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2023-05-21Expand some more uses of "deleg" to "delegation" or "delegated".Tom Lane
Complete the task begun in 9c0a0e2ed: we don't want to use the abbreviation "deleg" for GSS delegation in any user-visible places. (For consistency, this also changes most internal uses too.) Abhijit Menon-Sen and Tom Lane Discussion: https://postgr.es/m/949048.1684639317@sss.pgh.pa.us
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
2023-05-19Allocate hash join files in a separate memory contextTomas Vondra
Should a hash join exceed memory limit, the hashtable is split up into multiple batches. The number of batches is doubled each time a given batch is determined not to fit in memory. Each batch file is allocated with a block-sized buffer for buffering tuples and parallel hash join has additional sharedtuplestore accessor buffers. In some pathological cases requiring a lot of batches, often with skewed data, bad stats, or very large datasets, users can run out-of-memory solely from the memory overhead of all the batch files' buffers. Batch files were allocated in the ExecutorState memory context, making it very hard to identify when this batch explosion was the source of an OOM. This commit allocates the batch files in a dedicated memory context, making it easier to identify the cause of an OOM and work to avoid it. Based on initial draft by Tomas Vondra, with significant reworks and improvements by Jehan-Guillaume de Rorthais. Author: Jehan-Guillaume de Rorthais <jgdr@dalibo.com> Author: Tomas Vondra <tomas.vondra@enterprisedb.com> Reviewed-by: Melanie Plageman <melanieplageman@gmail.com> Discussion: https://postgr.es/m/20190421114618.z3mpgmimc3rmubi4@development Discussion: https://postgr.es/m/20230504193006.1b5b9622%40karst#273020ff4061fc7a2fbb1ba96b281f17
2023-05-19pageinspect: Fix gist_page_items() with included columnsMichael Paquier
Non-leaf pages of GiST indexes contain key attributes, leaf pages contain both key and non-key attributes, and gist_page_items() ignored the handling of non-key attributes. This caused a few problems when using gist_page_items() on a GiST index with INCLUDE: - On a non-leaf page, the function would crash. - On a leaf page, the function would work, but miss to display all the values for included attributes. This commit fixes gist_page_items() to handle such cases in a more appropriate way, and now displays the values of key and non-key attributes for each item separately in a style consistent with what ruleutils.c would generate for the attribute list, depending on the page type dealt with. In a way similar to how a record is displayed, values would be double-quoted for key or non-key attributes if required. ruleutils.c did not provide a routine able to control if non-key attributes should be displayed, so an extended() routine for index definitions is added to work around the leaf and non-leaf page differences. While on it, this commit fixes a third problem related to the amount of data reported for key attributes. The code originally relied on BuildIndexValueDescription() (used for error reports on constraints) that would not print all the data stored in the index but the index opclass's input type, so this limited the amount of information available. This switch makes gist_page_items() much cheaper as there is no need to run ACL checks for each item printed, which is not an issue anyway as superuser rights are required to execute the functions of pageinspect. Opclasses whose data cannot be displayed can rely on gist_page_items_bytea(). The documentation of this function was slightly incorrect for the output results generated on HEAD and v15, so adjust it on these branches. Author: Alexander Lakhin, Michael Paquier Discussion: https://postgr.es/m/17884-cb8c326522977acb@postgresql.org Backpatch-through: 14
2023-05-17ICU: check for U_STRING_NOT_TERMINATED_WARNING.Jeff Davis
Fixes memory error in cases where the length of the language name returned by uloc_getLanguage() is exactly ULOC_LANG_CAPACITY, in which case the status is set to U_STRING_NOT_TERMINATED_WARNING. Also check in call sites for other ICU functions that are expected to return a C string to be safe (no bug is known at these other call sites). Reported-by: Alexander Lakhin Discussion: https://postgr.es/m/2098874d-c111-41e4-9063-30bcf135226b@gmail.com
2023-05-17Reduce icu_validation_level default to WARNING.Jeff Davis
Discussion: https://postgr.es/m/daa9f060aa2349ebc84444515efece49e7b32c5d.camel@j-davis.com
2023-05-17Add writeback to pg_stat_ioAndres Freund
28e626bde00 added the concept of IOOps but neglected to include writeback operations. ac8d53dae5 added time spent doing these I/O operations. Without counting writeback, checkpointer write time in the log often differed substantially from that in pg_stat_io. To fix this, add IOOp IOOP_WRITEBACK and track writeback in pg_stat_io. Bumps catversion. Author: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Reported-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/20230419172326.dhgyo4wrrhulovt6%40awork3.anarazel.de
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
2023-05-17Add back SQLValueFunction for SQL keywordsMichael Paquier
This is equivalent to a revert of f193883 and fb32748, with the addition that the declaration of the SQLValueFunction node needs to gain a couple of node_attr for query jumbling. The performance impact of removing the function call inlining is proving to be too huge for some workloads where these are used. A worst-case test case of involving only simple SELECT queries with a SQL keyword is proving to lead to a reduction of 10% in TPS via pgbench and prepared queries on a high-end machine. None of the tests I ran back for this set of changes saw such a huge gap, but Alexander Lakhin and Andres Freund have found that this can be noticeable. Keeping the older performance would mean to do more inlining in the executor when using COERCE_SQL_SYNTAX for a function expression, similarly to what SQLValueFunction does. This requires more redesign work and there is little time until 16beta1 is released, so for now reverting the change is the best way forward, bringing back the previous performance. Bump catalog version. Reported-by: Alexander Lakhin Discussion: https://postgr.es/m/b32bed1b-0746-9b20-1472-4bdc9ca66d52@gmail.com
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
2023-05-08Revert "ICU: do not convert locale 'C' to 'en-US-u-va-posix'."Jeff Davis
This reverts commit f7faa9976cc0504c027a20ed66ceca9018041dd4. Discussion: https://postgr.es/m/483826.1683582475@sss.pgh.pa.us
2023-05-08ICU: do not convert locale 'C' to 'en-US-u-va-posix'.Jeff Davis
The conversion was intended to be for convenience, but it's more likely to be confusing than useful. The user can still directly specify 'en-US-u-va-posix' if desired. Discussion: https://postgr.es/m/f83f089ee1e9acd5dbbbf3353294d24e1f196e95.camel@j-davis.com Discussion: https://postgr.es/m/37520ec1ae9591f83132f82dbd625f3fc2d69c16.camel@j-davis.com
2023-05-07Add ruleutils support for decompiling MERGE commands.Tom Lane
This was overlooked when MERGE was added, but it's essential support for MERGE in new-style SQL functions. Alvaro Herrera Discussion: https://postgr.es/m/3579737.1683293801@sss.pgh.pa.us
2023-05-04Fix ExecCheckPermissions call in RI_Initial_CheckAlvaro Herrera
RI_Initial_Check was setting up a list of RTEPermissionInfo for ExecCheckPermissions() wrong, and the problem is subtle enough that it doesn't have any immediate effect in core code. However, if an extension is using the ExecutorCheckPerms_hook, then it would get the wrong parameters and perhaps arrive at a wrong conclusion, or outright malfunction. Fix by constructing that list and the RTE list more honestly. We also add an assertion check to verify that these lists match. This new assertion would have caught this bug. Co-authored-by: Олег Целебровский (Oleg Tselebrovskii) <o.tselebrovskiy@postgrespro.ru> Co-authored-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Amit Langote <amitlangote09@gmail.com> Discussion: https://postgr.es/m/3722b7a2cbe27a1796ee40824bd86dd1@postgrespro.ru
2023-05-04In array_position()/array_positions(), beware of empty input array.Tom Lane
These functions incautiously fetched the array's first lower bound even when the array is zero-dimensional, thus fetching the word after the allocated array space. While almost always harmless, with very bad luck this could result in SIGSEGV. Fix by adding an early exit for empty input. Per bug #17920 from Alexander Lakhin. Discussion: https://postgr.es/m/17920-f7c228c627b6d02e%40postgresql.org
2023-05-02Fix typos in commentsMichael Paquier
The changes done in this commit impact comments with no direct user-visible changes, with fixes for incorrect function, variable or structure names. Author: Alexander Lakhin Discussion: https://postgr.es/m/e8c38840-596a-83d6-bd8d-cebc51111572@gmail.com
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
2023-04-24Remove duplicate lines of codeDaniel Gustafsson
Commit 6df7a9698bb accidentally included two identical prototypes for default_multirange_selectivi() and commit 086cf1458c6 added a break; statement where one was already present, thus duplicating it. While there is no bug caused by this, fix by removing the duplicated lines as they provide no value. Backpatch the fix for duplicate prototypes to v14 and the duplicate break statement fix to all supported branches to avoid backpatching hazards due to the removal. Reported-by: Anton Voloshin <a.voloshin@postgrespro.ru> Discussion: https://postgr.es/m/0e69cb60-0176-f6d0-7e15-6478b7d85724@postgrespro.ru
2023-04-21Fix incorrect function name referenceDavid Rowley
This function was renamed in 0c9d84427 but this comment wasn't updated. Author: Alexander Lakhin Discussion: https://postgr.es/m/699beab4-a6ca-92c9-f152-f559caf6dc25@gmail.com
2023-04-21Remove io prefix from pg_stat_io columnsMichael Paquier
a9c70b46 added the statistics view pg_stat_io which contained columns "io_context" and "io_object". Given that the columns are in the pg_stat_io view, the "io" prefix is somewhat redundant, so remove it. The code variables referring to these fields are kept unchanged so as they can keep their context about I/O. Bump catalog version. Author: Melanie Plageman Reviewed-by: Kyotaro Horiguchi, Fabrízio de Royes Mello Discussion: https://postgr.es/m/CAAKRu_aAQoJWrvT2BYYQvJChFKra_O-5ra3jhzKJZqWsTR1CPQ@mail.gmail.com
2023-04-20Remove obsolete defense against strxfrm() bugs.Thomas Munro
Old versions of Solaris and illumos had buffer overrun bugs in their strxfrm() implementations. The bugs were fixed more than a decade ago and the relevant releases are long out of vendor support. It's time to remove the defense added by commit be8b06c3. Reviewed-by: Nathan Bossart <nathandbossart@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/CA+hUKGJ-ZPJwKHVLbqye92-ZXeLoCHu5wJL6L6HhNP7FkJ=meA@mail.gmail.com
2023-04-19Fix various typos and incorrect/outdated name referencesDavid Rowley
Author: Alexander Lakhin Discussion: https://postgr.es/m/699beab4-a6ca-92c9-f152-f559caf6dc25@gmail.com
2023-04-18Fix some typos and some incorrectly duplicated wordsDavid Rowley
Author: Justin Pryzby Reviewed-by: David Rowley Discussion: https://postgr.es/m/ZD3D1QxoccnN8A1V@telsasoft.com
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
2023-04-15Adjust Valgrind macro usage to protect chunk headersDavid Rowley
Prior to this commit we only ever protected MemoryChunk's requested_size field with Valgrind NOACCESS. This means that if the hdrmask field is ever accessed accidentally then we're not going to get any warnings from Valgrind about it. Valgrind would have warned us about the problem fixed in 92957ed98 had we already been doing this. Per suggestion from Tom Lane Reviewed-by: Richard Guo Discussion: https://postgr.es/m/1650235.1672694719@sss.pgh.pa.us Discussion: https://postgr.es/m/CAApHDvr=FZNGbj252Z6M9BSFKoq6BMxgkQ2yEAGUYoo7RquqZg@mail.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
2023-04-13Harmonize some more function parameter names.Peter Geoghegan
Make sure that function declarations use names that exactly match the corresponding names from function definitions in a few places. These inconsistencies were all introduced relatively recently, after the code base had parameter name mismatches fixed in bulk (see commits starting with commits 4274dc22 and 035ce1fe). pg_bsd_indent still has a couple of similar inconsistencies, which I (pgeoghegan) have left untouched for now. Like all earlier commits that cleaned up function parameter names, this commit was written with help from clang-tidy.
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
2023-04-12Revert "Catalog NOT NULL constraints" and falloutAlvaro Herrera
This reverts commit e056c557aef4 and minor later fixes thereof. There's a few problems in this new feature -- most notably regarding pg_upgrade behavior, but others as well. This new feature is not in any way critical on its own, so instead of scrambling to fix it we revert it and try again in early 17 with these issues in mind. Discussion: https://postgr.es/m/3801207.1681057430@sss.pgh.pa.us
2023-04-12Fix incorrect format placeholdersPeter Eisentraut
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
2023-04-08Redesign interrupt/cancel API for regex engine.Thomas Munro
Previously, a PostgreSQL-specific callback checked by the regex engine had a way to trigger a special error code REG_CANCEL if it detected that the next call to CHECK_FOR_INTERRUPTS() would certainly throw via ereport(). A later proposed bugfix aims to move some complex logic out of signal handlers, so that it won't run until the next CHECK_FOR_INTERRUPTS(), which makes the above design impossible unless we split CHECK_FOR_INTERRUPTS() into two phases, one to run logic and another to ereport(). We may develop such a system in the future, but for the regex code it is no longer necessary. An earlier commit moved regex memory management over to our MemoryContext system. Given that the purpose of the two-phase interrupt checking was to free memory before throwing, something we don't need to worry about anymore, it seems simpler to inject CHECK_FOR_INTERRUPTS() directly into cancelation points, and just let it throw. Since the plan is to keep PostgreSQL-specific concerns separate from the main regex engine code (with a view to bein able to stay in sync with other projects), do this with a new macro INTERRUPT(), customizable in regcustom.h and defaulting to nothing. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/CA%2BhUKGK3PGKwcKqzoosamn36YW-fsuTdOPPF1i_rtEO%3DnEYKSg%40mail.gmail.com
2023-04-08Use MemoryContext API for regex memory management.Thomas Munro
Previously, regex_t objects' memory was managed with malloc() and free() directly. Switch to palloc()-based memory management instead. Advantages: * memory used by cached regexes is now visible with MemoryContext observability tools * cleanup can be done automatically in certain failure modes (something that later commits will take advantage of) * cleanup can be done in bulk On the downside, there may be more fragmentation (wasted memory) due to per-regex MemoryContext objects. This is a problem shared with other cached objects in PostgreSQL and can probably be improved with later tuning. Thanks to Noah Misch for suggesting this general approach, which unblocks later work on interrupts. Suggested-by: Noah Misch <noah@leadboat.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/CA%2BhUKGK3PGKwcKqzoosamn36YW-fsuTdOPPF1i_rtEO%3DnEYKSg%40mail.gmail.com
2023-04-08Handle logical slot conflicts on standbyAndres Freund
During WAL replay on the standby, when a conflict with a logical slot is identified, invalidate such slots. There are two sources of conflicts: 1) Using the information added in 6af1793954e, logical slots are invalidated if required rows are removed 2) wal_level on the primary server is reduced to below logical Uses the infrastructure introduced in the prior commit. FIXME: add commit reference. Change InvalidatePossiblyObsoleteSlot() to use a recovery conflict to interrupt use of a slot, if called in the startup process. The new recovery conflict is added to pg_stat_database_conflicts, as confl_active_logicalslot. See 6af1793954e for an overall design of logical decoding on a standby. Bumps catversion for the addition of the pg_stat_database_conflicts column. Bumps PGSTAT_FILE_FORMAT_ID for the same reason. Author: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Author: Andres Freund <andres@anarazel.de> Author: Amit Khandekar <amitdkhan.pg@gmail.com> (in an older version) Reviewed-by: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Fabrízio de Royes Mello <fabriziomello@gmail.com> Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20230407075009.igg7be27ha2htkbt@awork3.anarazel.de
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
2023-04-08Introduce PG_IO_ALIGN_SIZE and align all I/O buffers.Thomas Munro
In order to have the option to use O_DIRECT/FILE_FLAG_NO_BUFFERING in a later commit, we need the addresses of user space buffers to be well aligned. The exact requirements vary by OS and file system (typically sectors and/or memory pages). The address alignment size is set to 4096, which is enough for currently known systems: it matches modern sectors and common memory page size. There is no standard governing O_DIRECT's requirements so we might eventually have to reconsider this with more information from the field or future systems. Aligning I/O buffers on memory pages is also known to improve regular buffered I/O performance. Three classes of I/O buffers for regular data pages are adjusted: (1) Heap buffers are now allocated with the new palloc_aligned() or MemoryContextAllocAligned() functions introduced by commit 439f6175. (2) Stack buffers now use a new struct PGIOAlignedBlock to respect PG_IO_ALIGN_SIZE, if possible with this compiler. (3) The buffer pool is also aligned in shared memory. WAL buffers were already aligned on XLOG_BLCKSZ. It's possible for XLOG_BLCKSZ to be configured smaller than PG_IO_ALIGNED_SIZE and thus for O_DIRECT WAL writes to fail to be well aligned, but that's a pre-existing condition and will be addressed by a later commit. BufFiles are not yet addressed (there's no current plan to use O_DIRECT for those, but they could potentially get some incidental speedup even in plain buffered I/O operations through better alignment). If we can't align stack objects suitably using the compiler extensions we know about, we disable the use of O_DIRECT by setting PG_O_DIRECT to 0. This avoids the need to consider systems that have O_DIRECT but can't align stack objects the way we want; such systems could in theory be supported with more work but we don't currently know of any such machines, so it's easier to pretend there is no O_DIRECT support instead. That's an existing and tested class of system. Add assertions that all buffers passed into smgrread(), smgrwrite() and smgrextend() are correctly aligned, unless PG_O_DIRECT is 0 (= stack alignment tricks may be unavailable) or the block size has been set too small to allow arrays of buffers to be all aligned. Author: Thomas Munro <thomas.munro@gmail.com> Author: Andres Freund <andres@anarazel.de> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Discussion: https://postgr.es/m/CA+hUKGK1X532hYqJ_MzFWt0n1zt8trz980D79WbjwnT-yYLZpg@mail.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
2023-04-07Track IO times in pg_stat_ioAndres Freund
a9c70b46dbe and 8aaa04b32S added counting of IO operations to a new view, pg_stat_io. Now, add IO timing for reads, writes, extends, and fsyncs to pg_stat_io as well. This combines the tracking for pgBufferUsage with the tracking for pg_stat_io into a new function pgstat_count_io_op_time(). This should make it a bit easier to avoid the somewhat costly instr_time conversion done for pgBufferUsage. Author: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com> Discussion: https://postgr.es/m/flat/CAAKRu_ay5iKmnbXZ3DsauViF3eMxu4m1oNnJXqV_HyqYeg55Ww%40mail.gmail.com
2023-04-07Catalog NOT NULL constraintsAlvaro Herrera
We now create pg_constaint rows for NOT NULL constraints with contype='n'. We propagate these constraints during operations such as adding inheritance relationships, creating and attaching partitions, creating tables LIKE other tables. We mostly follow the well-known rules of conislocal and coninhcount that we have for CHECK constraints, with some adaptations; for example, as opposed to CHECK constraints, we don't match NOT NULL ones by name when descending a hierarchy to alter it; instead we match by column number. This means we don't require the constraint names to be identical across a hierarchy. For now, we omit them from system catalogs. Maybe this is worth reconsidering. We don't support NOT VALID nor DEFERRABLE clauses either; these can be added as separate features later (this patch is already large and complicated enough.) This has been very long in the making. The first patch was written by Bernd Helmle in 2010 to add a new pg_constraint.contype value ('n'), which I (Álvaro) then hijacked in 2011 and 2012, until that one was killed by the realization that we ought to use contype='c' instead: manufactured CHECK constraints. However, later SQL standard development, as well as nonobvious emergent properties of that design (mostly, failure to distinguish them from "normal" CHECK constraints as well as the performance implication of having to test the CHECK expression) led us to reconsider this choice, so now the current implementation uses contype='n' again. In 2016 Vitaly Burovoy also worked on this feature[1] but found no consensus for his proposed approach, which was claimed to be closer to the letter of the standard, requiring additional pg_attribute columns to track the OID of the NOT NULL constraint for that column. [1] https://postgr.es/m/CAKOSWNkN6HSyatuys8xZxzRCR-KL1OkHS5-b9qd9bf1Rad3PLA@mail.gmail.com Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Author: Bernd Helmle <mailings@oopsware.de> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com> Discussion: https://postgr.es/m/CACA0E642A0267EDA387AF2B%40%5B172.26.14.62%5D Discussion: https://postgr.es/m/AANLkTinLXMOEMz+0J29tf1POokKi4XDkWJ6-DDR9BKgU@mail.gmail.com Discussion: https://postgr.es/m/20110707213401.GA27098@alvh.no-ip.org Discussion: https://postgr.es/m/1343682669-sup-2532@alvh.no-ip.org Discussion: https://postgr.es/m/CAKOSWNkN6HSyatuys8xZxzRCR-KL1OkHS5-b9qd9bf1Rad3PLA@mail.gmail.com Discussion: https://postgr.es/m/20220817181249.q7qvj3okywctra3c@alvherre.pgsql
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 array_sample() and array_shuffle() functions.Tom Lane
These are useful in Monte Carlo applications. Martin Kalcher, reviewed/adjusted by Daniel Gustafsson and myself Discussion: https://postgr.es/m/9d160a44-7675-51e8-60cf-6d64b76db831@aboutsource.net
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
2023-04-05bufmgr: Introduce infrastructure for faster relation extensionAndres Freund
The primary bottlenecks for relation extension are: 1) The extension lock is held while acquiring a victim buffer for the new page. Acquiring a victim buffer can require writing out the old page contents including possibly needing to flush WAL. 2) When extending via ReadBuffer() et al, we write a zero page during the extension, and then later write out the actual page contents. This can nearly double the write rate. 3) The existing bulk relation extension infrastructure in hio.c just amortized the cost of acquiring the relation extension lock, but none of the other costs. Unfortunately 1) cannot currently be addressed in a central manner as the callers to ReadBuffer() need to acquire the extension lock. To address that, this this commit moves the responsibility for acquiring the extension lock into bufmgr.c functions. That allows to acquire the relation extension lock for just the required time. This will also allow us to improve relation extension further, without changing callers. The reason we write all-zeroes pages during relation extension is that we hope to get ENOSPC errors earlier that way (largely works, except for CoW filesystems). It is easier to handle out-of-space errors gracefully if the page doesn't yet contain actual tuples. This commit addresses 2), by using the recently introduced smgrzeroextend(), which extends the relation, without dirtying the kernel page cache for all the extended pages. To address 3), this commit introduces a function to extend a relation by multiple blocks at a time. There are three new exposed functions: ExtendBufferedRel() for extending the relation by a single block, ExtendBufferedRelBy() to extend a relation by multiple blocks at once, and ExtendBufferedRelTo() for extending a relation up to a certain size. To avoid duplicating code between ReadBuffer(P_NEW) and the new functions, ReadBuffer(P_NEW) now implements relation extension with ExtendBufferedRel(), using a flag to tell ExtendBufferedRel() that the relation lock is already held. Note that this commit does not yet lead to a meaningful performance or scalability improvement - for that uses of ReadBuffer(P_NEW) will need to be converted to ExtendBuffered*(), which will be done in subsequent commits. Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Reviewed-by: Melanie Plageman <melanieplageman@gmail.com> Discussion: https://postgr.es/m/20221029025420.eplyow6k7tgu6he3@awork3.anarazel.de