aboutsummaryrefslogtreecommitdiff
path: root/src/backend/access
Commit message (Collapse)AuthorAge
...
* Remove retry loop in heap_page_prune().Robert Haas2023-10-02
| | | | | | | | | | | | | | | The retry loop is needed because heap_page_prune() calls HeapTupleSatisfiesVacuum() and then lazy_scan_prune() does the same thing again, and they might get different answers due to concurrent clog updates. But this patch makes heap_page_prune() return the HeapTupleSatisfiesVacuum() results that it computed back to the caller, which allows lazy_scan_prune() to avoid needing to recompute those values in the first place. That's nice both because it eliminates the need for a retry loop and also because it's cheaper. Melanie Plageman, reviewed by David Geier, Andres Freund, and me. Discussion: https://postgr.es/m/CAAKRu_br124qsGJieuYA0nGjywEukhK1dKBfRdby_4yY3E9SXA%40mail.gmail.com
* Add rmgrdesc READMEHeikki Linnakangas2023-10-02
| | | | | | | | | | In the README, briefly explain what rmgrdesc functions are, and why they are in a separate directory. Commit c03c2eae0a added some guidelines on the preferred output format; move that to the README too. Reviewed-by: Melanie Plageman, Peter Geoghegan Discussion: https://www.postgresql.org/message-id/9159daf7-f42d-781b-458f-1b2cf32cb256%40iki.fi
* Correct assertion and comments about XLogRecordMaxSize.Noah Misch2023-10-01
| | | | | | The largest allocation, of xl_tot_len+8192, is in allocate_recordbuf(). Discussion: https://postgr.es/m/20230812211327.GB2326466@rfd.leadboat.com
* Fix btmarkpos/btrestrpos array key wraparound bug.Peter Geoghegan2023-09-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nbtree's mark/restore processing failed to correctly handle an edge case involving array key advancement and related search-type scan key state. Scans with ScalarArrayScalarArrayOpExpr quals requiring mark/restore processing (for a merge join) could incorrectly conclude that an affected array/scan key must not have advanced during the time between marking and restoring the scan's position. As a result of all this, array key handling within btrestrpos could skip a required call to _bt_preprocess_keys(). This confusion allowed later primitive index scans to overlook tuples matching the true current array keys. The scan's search-type scan keys would still have spurious values corresponding to the final array element(s) -- not values matching the first/now-current array element(s). To fix, remember that "array key wraparound" has taken place during the ongoing btrescan in a flag variable stored in the scan's state, and use that information at the point where btrestrpos decides if another call to _bt_preprocess_keys is required. Oversight in commit 70bc5833, which taught nbtree to handle array keys during mark/restore processing, but missed this subtlety. That commit was itself a bug fix for an issue in commit 9e8da0f7, which taught nbtree to handle ScalarArrayOpExpr quals natively. Author: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAH2-WzkgP3DDRJxw6DgjCxo-cu-DKrvjEv_ArkP2ctBJatDCYg@mail.gmail.com Backpatch: 11- (all supported branches).
* Return data from heap_page_prune via a struct.Robert Haas2023-09-28
| | | | | | | | | | | Previously, one of the values in the struct was returned as the return value, and another was returned via an output parameter. In preparation for returning more stuff, consolidate both values into a struct returned via an output parameter. Melanie Plageman, reviewed by Andres Freund and by me. Discussion: https://postgr.es/m/CAAKRu_br124qsGJieuYA0nGjywEukhK1dKBfRdby_4yY3E9SXA%40mail.gmail.com
* Fix typo in src/backend/access/transam/README.Etsuro Fujita2023-09-28
|
* Add TupleDescGetDefault()Peter Eisentraut2023-09-27
| | | | | | | | | | | | | | | This unifies some repetitive code. Note: I didn't push the "not found" error message into the new function, even though all existing callers would be able to make use of it. Using the existing error handling as-is would probably require exposing the Relation type via tupdesc.h, which doesn't seem desirable. (Or even if we changed it to just report the OID, it would inject the concept of a relation containing the tuple descriptor into tupdesc.h, which might be a layering violation. Perhaps some further improvements could be considered here separately.) Discussion: https://www.postgresql.org/message-id/flat/52a125e4-ff9a-95f5-9f61-b87cf447e4da%40eisentraut.org
* MergeAttributes() and related variable renamingPeter Eisentraut2023-09-26
| | | | | | | Mainly, rename "schema" to "columns" and related changes. The previous naming has long been confusing. Discussion: https://www.postgresql.org/message-id/flat/52a125e4-ff9a-95f5-9f61-b87cf447e4da%40eisentraut.org
* Fix another bug in parent page splitting during GiST index build.Heikki Linnakangas2023-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yet another bug in the ilk of commits a7ee7c851 and 741b88435. In 741b88435, we took care to clear the memorized location of the downlink when we split the parent page, because splitting the parent page can move the downlink. But we missed that even *updating* a tuple on the parent can move it, because updating a tuple on a gist page is implemented as a delete+insert, so the updated tuple gets moved to the end of the page. This commit fixes the bug in two different ways (belt and suspenders): 1. Clear the downlink when we update a tuple on the parent page, even if it's not split. This the same approach as in commits a7ee7c851 and 741b88435. I also noticed that gistFindCorrectParent did not clear the 'downlinkoffnum' when it stepped to the right sibling. Fix that too, as it seems like a clear bug even though I haven't been able to find a test case to hit that. 2. Change gistFindCorrectParent so that it treats 'downlinkoffnum' merely as a hint. It now always first checks if the downlink is still at that location, and if not, it scans the page like before. That's more robust if there are still more cases where we fail to clear 'downlinkoffnum' that we haven't yet uncovered. With this, it's no longer necessary to meticulously clear 'downlinkoffnum', so this makes the previous fixes unnecessary, but I didn't revert them because it still seems nice to clear it when we know that the downlink has moved. Also add the test case using the same test data that Alexander posted. I tried to reduce it to a smaller test, and I also tried to reproduce this with different test data, but I was not able to, so let's just include what we have. Backpatch to v12, like the previous fixes. Reported-by: Alexander Lakhin Discussion: https://www.postgresql.org/message-id/18129-caca016eaf0c3702@postgresql.org
* Fix edge-case for xl_tot_len broken by bae868ca.Thomas Munro2023-09-26
| | | | | | | | | | | | | | | | | bae868ca removed a check that was still needed. If you had an xl_tot_len at the end of a page that was too small for a record header, but not big enough to span onto the next page, we'd immediately perform the CRC check using a bogus large length. Because of arbitrary coding differences between the CRC implementations on different platforms, nothing very bad happened on common modern systems. On systems using the _sb8.c fallback we could segfault. Restore that check, add a new assertion and supply a test for that case. Back-patch to 12, like bae868ca. Tested-by: Tom Lane <tgl@sss.pgh.pa.us> Tested-by: Alexander Lakhin <exclusion@gmail.com> Discussion: https://postgr.es/m/CA%2BhUKGLCkTT7zYjzOxuLGahBdQ%3DMcF%3Dz5ZvrjSOnW4EDhVjT-g%40mail.gmail.com
* Don't trust unvalidated xl_tot_len.Thomas Munro2023-09-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | xl_tot_len comes first in a WAL record. Usually we don't trust it to be the true length until we've validated the record header. If the record header was split across two pages, previously we wouldn't do the validation until after we'd already tried to allocate enough memory to hold the record, which was bad because it might actually be garbage bytes from a recycled WAL file, so we could try to allocate a lot of memory. Release 15 made it worse. Since 70b4f82a4b5, we'd at least generate an end-of-WAL condition if the garbage 4 byte value happened to be > 1GB, but we'd still try to allocate up to 1GB of memory bogusly otherwise. That was an improvement, but unfortunately release 15 tries to allocate another object before that, so you could get a FATAL error and recovery could fail. We can fix both variants of the problem more fundamentally using pre-existing page-level validation, if we just re-order some logic. The new order of operations in the split-header case defers all memory allocation based on xl_tot_len until we've read the following page. At that point we know that its first few bytes are not recycled data, by checking its xlp_pageaddr, and that its xlp_rem_len agrees with xl_tot_len on the preceding page. That is strong evidence that xl_tot_len was truly the start of a record that was logged. This problem was most likely to occur on a standby, because walreceiver.c recycles WAL files without zeroing out trailing regions of each page. We could fix that too, but it wouldn't protect us from rare crash scenarios where the trailing zeroes don't make it to disk. With reliable xl_tot_len validation in place, the ancient policy of considering malloc failure to indicate corruption at end-of-WAL seems quite surprising, but changing that is left for later work. Also included is a new TAP test to exercise various cases of end-of-WAL detection by writing contrived data into the WAL from Perl. Back-patch to 12. We decided not to put this change into the final release of 11. Author: Thomas Munro <thomas.munro@gmail.com> Author: Michael Paquier <michael@paquier.xyz> Reported-by: Alexander Lakhin <exclusion@gmail.com> Reviewed-by: Noah Misch <noah@leadboat.com> (the idea, not the code) Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Sergei Kornilov <sk@zsrv.org> Reviewed-by: Alexander Lakhin <exclusion@gmail.com> Discussion: https://postgr.es/m/17928-aa92416a70ff44a2%40postgresql.org
* Fix COMMIT/ROLLBACK AND CHAIN in the presence of subtransactions.Tom Lane2023-09-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In older branches, COMMIT/ROLLBACK AND CHAIN failed to propagate the current transaction's properties to the new transaction if there was any open subtransaction (unreleased savepoint). Instead, some previous transaction's properties would be restored. This is because the "if (s->chain)" check in CommitTransactionCommand examined the wrong instance of the "chain" flag and falsely concluded that it didn't need to save transaction properties. Our regression tests would have noticed this, except they used identical transaction properties for multiple tests in a row, so that the faulty behavior was not distinguishable from correct behavior. Commit 12d768e70 fixed the problem in v15 and later, but only rather accidentally, because I removed the "if (s->chain)" test to avoid a compiler warning, while not realizing that the warning was flagging a real bug. In v14 and before, remove the if-test and save transaction properties unconditionally; just as in the newer branches, that's not expensive enough to justify thinking harder. Add the comment and extra regression test to v15 and later to forestall any future recurrence, but there's no live bug in those branches. Patch by me, per bug #18118 from Liu Xiang. Back-patch to v12 where the AND CHAIN feature was added. Discussion: https://postgr.es/m/18118-4b72fcbb903aace6@postgresql.org
* Fix GiST README's explanation of the NSN cross-check.Heikki Linnakangas2023-09-19
| | | | | | | | The text got the condition backwards, it's "NSN > LSN", not "NSN < LSN". While we're at it, expand it a little for clarity. Reviewed-by: Daniel Gustafsson Discussion: https://www.postgresql.org/message-id/4cb46e18-e688-524a-0f73-b1f03ed5d6ee@iki.fi
* Rename variable for code clarityDaniel Gustafsson2023-09-15
| | | | | | | | | | | When tracking IO timing for WAL, the duration is what we calculate based on the start and end timestamps, it's not what the variable contains. Rename the timestamp variable to end to better communicate what it contains. Original patch by Krishnakumar with additional hacking to fix another occurrence by me. Author: Krishnakumar R <kksrcv001@gmail.com> Discussion: https://postgr.es/m/CAPMWgZ9f9o8awrQpjo8oxnNQ=bMDVPx00NE0QcDzvHD_ZrdLPw@mail.gmail.com
* Remove unnecessary smgrimmedsync() when creating unlogged table.Heikki Linnakangas2023-09-15
| | | | | | | | | | | | | | This became safe after commit 4b4798e138. The smgrcreate() call will now register the segment for syncing at the next checkpoint, so we don't need to sync it here. If a checkpoint happens before the creation is WAL-logged, the records will be replayed when starting recovery from the checkpoint. If a checkpoint happens after the WAL logging, the checkpoint will fsync() it. In the passing, clarify a comment in smgrDoPendingSyncs(). Discussion: https://www.postgresql.org/message-id/6e5bbc08-cdfc-b2b3-9e23-1a914b9850a9%40iki.fi Reviewed-by: Robert Haas
* Quote filenames in error messagesDaniel Gustafsson2023-09-14
| | | | | | | | | | | | | | The majority of all filenames are quoted in user facing error and log messages, but a few were still printed without quotes. While these filenames do not risk causing any ambiguity as their format is strict, quote them anyways to be consistent across all logs. Also concatenate a message to keep it one line to make it easier to grep for in the code. Reviewed-by: Peter Eisentraut <peter@eisentraut.org> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/080EEABE-6645-4A46-AB20-6285ADAC44FE@yesql.se
* Flush logical slots to disk during a shutdown checkpoint if required.Amit Kapila2023-09-14
| | | | | | | | | | | | | | | | | | | | | It's entirely possible for a logical slot to have a confirmed_flush LSN higher than the last value saved on disk while not being marked as dirty. Currently, it is not a major problem but a later patch adding support for the upgrade of slots relies on that value being properly flushed to disk. It can also help avoid processing the same transactions again in some boundary cases after the clean shutdown and restart. Say, we process some transactions for which we didn't send anything downstream (the changes got filtered) but the confirm_flush LSN is updated due to keepalives. As we don't flush the latest value of confirm_flush LSN, it may lead to processing the same changes again without this patch. The approach taken by this patch has been suggested by Ashutosh Bapat. Author: Vignesh C, Julien Rouhaud, Kuroda Hayato Reviewed-by: Amit Kapila, Dilip Kumar, Michael Paquier, Ashutosh Bapat, Peter Smith, Hou Zhijie Discussion: http://postgr.es/m/CAA4eK1JzJagMmb_E8D4au=GYQkxox0AfNBm1FbP7sy7t4YWXPQ@mail.gmail.com Discussion: http://postgr.es/m/TYAPR01MB58664C81887B3AF2EB6B16E3F5939@TYAPR01MB5866.jpnprd01.prod.outlook.com
* Remove some more "snapshot too old" vestiges.Thomas Munro2023-09-08
| | | | | | | | | Commit f691f5b8 removed the logic, but left behind some now-useless Snapshot arguments to various AM-internal functions, and missed a couple of comments. Reported-by: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAH2-Wznj9qSNXZ1P1uWTUD_FeaTezbUazb416EPwi4Qr_jR_6A%40mail.gmail.com
* Remove the "snapshot too old" feature.Thomas Munro2023-09-05
| | | | | | | | | | | | | | | | | Remove the old_snapshot_threshold setting and mechanism for producing the error "snapshot too old", originally added by commit 848ef42b. Unfortunately it had a number of known problems in terms of correctness and performance, mostly reported by Andres in the course of his work on snapshot scalability. We agreed to remove it, after a long period without an active plan to fix it. This is certainly a desirable feature, and someone might propose a new or improved implementation in the future. Reported-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CACG%3DezYV%2BEvO135fLRdVn-ZusfVsTY6cH1OZqWtezuEYH6ciQA%40mail.gmail.com Discussion: https://postgr.es/m/20200401064008.qob7bfnnbu4w5cw4%40alap3.anarazel.de Discussion: https://postgr.es/m/CA%2BTgmoY%3Daqf0zjTD%2B3dUWYkgMiNDegDLFjo%2B6ze%3DWtpik%2B3XqA%40mail.gmail.com
* Report syncscan position at end of scan.Heikki Linnakangas2023-08-31
| | | | | | | | | | | | | | | | | | | The comment in heapgettup_advance_block() says that it reports the scan position before checking for end of scan, but that didn't match the code. The code was refactored in commit 7ae0ab0ad9, which inadvertently changed the order of the check and reporting. Change it back. This caused a few regression test failures with a small shared_buffers setting like 10 MB. The 'portals' and 'cluster' tests perform seqscans that are large enough that sync seqscans kick in. When the sync scan position is not updated at end of scan, the next seq scan doesn't start at the beginning of the table, and the test queries are sensitive to that. Reviewed-by: Melanie Plageman, David Rowley Discussion: https://www.postgresql.org/message-id/6f991389-ae22-d844-a9d8-9aceb7c01a9a@iki.fi Backpatch-through: 16
* Tweak pg_promote() to report failures on kill() or postmaster failuresMichael Paquier2023-08-29
| | | | | | | | | | | | | | | | | | | | | Since its introduction in 10074651e335, pg_promote() has been returning a false status in three cases: - SIGUSR1 not sent to the postmaster process. - Postmaster death during standby promotion. - Standby not promoted within the specified wait time. An application calling this function will have a hard time understanding what a false state returned actually means. Per discussion, this switches the two first states to fail rather than return a "false" status, making the second case more consistent with the existing CHECK_FOR_INTERRUPTS in the wait loop. False is only returned when the promotion is not completed within the specified time (60s by default). Author: Ashutosh Sharma Reviewed-by: Fujii Masao, Laurenz Albe, Michael Paquier Discussion: https://postgr.es/m/CAE9k0P=QTrwptL0t4J0fuBRDDjgsT-0PVKd-ikd96i1hyL7Bcg@mail.gmail.com
* Make error messages about WAL segment size more consistentPeter Eisentraut2023-08-28
| | | | | | | | | | | | | | | | Make the primary messages more compact and make the detail messages uniform. In initdb.c and pg_resetwal.c, use the newish option_parse_int() to simplify some of the option parsing. For the backend GUC wal_segment_size, add a GUC check hook to do the verification instead of coding it in bootstrap.c. This might be overkill, but that way the check is in the right place and it becomes more self-documenting. In passing, make pg_controldata use the logging API for warning messages. Reviewed-by: Aleksander Alekseev <aleksander@timescale.com> Discussion: https://www.postgresql.org/message-id/flat/9939aa8a-d7be-da2c-7715-0a0b5535a1f7@eisentraut.org
* Fix _bt_allequalimage() call within critical section.Heikki Linnakangas2023-08-23
| | | | | | | | | _bt_allequalimage() does complicated things, so it's not OK to call it in a critical section. Per buildfarm failure on 'prion', which uses -DRELCACHE_FORCE_RELEASE -DCATCACHE_FORCE_RELEASE options. Discussion: https://www.postgresql.org/message-id/6e5bbc08-cdfc-b2b3-9e23-1a914b9850a9@iki.fi Backpatch-through: 16, like commit ccadf73163 that introduced this
* Use the buffer cache when initializing an unlogged index.Heikki Linnakangas2023-08-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some of the ambuildempty functions used smgrwrite() directly, followed by smgrimmedsync(). A few small problems with that: Firstly, one is supposed to use smgrextend() when extending a relation, not smgrwrite(). It doesn't make much difference in production builds. smgrextend() updates the relation size cache, so you miss that, but that's harmless because we never use the cached relation size of an init fork. But if you compile with CHECK_WRITE_VS_EXTEND, you get an assertion failure. Secondly, the smgrwrite() calls were performed before WAL-logging, so the page image written to disk had 0/0 as the LSN, not the LSN of the WAL record. That's also harmless in practice, but seems sloppy. Thirdly, it's better to use the buffer cache, because then you don't need to smgrimmedsync() the relation to disk, which adds latency. Bypassing the cache makes sense for bulk operations like index creation, but not when you're just initializing an empty index. Creation of unlogged tables is hardly performance bottleneck in any real world applications, but nevertheless. Backpatch to v16, but no further. These issues should be harmless in practice, so better to not rock the boat in older branches. Reviewed-by: Robert Haas Discussion: https://www.postgresql.org/message-id/6e5bbc08-cdfc-b2b3-9e23-1a914b9850a9@iki.fi
* Introduce macros for protocol characters.Nathan Bossart2023-08-22
| | | | | | | | | | | This commit introduces descriptively-named macros for the identifiers used in wire protocol messages. These new macros are placed in a new header file so that they can be easily used by third-party code. Author: Dave Cramer Reviewed-by: Alvaro Herrera, Tatsuo Ishii, Peter Smith, Robert Haas, Tom Lane, Peter Eisentraut, Michael Paquier Discussion: https://postgr.es/m/CADK3HHKbBmK-PKf1bPNFoMC%2BoBt%2BpD9PH8h5nvmBQskEHm-Ehw%40mail.gmail.com
* ExtendBufferedWhat -> BufferManagerRelation.Thomas Munro2023-08-23
| | | | | | | | | | | | | | | | | Commit 31966b15 invented a way for functions dealing with relation extension to accept a Relation in online code and an SMgrRelation in recovery code. It seems highly likely that future bufmgr.c interfaces will face the same problem, and need to do something similar. Generalize the names so that each interface doesn't have to re-invent the wheel. Back-patch to 16. Since extension AM authors might start using the constructor macros once 16 ships, we agreed to do the rename in 16 rather than waiting for 17. Reviewed-by: Peter Geoghegan <pg@bowt.ie> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CA%2BhUKG%2B6tLD2BhpRWycEoti6LVLyQq457UL4ticP5xd8LqHySA%40mail.gmail.com
* Cache by-reference missing values in a long lived contextAndrew Dunstan2023-08-22
| | | | | | | | | | | | | | | | Attribute missing values might be needed past the lifetime of the tuple descriptors from which they are extracted. To avoid possibly using pointers for by-reference values which might thus be left dangling, we cache a datumCopy'd version of the datum in the TopMemoryContext. Since we first search for the value this only needs to be done once per session for any such value. Original complaint from Tom Lane, idea for mitigation by Andrew Dunstan, tweaked by Tom Lane. Backpatch to version 11 where missing values were introduced. Discussion: https://postgr.es/m/1306569.1687978174@sss.pgh.pa.us
* hio: Take number of prior relation extensions into accountAndres Freund2023-08-14
| | | | | | | | | | | | | | | | | | | | | | | | The new relation extension logic, introduced in 00d1e02be24, could lead to slowdowns in some scenarios. E.g., when loading narrow rows into a table using COPY, the caller of RelationGetBufferForTuple() will only request a small number of pages. Without concurrency, we just extended using pwritev() in that case. However, if there is *some* concurrency, we switched between extending by a small number of pages and a larger number of pages, depending on the number of waiters for the relation extension logic. However, some filesystems, XFS in particular, do not perform well when switching between extending files using fallocate() and pwritev(). To avoid that issue, remember the number of prior relation extensions in BulkInsertState and extend more aggressively if there were prior relation extensions. That not just avoids the aforementioned slowdown, but also leads to noticeable performance gains in other situations, primarily due to extending more aggressively when there is no concurrency. I should have done it this way from the get go. Reported-by: Masahiko Sawada <sawada.mshk@gmail.com> Author: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CAD21AoDvDmUQeJtZrau1ovnT_smN940=Kp6mszNGK3bq9yRN6g@mail.gmail.com Backpatch: 16-, where the new relation extension code was added
* Fix off-by-one in XLogRecordMaxSize check.Noah Misch2023-08-12
| | | | | | | | | pg_logical_emit_message(false, '_', repeat('x', 1069547465)) failed with self-contradictory message "WAL record would be 1069547520 bytes (of maximum 1069547520 bytes)". There's no particular benefit from allowing or denying one byte in either direction; XLogRecordMaxSize could rise a few megabytes without trouble. Hence, this is just for cleanliness. Back-patch to v16, where this check first appeared.
* Document more assumptions of LWLock variable changes with WAL insertsMichael Paquier2023-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | This commit adds a few comments about what LWLockWaitForVar() relies on when a backend waits for a variable update on its LWLocks for WAL insertions up to an expected LSN. First, LWLockWaitForVar() does not include a memory barrier, relying on a spinlock taken at the beginning of WaitXLogInsertionsToFinish(). This was hidden behind two layers of routines in lwlock.c. This assumption is now documented at the top of LWLockWaitForVar(), and detailed at bit more within LWLockConflictsWithVar(). Second, document why WaitXLogInsertionsToFinish() does not include memory barriers, relying on a spinlock at its top, which is, per Andres' input, fine for two different reasons, both depending on the fact that the caller of WaitXLogInsertionsToFinish() is waiting for a LSN up to a certain value. This area's documentation and assumptions could be improved more in the future, but at least that's a beginning. Author: Bharath Rupireddy, Andres Freund Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/CALj2ACVF+6jLvqKe6xhDzCCkr=rfd6upaGc3477Pji1Ke9G7Bg@mail.gmail.com
* Optimize WAL insertion lock acquisition and release with some atomicsMichael Paquier2023-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The WAL insertion lock variable insertingAt is currently being read and written with the help of the LWLock wait list lock to avoid any read of torn values. This wait list lock can become a point of contention on a highly concurrent write workloads. This commit switches insertingAt to a 64b atomic variable that provides torn-free reads/writes. On platforms without 64b atomic support, the fallback implementation uses spinlocks to provide the same guarantees for the values read. LWLockWaitForVar(), through LWLockConflictsWithVar(), reads the new value to check if it still needs to wait with a u64 atomic operation. LWLockUpdateVar() updates the variable before waking up the waiters with an exchange_u64 (full memory barrier). LWLockReleaseClearVar() now uses also an exchange_u64 to reset the variable. Before this commit, all these steps relied on LWLockWaitListLock() and LWLockWaitListUnlock(). This reduces contention on LWLock wait list lock and improves performance of highly-concurrent write workloads. Here are some numbers using pg_logical_emit_message() (HEAD at d6677b93) with various arbitrary record lengths and clients up to 1k on a rather-large machine (64 vCPUs, 512GB of RAM, 16 cores per sockets, 2 sockets), in terms of TPS numbers coming from pgbench: message_size_b | 16 | 64 | 256 | 1024 --------------------+--------+--------+--------+------- patch_4_clients | 83830 | 82929 | 80478 | 73131 patch_16_clients | 267655 | 264973 | 250566 | 213985 patch_64_clients | 380423 | 378318 | 356907 | 294248 patch_256_clients | 360915 | 354436 | 326209 | 263664 patch_512_clients | 332654 | 321199 | 287521 | 240128 patch_1024_clients | 288263 | 276614 | 258220 | 217063 patch_2048_clients | 252280 | 243558 | 230062 | 192429 patch_4096_clients | 212566 | 213654 | 205951 | 166955 head_4_clients | 83686 | 83766 | 81233 | 73749 head_16_clients | 266503 | 265546 | 249261 | 213645 head_64_clients | 366122 | 363462 | 341078 | 261707 head_256_clients | 132600 | 132573 | 134392 | 165799 head_512_clients | 118937 | 114332 | 116860 | 150672 head_1024_clients | 133546 | 115256 | 125236 | 151390 head_2048_clients | 137877 | 117802 | 120909 | 138165 head_4096_clients | 113440 | 115611 | 120635 | 114361 Bharath has been measuring similar improvements, where the limit of the WAL insertion lock begins to be felt when more than 256 concurrent clients are involved in this specific workload. An extra patch has been discussed to introduce a fast-exit path in LWLockUpdateVar() when there are no waiters, still this does not influence the write-heavy workload cases discussed as there are always waiters. This will be considered separately. Author: Bharath Rupireddy Reviewed-by: Nathan Bossart, Andres Freund, Michael Paquier Discussion: https://postgr.es/m/CALj2ACVF+6jLvqKe6xhDzCCkr=rfd6upaGc3477Pji1Ke9G7Bg@mail.gmail.com
* Fix indentation in twophase.cMichael Paquier2023-07-18
| | | | | | | | | This has been missed in cb0cca1, noticed before buildfarm member koel has been able to complain while poking at a different patch. Like the other commit, backpatch all the way down to limit the odds of merge conflicts. Backpatch-through: 11
* Fix recovery of 2PC transaction during crash recoveryMichael Paquier2023-07-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A crash in the middle of a checkpoint with some two-phase state data already flushed to disk by this checkpoint could cause a follow-up crash recovery to recover twice the same transaction, once from what has been found in pg_twophase/ at the beginning of recovery and a second time when replaying its corresponding record. This would lead to FATAL failures in the startup process during recovery, where the same transaction would have a state recovered twice instead of once: LOG: recovering prepared transaction 731 from shared memory LOG: recovering prepared transaction 731 from shared memory FATAL: lock ExclusiveLock on object 731/0/0 is already held This issue is fixed by skipping the addition of any 2PC state coming from a record whose equivalent 2PC state file has already been loaded in TwoPhaseState at the beginning of recovery by restoreTwoPhaseData(), which is OK as long as the system has not reached a consistent state. The timing to get a messed up recovery processing is very racy, and would very unlikely happen. The thread that has reported the issue has demonstrated the bug using injection points to force a PANIC in the middle of a checkpoint. Issue introduced in 728bd99, so backpatch all the way down. Reported-by: "suyu.cmj" <mengjuan.cmj@alibaba-inc.com> Author: "suyu.cmj" <mengjuan.cmj@alibaba-inc.com> Author: Michael Paquier Discussion: https://postgr.es/m/109e6994-b971-48cb-84f6-829646f18b4c.mengjuan.cmj@alibaba-inc.com Backpatch-through: 11
* Rename session_auth_is_superuser to current_role_is_superuser.Nathan Bossart2023-07-12
| | | | | | | | | | | This variable might've been accurately named when it was added in ea886339b8, but the name hasn't been accurate since at least the introduction of SET ROLE in e5d6b91220. The corresponding documentation was fixed in eedb068c0a. This commit renames the variable accordingly. Suggested-by: Joseph Koshakow Discussion: https://postgr.es/m/CAAvxfHc-HHzONQ2oXdvhFF9ayRnidPwK%2BfVBhRzaBWYYLVQL-g%40mail.gmail.com
* Report index vacuum progress.Masahiko Sawada2023-07-11
| | | | | | | | | | | | | | | | | This commit adds two columns: indexes_total and indexes_processed, to pg_stat_progress_vacuum system view to show the index vacuum progress. These numbers are reported in the "vacuuming indexes" and "cleaning up indexes" phases. This uses the new parallel message type for progress reporting added by be06506e7. Bump catversion because this changes the definition of pg_stat_progress_vacuum. Author: Sami Imseih Reviewed by: Masahiko Sawada, Michael Paquier, Nathan Bossart, Andres Freund Discussion: https://www.postgresql.org/message-id/flat/5478DFCD-2333-401A-B2F0-0D186AB09228@amazon.com
* Add new parallel message type to progress reporting.Masahiko Sawada2023-07-11
| | | | | | | | | | | | | | | | | | This commit adds a new type of parallel message 'P' to allow a parallel worker to poke at a leader to update the progress. Currently it supports only incremental progress reporting but it's possible to allow for supporting of other backend progress APIs in the future. There are no users of this new message type as of this commit. That will follow in future commits. Idea from Andres Freund. Author: Sami Imseih Reviewed by: Michael Paquier, Masahiko Sawada Discussion: https://www.postgresql.org/message-id/flat/5478DFCD-2333-401A-B2F0-0D186AB09228@amazon.com
* Message wording improvementsPeter Eisentraut2023-07-10
|
* Document relaxed HOT for summarizing indexesTomas Vondra2023-07-07
| | | | | | | | | | | | | Commit 19d8e2308b allowed a weaker check for HOT with summarizing indexes, but it did not update README.HOT. So do that now. Patch by Matthias van de Meent, minor changes by me. Backpatch to 16, where the optimization was introduced. Author: Matthias van de Meent Reviewed-by: Tomas Vondra Backpatch-through: 16 Discussion: https://postgr.es/m/CAEze2WiEOm8V+c9kUeYp2BPhbEc5s473fUf51xNeqvSFGv44Ew@mail.gmail.com
* Fix race in SSI interaction with gin fast path.Thomas Munro2023-07-04
| | | | | | | | | | | | | | | | | | The ginfast.c code previously checked for conflicts in before locking the relevant buffer, leaving a window where a RW conflict could be missed. Re-order. There was also a place where buffer ID and block number were confused while trying to predicate-lock a page, noted by visual inspection. Back-patch to all supported releases. Fixes one more problem discovered with the reproducer from bug #17949, in this case when Dmitry tried other index types. Reported-by: Artem Anisimov <artem.anisimov.255@gmail.com> Reported-by: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://postgr.es/m/17949-a0f17035294a55e2%40postgresql.org
* Fix race in SSI interaction with bitmap heap scan.Thomas Munro2023-07-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When performing a bitmap heap scan, we don't want to miss concurrent writes that occurred after we observed the heap's rs_nblocks, but before we took predicate locks on index pages. Therefore, we can't skip fetching any heap tuples that are referenced by the index, because we need to test them all with CheckForSerializableConflictOut(). The old optimization that would ignore any references to blocks >= rs_nblocks gets in the way of that requirement, because it means that concurrent writes in that window are ignored. Removing that optimization shouldn't affect correctness at any isolation level, because any new tuples shouldn't be visible to an MVCC snapshot. There also shouldn't be any error-causing references to heap blocks past the end, because we should have held at least an AccessShareLock on the table before the index scan. It can't get smaller while our transaction is running. For now, though, we'll keep the optimization at lower levels to avoid making unnecessary changes in a bug fix. Back-patch to all supported releases. In release 11, the code is in a different place but not fundamentally different. Fixes one aspect of bug #17949. Reported-by: Artem Anisimov <artem.anisimov.255@gmail.com> Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://postgr.es/m/17949-a0f17035294a55e2%40postgresql.org
* Fix race in SSI interaction with empty btrees.Thomas Munro2023-07-04
| | | | | | | | | | | | | | | | | When predicate-locking btrees, we have a special case for completely empty btrees, since there is no page to lock. This was racy, because, without buffer lock held, a matching key could be inserted between the _bt_search() and the PredicateLockRelation() calls. Fix, by rechecking _bt_search() after taking the relation-level SIREAD lock, if using SERIALIZABLE isolation and an empty btree is discovered. Back-patch to all supported releases. Fixes one aspect of bug #17949. Reported-by: Artem Anisimov <artem.anisimov.255@gmail.com> Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://postgr.es/m/17949-a0f17035294a55e2%40postgresql.org
* Consider fillfactor when estimating relation sizeTomas Vondra2023-07-03
| | | | | | | | | | | | | | | | | When table_block_relation_estimate_size() estimated the number of tuples in a relation without statistics (e.g. right after load), it did not consider fillfactor when calculating density. With non-default fillfactor values, this may result in significant overestimate of the number of tuples - up to 10x with the minimum 10% fillfactor. This may have unexpected consequences, e.g. when creating hash indexes. This considers the current fillfactor value in the "no statistics" code path. If the fillfactor changes after loading data into the table, the estimate may be off. But that seems much less likely than changing the fillfactor before the data load. Reviewed-by: Corey Huinker, Peter Eisentraut Discussion: https://postgr.es/m/cf154ef9-6bac-d268-b735-67a3443debba@enterprisedb.com
* Fix code indentation violationsTomas Vondra2023-07-03
| | | | | | | Commits ce5aaea8cd, 2b8b2852bb and 28d03feac3 violated the expected code indentation rules, upsetting the new buildfarm member "koel." Discussion: https://postgr.es/m/ZKIU4mhWpgJOM0W0%40paquier.xyz
* Silence "missing contrecord" error.Thomas Munro2023-07-03
| | | | | | | | | | | | | | | | | Commit dd38ff28ad added a new error message "missing contrecord" when we fail to reassemble a record. Unfortunately that caused noisy messages to be logged by pg_waldump at end of segment, and by walsender when asked to shut down on a segment boundary. Remove the new error message, so that this condition signals end-of- WAL without a message. It's arguably a reportable condition that should not be silenced while performing crash recovery, but fixing that without introducing noise in the other cases will require more research. Back-patch to 15. Reported-by: Tomas Vondra <tomas.vondra@enterprisedb.com> Discussion: https://postgr.es/m/6a1df56e-4656-b3ce-4b7a-a9cb41df8189%40enterprisedb.com
* Improve BRIN minmax-multi opclass test coverageTomas Vondra2023-07-02
| | | | | | | | | | | | | | | | | | | | | | Per the code coverage report, the existing regression tests did not exercice some a couple important BRIN minmax-multi code paths. - The tests focused on testing planning with a range of scan key strategies, but not the execution. Fixed by adding queries that actually test query execution for both equality and inequality. - All tests created indexes after inserting data, but this only exercises the CREATE INDEX strategy that sees all values at once, not incremental summary updates. The new tests flip the order and create the index before adding data. - The assert check(s) validating correctness of expanded ranges were present only in the "union" code path, which is not covered by regression tests at all (as it requires concurrency etc.). Fixed by adding the asserts to a couple more places. Reviewed-by: Heikki Linnakangas Discussion: https://postgr.es/m/57020b2e-d9c9-9bc7-4892-b36d9bb07563%40enterprisedb.com
* Introduce bloom_filter_size for BRIN bloom opclassTomas Vondra2023-07-02
| | | | | | | | | Move the calculation of Bloom filter parameters (for BRIN indexes) into a separate function to make reuse easier. At the moment we only call it from one place, but that may change and it's easier to read anyway. Reviewed-by: Heikki Linnakangas Discussion: https://postgr.es/m/0e1f3350-c9cf-ab62-43a5-5dae314de89c%40enterprisedb.com
* Minor cleanups in the BRIN codeTomas Vondra2023-07-02
| | | | | | | | | | | | BRIN bloom and minmax-multi opclasses were somewhat inconsistent when dealing with bool variables, assigning to them Datum values etc. While not a bug, it makes the code harder to understand, so fix that. While at it, update an incorrect comment copied to bloom opclass from minmax, talking about strategies not supported by bloom. Reviewed-by: Heikki Linnakangas Discussion: https://postgr.es/m/0e1f3350-c9cf-ab62-43a5-5dae314de89c%40enterprisedb.com
* nbtree VACUUM: cope with topparent inconsistencies.Peter Geoghegan2023-06-21
| | | | | | | | | | | | | | | | | | Avoid "right sibling %u of block %u is not next child" errors when vacuuming a corrupt nbtree index. Just LOG the issue and press on. That way VACUUM will have a decent chance of finishing off all required processing for the index (and for the table as a whole). This is similar to recent work from commit 5abff197, as well as work from commit 5b861baa (later backpatched as commit 43e409ce), which taught nbtree VACUUM to keep going when its "re-find" check fails. The hardening added by this commit takes place directly after the "re-find" check, right before the critical section for the first stage of page deletion. Author: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAH2-Wz=dayg0vjs4+er84TS9ami=csdzjpuiCGbEw=idhwqhzQ@mail.gmail.com Backpatch: 11- (all supported versions).
* Enable archiving in recovery TAP test 009_twophase.plMichael Paquier2023-06-20
| | | | | | | | | | | | | | | | | This is a follow-up of f663b00, that has been committed to v13 and v14, tweaking the TAP test for two-phase transactions so as it provides coverage for the bug that has been fixed. This change is done in its own commit for clarity, as v15 and HEAD did not show the problematic behavior, still missed coverage for it. While on it, this adds a comment about the dependency of the last partial segment rename and RecoverPreparedTransactions() at the end of recovery, as that can be easy to miss. Author: Michael Paquier Reviewed-by: Kyotaro Horiguchi Discussion: https://postgr.es/m/743b9b45a2d4013bd90b6a5cba8d6faeb717ee34.camel@cybertec.at Backpatch-through: 13
* nbtree: Allocate new pages in separate function.Peter Geoghegan2023-06-10
| | | | | | | | | | | | | | | | | | | | | | | | Split nbtree's _bt_getbuf function is two: code that read locks or write locks existing pages remains in _bt_getbuf, while code that deals with allocating new pages is moved to a new, dedicated function called _bt_allocbuf. This simplifies most _bt_getbuf callers, since it is no longer necessary for them to pass a heaprel argument. Many of the changes to nbtree from commit 61b313e4 can be reverted. This minimizes the divergence between HEAD/PostgreSQL 16 and earlier release branches. _bt_allocbuf replaces the previous nbtree idiom of passing P_NEW to _bt_getbuf. There are only 3 affected call sites, all of which continue to pass a heaprel for recovery conflict purposes. Note that nbtree's use of P_NEW was superficial; nbtree never actually relied on the P_NEW code paths in bufmgr.c, so this change is strictly mechanical. GiST already took the same approach; it has a dedicated function for allocating new pages called gistNewBuffer(). That factor allowed commit 61b313e4 to make much more targeted changes to GiST. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://postgr.es/m/CAH2-Wz=8Z9qY58bjm_7TAHgtW6RzZ5Ke62q5emdCEy9BAzwhmg@mail.gmail.com