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* Refactor code in tablecmds.c to check and process tablespace movesMichael Paquier2021-01-27
| | | | | | | | | | | | | | | | | | | | | | Two code paths of tablecmds.c (for relations with storage and without storage) use the same logic to check if the move of a relation to a new tablespace is allowed or not and to update pg_class.reltablespace and pg_class.relfilenode. A potential TABLESPACE clause for REINDEX, CLUSTER and VACUUM FULL needs similar checks to make sure that nothing is moved around in illegal ways (no mapped relations, shared relations only in pg_global, no move of temp tables owned by other backends). This reorganizes the existing code of ALTER TABLE so as all this logic is controlled by two new routines that can be reused for the other commands able to move relations across tablespaces, limiting the number of code paths in need of the same protections. This also removes some code that was duplicated for tables with and without storage for ALTER TABLE. Author: Alexey Kondratov, Michael Paquier Discussion: https://postgr.es/m/YA+9mAMWYLXJMVPL@paquier.xyz
* Rethink recently-added SPI interfaces.Tom Lane2021-01-26
| | | | | | | | | | | | | | SPI_execute_with_receiver and SPI_cursor_parse_open_with_paramlist are new in v14 (cf. commit 2f48ede08). Before they can get out the door, let's change their APIs to follow the practice recently established by SPI_prepare_extended etc: shove all optional arguments into a struct that callers are supposed to pre-zero. The hope is to allow future addition of more options without either API breakage or a continuing proliferation of new SPI entry points. With that in mind, choose slightly more generic names for them: SPI_execute_extended and SPI_cursor_parse_open respectively. Discussion: https://postgr.es/m/CAFj8pRCLPdDAETvR7Po7gC5y_ibkn_-bOzbeJb39WHms01194Q@mail.gmail.com
* Improve performance of repeated CALLs within plpgsql procedures.Tom Lane2021-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch essentially is cleaning up technical debt left behind by the original implementation of plpgsql procedures, particularly commit d92bc83c4. That patch (or more precisely, follow-on patches fixing its worst bugs) forced us to re-plan CALL and DO statements each time through, if we're in a non-atomic context. That wasn't for any fundamental reason, but just because use of a saved plan requires having a ResourceOwner to hold a reference count for the plan, and we had no suitable resowner at hand, nor would the available APIs support using one if we did. While it's not that expensive to create a "plan" for CALL/DO, the cycles do add up in repeated executions. This patch therefore makes the following API changes: * GetCachedPlan/ReleaseCachedPlan are modified to let the caller specify which resowner to use to pin the plan, rather than forcing use of CurrentResourceOwner. * spi.c gains a "SPI_execute_plan_extended" entry point that lets callers say which resowner to use to pin the plan. This borrows the idea of an options struct from the recently added SPI_prepare_extended, hopefully allowing future options to be added without more API breaks. This supersedes SPI_execute_plan_with_paramlist (which I've marked deprecated) as well as SPI_execute_plan_with_receiver (which is new in v14, so I just took it out altogether). * I also took the opportunity to remove the crude hack of letting plpgsql reach into SPI private data structures to mark SPI plans as "no_snapshot". It's better to treat that as an option of SPI_prepare_extended. Now, when running a non-atomic procedure or DO block that contains any CALL or DO commands, plpgsql creates a ResourceOwner that will be used to pin the plans of the CALL/DO commands. (In an atomic context, we just use CurrentResourceOwner, as before.) Having done this, we can just save CALL/DO plans normally, whether or not they are used across transaction boundaries. This seems to be good for something like 2X speedup of a CALL of a trivial procedure with a few simple argument expressions. By restricting the creation of an extra ResourceOwner like this, there's essentially zero penalty in cases that can't benefit. Pavel Stehule, with some further hacking by me Discussion: https://postgr.es/m/CAFj8pRCLPdDAETvR7Po7gC5y_ibkn_-bOzbeJb39WHms01194Q@mail.gmail.com
* Fix two typos in snapbuild.c.Andres Freund2021-01-25
| | | | | Reported-by: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://postgr.es/m/c94be044-818f-15e3-1ad3-7a7ae2dfed0a@iki.fi
* Fix broken ruleutils support for function TRANSFORM clauses.Tom Lane2021-01-25
| | | | | | | | I chanced to notice that this dumped core due to a faulty Assert. To add insult to injury, the output has been misformatted since v11. Obviously we need some regression testing here. Discussion: https://postgr.es/m/d1cc628c-3953-4209-957b-29427acc38c8@www.fastmail.com
* Remove CheckpointLock.Robert Haas2021-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up until now, we've held this lock when performing a checkpoint or restartpoint, but commit 076a055acf3c55314de267c62b03191586d79cf6 back in 2004 and commit 7e48b77b1cebb9a43f9fdd6b17128a0ba36132f9 from 2009, taken together, have removed all need for this. In the present code, there's only ever one process entitled to attempt a checkpoint: either the checkpointer, during normal operation, or the postmaster, during single-user operation. So, we don't need the lock. One possible concern in making this change is that it means that a substantial amount of code where HOLD_INTERRUPTS() was previously in effect due to the preceding LWLockAcquire() will now be running without that. This could mean that ProcessInterrupts() gets called in places from which it didn't before. However, this seems unlikely to do very much, because the checkpointer doesn't have any signal mapped to die(), so it's not clear how, for example, ProcDiePending = true could happen in the first place. Similarly with ClientConnectionLost and recovery conflicts. Also, if there are any such problems, we might want to fix them rather than reverting this, since running lots of code with interrupt handling suspended is generally bad. Patch by me, per an inquiry by Amul Sul. Review by Tom Lane and Michael Paquier. Discussion: http://postgr.es/m/CAAJ_b97XnBBfYeSREDJorFsyoD1sHgqnNuCi=02mNQBUMnA=FA@mail.gmail.com
* Fix hypothetical bug in heap backward scansDavid Rowley2021-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | Both heapgettup() and heapgettup_pagemode() incorrectly set the first page to scan in a backward scan in which the number of pages to scan was specified by heap_setscanlimits(). The code incorrectly started the scan at the end of the relation when startBlk was 0, or otherwise at startBlk - 1, neither of which is correct when only scanning a subset of pages. The fix here checks if heap_setscanlimits() has changed the number of pages to scan and if so we set the first page to scan as the final page in the specified range during backward scans. Proper adjustment of this code was forgotten when heap_setscanlimits() was added in 7516f5259 back in 9.5. However, practice, nowhere in core code performs backward scans after having used heap_setscanlimits(), yet, it is possible an extension uses the heap functions in this way, hence backpatch. An upcoming patch does use heap_setscanlimits() with backward scans, so this must be fixed before that can go in. Author: David Rowley Discussion: https://postgr.es/m/CAApHDvpGc9h0_oVD2CtgBcxCS1N-qDYZSeBRnUh+0CWJA9cMaA@mail.gmail.com Backpatch-through: 9.5, all supported versions
* Fix ALTER PUBLICATION...DROP TABLE behavior.Amit Kapila2021-01-25
| | | | | | | | | | | | Commit 69bd60672 fixed the initialization of streamed transactions for RelationSyncEntry. It forgot to initialize the publication actions while invalidating the RelationSyncEntry due to which even though the relation is dropped from a particular publication we still publish its changes. Fix it by initializing pubactions when entry got invalidated. Author: Japin Li and Bharath Rupireddy Reviewed-by: Amit Kapila Discussion: https://postgr.es/m/CALj2ACV+0UFpcZs5czYgBpujM9p0Hg1qdOZai_43OU7bqHU_xw@mail.gmail.com
* Fix COPY FREEZE with CLOBBER_CACHE_ALWAYSTomas Vondra2021-01-24
| | | | | | | | | | | | | This adds code omitted from commit 7db0cd2145 by accident, which had two consequences. Firstly, only rows inserted by heap_multi_insert were frozen as expected when running COPY FREEZE, while heap_insert left rows unfrozen. That however includes rows in TOAST tables, so a lot of data might have been left unfrozen. Secondly, page might have been left partially empty after relcache invalidation. This addresses both of those issues. Discussion: https://postgr.es/m/CABOikdN-ptGv0mZntrK2Q8OtfUuAjqaYMGmkdU1dCKFtUxVLrg@mail.gmail.com
* Re-allow DISTINCT in pl/pgsql expressions.Tom Lane2021-01-22
| | | | | | | | | | | | | | | I'd omitted this from the grammar in commit c9d529848, figuring that it wasn't worth supporting. However we already have one complaint, so it seems that judgment was wrong. It doesn't require a huge amount of code, so add it back. (I'm still drawing the line at UNION/INTERSECT/EXCEPT though: those'd require an unreasonable amount of grammar refactoring, and the single-result-row restriction makes them near useless anyway.) Also rethink the documentation: this behavior is a property of all pl/pgsql expressions, not just assignments. Discussion: https://postgr.es/m/20210122134106.e94c5cd7@mail.verfriemelt.org
* Remove bogus tracepointPeter Eisentraut2021-01-22
| | | | | | | | | Calls to LWLockWaitForVar() fired the TRACE_POSTGRESQL_LWLOCK_ACQUIRE tracepoint, but LWLockWaitForVar() never actually acquires the LWLock. (Probably a copy/paste bug in 68a2e52bbaf.) Remove it. Author: Craig Ringer <craig.ringer@enterprisedb.com> Discussion: https://www.postgresql.org/message-id/flat/CAGRY4nxJo+-HCC2i5H93ttSZ4gZO-FSddCwvkb-qAfQ1zdXd1w@mail.gmail.com
* Move SSL information callback earlier to capture more informationMichael Paquier2021-01-22
| | | | | | | | | | | | | | | | The callback for retrieving state change information during connection setup was only installed when the connection was mostly set up, and thus didn't provide much information and missed all the details related to the handshake. This also extends the callback with SSL_state_string_long() to print more information about the state change within the SSL object handled. While there, fix some comments which were incorrectly referring to the callback and its previous location in fe-secure.c. Author: Daniel Gustafsson Discussion: https://postgr.es/m/232CF476-94E1-42F1-9408-719E2AEC5491@yesql.se
* Fix pull_varnos' miscomputation of relids set for a PlaceHolderVar.Tom Lane2021-01-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, pull_varnos() took the relids of a PlaceHolderVar as being equal to the relids in its contents, but that fails to account for the possibility that we have to postpone evaluation of the PHV due to outer joins. This could result in a malformed plan. The known cases end up triggering the "failed to assign all NestLoopParams to plan nodes" sanity check in createplan.c, but other symptoms may be possible. The right value to use is the join level we actually intend to evaluate the PHV at. We can get that from the ph_eval_at field of the associated PlaceHolderInfo. However, there are some places that call pull_varnos() before the PlaceHolderInfos have been created; in that case, fall back to the conservative assumption that the PHV will be evaluated at its syntactic level. (In principle this might result in missing some legal optimization, but I'm not aware of any cases where it's an issue in practice.) Things are also a bit ticklish for calls occurring during deconstruct_jointree(), but AFAICS the ph_eval_at fields should have reached their final values by the time we need them. The main problem in making this work is that pull_varnos() has no way to get at the PlaceHolderInfos. We can fix that easily, if a bit tediously, in HEAD by passing it the planner "root" pointer. In the back branches that'd cause an unacceptable API/ABI break for extensions, so leave the existing entry points alone and add new ones with the additional parameter. (If an old entry point is called and encounters a PHV, it'll fall back to using the syntactic level, again possibly missing some valid optimization.) Back-patch to v12. The computation is surely also wrong before that, but it appears that we cannot reach a bad plan thanks to join order restrictions imposed on the subquery that the PlaceHolderVar came from. The error only became reachable when commit 4be058fe9 allowed trivial subqueries to be collapsed out completely, eliminating their join order restrictions. Per report from Stephan Springl. Discussion: https://postgr.es/m/171041.1610849523@sss.pgh.pa.us
* Fix initialization of FDW batching in ExecInitModifyTableTomas Vondra2021-01-21
| | | | | | | | | | ExecInitModifyTable has to initialize batching for all result relations, not just the first one. Furthermore, when junk filters were necessary, the pointer pointed past the mtstate->resultRelInfo array. Per reports from multiple non-x86 animals (florican, locust, ...). Discussion: https://postgr.es/m/20200628151002.7x5laxwpgvkyiu3q@development
* Implement support for bulk inserts in postgres_fdwTomas Vondra2021-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Extends the FDW API to allow batching inserts into foreign tables. That is usually much more efficient than inserting individual rows, due to high latency for each round-trip to the foreign server. It was possible to implement something similar in the regular FDW API, but it was inconvenient and there were issues with reporting the number of actually inserted rows etc. This extends the FDW API with two new functions: * GetForeignModifyBatchSize - allows the FDW picking optimal batch size * ExecForeignBatchInsert - inserts a batch of rows at once Currently, only INSERT queries support batching. Support for DELETE and UPDATE may be added in the future. This also implements batching for postgres_fdw. The batch size may be specified using "batch_size" option both at the server and table level. The initial patch version was written by me, but it was rewritten and improved in many ways by Takayuki Tsunakawa. Author: Takayuki Tsunakawa Reviewed-by: Tomas Vondra, Amit Langote Discussion: https://postgr.es/m/20200628151002.7x5laxwpgvkyiu3q@development
* Fix bug in detecting concurrent page splits in GiST insertHeikki Linnakangas2021-01-20
| | | | | | | | | | | | | | | | | In commit 9eb5607e699, I got the condition on checking for split or deleted page wrong: I used && instead of ||. The comment correctly said "concurrent split _or_ deletion". As a result, GiST insertion could miss a concurrent split, and insert to wrong page. Duncan Sands demonstrated this with a test script that did a lot of concurrent inserts. Backpatch to v12, where this was introduced. REINDEX is required to fix indexes that were affected by this bug. Backpatch-through: 12 Reported-by: Duncan Sands Discussion: https://www.postgresql.org/message-id/a9690483-6c6c-3c82-c8ba-dc1a40848f11%40deepbluecap.com
* Fix ALTER DEFAULT PRIVILEGES with duplicated objectsMichael Paquier2021-01-20
| | | | | | | | | | | | | | | | Specifying duplicated objects in this command would lead to unique constraint violations in pg_default_acl or "tuple already updated by self" errors. Similarly to GRANT/REVOKE, increment the command ID after each subcommand processing to allow this case to work transparently. A regression test is added by tweaking one of the existing queries of privileges.sql to stress this case. Reported-by: Andrus Author: Michael Paquier Reviewed-by: Álvaro Herrera Discussion: https://postgr.es/m/ae2a7dc1-9d71-8cba-3bb9-e4cb7eb1f44e@hot.ee Backpatch-through: 9.5
* Remove faulty support for MergeAppend plan with WHERE CURRENT OF.Tom Lane2021-01-19
| | | | | | | | | | | | | | | | | | | | | | | | | Somebody extended search_plan_tree() to treat MergeAppend exactly like Append, which is 100% wrong, because unlike Append we can't assume that only one input node is actively returning tuples. Hence a cursor using a MergeAppend across a UNION ALL or inheritance tree could falsely match a WHERE CURRENT OF query at a row that isn't actually the cursor's current output row, but coincidentally has the same TID (in a different table) as the current output row. Delete the faulty code; this means that such a case will now return an error like 'cursor "foo" is not a simply updatable scan of table "bar"', instead of silently misbehaving. Users should not find that surprising though, as the same cursor query could have failed that way already depending on the chosen plan. (It would fail like that if the sort were done with an explicit Sort node instead of MergeAppend.) Expand the clearly-inadequate commentary to be more explicit about what this code is doing, in hopes of forestalling future mistakes. It's been like this for awhile, so back-patch to all supported branches. Discussion: https://postgr.es/m/482865.1611075182@sss.pgh.pa.us
* pgindent worker.c.Amit Kapila2021-01-19
| | | | | | | | | This is a leftover from commit 0926e96c49. Changing this separately because this file is being modified for upcoming patch logical replication of 2PC. Author: Peter Smith Discussion: https://postgr.es/m/CAHut+Ps+EgG8KzcmAyAgBUi_vuTps6o9ZA8DG6SdnO0-YuOhPQ@mail.gmail.com
* Avoid crash with WHERE CURRENT OF and a custom scan plan.Tom Lane2021-01-18
| | | | | | | | | | | | | | | | | | | | | | | execCurrent.c's search_plan_tree() assumed that ForeignScanStates and CustomScanStates necessarily have a valid ss_currentRelation. This is demonstrably untrue for postgres_fdw's remote join and remote aggregation plans, and non-leaf custom scans might not have an identifiable scan relation either. Avoid crashing by ignoring such nodes when the field is null. This solution will lead to errors like 'cursor "foo" is not a simply updatable scan of table "bar"' in cases where maybe we could have allowed WHERE CURRENT OF to work. That's not an issue for postgres_fdw's usages, since joins or aggregations would render WHERE CURRENT OF invalid anyway. But an otherwise-transparent upper level custom scan node might find this annoying. When and if someone cares to expend work on such a scenario, we could invent a custom-scan-provider callback to determine what's safe. Report and patch by David Geier, commentary by me. It's been like this for awhile, so back-patch to all supported branches. Discussion: https://postgr.es/m/0253344d-9bdd-11c4-7f0d-d88c02cd7991@swarm64.com
* Narrow the scope of a local variable.Tom Lane2021-01-18
| | | | | | | | | | This is better style and more symmetrical with the other if-branch. This likely should have been included in 9de77b545 (which created the opportunity), but it was overlooked. Japin Li Discussion: https://postgr.es/m/MEYP282MB16699FA4A7CD57EB250E871FB6A40@MEYP282MB1669.AUSP282.PROD.OUTLOOK.COM
* Add bytea equivalents of ltrim() and rtrim().Tom Lane2021-01-18
| | | | | | | | We had bytea btrim() already, but for some reason not the other two. Joel Jacobson Discussion: https://postgr.es/m/d10cd5cd-a901-42f1-b832-763ac6f7ff3a@www.fastmail.com
* Allow for error or refusal while absorbing a ProcSignalBarrier.Robert Haas2021-01-18
| | | | | | | | | | | | | | | | | | | | Previously, the per-barrier-type functions tasked with absorbing them were expected to always succeed and never throw an error. However, that's a bit inconvenient. Further study has revealed that there are realistic cases where it might not be possible to absorb a ProcSignalBarrier without terminating the transaction, or even the whole backend. Similarly, for some barrier types, there might be other reasons where it's not reasonably possible to absorb the barrier at certain points in the code, so provide a way for a per-barrier-type function to reject absorbing the barrier. Unfortunately, there's still no committed code making use of this infrastructure; hopefully, we'll get there. :-( Patch by me, reviewed by Andres Freund and Amul Sul. Discussion: http://postgr.es/m/20200908182005.xya7wetdh3pndzim@alap3.anarazel.de Discussion: http://postgr.es/m/CA+Tgmob56Pk1-5aTJdVPCWFHon7me4M96ENpGe9n_R4JUjjhZA@mail.gmail.com
* Pause recovery for insufficient parameter settingsPeter Eisentraut2021-01-18
| | | | | | | | | | | | | | | | | | When certain parameters are changed on a physical replication primary, this is communicated to standbys using the XLOG_PARAMETER_CHANGE WAL record. The standby then checks whether its own settings are at least as big as the ones on the primary. If not, the standby shuts down with a fatal error. This patch changes this behavior for hot standbys to pause recovery at that point instead. That allows read traffic on the standby to continue while database administrators figure out next steps. When recovery is unpaused, the server shuts down (as before). The idea is to fix the parameters while recovery is paused and then restart when there is a maintenance window. Reviewed-by: Sergei Kornilov <sk@zsrv.org> Discussion: https://www.postgresql.org/message-id/flat/4ad69a4c-cc9b-0dfe-0352-8b1b0cd36c7b@2ndquadrant.com
* Refactor option handling of CLUSTER, REINDEX and VACUUMMichael Paquier2021-01-18
| | | | | | | | | | | | | | | | | | | | | | This continues the work done in b5913f6. All the options of those commands are changed to use hex values rather than enums to reduce the risk of compatibility bugs when introducing new options. Each option set is moved into a new structure that can be extended with more non-boolean options (this was already the case of VACUUM). The code of REINDEX is restructured so as manual REINDEX commands go through a single routine from utility.c, like VACUUM, to ease the allocation handling of option parameters when a command needs to go through multiple transactions. This can be used as a base infrastructure for future patches related to those commands, including reindex filtering and tablespace support. Per discussion with people mentioned below, as well as Alvaro Herrera and Peter Eisentraut. Author: Michael Paquier, Justin Pryzby Reviewed-by: Alexey Kondratov, Justin Pryzby Discussion: https://postgr.es/m/X8riynBLwxAD9uKk@paquier.xyz
* Set PD_ALL_VISIBLE and visibility map bits in COPY FREEZETomas Vondra2021-01-17
| | | | | | | | | | | | | | | | | | Make sure COPY FREEZE marks the pages as PD_ALL_VISIBLE and updates the visibility map. Until now we only marked individual tuples as frozen, but page-level flags were not updated, so the first VACUUM after the COPY FREEZE had to rewrite the whole table. This is a fairly old patch, and multiple people worked on it. The first version was written by Jeff Janes, and then reworked by Pavan Deolasee and Anastasia Lubennikova. Author: Anastasia Lubennikova, Pavan Deolasee, Jeff Janes Reviewed-by: Kuntal Ghosh, Jeff Janes, Tomas Vondra, Masahiko Sawada, Andres Freund, Ibrar Ahmed, Robert Haas, Tatsuro Ishii, Darafei Praliaskouski Discussion: https://postgr.es/m/CABOikdN-ptGv0mZntrK2Q8OtfUuAjqaYMGmkdU1dCKFtUxVLrg@mail.gmail.com Discussion: https://postgr.es/m/CAMkU%3D1w3osJJ2FneELhhNRLxfZitDgp9FPHee08NT2FQFmz_pQ%40mail.gmail.com
* Add pg_stat_database counters for sessions and session timeMagnus Hagander2021-01-17
| | | | | | | | | | | | | | | This add counters for number of sessions, the different kind of session termination types, and timers for how much time is spent in active vs idle in a database to pg_stat_database. Internally this also renames the parameter "force" to disconnect. This was the only use-case for the parameter before, so repurposing it to this mroe narrow usecase makes things cleaner than inventing something new. Author: Laurenz Albe Reviewed-By: Magnus Hagander, Soumyadeep Chakraborty, Masahiro Ikeda Discussion: https://postgr.es/m/b07e1f9953701b90c66ed368656f2aef40cac4fb.camel@cybertec.at
* Prevent excess SimpleLruTruncate() deletion.Noah Misch2021-01-16
| | | | | | | | | | | | | | | | | Every core SLRU wraps around. With the exception of pg_notify, the wrap point can fall in the middle of a page. Account for this in the PagePrecedes callback specification and in SimpleLruTruncate()'s use of said callback. Update each callback implementation to fit the new specification. This changes SerialPagePrecedesLogically() from the style of asyncQueuePagePrecedes() to the style of CLOGPagePrecedes(). (Whereas pg_clog and pg_serial share a key space, pg_serial is nothing like pg_notify.) The bug fixed here has the same symptoms and user followup steps as 592a589a04bd456410b853d86bd05faa9432cbbb. Back-patch to 9.5 (all supported versions). Reviewed by Andrey Borodin and (in earlier versions) by Tom Lane. Discussion: https://postgr.es/m/20190202083822.GC32531@gust.leadboat.com
* Remove unnecessary pstrdup in fetch_table_list.Amit Kapila2021-01-16
| | | | | | | | | | The result of TextDatumGetCString is already palloc'ed so we don't need to allocate memory for it again. We decide not to backpatch it as there doesn't seem to be any case where it can create a meaningful leak. Author: Zhijie Hou Reviewed-by: Daniel Gustafsson Discussion: https://postgr.es/m/229fed2eb8c54c71a96ccb99e516eb12@G08CNEXMBPEKD05.g08.fujitsu.local
* Disallow CREATE STATISTICS on system catalogsTomas Vondra2021-01-15
| | | | | | | | | | | | | | Add a check that CREATE STATISTICS does not add extended statistics on system catalogs, similarly to indexes etc. It can be overriden using the allow_system_table_mods GUC. This bug exists since 7b504eb282c, adding the extended statistics, so backpatch all the way back to PostgreSQL 10. Author: Tomas Vondra Reported-by: Dean Rasheed Backpatch-through: 10 Discussion: https://postgr.es/m/CAEZATCXAPrrOKwEsyZKQ4uzzJQWBCt6QAvOcgqRGdWwT1zb%2BrQ%40mail.gmail.com
* Avoid spurious wait in concurrent reindexAlvaro Herrera2021-01-15
| | | | | | | | | | | | | | This is like commit c98763bf51bf, but for REINDEX CONCURRENTLY. To wit: this flags indicates that the current process is safe to ignore for the purposes of waiting for other snapshots, when doing CREATE INDEX CONCURRENTLY and REINDEX CONCURRENTLY. This helps two processes doing either of those things not deadlock, and also avoids spurious waits. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Hamid Akhtar <hamid.akhtar@gmail.com> Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com> Discussion: https://postgr.es/m/20201130195439.GA24598@alvherre.pgsql
* Fix calculation of how much shared memory is required to store a TOC.Fujii Masao2021-01-15
| | | | | | | | | | | Commit ac883ac453 refactored shm_toc_estimate() but changed its calculation of shared memory size for TOC incorrectly. Previously this could cause too large memory to be allocated. Back-patch to v11 where the bug was introduced. Author: Takayuki Tsunakawa Discussion: https://postgr.es/m/TYAPR01MB2990BFB73170E2C4921E2C4DFEA80@TYAPR01MB2990.jpnprd01.prod.outlook.com
* Fix O(N^2) stat() calls when recycling WAL segmentsMichael Paquier2021-01-15
| | | | | | | | | | | | | | | | | | The counter tracking the last segment number recycled was getting initialized when recycling one single segment, while it should be used across a full cycle of segments recycled to prevent useless checks related to entries already recycled. This performance issue has been introduced by b2a5545, and it was first implemented in 61b86142. No backpatch is done per the lack of field complaints. Reported-by: Andres Freund, Thomas Munro Author: Michael Paquier Reviewed-By: Andres Freund Discussion: https://postgr.es/m/20170621211016.eln6cxxp3jrv7m4m@alap3.anarazel.de Discussion: https://postgr.es/m/CA+hUKG+DRiF9z1_MU4fWq+RfJMxP7zjoptfcmuCFPeO4JM2iVg@mail.gmail.com
* Prevent drop of tablespaces used by partitioned relationsAlvaro Herrera2021-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a tablespace is used in a partitioned relation (per commits ca4103025dfe in pg12 for tables and 33e6c34c3267 in pg11 for indexes), it is possible to drop the tablespace, potentially causing various problems. One such was reported in bug #16577, where a rewriting ALTER TABLE causes a server crash. Protect against this by using pg_shdepend to keep track of tablespaces when used for relations that don't keep physical files; we now abort a tablespace if we see that the tablespace is referenced from any partitioned relations. Backpatch this to 11, where this problem has been latent all along. We don't try to create pg_shdepend entries for existing partitioned indexes/tables, but any ones that are modified going forward will be protected. Note slight behavior change: when trying to drop a tablespace that contains both regular tables as well as partitioned ones, you'd previously get ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE and now you'll get ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST. Arguably, the latter is more correct. It is possible to add protecting pg_shdepend entries for existing tables/indexes, by doing ALTER TABLE ONLY some_partitioned_table SET TABLESPACE pg_default; ALTER TABLE ONLY some_partitioned_table SET TABLESPACE original_tablespace; for each partitioned table/index that is not in the database default tablespace. Because these partitioned objects do not have storage, no file needs to be actually moved, so it shouldn't take more time than what's required to acquire locks. This query can be used to search for such relations: SELECT ... FROM pg_class WHERE relkind IN ('p', 'I') AND reltablespace <> 0 Reported-by: Alexander Lakhin <exclusion@gmail.com> Discussion: https://postgr.es/m/16577-881633a9f9894fd5@postgresql.org Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Michael Paquier <michael@paquier.xyz>
* Ensure that a standby is able to follow a primary on a newer timeline.Fujii Masao2021-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 709d003fbd refactored WAL-reading code, but accidentally caused WalSndSegmentOpen() to fail to follow a timeline switch while reading from a historic timeline. This issue caused a standby to fail to follow a primary on a newer timeline when WAL archiving is enabled. If there is a timeline switch within the segment, WalSndSegmentOpen() should read from the WAL segment belonging to the new timeline. But previously since it failed to follow a timeline switch, it tried to read the WAL segment with old timeline. When WAL archiving is enabled, that WAL segment with old timeline doesn't exist because it's renamed to .partial. This leads a primary to have tried to read non-existent WAL segment, and which caused replication to faill with the error "ERROR: requested WAL segment ... has already been removed". This commit fixes WalSndSegmentOpen() so that it's able to follow a timeline switch, to ensure that a standby is able to follow a primary on a newer timeline even when WAL archiving is enabled. This commit also adds the regression test to check whether a standby is able to follow a primary on a newer timeline when WAL archiving is enabled. Back-patch to v13 where the bug was introduced. Reported-by: Kyotaro Horiguchi Author: Kyotaro Horiguchi, tweaked by Fujii Masao Reviewed-by: Alvaro Herrera, Fujii Masao Discussion: https://postgr.es/m/20201209.174314.282492377848029776.horikyota.ntt@gmail.com
* Rework refactoring of hex and encoding routinesMichael Paquier2021-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit addresses some issues with c3826f83 that moved the hex decoding routine to src/common/: - The decoding function lacked overflow checks, so when used for security-related features it was an open door to out-of-bound writes if not carefully used that could remain undetected. Like the base64 routines already in src/common/ used by SCRAM, this routine is reworked to check for overflows by having the size of the destination buffer passed as argument, with overflows checked before doing any writes. - The encoding routine was missing. This is moved to src/common/ and it gains the same overflow checks as the decoding part. On failure, the hex routines of src/common/ issue an error as per the discussion done to make them usable by frontend tools, but not by shared libraries. Note that this is why ECPG is left out of this commit, and it still includes a duplicated logic doing hex encoding and decoding. While on it, this commit uses better variable names for the source and destination buffers in the existing escape and base64 routines in encode.c and it makes them more robust to overflow detection. The previous core code issued a FATAL after doing out-of-bound writes if going through the SQL functions, which would be enough to detect problems when working on changes that impacted this area of the code. Instead, an error is issued before doing an out-of-bound write. The hex routines were being directly called for bytea conversions and backup manifests without such sanity checks. The current calls happen to not have any problems, but careless uses of such APIs could easily lead to CVE-class bugs. Author: Bruce Momjian, Michael Paquier Reviewed-by: Sehrope Sarkuni Discussion: https://postgr.es/m/20201231003557.GB22199@momjian.us
* Move our p{read,write}v replacements into their own files.Thomas Munro2021-01-14
| | | | | | | | | | | | | macOS's ranlib issued a warning about an empty pread.o file with the previous arrangement, on systems new enough to require no replacement functions. Let's go back to using configure's AC_REPLACE_FUNCS system to build and include each .o in the library only if it's needed, which requires moving the *v() functions to their own files. Also move the _with_retry() wrapper to a more permanent home. Reported-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/1283127.1610554395%40sss.pgh.pa.us
* Enhance nbtree index tuple deletion.Peter Geoghegan2021-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Teach nbtree and heapam to cooperate in order to eagerly remove duplicate tuples representing dead MVCC versions. This is "bottom-up deletion". Each bottom-up deletion pass is triggered lazily in response to a flood of versions on an nbtree leaf page. This usually involves a "logically unchanged index" hint (these are produced by the executor mechanism added by commit 9dc718bd). The immediate goal of bottom-up index deletion is to avoid "unnecessary" page splits caused entirely by version duplicates. It naturally has an even more useful effect, though: it acts as a backstop against accumulating an excessive number of index tuple versions for any given _logical row_. Bottom-up index deletion complements what we might now call "top-down index deletion": index vacuuming performed by VACUUM. Bottom-up index deletion responds to the immediate local needs of queries, while leaving it up to autovacuum to perform infrequent clean sweeps of the index. The overall effect is to avoid certain pathological performance issues related to "version churn" from UPDATEs. The previous tableam interface used by index AMs to perform tuple deletion (the table_compute_xid_horizon_for_tuples() function) has been replaced with a new interface that supports certain new requirements. Many (perhaps all) of the capabilities added to nbtree by this commit could also be extended to other index AMs. That is left as work for a later commit. Extend deletion of LP_DEAD-marked index tuples in nbtree by adding logic to consider extra index tuples (that are not LP_DEAD-marked) for deletion in passing. This increases the number of index tuples deleted significantly in many cases. The LP_DEAD deletion process (which is now called "simple deletion" to clearly distinguish it from bottom-up deletion) won't usually need to visit any extra table blocks to check these extra tuples. We have to visit the same table blocks anyway to generate a latestRemovedXid value (at least in the common case where the index deletion operation's WAL record needs such a value). Testing has shown that the "extra tuples" simple deletion enhancement increases the number of index tuples deleted with almost any workload that has LP_DEAD bits set in leaf pages. That is, it almost never fails to delete at least a few extra index tuples. It helps most of all in cases that happen to naturally have a lot of delete-safe tuples. It's not uncommon for an individual deletion operation to end up deleting an order of magnitude more index tuples compared to the old naive approach (e.g., custom instrumentation of the patch shows that this happens fairly often when the regression tests are run). Add a further enhancement that augments simple deletion and bottom-up deletion in indexes that make use of deduplication: Teach nbtree's _bt_delitems_delete() function to support granular TID deletion in posting list tuples. It is now possible to delete individual TIDs from posting list tuples provided the TIDs have a tableam block number of a table block that gets visited as part of the deletion process (visiting the table block can be triggered directly or indirectly). Setting the LP_DEAD bit of a posting list tuple is still an all-or-nothing thing, but that matters much less now that deletion only needs to start out with the right _general_ idea about which index tuples are deletable. Bump XLOG_PAGE_MAGIC because xl_btree_delete changed. No bump in BTREE_VERSION, since there are no changes to the on-disk representation of nbtree indexes. Indexes built on PostgreSQL 12 or PostgreSQL 13 will automatically benefit from bottom-up index deletion (i.e. no reindexing required) following a pg_upgrade. The enhancement to simple deletion is available with all B-Tree indexes following a pg_upgrade, no matter what PostgreSQL version the user upgrades from. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Heikki Linnakangas <hlinnaka@iki.fi> Reviewed-By: Victor Yegorov <vyegorov@gmail.com> Discussion: https://postgr.es/m/CAH2-Wzm+maE3apHB8NOtmM=p-DO65j2V5GzAWCOEEuy3JZgb2g@mail.gmail.com
* Pass down "logically unchanged index" hint.Peter Geoghegan2021-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an executor aminsert() hint mechanism that informs index AMs that the incoming index tuple (the tuple that accompanies the hint) is not being inserted by execution of an SQL statement that logically modifies any of the index's key columns. The hint is received by indexes when an UPDATE takes place that does not apply an optimization like heapam's HOT (though only for indexes where all key columns are logically unchanged). Any index tuple that receives the hint on insert is expected to be a duplicate of at least one existing older version that is needed for the same logical row. Related versions will typically be stored on the same index page, at least within index AMs that apply the hint. Recognizing the difference between MVCC version churn duplicates and true logical row duplicates at the index AM level can help with cleanup of garbage index tuples. Cleanup can intelligently target tuples that are likely to be garbage, without wasting too many cycles on less promising tuples/pages (index pages with little or no version churn). This is infrastructure for an upcoming commit that will teach nbtree to perform bottom-up index deletion. No index AM actually applies the hint just yet. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Victor Yegorov <vyegorov@gmail.com> Discussion: https://postgr.es/m/CAH2-Wz=CEKFa74EScx_hFVshCOn6AA5T-ajFASTdzipdkLTNQQ@mail.gmail.com
* Log long wait time on recovery conflict when it's resolved.Fujii Masao2021-01-13
| | | | | | | | | | | | | This is a follow-up of the work done in commit 0650ff2303. This commit extends log_recovery_conflict_waits so that a log message is produced also when recovery conflict has already been resolved after deadlock_timeout passes, i.e., when the startup process finishes waiting for recovery conflict after deadlock_timeout. This is useful in investigating how long recovery conflicts prevented the recovery from applying WAL. Author: Fujii Masao Reviewed-by: Kyotaro Horiguchi, Bertrand Drouvot Discussion: https://postgr.es/m/9a60178c-a853-1440-2cdc-c3af916cff59@amazon.com
* Fix memory leak in SnapBuildSerialize.Amit Kapila2021-01-13
| | | | | | | | | | | | | | The memory for the snapshot was leaked while serializing it to disk during logical decoding. This memory will be freed only once walsender stops streaming the changes. This can lead to a huge memory increase when master logs Standby Snapshot too frequently say when the user is trying to create many replication slots. Reported-by: funnyxj.fxj@alibaba-inc.com Diagnosed-by: funnyxj.fxj@alibaba-inc.com Author: Amit Kapila Backpatch-through: 9.5 Discussion: https://postgr.es/m/033ab54c-6393-42ee-8ec9-2b399b5d8cde.funnyxj.fxj@alibaba-inc.com
* Optimize DropRelFileNodesAllBuffers() for recovery.Amit Kapila2021-01-13
| | | | | | | | | | | | | | | Similar to commit d6ad34f341, this patch optimizes DropRelFileNodesAllBuffers() by avoiding the complete buffer pool scan and instead find the buffers to be invalidated by doing lookups in the BufMapping table. This optimization helps operations where the relation files need to be removed like Truncate, Drop, Abort of Create Table, etc. Author: Kirk Jamison Reviewed-by: Kyotaro Horiguchi, Takayuki Tsunakawa, and Amit Kapila Tested-By: Haiying Tang Discussion: https://postgr.es/m/OSBPR01MB3207DCA7EC725FDD661B3EDAEF660@OSBPR01MB3207.jpnprd01.prod.outlook.com
* Fix routine name in comment of catcache.cMichael Paquier2021-01-13
| | | | | Author: Bharath Rupireddy Discussion: https://postgr.es/m/CALj2ACUDXLAkf_XxQO9tAUtnTNGi3Lmd8fANd+vBJbcHn1HoWA@mail.gmail.com
* Invent struct ReindexIndexInfoAlvaro Herrera2021-01-12
| | | | | | | | | | | This struct is used by ReindexRelationConcurrently to keep track of the relations to process. This saves having to obtain some data repeatedly, and has future uses as well. Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Hamid Akhtar <hamid.akhtar@gmail.com> Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com> Discussion: https://postgr.es/m/20201130195439.GA24598@alvherre.pgsql
* Fix thinko in commentAlvaro Herrera2021-01-12
| | | | | | | | This comment has been wrong since its introduction in commit 2c03216d8311. Author: Masahiko Sawada <sawada.mshk@gmail.com> Discussion: https://postgr.es/m/CAD21AoAzz6qipFJBbGEaHmyWxvvNDp8httbwLR9tUQWaTjUs2Q@mail.gmail.com
* Fix relation descriptor leak.Amit Kapila2021-01-12
| | | | | | | | | | | We missed closing the relation descriptor while sending changes via the root of partitioned relations during logical replication. Author: Amit Langote and Mark Zhao Reviewed-by: Amit Kapila and Ashutosh Bapat Backpatch-through: 13, where it was introduced Discussion: https://postgr.es/m/tencent_41FEA657C206F19AB4F406BE9252A0F69C06@qq.com Discussion: https://postgr.es/m/tencent_6E296D2F7D70AFC90D83353B69187C3AA507@qq.com
* Optimize DropRelFileNodeBuffers() for recovery.Amit Kapila2021-01-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The recovery path of DropRelFileNodeBuffers() is optimized so that scanning of the whole buffer pool can be avoided when the number of blocks to be truncated in a relation is below a certain threshold. For such cases, we find the buffers by doing lookups in BufMapping table. This improves the performance by more than 100 times in many cases when several small tables (tested with 1000 relations) are truncated and where the server is configured with a large value of shared buffers (greater than equal to 100GB). This optimization helps cases (a) when vacuum or autovacuum truncated off any of the empty pages at the end of a relation, or (b) when the relation is truncated in the same transaction in which it was created. This commit introduces a new API smgrnblocks_cached which returns a cached value for the number of blocks in a relation fork. This helps us to determine the exact size of relation which is required to apply this optimization. The exact size is required to ensure that we don't leave any buffer for the relation being dropped as otherwise the background writer or checkpointer can lead to a PANIC error while flushing buffers corresponding to files that don't exist. Author: Kirk Jamison based on ideas by Amit Kapila Reviewed-by: Kyotaro Horiguchi, Takayuki Tsunakawa, and Amit Kapila Tested-By: Haiying Tang Discussion: https://postgr.es/m/OSBPR01MB3207DCA7EC725FDD661B3EDAEF660@OSBPR01MB3207.jpnprd01.prod.outlook.com
* Rethink SQLSTATE code for ERRCODE_IDLE_SESSION_TIMEOUT.Tom Lane2021-01-11
| | | | | | | | | | | | Move it to class 57 (Operator Intervention), which seems like a better choice given that from the client's standpoint it behaves a heck of a lot like, e.g., ERRCODE_ADMIN_SHUTDOWN. In a green field I'd put ERRCODE_IDLE_IN_TRANSACTION_SESSION_TIMEOUT here as well. But that's been around for a few years, so it's probably too late to change its SQLSTATE code. Discussion: https://postgr.es/m/763A0689-F189-459E-946F-F0EC4458980B@hotmail.com
* Use vectored I/O to fill new WAL segments.Thomas Munro2021-01-11
| | | | | | | | | | | | | Instead of making many block-sized write() calls to fill a new WAL file with zeroes, make a smaller number of pwritev() calls (or various emulations). The actual number depends on the OS's IOV_MAX, which PG_IOV_MAX currently caps at 32. That means we'll write 256kB per call on typical systems. We may want to tune the number later with more experience. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CA%2BhUKGJA%2Bu-220VONeoREBXJ9P3S94Y7J%2BkqCnTYmahvZJwM%3Dg%40mail.gmail.com
* Fix ancient bug in parsing of BRE-mode regular expressions.Tom Lane2021-01-08
| | | | | | | | | | | | | | | | | brenext(), when parsing a '*' quantifier, forgot to return any "value" for the token; per the equivalent case in next(), it should return value 1 to indicate that greedy rather than non-greedy behavior is wanted. The result is that the compiled regexp could behave like 'x*?' rather than the intended 'x*', if we were unlucky enough to have a zero in v->nextvalue at this point. That seems to happen with some reliability if we have '.*' at the beginning of a BRE-mode regexp, although that depends on the initial contents of a stack-allocated struct, so it's not guaranteed to fail. Found by Alexander Lakhin using valgrind testing. This bug seems to be aboriginal in Spencer's code, so back-patch all the way. Discussion: https://postgr.es/m/16814-6c5e3edd2bdf0d50@postgresql.org