df8e5ebb709e5eb4f2a82b.camel@j-davis.com Reviewed-by: Peter Eisentraut
2023-03-27Make SCRAM iteration count configurableDaniel Gustafsson
Replace the hardcoded value with a GUC such that the iteration count can be raised in order to increase protection against brute-force attacks. The hardcoded value for SCRAM iteration count was defined to be 4096, which is taken from RFC 7677, so set the default for the GUC to 4096 to match. In RFC 7677 the recommendation is at least 15000 iterations but 4096 is listed as a SHOULD requirement given that it's estimated to yield a 0.5s processing time on a mobile handset of the time of RFC writing (late 2015). Raising the iteration count of SCRAM will make stored passwords more resilient to brute-force attacks at a higher computational cost during connection establishment. Lowering the count will reduce computational overhead during connections at the tradeoff of reducing strength against brute-force attacks. There are however platforms where even a modest iteration count yields a too high computational overhead, with weaker password encryption schemes chosen as a result. In these situations, SCRAM with a very low iteration count still gives benefits over weaker schemes like md5, so we allow the iteration count to be set to one at the low end. The new GUC is intentionally generically named such that it can be made to support future SCRAM standards should they emerge. At that point the value can be made into key:value pairs with an undefined key as a default which will be backwards compatible with this. Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Jonathan S. Katz <jkatz@postgresql.org> Discussion: https://postgr.es/m/F72E7BC7-189F-4B17-BF47-9735EB72C364@yesql.se
2023-03-17Improve several permission-related error messages.Peter Eisentraut
Mainly move some detail from errmsg to errdetail, remove explicit mention of superuser where appropriate, since that is implied in most permission checks, and make messages more uniform. Author: Nathan Bossart <nathandbossart@gmail.com> Discussion: https://www.postgresql.org/message-id/20230316234701.GA903298@nathanxps13
2023-02-20Speedup and increase usability of set proc title functionsDavid Rowley
The setting of the process title could be seen on profiles of very fast-to-execute queries. In many locations where we call set_ps_display() we pass along a string constant, the length of which is known during compilation. Here we effectively rename set_ps_display() to set_ps_display_with_len() and then add a static inline function named set_ps_display() which calls strlen() on the given string. This allows the compiler to optimize away the strlen() call when dealing with call sites passing a string constant. We can then also use memcpy() instead of strlcpy() to copy the string into the destination buffer. That's significantly faster than strlcpy's byte-at-a-time way of copying. Here we also take measures to improve some code which was adjusting the process title to add a " waiting" suffix to it. Call sites which require this can now just call set_ps_display_suffix() to add or adjust the suffix and call set_ps_display_remove_suffix() to remove it again. Reviewed-by: Andres Freund Discussion: https://postgr.es/m/CAApHDvocBvvk-0gWNA2Gohe+sv9fMcv+fK_G+siBKJrgDG4O7g@mail.gmail.com
2023-02-17Redesign archive modulesMichael Paquier
A new callback named startup_cb, called shortly after a module is loaded, is added. This makes possible the initialization of any additional state data required by a module. This initial state data can be saved in a ArchiveModuleState, that is now passed down to all the callbacks that can be defined in a module. With this design, it is possible to have a per-module state, aimed at opening the door to the support of more than one archive module. The initialization of the callbacks is changed so as _PG_archive_module_init() does not anymore give in input a ArchiveModuleCallbacks that a module has to fill in with callback definitions. Instead, a module now needs to return a const ArchiveModuleCallbacks. All the structure and callback definitions of archive modules are moved into their own header, named archive_module.h, from pgarch.h. Command-based archiving follows the same line, with a new set of files named shell_archive.{c,h}. There are a few more items that are under discussion to improve the design of archive modules, like the fact that basic_archive calls sigsetjmp() by itself to define its own error handling flow. These will be adjusted later, the changes done here cover already a good portion of what has been discussed. Any modules created for v15 will need to be adjusted to this new design. Author: Nathan Bossart Reviewed-by: Andres Freund Discussion: https://postgr.es/m/20230130194810.6fztfgbn32e7qarj@awork3.anarazel.de
2023-02-17Remove obsolete platforms from ps_status.c.Thomas Munro
Time to remove various code, comments and configure/meson probes relating to ancient BSD, SunOS, GNU/Hurd, IRIX, NeXT and Unixware. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/CA%2BhUKGJMNGUAqf27WbckYFrM-Mavy0RKJvocfJU%3DJ2XcAZyv%2Bw%40mail.gmail.com
2023-02-15Rename force_parallel_mode to debug_parallel_queryDavid Rowley
force_parallel_mode is meant to be used to allow us to exercise the parallel query infrastructure to ensure that it's working as we expect. It seems some users think this GUC is for forcing the query planner into picking a parallel plan regardless of the costs. A quick look at the documentation would have made them realize that they were wrong, but the GUC is likely too conveniently named which, evidently, seems to often result in users expecting that it forces the planner into usefully parallelizing queries. Here we rename the GUC to something which casual users are less likely to mistakenly think is what they need to make their query run more quickly. For now, the old name can still be used. We'll revisit if the old name mapping can be removed once the buildfarm configs are all updated. Reviewed-by: John Naylor Discussion: https://postgr.es/m/CAApHDvrsOi92_uA7PEaHZMH-S4Xv+MGhQWA+GrP8b1kjpS1HjQ@mail.gmail.com
2023-02-06Extend check_GUC_init() with checks on flag combinations when loading GUCsMichael Paquier
This extends the work begun by a73952b, with the addition of a GUC check for flag combinations in check_GUC_init(), making sure that anything defined with GUC_NO_SHOW_ALL also includes GUC_NOT_IN_SAMPLE, as first step. There has never been any GUCs of this kind in the core code, and this combination makes little sense as a parameter marked as not fit for SHOW ALL should not be hidden in postgresql.conf.sample. Note that GUCs marked with GUC_NO_SHOW_ALL are not listed under pg_settings or SHOW ALL (still they can be queried individually), making them unfit for checks via SQL queries in the regression tests that do a full scan of the parameters available. The SQL tests are still a bit incorrect about that, and will be cleaned up in a separate commit. We have also discussed the possibility to extend the SQL functions for GUCs so as they could show more information about parameters defined with GUC_NO_SHOW_ALL, though it has been concluded that this is not worth the extra complication in the long run, an enforced policy at initialization time being enough to do the same job. Per discussion with Nitin Jadhav and Tom Lane. Discussion: https://postgr.es/m/CAMm1aWaYe0muu3ABo7iSAgK+OWDS9yNe8GGRYnCyeEpScYKa+g@mail.gmail.com
2023-02-02Allow the logical_replication_mode to be used on the subscriber.Amit Kapila
Extend the existing developer option 'logical_replication_mode' to help test the parallel apply of large transactions on the subscriber. When set to 'buffered', the leader sends changes to parallel apply workers via a shared memory queue. When set to 'immediate', the leader serializes all changes to files and notifies the parallel apply workers to read and apply them at the end of the transaction. This helps in adding tests to cover the serialization code path in parallel streaming mode. Author: Hou Zhijie Reviewed-by: Peter Smith, Kuroda Hayato, Sawada Masahiko, Amit Kapila Discussion: https://postgr.es/m/CAA4eK1+wyN6zpaHUkCLorEWNx75MG0xhMwcFhvjqm2KURZEAGw@mail.gmail.com
2023-01-30Rename GUC logical_decoding_mode to logical_replication_mode.Amit Kapila
Rename the developer option 'logical_decoding_mode' to the more flexible name 'logical_replication_mode' because doing so will make it easier to extend this option in the future to help test other areas of logical replication. Currently, it is used on the publisher side to allow streaming or serializing each change in logical decoding. In the upcoming patch, we are planning to use it on the subscriber. On the subscriber, it will allow serializing the changes to file and notifies the parallel apply workers to read and apply them at the end of the transaction. We discussed exposing this parameter as a subscription option but it did not seem advisable since it is primarily used for testing/debugging and there is no other such parameter. We also discussed having separate GUCs for publisher and subscriber but for current testing/debugging requirements, one GUC is sufficient. Author: Hou Zhijie Reviewed-by: Peter Smith, Kuroda Hayato, Sawada Masahiko, Amit Kapila Discussion: https://postgr.es/m/CAD21AoAy2c=Mx=FTCs+EwUsf2kQL5MmU3N18X84k0EmCXntK4g@mail.gmail.com Discussion: https://postgr.es/m/CAA4eK1+wyN6zpaHUkCLorEWNx75MG0xhMwcFhvjqm2KURZEAGw@mail.gmail.com
2023-01-27Minor GUC code refactoring.Tom Lane
Split out "ConfigOptionIsVisible" to perform the privilege check for GUC_SUPERUSER_ONLY GUCs (which these days can also be read by pg_read_all_settings role members), and move the should-we-show-it checks from GetConfigOptionValues to its sole caller. This commit also removes get_explain_guc_options's check of GUC_NO_SHOW_ALL, which seems to have got cargo-culted in there. While there's no obvious use-case for marking a GUC both GUC_EXPLAIN and GUC_NO_SHOW_ALL, if it were set up that way one would expect EXPLAIN to show it --- if that's not what you want, then don't set GUC_EXPLAIN. In passing, simplify the loop logic in show_all_settings. Nitin Jadhav, Bharath Rupireddy, Tom Lane Discussion: https://postgr.es/m/CAMm1aWYgfekpRK-Jz5=pM_bV+Om=ktGq1vxTZ_dr1Z6MV-qokA@mail.gmail.com
2023-01-25Revert "Add eager and lazy freezing strategies to VACUUM."Peter Geoghegan
This reverts commit 4d417992613949af35530b4e8e83670c4e67e1b2. Broad concerns about regressions caused by eager freezing strategy have been raised. Whether or not these concerns can be worked through in any time frame is far from certain. Discussion: https://postgr.es/m/20230126004347.gepcmyenk2csxrri@awork3.anarazel.de
2023-01-25Add eager and lazy freezing strategies to VACUUM.Peter Geoghegan
Eager freezing strategy avoids large build-ups of all-visible pages. It makes VACUUM trigger page-level freezing whenever doing so will enable the page to become all-frozen in the visibility map. This is useful for tables that experience continual growth, particularly strict append-only tables such as pgbench's history table. Eager freezing significantly improves performance stability by spreading out the cost of freezing over time, rather than doing most freezing during aggressive VACUUMs. It complements the insert autovacuum mechanism added by commit b07642db. VACUUM determines its freezing strategy based on the value of the new vacuum_freeze_strategy_threshold GUC (or reloption) with logged tables. Tables that exceed the size threshold use the eager freezing strategy. Unlogged tables and temp tables always use eager freezing strategy, since the added cost is negligible there. Non-permanent relations won't incur any extra overhead in WAL written (for the obvious reason), nor in pages dirtied (since any extra freezing will only take place on pages whose PD_ALL_VISIBLE bit needed to be set either way). VACUUM uses lazy freezing strategy for logged tables that fall under the GUC size threshold. Page-level freezing triggers based on the criteria established in commit 1de58df4, which added basic page-level freezing. Eager freezing is strictly more aggressive than lazy freezing. Settings like vacuum_freeze_min_age still get applied in just the same way in every VACUUM, independent of the strategy in use. The only mechanical difference between eager and lazy freezing strategies is that only the former applies its own additional criteria to trigger freezing pages. Note that even lazy freezing strategy will trigger freezing whenever a page happens to have required that an FPI be written during pruning, provided that the page will thereby become all-frozen in the visibility map afterwards (due to the FPI optimization from commit 1de58df4). The vacuum_freeze_strategy_threshold default setting is 4GB. This is a relatively low setting that prioritizes performance stability. It will be reviewed at the end of the Postgres 16 beta period. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Jeff Davis <pgsql@j-davis.com> Reviewed-By: Andres Freund <andres@anarazel.de> Reviewed-By: Matthias van de Meent <boekewurm+postgres@gmail.com> Discussion: https://postgr.es/m/CAH2-WzkFok_6EAHuK39GaW4FjEFQsY=3J0AAd6FXk93u-Xq3Fg@mail.gmail.com
2023-01-21Move queryjumble.c code to src/backend/nodes/Michael Paquier
This will ease a follow-up move that will generate automatically this code. The C file is renamed, for consistency with the node-related files whose code are generated by gen_node_support.pl: - queryjumble.c -> queryjumblefuncs.c - utils/queryjumble.h -> nodes/queryjumble.h Per a suggestion from Peter Eisentraut. Reviewed-by: Peter Eisentraut Discussion: https://postgr.es/m/Y5BHOUhX3zTH/ig6@paquier.xyz
2023-01-20Add new GUC reserved_connections.Robert Haas
This provides a way to reserve connection slots for non-superusers. The slots reserved via the new GUC are available only to users who have the new predefined role pg_use_reserved_connections. superuser_reserved_connections remains as a final reserve in case reserved_connections has been exhausted. Patch by Nathan Bossart. Reviewed by Tushar Ahuja and by me. Discussion: http://postgr.es/m/20230119194601.GA4105788@nathanxps13
2023-01-20Rename ReservedBackends variable to SuperuserReservedConnections.Robert Haas
This is in preparation for adding a new reserved_connections GUC, but aligning the GUC name with the variable name is also a good idea on general principle. Patch by Nathan Bossart. Reviewed by Tushar Ahuja and by me. Discussion: http://postgr.es/m/20230119194601.GA4105788@nathanxps13
2023-01-19Add missing assign hook for GUC checkpoint_completion_targetMichael Paquier
This is wrong since 88e9823, that has switched the WAL sizing configuration from checkpoint_segments to min_wal_size and max_wal_size. This missed the recalculation of the internal value of the internal "CheckPointSegments", that works as a mapping of the old GUC checkpoint_segments, on reload, for example, and it controls the timing of checkpoints depending on the volume of WAL generated. Most users tend to leave checkpoint_completion_target at 0.9 to smooth the I/O workload, which is why I guess this has gone unnoticed for so long, still it can be useful to tweak and reload the value dynamically in some cases to control the timing of checkpoints. Author: Bharath Rupireddy Discussion: https://postgr.es/m/CALj2ACXgPPAm28mruojSBno+F_=9cTOOxHAywu_dfZPeBdybQw@mail.gmail.com Backpatch-through: 11
2023-01-10Add new GUC createrole_self_grant.Robert Haas
Can be set to the empty string, or to either or both of "set" or "inherit". If set to a non-empty value, a non-superuser who creates a role (necessarily by relying up the CREATEROLE privilege) will grant that role back to themselves with the specified options. This isn't a security feature, because the grant that this feature triggers can also be performed explicitly. Instead, it's a user experience feature. A superuser would necessarily inherit the privileges of any created role and be able to access all such roles via SET ROLE; with this patch, you can configure createrole_self_grant = 'set, inherit' to provide a similar experience for a user who has CREATEROLE but not SUPERUSER. Discussion: https://postgr.es/m/CA+TgmobN59ct+Emmz6ig1Nua2Q-_o=r6DSD98KfU53kctq_kQw@mail.gmail.com
2023-01-09Perform apply of large transactions by parallel workers.Amit Kapila
Currently, for large transactions, the publisher sends the data in multiple streams (changes divided into chunks depending upon logical_decoding_work_mem), and then on the subscriber-side, the apply worker writes the changes into temporary files and once it receives the commit, it reads from those files and applies the entire transaction. To improve the performance of such transactions, we can instead allow them to be applied via parallel workers. In this approach, we assign a new parallel apply worker (if available) as soon as the xact's first stream is received and the leader apply worker will send changes to this new worker via shared memory. The parallel apply worker will directly apply the change instead of writing it to temporary files. However, if the leader apply worker times out while attempting to send a message to the parallel apply worker, it will switch to "partial serialize" mode - in this mode, the leader serializes all remaining changes to a file and notifies the parallel apply workers to read and apply them at the end of the transaction. We use a non-blocking way to send the messages from the leader apply worker to the parallel apply to avoid deadlocks. We keep this parallel apply assigned till the transaction commit is received and also wait for the worker to finish at commit. This preserves commit ordering and avoid writing to and reading from files in most cases. We still need to spill if there is no worker available. This patch also extends the SUBSCRIPTION 'streaming' parameter so that the user can control whether to apply the streaming transaction in a parallel apply worker or spill the change to disk. The user can set the streaming parameter to 'on/off', or 'parallel'. The parameter value 'parallel' means the streaming will be applied via a parallel apply worker, if available. The parameter value 'on' means the streaming transaction will be spilled to disk. The default value is 'off' (same as current behaviour). In addition, the patch extends the logical replication STREAM_ABORT message so that abort_lsn and abort_time can also be sent which can be used to update the replication origin in parallel apply worker when the streaming transaction is aborted. Because this message extension is needed to support parallel streaming, parallel streaming is not supported for publications on servers < PG16. Author: Hou Zhijie, Wang wei, Amit Kapila with design inputs from Sawada Masahiko Reviewed-by: Sawada Masahiko, Peter Smith, Dilip Kumar, Shi yu, Kuroda Hayato, Shveta Mallik Discussion: https://postgr.es/m/CAA4eK1+wyN6zpaHUkCLorEWNx75MG0xhMwcFhvjqm2KURZEAGw@mail.gmail.com
2023-01-03Fix typos in comments, code and documentationMichael Paquier
While on it, newlines are removed from the end of two elog() strings. The others are simple grammar mistakes. One comment in pg_upgrade referred incorrectly to sequences since a7e5457. Author: Justin Pryzby Discussion: https://postgr.es/m/20221230231257.GI1153@telsasoft.com Backpatch-through: 11