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* Fix an asssortment of typos in brin_minmax_multi.c and mcv.cDavid Rowley2021-06-10
| | | | Discussion: https://postgr.es/m/CAApHDvrbyJNOPBws4RUhXghZ7+TBjtdO-rznTsqZECuowNorXg@mail.gmail.com
* Fix corner case failure of new standby to follow new primary.Robert Haas2021-06-09
| | | | | | | | | | | | | | | | | | | | | | | | | This only happens if (1) the new standby has no WAL available locally, (2) the new standby is starting from the old timeline, (3) the promotion happened in the WAL segment from which the new standby is starting, (4) the timeline history file for the new timeline is available from the archive but the WAL files for are not (i.e. this is a race), (5) the WAL files for the new timeline are available via streaming, and (6) recovery_target_timeline='latest'. Commit ee994272ca50f70b53074f0febaec97e28f83c4e introduced this logic and was an improvement over the previous code, but it mishandled this case. If recovery_target_timeline='latest' and restore_command is set, validateRecoveryParameters() can change recoveryTargetTLI to be different from receiveTLI. If streaming is then tried afterward, expectedTLEs gets initialized with the history of the wrong timeline. It's supposed to be a list of entries explaining how to get to the target timeline, but in this case it ends up with a list of entries explaining how to get to the new standby's original timeline, which isn't right. Dilip Kumar and Robert Haas, reviewed by Kyotaro Horiguchi. Discussion: http://postgr.es/m/CAFiTN-sE-jr=LB8jQuxeqikd-Ux+jHiXyh4YDiZMPedgQKup0g@mail.gmail.com
* Fix pg_visibility regression failure with CLOBBER_CACHE_ALWAYSTomas Vondra2021-06-08
| | | | | | | | | | | Commit 8e03eb92e9 reverted a bit too much code, reintroducing one of the issues fixed by 39b66a91bd - a page might have been left partially empty after relcache invalidation. Reported-By: Tom Lane Author: Masahiko Sawada Discussion: https://postgr.es/m/822752.1623032114@sss.pgh.pa.us Discussion: https://postgr.es/m/CAD21AoA%3D%3Df2VSw3c-Cp_y%3DWLKHMKc1D6s7g3YWsCOvgaYPpJcg%40mail.gmail.com
* Clean up some questionable usages of DatumGet* macrosDavid Rowley2021-06-04
| | | | | | | | | | | | | | | | | | | | | This tidies up some questionable coding which made use of DatumGetPointer() for Datums being passed into functions where the parameter is expected to be a cstring. We saw no compiler warnings with the old code as the Pointer type used in DatumGetPointer() happens to be a char * rather than a void *. However, that's no excuse and we should be using the correct macro for the job. Here we also make use of OutputFunctionCall() rather than using FunctionCall1() directly to call the type's output function. OutputFunctionCall() is the standard way to do this. It casts the returned value to a cstring for us. In passing get rid of a duplicate call to strlen(). Most compilers will likely optimize away the 2nd call, but there may be some that won't. In any case, this just aligns the code to some other nearby code that already does this. Discussion: https://postgr.es/m/CAApHDvq1D=ehZ8hey8Hz67N+_Zth0GHO5wiVCfv1YcGPMXJq0A@mail.gmail.com
* Adjust locations which have an incorrect copyright yearDavid Rowley2021-06-04
| | | | | | | A few patches committed after ca3b37487 mistakenly forgot to make the copyright year 2021. Fix these. Discussion: https://postgr.es/m/CAApHDvqyLmd9P2oBQYJ=DbrV8QwyPRdmXtCTFYPE08h+ip0UJw@mail.gmail.com
* Standardize usages of appendStringInfo and appendPQExpBufferDavid Rowley2021-06-03
| | | | | | | | | | | | | | | | | | | Fix a few places that were using appendStringInfo() when they should have been using appendStringInfoString(). Also some cases of appendPQExpBuffer() that would have been better suited to use appendPQExpBufferChar(), and finally, some places that used appendPQExpBuffer() when appendPQExpBufferStr() would have suited better. There are no bugs are being fixed here. The aim is just to make the code use the most optimal function for the job. All the code being changed here is new to PG14. It makes sense to fix these before we branch for PG15. There are a few other places that we could fix, but those cases are older code so fixing those seems less worthwhile as it may cause unnecessary back-patching pain in the future. Author: Hou Zhijie Discussion: https://postgr.es/m/OS0PR01MB5716732158B1C4142C6FE375943D9@OS0PR01MB5716.jpnprd01.prod.outlook.com
* Revert most of 39b66a91bdTomas Vondra2021-06-03
| | | | | | | | | | Reverts most of commit 39b66a91bd, which was found to cause significant regression for REFRESH MATERIALIZED VIEW. This means only rows inserted by heap_multi_insert will benefit from the optimization, implemented in commit 7db0cd2145. Reported-by: Masahiko Sawada Discussion: https://postgr.es/m/CAD21AoA%3D%3Df2VSw3c-Cp_y%3DWLKHMKc1D6s7g3YWsCOvgaYPpJcg%40mail.gmail.com
* Fix VACUUM VERBOSE's LP_DEAD item pages output.Peter Geoghegan2021-05-27
| | | | Oversight in commit 5100010e.
* Rethink definition of pg_attribute.attcompression.Tom Lane2021-05-27
| | | | | | | | | | | | | | | | | | | | | | | Redefine '\0' (InvalidCompressionMethod) as meaning "if we need to compress, use the current setting of default_toast_compression". This allows '\0' to be a suitable default choice regardless of datatype, greatly simplifying code paths that initialize tupledescs and the like. It seems like a more user-friendly approach as well, because now the default compression choice doesn't migrate into table definitions, meaning that changing default_toast_compression is usually sufficient to flip an installation's behavior; one needn't tediously issue per-column ALTER SET COMPRESSION commands. Along the way, fix a few minor bugs and documentation issues with the per-column-compression feature. Adopt more robust APIs for SetIndexStorageProperties and GetAttributeCompression. Bump catversion because typical contents of attcompression will now be different. We could get away without doing that, but it seems better to ensure v14 installations all agree on this. (We already forced initdb for beta2, anyway.) Discussion: https://postgr.es/m/626613.1621787110@sss.pgh.pa.us
* Fix typo in heapam.cMichael Paquier2021-05-26
| | | | | Author: Hou Zhijie Discussion: https://postgr.es/m/OS0PR01MB571612191738540B27A8DE5894249@OS0PR01MB5716.jpnprd01.prod.outlook.com
* Fix memory leak when de-toasting compressed values in VACUUM FULL/CLUSTERMichael Paquier2021-05-25
| | | | | | | | | | | | | | | | | | | | | | VACUUM FULL and CLUSTER can be used to enforce the use of the existing compression method of a toastable column if a value currently stored is compressed with a method that does not match the column's defined method. The code in charge of decompressing and recompressing toast values at rewrite left around the detoasted values, causing an accumulation of memory allocated in TopTransactionContext. When processing large relations, this could cause the system to run out of memory. The detoasted values are not needed once their tuple is rewritten, and this commit ensures that the necessary cleanup happens. Issue introduced by bbe0a81d. The comments of the area are reordered a bit while on it. Reported-by: Andres Freund Analyzed-by: Andres Freund Author: Michael Paquier Reviewed-by: Dilip Kumar Discussion: https://postgr.es/m/20210521211929.pcehg6f23icwstdb@alap3.anarazel.de
* Consider triggering VACUUM failsafe during scan.Peter Geoghegan2021-05-24
| | | | | | | | | | | | | | | | | | | | | The wraparound failsafe mechanism added by commit 1e55e7d1 handled the one-pass strategy case (i.e. the "table has no indexes" case) by adding a dedicated failsafe check. This made up for the fact that the usual one-pass checks inside lazy_vacuum_all_indexes() cannot ever be reached during a one-pass strategy VACUUM. This approach failed to account for two-pass VACUUMs that opt out of index vacuuming up-front. The INDEX_CLEANUP off case in the only case that works like that. Fix this by performing a failsafe check every 4GB during the first scan of the heap, regardless of the details of the VACUUM. This eliminates the special case, and will make the failsafe trigger more reliably. Author: Peter Geoghegan <pg@bowt.ie> Reported-By: Andres Freund <andres@anarazel.de> Reviewed-By: Masahiko Sawada <sawada.mshk@gmail.com> Discussion: https://postgr.es/m/20210424002921.pb3t7h6frupdqnkp@alap3.anarazel.de
* Re-order pg_attribute columns to eliminate some padding space.Tom Lane2021-05-23
| | | | | | | | | | | | | | | | | | Now that attcompression is just a char, there's a lot of wasted padding space after it. Move it into the group of char-wide columns to save a net of 4 bytes per pg_attribute entry. While we're at it, swap the order of attstorage and attalign to make for a more logical grouping of these columns. Also re-order actions in related code to match the new field ordering. This patch also fixes one outright bug: equalTupleDescs() failed to compare attcompression. That could, for example, cause relcache reload to fail to adopt a new value following a change. Michael Paquier and Tom Lane, per a gripe from Andres Freund. Discussion: https://postgr.es/m/20210517204803.iyk5wwvwgtjcmc5w@alap3.anarazel.de
* Avoid detoasting failure after COMMIT inside a plpgsql FOR loop.Tom Lane2021-05-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | exec_for_query() normally tries to prefetch a few rows at a time from the query being iterated over, so as to reduce executor entry/exit overhead. Unfortunately this is unsafe if we have COMMIT or ROLLBACK within the loop, because there might be TOAST references in the data that we prefetched but haven't yet examined. Immediately after the COMMIT/ROLLBACK, we have no snapshots in the session, meaning that VACUUM is at liberty to remove recently-deleted TOAST rows. This was originally reported as a case triggering the "no known snapshots" error in init_toast_snapshot(), but even if you miss hitting that, you can get "missing toast chunk", as illustrated by the added isolation test case. To fix, just disable prefetching in non-atomic contexts. Maybe there will be performance complaints prompting us to work harder later, but it's not clear at the moment that this really costs much, and I doubt we'd want to back-patch any complicated fix. In passing, adjust that error message in init_toast_snapshot() to be a little clearer about the likely cause of the problem. Patch by me, based on earlier investigation by Konstantin Knizhnik. Per bug #15990 from Andreas Wicht. Back-patch to v11 where intra-procedure COMMIT was added. Discussion: https://postgr.es/m/15990-eee2ac466b11293d@postgresql.org
* Make standby promotion reset the recovery pause state to 'not paused'.Fujii Masao2021-05-19
| | | | | | | | | | | | | | If a promotion is triggered while recovery is paused, the paused state ends and promotion continues. But previously in that case pg_get_wal_replay_pause_state() returned 'paused' wrongly while a promotion was ongoing. This commit changes a standby promotion so that it marks the recovery pause state as 'not paused' when it's triggered, to fix the issue. Author: Fujii Masao Reviewed-by: Dilip Kumar, Kyotaro Horiguchi Discussion: https://postgr.es/m/f706876c-4894-0ba5-6f4d-79803eeea21b@oss.nttdata.com
* Harden nbtree deduplication posting split code.Peter Geoghegan2021-05-14
| | | | | | | | | | | | | | | | | | Add a defensive "can't happen" error to code that handles nbtree posting list splits (promote an existing assertion). This avoids a segfault in the event of an insertion of a newitem that is somehow identical to an existing non-pivot tuple in the index. An nbtree index should never have two index tuples with identical TIDs. This scenario is not particular unlikely in the event of any kind of corruption that leaves the index in an inconsistent state relative to the heap relation that is indexed. There are two known reports of preventable hard crashes. Doing nothing seems unacceptable given the general expectation that nbtree will cope reasonably well with corrupt data. Discussion: https://postgr.es/m/CAH2-Wz=Jr_d-dOYEEmwz0-ifojVNWho01eAqewfQXgKfoe114w@mail.gmail.com Backpatch: 13-, where nbtree deduplication was introduced.
* Prevent infinite insertion loops in spgdoinsert().Tom Lane2021-05-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Formerly we just relied on operator classes that assert longValuesOK to eventually shorten the leaf value enough to fit on an index page. That fails since the introduction of INCLUDE-column support (commit 09c1c6ab4), because the INCLUDE columns might alone take up more than a page, meaning no amount of leaf-datum compaction will get the job done. At least with spgtextproc.c, that leads to an infinite loop, since spgtextproc.c won't throw an error for not being able to shorten the leaf datum anymore. To fix without breaking cases that would otherwise work, add logic to spgdoinsert() to verify that the leaf tuple size is decreasing after each "choose" step. Some opclasses might not decrease the size on every single cycle, and in any case, alignment roundoff of the tuple size could obscure small gains. Therefore, allow up to 10 cycles without additional savings before throwing an error. (Perhaps this number will need adjustment, but it seems quite generous right now.) As long as we've developed this logic, let's back-patch it. The back branches don't have INCLUDE columns to worry about, but this seems like a good defense against possible bugs in operator classes. We already know that an infinite loop here is pretty unpleasant, so having a defense seems to outweigh the risk of breaking things. (Note that spgtextproc.c is actually the only known opclass with longValuesOK support, so that this is all moot for known non-core opclasses anyway.) Per report from Dilip Kumar. Discussion: https://postgr.es/m/CAFiTN-uxP_soPhVG840tRMQTBmtA_f_Y8N51G7DKYYqDh7XN-A@mail.gmail.com
* Fix query-cancel handling in spgdoinsert().Tom Lane2021-05-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Knowing that a buggy opclass could cause an infinite insertion loop, spgdoinsert() intended to allow its loop to be interrupted by query cancel. However, that never actually worked, because in iterations after the first, we'd be holding buffer lock(s) which would cause InterruptHoldoffCount to be positive, preventing servicing of the interrupt. To fix, check if an interrupt is pending, and if so fall out of the insertion loop and service the interrupt after we've released the buffers. If it was indeed a query cancel, that's the end of the matter. If it was a non-canceling interrupt reason, make use of the existing provision to retry the whole insertion. (This isn't as wasteful as it might seem, since any upper-level index tuples we already created should be usable in the next attempt.) While there's no known instance of such a bug in existing release branches, it still seems like a good idea to back-patch this to all supported branches, since the behavior is fairly nasty if a loop does happen --- not only is it uncancelable, but it will quickly consume memory to the point of an OOM failure. In any case, this code is certainly not working as intended. Per report from Dilip Kumar. Discussion: https://postgr.es/m/CAFiTN-uxP_soPhVG840tRMQTBmtA_f_Y8N51G7DKYYqDh7XN-A@mail.gmail.com
* Fix autovacuum log output heap truncation issue.Peter Geoghegan2021-05-13
| | | | | | | | | | | | | | | The percentage of blocks from the table value reported by autovacuum log output (following commit 5100010ee4d) should never exceed 100% because it describes the state of the table back when lazy_vacuum() was called. The value could nevertheless exceed 100% in the event of heap relation truncation. We failed to compensate for how truncation affects rel_pages. Fix the faulty accounting by using the original rel_pages value instead of the current/final rel_pages value. Reported-By: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/20210423204306.5osfpkt2ggaedyvy@alap3.anarazel.de
* Initial pgindent and pgperltidy run for v14.Tom Lane2021-05-12
| | | | | | | | Also "make reformat-dat-files". The only change worthy of note is that pgindent messed up the formatting of launcher.c's struct LogicalRepWorkerId, which led me to notice that that struct wasn't used at all anymore, so I just took it out.
* Refactor some error messages for easier translationPeter Eisentraut2021-05-12
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* Change data type of counters in BufferUsage and WalUsage from long to int64.Fujii Masao2021-05-12
| | | | | | | | | | | | | | | | Previously long was used as the data type for some counters in BufferUsage and WalUsage. But long is only four byte, e.g., on Windows, and it's entirely possible to wrap a four byte counter. For example, emitting more than four billion WAL records in one transaction isn't actually particularly rare. To avoid the overflows of those counters, this commit changes the data type of them from long to int64. Suggested-by: Andres Freund Author: Masahiro Ikeda Reviewed-by: Fujii Masao Discussion: https://postgr.es/m/20201221211650.k7b53tcnadrciqjo@alap3.anarazel.de Discussion: https://postgr.es/m/af0964ac-7080-1984-dc23-513754987716@oss.nttdata.com
* Fix mishandling of resjunk columns in ON CONFLICT ... UPDATE tlists.Tom Lane2021-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's unusual to have any resjunk columns in an ON CONFLICT ... UPDATE list, but it can happen when MULTIEXPR_SUBLINK SubPlans are present. If it happens, the ON CONFLICT UPDATE code path would end up storing tuples that include the values of the extra resjunk columns. That's fairly harmless in the short run, but if new columns are added to the table then the values would become accessible, possibly leading to malfunctions if they don't match the datatypes of the new columns. This had escaped notice through a confluence of missing sanity checks, including * There's no cross-check that a tuple presented to heap_insert or heap_update matches the table rowtype. While it's difficult to check that fully at reasonable cost, we can easily add assertions that there aren't too many columns. * The output-column-assignment cases in execExprInterp.c lacked any sanity checks on the output column numbers, which seems like an oversight considering there are plenty of assertion checks on input column numbers. Add assertions there too. * We failed to apply nodeModifyTable's ExecCheckPlanOutput() to the ON CONFLICT UPDATE tlist. That wouldn't have caught this specific error, since that function is chartered to ignore resjunk columns; but it sure seems like a bad omission now that we've seen this bug. In HEAD, the right way to fix this is to make the processing of ON CONFLICT UPDATE tlists work the same as regular UPDATE tlists now do, that is don't add "SET x = x" entries, and use ExecBuildUpdateProjection to evaluate the tlist and combine it with old values of the not-set columns. This adds a little complication to ExecBuildUpdateProjection, but allows removal of a comparable amount of now-dead code from the planner. In the back branches, the most expedient solution seems to be to (a) use an output slot for the ON CONFLICT UPDATE projection that actually matches the target table, and then (b) invent a variant of ExecBuildProjectionInfo that can be told to not store values resulting from resjunk columns, so it doesn't try to store into nonexistent columns of the output slot. (We can't simply ignore the resjunk columns altogether; they have to be evaluated for MULTIEXPR_SUBLINK to work.) This works back to v10. In 9.6, projections work much differently and we can't cheaply give them such an option. The 9.6 version of this patch works by inserting a JunkFilter when it's necessary to get rid of resjunk columns. In addition, v11 and up have the reverse problem when trying to perform ON CONFLICT UPDATE on a partitioned table. Through a further oversight, adjust_partition_tlist() discarded resjunk columns when re-ordering the ON CONFLICT UPDATE tlist to match a partition. This accidentally prevented the storing-bogus-tuples problem, but at the cost that MULTIEXPR_SUBLINK cases didn't work, typically crashing if more than one row has to be updated. Fix by preserving resjunk columns in that routine. (I failed to resist the temptation to add more assertions there too, and to do some minor code beautification.) Per report from Andres Freund. Back-patch to all supported branches. Security: CVE-2021-32028
* Revert recovery prefetching feature.Thomas Munro2021-05-10
| | | | | | | | | | | | | | | | | | This set of commits has some bugs with known fixes, but at this late stage in the release cycle it seems best to revert and resubmit next time, along with some new automated test coverage for this whole area. Commits reverted: dc88460c: Doc: Review for "Optionally prefetch referenced data in recovery." 1d257577: Optionally prefetch referenced data in recovery. f003d9f8: Add circular WAL decoding buffer. 323cbe7c: Remove read_page callback from XLogReader. Remove the new GUC group WAL_RECOVERY recently added by a55a9847, as the corresponding section of config.sgml is now reverted. Discussion: https://postgr.es/m/CAOuzzgrn7iKnFRsB4MHp3UisEQAGgZMbk_ViTN4HV4-Ksq8zCg%40mail.gmail.com
* Remove overzealous VACUUM visibility map assertion.Peter Geoghegan2021-05-06
| | | | | | | | | | | | | The all_visible_according_to_vm variable's value is inherently prone to becoming invalidated concurrently, since it is set before we even acquire a lock on a related heap page buffer. Oversight in commit 7136bf34, which added the assertion in passing. Author: Masahiko Sawada <sawada.mshk@gmail.com> Reported-By: Tang <tanghy.fnst@fujitsu.com> Diagnosed-By:: Masahiko Sawada <sawada.mshk@gmail.com> Discussion: https://postgr.es/m/CAD21AoDzgc8_MYrA5m1fyydomw_eVKtQiYh7sfDK4KEhdMsf_g@mail.gmail.com
* Add some forgotten LSN_FORMAT_ARGS() in xlogreader.cMichael Paquier2021-04-24
| | | | | | | | | | 6f6f284 has introduced a specific macro to make printf()-ing of LSNs easier. This takes care of what looks like the remaining code paths that did not get the call. Author: Michael Paquier Reviewed-by: Kyotaro Horiguchi, Tom Lane Discussion: https://postgr.es/m/YIJS9x6K8ruizN7j@paquier.xyz
* Remove use of [U]INT64_FORMAT in some translatable stringsMichael Paquier2021-04-23
| | | | | | | | %lld with (long long), or %llu with (unsigned long long) are more adapted. This is similar to 3286065. Author: Kyotaro Horiguchi Discussion: https://postgr.es/m/20210421.200000.1462448394029407895.horikyota.ntt@gmail.com
* Fix typoPeter Eisentraut2021-04-21
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* Improve WAL record descriptions for SP-GiST records.Tom Lane2021-04-20
| | | | | | While tracking down the bug fixed in the preceding commit, I got quite annoyed by the low quality of spg_desc's output. Add missing fields, try to make the formatting consistent.
* Document LP_DEAD accounting issues in VACUUM.Peter Geoghegan2021-04-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | Document VACUUM's soft assumption that any LP_DEAD items encountered during pruning will become LP_UNUSED items before VACUUM finishes up. This is integral to the accounting used by VACUUM to generate its final report on the table to the stats collector. It also affects how VACUUM determines which heap pages are truncatable. In both cases VACUUM is concerned with the likely contents of the page in the near future, not the current contents of the page. This state of affairs created the false impression that VACUUM's dead tuple accounting had significant difference with similar accounting used during ANALYZE. There were and are no substantive differences, at least when the soft assumption completely works out. This is far clearer now. Also document cases where things don't quite work out for VACUUM's dead tuple accounting. It's possible that a significant number of LP_DEAD items will be left behind by VACUUM, and won't be recorded as remaining dead tuples in VACUUM's statistics collector report. This behavior dates back to commit a96c41fe, which taught VACUUM to run without index and heap vacuuming at the user's request. The failsafe mechanism added to VACUUM more recently by commit 1e55e7d1 takes the same approach to dead tuple accounting. Reported-By: Masahiko Sawada <sawada.mshk@gmail.com> Discussion: https://postgr.es/m/CAH2-Wz=Jmtu18PrsYq3EvvZJGOmZqSO2u3bvKpx9xJa5uhNp=Q@mail.gmail.com
* Fix typos and grammar in comments and docsMichael Paquier2021-04-19
| | | | | Author: Justin Pryzby Discussion: https://postgr.es/m/20210416070310.GG3315@telsasoft.com
* Use correct format placeholder for block numbersPeter Eisentraut2021-04-17
| | | | Should be %u rather than %d.
* Improve quoting in some error messagesPeter Eisentraut2021-04-14
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* Don't truncate heap when VACUUM's failsafe is in effect.Peter Geoghegan2021-04-13
| | | | | | | | | | | | It seems like a good idea to bypass heap truncation when the wraparound failsafe mechanism (which was added in commit 1e55e7d1) is in effect. Deliberately don't bypass heap truncation in the INDEX_CLEANUP=off case, even though it is similar to the failsafe case. There is already a separate reloption (and related VACUUM parameter) for that. Reported-By: Masahiko Sawada <sawada.mshk@gmail.com> Discussion: https://postgr.es/m/CAD21AoDWRh6oTN5T8wa+cpZUVpHXET8BJ8Da7WHVHpwkPP6KLg@mail.gmail.com
* Avoid improbable PANIC during heap_update.Tom Lane2021-04-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | heap_update needs to clear any existing "all visible" flag on the old tuple's page (and on the new page too, if different). Per coding rules, to do this it must acquire pin on the appropriate visibility-map page while not holding exclusive buffer lock; which creates a race condition since someone else could set the flag whenever we're not holding the buffer lock. The code is supposed to handle that by re-checking the flag after acquiring buffer lock and retrying if it became set. However, one code path through heap_update itself, as well as one in its subroutine RelationGetBufferForTuple, failed to do this. The end result, in the unlikely event that a concurrent VACUUM did set the flag while we're transiently not holding lock, is a non-recurring "PANIC: wrong buffer passed to visibilitymap_clear" failure. This has been seen a few times in the buildfarm since recent VACUUM changes that added code paths that could set the all-visible flag while holding only exclusive buffer lock. Previously, the flag was (usually?) set only after doing LockBufferForCleanup, which would insist on buffer pin count zero, thus preventing the flag from becoming set partway through heap_update. However, it's clear that it's heap_update not VACUUM that's at fault here. What's less clear is whether there is any hazard from these bugs in released branches. heap_update is certainly violating API expectations, but if there is no code path that can set all-visible without a cleanup lock then it's only a latent bug. That's not 100% certain though, besides which we should worry about extensions or future back-patch fixes that could introduce such code paths. I chose to back-patch to v12. Fixing RelationGetBufferForTuple before that would require also back-patching portions of older fixes (notably 0d1fe9f74), which is more code churn than seems prudent to fix a hypothetical issue. Discussion: https://postgr.es/m/2247102.1618008027@sss.pgh.pa.us
* Fix potential SSI hazard in heap_update().Thomas Munro2021-04-13
| | | | | | | | | | | | | | | | | Commit 6f38d4dac38 failed to heed a warning about the stability of the value pointed to by "otid". The caller is allowed to pass in a pointer to newtup->t_self, which will be updated during the execution of the function. Instead, the SSI check should use the value we copy into oldtup.t_self near the top of the function. Not a live bug, because newtup->t_self doesn't really get updated until a bit later, but it was confusing and broke the rule established by the comment. Back-patch to 13. Reported-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/2689164.1618160085%40sss.pgh.pa.us
* Remove COMMIT_TS_SETTS record.Fujii Masao2021-04-12
| | | | | | | | | | | | | | | | | | | Commit 438fc4a39c prevented the WAL replay from writing COMMIT_TS_SETTS record. By this change there is no code that generates COMMIT_TS_SETTS record in PostgreSQL core. Also we can think that there are no extensions using the record because we've not received so far any complaints about the issue that commit 438fc4a39c fixed. Therefore this commit removes COMMIT_TS_SETTS record and its related code. Even without this record, the timestamp required for commit timestamp feature can be acquired from the COMMIT record. Bump WAL page magic. Reported-by: lx zou <zoulx1982@163.com> Author: Fujii Masao Reviewed-by: Alvaro Herrera Discussion: https://postgr.es/m/16931-620d0f2fdc6108f1@postgresql.org
* Doc: Review for "Optionally prefetch referenced data in recovery."Thomas Munro2021-04-10
| | | | | | | | Typos, corrections and language improvements in the docs, and a few in code comments too. Reported-by: Justin Pryzby <pryzby@telsasoft.com> Discussion: https://postgr.es/m/20210409033703.GP6592%40telsasoft.com
* Silence another _bt_check_unique compiler warning.Peter Geoghegan2021-04-08
| | | | | | Per complaint from Tom Lane Discussion: https://postgr.es/m/1922884.1617909599@sss.pgh.pa.us
* Optionally prefetch referenced data in recovery.Thomas Munro2021-04-08
| | | | | | | | | | | | | | | | | | | | | | | | Introduce a new GUC recovery_prefetch, disabled by default. When enabled, look ahead in the WAL and try to initiate asynchronous reading of referenced data blocks that are not yet cached in our buffer pool. For now, this is done with posix_fadvise(), which has several caveats. Better mechanisms will follow in later work on the I/O subsystem. The GUC maintenance_io_concurrency is used to limit the number of concurrent I/Os we allow ourselves to initiate, based on pessimistic heuristics used to infer that I/Os have begun and completed. The GUC wal_decode_buffer_size is used to limit the maximum distance we are prepared to read ahead in the WAL to find uncached blocks. Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com> (parts) Reviewed-by: Andres Freund <andres@anarazel.de> (parts) Reviewed-by: Tomas Vondra <tomas.vondra@2ndquadrant.com> (parts) Tested-by: Tomas Vondra <tomas.vondra@2ndquadrant.com> Tested-by: Jakub Wartak <Jakub.Wartak@tomtom.com> Tested-by: Dmitry Dolgov <9erthalion6@gmail.com> Tested-by: Sait Talha Nisanci <Sait.Nisanci@microsoft.com> Discussion: https://postgr.es/m/CA%2BhUKGJ4VJN8ttxScUFM8dOKX0BrBiboo5uz1cq%3DAovOddfHpA%40mail.gmail.com
* Add circular WAL decoding buffer.Thomas Munro2021-04-08
| | | | | | | | | | | | | | | | | | | | | | | | | Teach xlogreader.c to decode its output into a circular buffer, to support optimizations based on looking ahead. * XLogReadRecord() works as before, consuming records one by one, and allowing them to be examined via the traditional XLogRecGetXXX() macros. * An alternative new interface XLogNextRecord() is added that returns pointers to DecodedXLogRecord structs that can be examined directly. * XLogReadAhead() provides a second cursor that lets you see further ahead, as long as data is available and there is enough space in the decoding buffer. This returns DecodedXLogRecord pointers to the caller, but also adds them to a queue of records that will later be consumed by XLogNextRecord()/XLogReadRecord(). The buffer's size is controlled with wal_decode_buffer_size. The buffer could potentially be placed into shared memory, for future projects. Large records that don't fit in the circular buffer are called "oversized" and allocated separately with palloc(). Discussion: https://postgr.es/m/CA+hUKGJ4VJN8ttxScUFM8dOKX0BrBiboo5uz1cq=AovOddfHpA@mail.gmail.com
* Remove read_page callback from XLogReader.Thomas Munro2021-04-08
| | | | | | | | | | | | | | | | | | | | | Previously, the XLogReader module would fetch new input data using a callback function. Redesign the interface so that it tells the caller to insert more data with a special return value instead. This API suits later patches for prefetching, encryption and maybe other future projects that would otherwise require continually extending the callback interface. As incidental cleanup work, move global variables readOff, readLen and readSegNo inside XlogReaderState. Author: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp> Author: Heikki Linnakangas <hlinnaka@iki.fi> (parts of earlier version) Reviewed-by: Antonin Houska <ah@cybertec.at> Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com> Reviewed-by: Takashi Menjo <takashi.menjo@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Thomas Munro <thomas.munro@gmail.com> Discussion: https://postgr.es/m/20190418.210257.43726183.horiguchi.kyotaro%40lab.ntt.co.jp
* autovacuum: handle analyze for partitioned tablesAlvaro Herrera2021-04-08
| | | | | | | | | | | | | | | | | | | Previously, autovacuum would completely ignore partitioned tables, which is not good regarding analyze -- failing to analyze those tables means poor plans may be chosen. Make autovacuum aware of those tables by propagating "changes since analyze" counts from the leaf partitions up the partitioning hierarchy. This also introduces necessary reloptions support for partitioned tables (autovacuum_enabled, autovacuum_analyze_scale_factor, autovacuum_analyze_threshold). It's unclear how best to document this aspect. Author: Yuzuko Hosoya <yuzukohosoya@gmail.com> Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/CAKkQ508_PwVgwJyBY=0Lmkz90j8CmWNPUxgHvCUwGhMrouz6UA@mail.gmail.com
* Teach VACUUM to bypass unnecessary index vacuuming.Peter Geoghegan2021-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | VACUUM has never needed to call ambulkdelete() for each index in cases where there are precisely zero TIDs in its dead_tuples array by the end of its first pass over the heap (also its only pass over the heap in this scenario). Index vacuuming is simply not required when this happens. Index cleanup will still go ahead, but in practice most calls to amvacuumcleanup() are usually no-ops when there were zero preceding ambulkdelete() calls. In short, VACUUM has generally managed to avoid index scans when there were clearly no index tuples to delete from indexes. But cases with _close to_ no index tuples to delete were another matter -- a round of ambulkdelete() calls took place (one per index), each of which performed a full index scan. VACUUM now behaves just as if there were zero index tuples to delete in cases where there are in fact "virtually zero" such tuples. That is, it can now bypass index vacuuming and heap vacuuming as an optimization (though not index cleanup). Whether or not VACUUM bypasses indexes is determined dynamically, based on the just-observed number of heap pages in the table that have one or more LP_DEAD items (LP_DEAD items in heap pages have a 1:1 correspondence with index tuples that still need to be deleted from each index in the worst case). We only skip index vacuuming when 2% or less of the table's pages have one or more LP_DEAD items -- bypassing index vacuuming as an optimization must not noticeably impede setting bits in the visibility map. As a further condition, the dead_tuples array (i.e. VACUUM's array of LP_DEAD item TIDs) must not exceed 32MB at the point that the first pass over the heap finishes, which is also when the decision to bypass is made. (The VACUUM must also have been able to fit all TIDs in its maintenance_work_mem-bound dead_tuples space, though with a default maintenance_work_mem setting it can't matter.) This avoids surprising jumps in the duration and overhead of routine vacuuming with workloads where successive VACUUM operations consistently have almost zero dead index tuples. The number of LP_DEAD items may well accumulate over multiple VACUUM operations, before finally the threshold is crossed and VACUUM performs conventional index vacuuming. Even then, the optimization will have avoided a great deal of largely unnecessary index vacuuming. In the future we may teach VACUUM to skip index vacuuming on a per-index basis, using a much more sophisticated approach. For now we only consider the extreme cases, where we can be quite confident that index vacuuming just isn't worth it using simple heuristics. Also log information about how many heap pages have one or more LP_DEAD items when autovacuum logging is enabled. Author: Masahiko Sawada <sawada.mshk@gmail.com> Author: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAD21AoD0SkE11fMw4jD4RENAwBMcw1wasVnwpJVw3tVqPOQgAw@mail.gmail.com Discussion: https://postgr.es/m/CAH2-WzmkebqPd4MVGuPTOS9bMFvp9MDs5cRTCOsv1rQJ3jCbXw@mail.gmail.com
* Add wraparound failsafe to VACUUM.Peter Geoghegan2021-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a failsafe mechanism that is triggered by VACUUM when it notices that the table's relfrozenxid and/or relminmxid are dangerously far in the past. VACUUM checks the age of the table dynamically, at regular intervals. When the failsafe triggers, VACUUM takes extraordinary measures to finish as quickly as possible so that relfrozenxid and/or relminmxid can be advanced. VACUUM will stop applying any cost-based delay that may be in effect. VACUUM will also bypass any further index vacuuming and heap vacuuming -- it only completes whatever remaining pruning and freezing is required. Bypassing index/heap vacuuming is enabled by commit 8523492d, which made it possible to dynamically trigger the mechanism already used within VACUUM when it is run with INDEX_CLEANUP off. It is expected that the failsafe will almost always trigger within an autovacuum to prevent wraparound, long after the autovacuum began. However, the failsafe mechanism can trigger in any VACUUM operation. Even in a non-aggressive VACUUM, where we're likely to not advance relfrozenxid, it still seems like a good idea to finish off remaining pruning and freezing. An aggressive/anti-wraparound VACUUM will be launched immediately afterwards. Note that the anti-wraparound VACUUM that follows will itself trigger the failsafe, usually before it even begins its first (and only) pass over the heap. The failsafe is controlled by two new GUCs: vacuum_failsafe_age, and vacuum_multixact_failsafe_age. There are no equivalent reloptions, since that isn't expected to be useful. The GUCs have rather high defaults (both default to 1.6 billion), and are expected to generally only be used to make the failsafe trigger sooner/more frequently. Author: Masahiko Sawada <sawada.mshk@gmail.com> Author: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAD21AoD0SkE11fMw4jD4RENAwBMcw1wasVnwpJVw3tVqPOQgAw@mail.gmail.com Discussion: https://postgr.es/m/CAH2-WzmgH3ySGYeC-m-eOBsa2=sDwa292-CFghV4rESYo39FsQ@mail.gmail.com
* Truncate line pointer array during VACUUM.Peter Geoghegan2021-04-07
| | | | | | | | | | | | | | | | | | | | | | | Teach VACUUM to truncate the line pointer array of each heap page when a contiguous group of LP_UNUSED line pointers appear at the end of the array -- these unused and unreferenced items are excluded. This process occurs during VACUUM's second pass over the heap, right after LP_DEAD line pointers on the page (those encountered/pruned during the first pass) are marked LP_UNUSED. Truncation avoids line pointer bloat with certain workloads, particularly those involving continual range DELETEs and bulk INSERTs against the same table. Also harden heapam code to check for an out-of-range page offset number in places where we weren't already doing so. Author: Matthias van de Meent <boekewurm+postgres@gmail.com> Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Masahiko Sawada <sawada.mshk@gmail.com> Reviewed-By: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAEze2WjgaQc55Y5f5CQd3L=eS5CZcff2Obxp=O6pto8-f0hC4w@mail.gmail.com Discussion: https://postgr.es/m/CAH2-Wzn6a64PJM1Ggzm=uvx2otsopJMhFQj_g1rAj4GWr3ZSzw@mail.gmail.com
* Don't add non-existent pages to bitmap from BRINTomas Vondra2021-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code in bringetbitmap() simply added the whole matching page range to the TID bitmap, as determined by pages_per_range, even if some of the pages were beyond the end of the heap. The query then might fail with an error like this: ERROR: could not open file "base/20176/20228.2" (target block 262144): previous segment is only 131021 blocks In this case, the relation has 262093 pages (131072 and 131021 pages), but we're trying to acess block 262144, i.e. first block of the 3rd segment. At that point _mdfd_getseg() notices the preceding segment is incomplete, and fails. Hitting this in practice is rather unlikely, because: * Most indexes use power-of-two ranges, so segments and page ranges align perfectly (segment end is also a page range end). * The table size has to be just right, with the last segment being almost full - less than one page range from full segment, so that the last page range actually crosses the segment boundary. * Prefetch has to be enabled. The regular page access checks that pages are not beyond heap end, but prefetch does not. On older releases (before 12) the execution stops after hitting the first non-existent page, so the prefetch distance has to be sufficient to reach the first page in the next segment to trigger the issue. Since 12 it's enough to just have prefetch enabled, the prefetch distance does not matter. Fixed by not adding non-existent pages to the TID bitmap. Backpatch all the way back to 9.6 (BRIN indexes were introduced in 9.5, but that release is EOL). Backpatch-through: 9.6
* Revert "Add sortsupport for gist_btree opclasses, for faster index builds."Heikki Linnakangas2021-04-07
| | | | | | | | | | This reverts commit 9f984ba6d23dc6eecebf479ab1d3f2e550a4e9be. It was making the buildfarm unhappy, apparently setting client_min_messages in a regression test produces different output if log_statement='all'. Another issue is that I now suspect the bit sortsupport function was in fact not correct to call byteacmp(). Revert to investigate both of those issues.
* Add sortsupport for gist_btree opclasses, for faster index builds.Heikki Linnakangas2021-04-07
| | | | | | | | | Commit 16fa9b2b30 introduced a faster way to build GiST indexes, by sorting all the data. This commit adds the sortsupport functions needed to make use of that feature for btree_gist. Author: Andrey Borodin Discussion: https://www.postgresql.org/message-id/2F3F7265-0D22-44DB-AD71-8554C743D943@yandex-team.ru
* Remove redundant memset(0) calls for page init of some index AMsMichael Paquier2021-04-07
| | | | | | | | | | | | | | | | | | | Bloom, GIN, GiST and SP-GiST rely on PageInit() to initialize the contents of a page, and this routine fills entirely a page with zeros for a size of BLCKSZ, including the special space. Those index AMs have been using an extra memset() call to fill with zeros the special page space, or even the whole page, which is not necessary as PageInit() already does this work, so let's remove them. GiST was not doing this extra call, but has commented out a system call that did so since 6236991. While on it, remove one MAXALIGN() for SP-GiST as PageInit() takes care of that. This makes the whole page initialization logic more consistent across all index AMs. Author: Bharath Rupireddy Reviewed-by: Vignesh C, Mahendra Singh Thalor Discussion: https://postgr.es/m/CALj2ACViOo2qyaPT7krWm4LRyRTw9kOXt+g6PfNmYuGA=YHj9A@mail.gmail.com