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* Fix past pd_upper write in ginRedoRecompress()Alexander Korotkov2018-09-09
| | | | | | | | | | | | | | | | ginRedoRecompress() replays actions over compressed segments of posting list in-place. However, it might lead to write past pg_upper, because intermediate state during playing the changes can take more space than both original state and final state. This commit fixes that by refuse from in-place modification. Instead page tail is copied once modification is started, and then it's used as the source of original segments. Backpatch to 9.4 where posting list compression was introduced. Reported-by: Sivasubramanian Ramasubramanian Discussion: https://postgr.es/m/1536091151804.6588%40amazon.com Author: Alexander Korotkov based on patch from and ideas by Sivasubramanian Ramasubramanian Review: Sivasubramanian Ramasubramanian Backpatch-through: 9.4
* During the split, set checksum on an empty hash index page.Amit Kapila2018-09-04
| | | | | | | | | | | | | | | | On a split, we allocate a new splitpoint's worth of bucket pages wherein we initialize the last page with zeros which is fine, but we forgot to set the checksum for that last page. We decided to back-patch this fix till 10 because we don't have an easy way to test it in prior versions. Another reason is that the hash-index code is changed heavily in 10, so it is not advisable to push the fix without testing it in prior versions. Author: Amit Kapila Reviewed-by: Yugo Nagata Backpatch-through: 10 Discussion: https://postgr.es/m/5d03686d-727c-dbf8-0064-bf8b97ffe850@2ndquadrant.com
* Avoid using potentially-under-aligned page buffers.Tom Lane2018-09-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a project policy against using plain "char buf[BLCKSZ]" local or static variables as page buffers; preferred style is to palloc or malloc each buffer to ensure it is MAXALIGN'd. However, that policy's been ignored in an increasing number of places. We've apparently got away with it so far, probably because (a) relatively few people use platforms on which misalignment causes core dumps and/or (b) the variables chance to be sufficiently aligned anyway. But this is not something to rely on. Moreover, even if we don't get a core dump, we might be paying a lot of cycles for misaligned accesses. To fix, invent new union types PGAlignedBlock and PGAlignedXLogBlock that the compiler must allocate with sufficient alignment, and use those in place of plain char arrays. I used these types even for variables where there's no risk of a misaligned access, since ensuring proper alignment should make kernel data transfers faster. I also changed some places where we had been palloc'ing short-lived buffers, for coding style uniformity and to save palloc/pfree overhead. Since this seems to be a live portability hazard (despite the lack of field reports), back-patch to all supported versions. Patch by me; thanks to Michael Paquier for review. Discussion: https://postgr.es/m/1535618100.1286.3.camel@credativ.de
* Ensure correct minimum consistent point on standbysMichael Paquier2018-08-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Startup process has improved its calculation of incorrect minimum consistent point in 8d68ee6, which ensures that all WAL available gets replayed when doing crash recovery, and has introduced an incorrect calculation of the minimum recovery point for non-startup processes, which can cause incorrect page references on a standby when for example the background writer flushed a couple of pages on-disk but was not updating the control file to let a subsequent crash recovery replay to where it should have. The only case where this has been reported to be a problem is when a standby needs to calculate the latest removed xid when replaying a btree deletion record, so one would need connections on a standby that happen just after recovery has thought it reached a consistent point. Using a background worker which is started after the consistent point is reached would be the easiest way to get into problems if it connects to a database. Having clients which attempt to connect periodically could also be a problem, but the odds of seeing this problem are much lower. The fix used is pretty simple, as the idea is to give access to the minimum recovery point written in the control file to non-startup processes so as they use a reference, while the startup process still initializes its own references of the minimum consistent point so as the original problem with incorrect page references happening post-promotion with a crash do not show up. Reported-by: Alexander Kukushkin Diagnosed-by: Alexander Kukushkin Author: Michael Paquier Reviewed-by: Kyotaro Horiguchi, Alexander Kukushkin Discussion: https://postgr.es/m/153492341830.1368.3936905691758473953@wrigleys.postgresql.org Backpatch-through: 9.3
* doc: Update uses of the word "procedure"Peter Eisentraut2018-08-22
| | | | | | | | | | | | | | | | | | | Historically, the term procedure was used as a synonym for function in Postgres/PostgreSQL. Now we have procedures as separate objects from functions, so we need to clean up the documentation to not mix those terms. In particular, mentions of "trigger procedures" are changed to "trigger functions", and access method "support procedures" are changed to "support functions". (The latter already used FUNCTION in the SQL syntax anyway.) Also, the terminology in the SPI chapter has been cleaned up. A few tests, examples, and code comments are also adjusted to be consistent with documentation changes, but not everything. Reported-by: Peter Geoghegan <pg@bowt.ie> Reviewed-by: Jonathan S. Katz <jonathan.katz@excoventures.com>
* fix typoAlvaro Herrera2018-08-21
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* Update FSM on WAL replay of page all-visible/frozenAlvaro Herrera2018-08-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We aren't very strict about keeping FSM up to date on WAL replay, because per-page freespace values aren't critical in replicas (can't write to heap in a replica; and if the replica is promoted, the values would be updated by VACUUM anyway). However, VACUUM since 9.6 can skip processing pages marked all-visible or all-frozen, and if such pages are recorded in FSM with wrong values, those values are blindly propagated to FSM's upper layers by VACUUM's FreeSpaceMapVacuum. (This rationale assumes that crashes are not very frequent, because those would cause outdated FSM to occur in the primary.) Even when the FSM is outdated in standby, things are not too bad normally, because, most per-page FSM values will be zero (other than those propagated with the base-backup that created the standby); only once the remaining free space is less than 0.2*BLCKSZ the per-page value is maintained by WAL replay of heap ins/upd/del. However, if wal_log_hints=on causes complete FSM pages to be propagated to a standby via full-page images, many too-optimistic per-page values can end up being registered in the standby. Incorrect per-page values aren't critical in most cases, since an inserter that is given a page that doesn't actually contain the claimed free space will update FSM with the correct value, and retry until it finds a usable page. However, if there are many such updates to do, an inserter can spend a long time doing them before a usable page is found; in a heavily trafficked insert-only table with many concurrent inserters this has been observed to cause several second stalls, causing visible application malfunction. To fix this problem, it seems sufficient to have heap_xlog_visible (replay of setting all-visible and all-frozen VM bits for a heap page) update the FSM value for the page being processed. This fixes the per-page counters together with making the page skippable to vacuum, so when vacuum does FreeSpaceMapVacuum, the values propagated to FSM upper layers are the correct ones, avoiding the problem. While at it, apply the same fix to heap_xlog_clean (replay of tuple removal by HOT pruning and vacuum). This makes any space freed by the cleaning available earlier than the next vacuum in the promoted replica. Backpatch to 9.6, where this problem was diagnosed on an insert-only table with all-frozen pages, which were introduced as a concept in that release. Theoretically it could apply with all-visible pages to older branches, but there's been no report of that and it doesn't backpatch cleanly anyway. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/20180802172857.5skoexsilnjvgruk@alvherre.pgsql
* Make autovacuum more aggressive to remove orphaned temp tablesMichael Paquier2018-08-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit dafa084, added in 10, made the removal of temporary orphaned tables more aggressive. This commit makes an extra step into the aggressiveness by adding a flag in each backend's MyProc which tracks down any temporary namespace currently in use. The flag is set when the namespace gets created and can be reset if the temporary namespace has been created in a transaction or sub-transaction which is aborted. The flag value assignment is assumed to be atomic, so this can be done in a lock-less fashion like other flags already present in PGPROC like databaseId or backendId, still the fact that the temporary namespace and table created are still locked until the transaction creating those commits acts as a barrier for other backends. This new flag gets used by autovacuum to discard more aggressively orphaned tables by additionally checking for the database a backend is connected to as well as its temporary namespace in-use, removing orphaned temporary relations even if a backend reuses the same slot as one which created temporary relations in a past session. The base idea of this patch comes from Robert Haas, has been written in its first version by Tsunakawa Takayuki, then heavily reviewed by me. Author: Tsunakawa Takayuki Reviewed-by: Michael Paquier, Kyotaro Horiguchi, Andres Freund Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F8A4DC6@G01JPEXMBYT05 Backpatch: 11-, as PGPROC gains a new flag and we don't want silent ABI breakages on already released versions.
* Fix typo in SP-GiST error messageAlexander Korotkov2018-08-10
| | | | | | | | | Error message didn't match the actual check. Fix that. Compression of leaf SP-GiST values was introduced in 11. So, backpatch. Discussion: https://postgr.es/m/20180810.100742.15469435.horiguchi.kyotaro%40lab.ntt.co.jp Author: Kyotaro Horiguchi Backpatch-through: 11
* Reset properly errno before calling write()Michael Paquier2018-08-05
| | | | | | | | | | | | 6cb3372 enforces errno to ENOSPC when less bytes than what is expected have been written when it is unset, though it forgot to properly reset errno before doing a system call to write(), causing errno to potentially come from a previous system call. Reported-by: Tom Lane Author: Michael Paquier Reviewed-by: Tom Lane Discussion: https://postgr.es/m/31797.1533326676@sss.pgh.pa.us
* Fix the buffer release order for parallel index scans.Amit Kapila2018-07-27
| | | | | | | | | | | | | | | | | | | | | | | | | During parallel index scans, if the current page to be read is deleted, we skip it and try to get the next page for a scan without releasing the buffer lock on the current page. To get the next page, sometimes it needs to wait for another process to complete its scan and advance it to the next page. Now, it is quite possible that the master backend has errored out before advancing the scan and issued a termination signal for all workers. The workers failed to notice the termination request during wait because the interrupts are held due to buffer lock on the previous page. This lead to all workers being stuck. The fix is to release the buffer lock on current page before trying to get the next page. We are already doing same in backward scans, but missed it for forward scans. Reported-by: Victor Yegorov Bug: 15290 Diagnosed-by: Thomas Munro and Amit Kapila Author: Amit Kapila Reviewed-by: Thomas Munro Tested-By: Thomas Munro and Victor Yegorov Backpatch-through: 10 where parallel index scans were introduced Discussion:https://postgr.es/m/153228422922.1395.1746424054206154747@wrigleys.postgresql.org
* Fix calculation for WAL segment recycling and removalMichael Paquier2018-07-24
| | | | | | | | | | | | | | Commit 4b0d28de06 has removed the prior checkpoint and related facilities but has left WAL recycling based on the LSN of the prior checkpoint, which causes incorrect calculations for WAL removal and recycling for max_wal_size and min_wal_size. This commit changes things so as the base calculation point is the last checkpoint generated. Reported-by: Kyotaro Horiguchi Author: Kyotaro Horiguchi Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/20180723.135748.42558387.horiguchi.kyotaro@lab.ntt.co.jp Backpatch: 11-, where the prior checkpoint has been removed.
* Fix handling of empty uncompressed posting list pages in GINAlexander Korotkov2018-07-19
| | | | | | | | | | | | | | PostgreSQL 9.4 introduces posting list compression in GIN. This feature supports online upgrade, so that after pg_upgrade uncompressed posting lists are compressed on-the-fly. Underlying code appears to always expect at least one item on uncompressed posting list page. But there could be completely empty pages, because VACUUM never deletes leftmost and rightmost pages from posting trees. This commit fixes that. Reported-by: Sivasubramanian Ramasubramanian Discussion: https://postgr.es/m/1531867212836.63354%40amazon.com Author: Sivasubramanian Ramasubramanian, Alexander Korotkov Backpatch-through: 9.4
* Fix misc typos, mostly in comments.Heikki Linnakangas2018-07-18
| | | | | | | | A collection of typos I happened to spot while reading code, as well as grepping for common mistakes. Backpatch to all supported versions, as applicable, to avoid conflicts when backporting other commits in the future.
* Add subtransaction handling for table synchronization workers.Robert Haas2018-07-16
| | | | | | | | | | | Since the old logic was completely unaware of subtransactions, a change made in a subsequently-aborted subtransaction would still cause workers to be stopped at toplevel transaction commit. Fix that by managing a stack of worker lists rather than just one. Amit Khandekar and Robert Haas Discussion: http://postgr.es/m/CAJ3gD9eaG_mWqiOTA2LfAug-VRNn1hrhf50Xi1YroxL37QkZNg@mail.gmail.com
* Fix inadequate buffer locking in FSM and VM page re-initialization.Tom Lane2018-07-13
| | | | | | | | | | | | | | | | | | | When reading an existing FSM or VM page that was found to be corrupt by the buffer manager, the code applied PageInit() to reinitialize the page, but did so without any locking. There is thus a hazard that two backends might concurrently do PageInit, which in itself would still be OK, but the slower one might then zero over subsequent data changes applied by the faster one. Even that is unlikely to be fatal; but it's not desirable, so add locking to prevent it. This does not add any locking overhead in the normal code path where the page is OK. It's not immediately obvious that that's safe, but I believe it is, for reasons explained in the added comments. Problem noted by R P Asim. It's been like this for a long time, so back-patch to all supported branches. Discussion: https://postgr.es/m/CANXE4Te4G0TGq6cr0-TvwP0H4BNiK_-hB5gHe8mF+nz0mcYfMQ@mail.gmail.com
* Avoid emitting a bogus WAL record when recycling an all-zero btree page.Tom Lane2018-07-09
| | | | | | | | | | | | | | | | | | | | Commit fafa374f2 caused _bt_getbuf() to possibly emit a WAL record for a page that it was about to recycle. However, it failed to distinguish all-zero pages from dead pages, which is important because only the latter have valid btpo.xact values, or indeed any special space at all. Recycling an all-zero page with XLogStandbyInfoActive() enabled therefore led to an Assert failure, or to emission of a WAL record containing a bogus cutoff XID, which might lead to unnecessary query cancellations on hot standby servers. Per reports from Antonin Houska and 自己. Amit Kapila was first to propose this fix, and Robert Haas, myself, and Kyotaro Horiguchi reviewed it at various times. This is an old bug, so back-patch to all supported branches. Discussion: https://postgr.es/m/2628.1474272158@localhost Discussion: https://postgr.es/m/48875502.f4a0.1635f0c27b0.Coremail.zoulx1982@163.com
* Flip argument order in XLogSegNoOffsetToRecPtrAlvaro Herrera2018-07-09
| | | | | | | | | Commit fc49e24fa69a added an input argument after the existing output argument. Flip those. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/20180708182345.imdgovmkffgtihhk@alvherre.pgsql
* Rework order of end-of-recovery actions to delay timeline history writeMichael Paquier2018-07-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A critical failure in some of the end-of-recovery actions before the end-of-recovery record is written can cause PostgreSQL to react inconsistently with the rest of the cluster in the event of a crash before the final record is written. Two such failures are for example an error while processing a two-phase state files or when operating on recovery.conf. With this commit, the failures are still considered FATAL, but the write of the timeline history file is delayed as much as possible so as the window between the moment the file is written and the end-of-recovery record is generated gets minimized. This way, in the event of a crash or a failure, the new timeline decided at promotion will not seem taken by other nodes in the cluster. It is not really possible to reduce to zero this window, hence one could still see failures if a crash happens between the history file write and the end-of-recovery record, so any future code should be careful when adding new end-of-recovery actions. The original report from Magnus Hagander mentioned a renamed recovery.conf as original end-of-recovery failure which caused a timeline to be seen as taken but the subsequent processing on the now-missing recovery.conf cause the startup process to issue stop on FATAL, which at follow-up startup made the system inconsistent because of on-disk changes which already happened. Processing of two-phase state files still needs some work as corrupted entries are simply ignored now. This is left as a future item and this commit fixes the original complain. Reported-by: Magnus Hagander Author: Heikki Linnakangas Reviewed-by: Alexander Korotkov, Michael Paquier, David Steele Discussion: https://postgr.es/m/CABUevEz09XY2EevA2dLjPCY-C5UO4Hq=XxmXLmF6ipNFecbShQ@mail.gmail.com
* Prevent references to invalid relation pages after fresh promotionMichael Paquier2018-07-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a standby crashes after promotion before having completed its first post-recovery checkpoint, then the minimal recovery point which marks the LSN position where the cluster is able to reach consistency may be set to a position older than the first end-of-recovery checkpoint while all the WAL available should be replayed. This leads to the instance thinking that it contains inconsistent pages, causing a PANIC and a hard instance crash even if all the WAL available has not been replayed for certain sets of records replayed. When in crash recovery, minRecoveryPoint is expected to always be set to InvalidXLogRecPtr, which forces the recovery to replay all the WAL available, so this commit makes sure that the local copy of minRecoveryPoint from the control file is initialized properly and stays as it is while crash recovery is performed. Once switching to archive recovery or if crash recovery finishes, then the local copy minRecoveryPoint can be safely updated. Pavan Deolasee has reported and diagnosed the failure in the first place, and the base fix idea to rely on the local copy of minRecoveryPoint comes from Kyotaro Horiguchi, which has been expanded into a full-fledged patch by me. The test included in this commit has been written by Álvaro Herrera and Pavan Deolasee, which I have modified to make it faster and more reliable with sleep phases. Backpatch down to all supported versions where the bug appears, aka 9.3 which is where the end-of-recovery checkpoint is not run by the startup process anymore. The test gets easily supported down to 10, still it has been tested on all branches. Reported-by: Pavan Deolasee Diagnosed-by: Pavan Deolasee Reviewed-by: Pavan Deolasee, Kyotaro Horiguchi Author: Michael Paquier, Kyotaro Horiguchi, Pavan Deolasee, Álvaro Herrera Discussion: https://postgr.es/m/CABOikdPOewjNL=05K5CbNMxnNtXnQjhTx2F--4p4ruorCjukbA@mail.gmail.com
* Check for interrupts inside the nbtree page deletion code.Andres Freund2018-07-04
| | | | | | | | | | | | | | | | | | | | When deleting pages the nbtree code has to walk through siblings of a tree node. When those sibling links are corrupted that can lead to endless loops - which are currently not interruptible. This is especially problematic if autovacuum is repeatedly blocked on such indexes, as it can be hard to get out of that situation without resorting to single user mode. Thus add interrupt checks to appropriate places in such loops. Unfortunately in one of the cases it's it's not easy to do so. Between 9.3 and 9.4 the page deletion (and page split) code changed significantly. Before it was significantly less robust against interruptions. Therefore don't backpatch to 9.3. Author: Andres Freund Discussion: https://postgr.es/m/20180627191629.wkunw2qbibnvlz53@alap3.anarazel.de Backpatch: 9.4-
* Improve the performance of relation deletes during recovery.Fujii Masao2018-07-05
| | | | | | | | | | | | | | | | | | | | | | When multiple relations are deleted at the same transaction, the files of those relations are deleted by one call to smgrdounlinkall(), which leads to scan whole shared_buffers only one time. OTOH, previously, during recovery, smgrdounlink() (not smgrdounlinkall()) was called for each file to delete, which led to scan shared_buffers multiple times. Obviously this could cause to increase the WAL replay time very much especially when shared_buffers was huge. To alleviate this situation, this commit changes the recovery so that it also calls smgrdounlinkall() only one time to delete multiple relation files. This is just fix for oversight of commit 279628a0a7, not new feature. So, per discussion on pgsql-hackers, we concluded to backpatch this to all supported versions. Author: Fujii Masao Reviewed-by: Michael Paquier, Andres Freund, Thomas Munro, Kyotaro Horiguchi, Takayuki Tsunakawa Discussion: https://postgr.es/m/CAHGQGwHVQkdfDqtvGVkty+19cQakAydXn1etGND3X0PHbZ3+6w@mail.gmail.com
* pgindent run prior to branchingAndrew Dunstan2018-06-30
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* Cosmetic improvements for faster column addition.Amit Kapila2018-06-27
| | | | | | | | | | Changed the name of few structure members for the sake of clarity and removed spurious whitespace. Reported-by: Amit Kapila Author: Amit Kapila, based on suggestion by Andrew Dunstan Reviewed-by: Alvaro Herrera Discussion: https://postgr.es/m/CAA4eK1K2znsFpC+NQ9A4vxT4uDxADN4RmvHX0L6Y=aHVo9gB4Q@mail.gmail.com
* Fix upper limit for vacuum_cleanup_index_scale_factorAlexander Korotkov2018-06-26
| | | | | | | | | | | | | | | 6ca33a88 sets upper limit for vacuum_cleanup_index_scale_factor to DBL_MAX. DBL_MAX appears to be platform-dependent. That causes many buildfarm animals to fail, because we check boundaries of vacuum_cleanup_index_scale_factor in regression tests. This commit changes upper limit from DBL_MAX to just "large enough" limit, which was arbitrary selected as 1e10. Author: Alexander Korotkov Reported-by: Tom Lane, Darafei Praliaskouski Discussion: https://postgr.es/m/CAPpHfdvewmr4PcpRjrkstoNn1n2_6dL-iHRB21CCfZ0efZdBTg%40mail.gmail.com Discussion: https://postgr.es/m/CAC8Q8tLYFOpKNaPS_E7V8KtPdE%3D_TnAn16t%3DA3LuL%3DXjfOO-BQ%40mail.gmail.com
* Remove obsolete comment block in nbtsort.c.Peter Geoghegan2018-06-26
| | | | | | | | | | | Building a new nbtree index through incremental insertions would always be slower than our actual approach of sorting using tuplesort, assembling leaf pages from tuplesort output, and writing and WAL-logging whole pages. Remove a comment block from the Berkeley days claiming that incremental insertions might be slightly faster with presorted input. Discussion: https://postgr.es/m/CAH2-WzmKs4mLAoFgJ3yHMRYc849efc=dw+pNRb3NEog2oJoCNw@mail.gmail.com
* Increase upper limit for vacuum_cleanup_index_scale_factorAlexander Korotkov2018-06-26
| | | | | | | | | | | | | | | | | | Upper limits for vacuum_cleanup_index_scale_factor GUC and reloption were initially set to 100.0 in 857f9c36. However, after further discussion, it appears that some users like to disable B-tree cleanup index scan completely (assuming there are no deleted pages). vacuum_cleanup_index_scale_factor is used barely to protect against stalled index statistics. And after detailed consideration it appears that risk of stalled index statistics is low. And it would be nice to allow advanced users setting higher values of vacuum_cleanup_index_scale_factor. So, set upper limit for these GUC and reloption to DBL_MAX. Author: Alexander Korotkov Reviewed-by: Masahiko Sawada Discussion: https://postgr.es/m/CAC8Q8tJCb%3DgxhzcV7T6ctx7PY-Ux1oA-AsTJc6cAVNsQiYcCzA%40mail.gmail.com
* Address set of issues with errno handlingMichael Paquier2018-06-25
| | | | | | | | | | | | | | | | | | | | System calls mixed up in error code paths are causing two issues which several code paths have not correctly handled: 1) For write() calls, sometimes the system may return less bytes than what has been written without errno being set. Some paths were careful enough to consider that case, and assumed that errno should be set to ENOSPC, other calls missed that. 2) errno generated by a system call is overwritten by other system calls which may succeed once an error code path is taken, causing what is reported to the user to be incorrect. This patch uses the brute-force approach of correcting all those code paths. Some refactoring could happen in the future, but this is let as future work, which is not targeted for back-branches anyway. Author: Michael Paquier Reviewed-by: Ashutosh Sharma Discussion: https://postgr.es/m/20180622061535.GD5215@paquier.xyz
* Fix typo in comment of commit_ts.c for incorrect reference to CLOGMichael Paquier2018-06-22
| | | | Author: Shao Bret
* Prevent hard failures of standbys caused by recycled WAL segmentsMichael Paquier2018-06-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a standby's WAL receiver stops reading WAL from a WAL stream, it writes data to the current WAL segment without having priorily zero'ed the page currently written to, which can cause the WAL reader to read junk data from a past recycled segment and then it would try to get a record from it. While sanity checks in place provide most of the protection needed, in some rare circumstances, with chances increasing when a record header crosses a page boundary, then the startup process could fail violently on an allocation failure, as follows: FATAL: invalid memory alloc request size XXX This is confusing for the user and also unhelpful as this requires in the worst case a manual restart of the instance, impacting potentially the availability of the cluster, and this also makes WAL data look like it is in a corrupted state. The chances of seeing failures are higher if the connection between the standby and its root node is unstable, causing WAL pages to be written in the middle. A couple of approaches have been discussed, like zero-ing new WAL pages within the WAL receiver itself but this has the disadvantage of impacting performance of any existing instances as this breaks the sequential writes done by the WAL receiver. This commit deals with the problem with a more simple approach, which has no performance impact without reducing the detection of the problem: if a record is found with a length higher than 1GB for backends, then do not try any allocation and report a soft failure which will force the standby to retry reading WAL. It could be possible that the allocation call passes and that an unnecessary amount of memory is allocated, however follow-up checks on records would just fail, making this allocation short-lived anyway. This patch owes a great deal to Tsunakawa Takayuki for reporting the failure first, and then discussing a couple of potential approaches to the problem. Backpatch down to 9.5, which is where palloc_extended has been introduced. Reported-by: Tsunakawa Takayuki Reviewed-by: Tsunakawa Takayuki Author: Michael Paquier Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F8B57AD@G01JPEXMBYT05
* Remove AELs from subxids correctly on standbySimon Riggs2018-06-16
| | | | | | | | | | | | | | | | | | | | Issues relate only to subtransactions that hold AccessExclusiveLocks when replayed on standby. Prior to PG10, aborting subtransactions that held an AccessExclusiveLock failed to release the lock until top level commit or abort. 49bff5300d527 fixed that. However, 49bff5300d527 also introduced a similar bug where subtransaction commit would fail to release an AccessExclusiveLock, leaving the lock to be removed sometimes early and sometimes late. This commit fixes that bug also. Backpatch to PG10 needed. Tested by observation. Note need for multi-node isolationtester to improve test coverage for this and other HS cases. Reported-by: Simon Riggs Author: Simon Riggs
* Fix off-by-one bug in XactLogCommitRecordAlvaro Herrera2018-06-15
| | | | | | | | | | | Commit 1eb6d6527aae introduced zeroed alignment bytes in the GID field of commit/abort WAL records. Fixup commit cf5a1890592b later changed that representation into a regular cstring with a single terminating zero byte, but it also introduced an off-by-one mistake. Fix that. Author: Nikhil Sontakke Reported-by: Nikhil Sontakke Discussion: https://postgr.es/m/CAMGcDxey6dG1DP34_tJMoWPcp5sPJUAL4K5CayUUXLQSx2GQpA@mail.gmail.com
* Fail BRIN control functions during recovery explicitlyAlvaro Herrera2018-06-14
| | | | | | | | | | | They already fail anyway, but prior to this patch they raise an ugly error message about a lock that cannot be acquired. This just improves the message. Author: Masahiko Sawada Reported-by: Masahiko Sawada Discussion: https://postgr.es/m/CAD21AoBZau4g4_NUf3BKNd=CdYK+xaPdtJCzvOC1TxGdTiJx_Q@mail.gmail.com Reviewed-by: Kuntal Ghosh, Alexander Korotkov, Simon Riggs, Michaël Paquier, Álvaro Herrera
* Fix function code in error reportAlvaro Herrera2018-06-06
| | | | | | | | | | | | | This bug causes a lseek() failure to be reported as a "could not open" failure in the error message, muddling bug reports. I introduced this copy-and-pasteo in commit 78e122010422. Noticed while reviewing code for bug report #15221, from lily liang. In version 10 the affected function is only used by multixact.c and commit_ts, and only in corner-case circumstances, neither of which are involved in the reported bug (a pg_subtrans failure.) Author: Álvaro Herrera
* Move _bt_upgrademetapage() into critical section.Teodor Sigaev2018-05-30
| | | | | | | | Any changes on page should be done in critical section, so move _bt_upgrademetapage into critical section. Improve comment. Found by Amit Kapila during post-commit review of 857f9c36. Author: Amit Kapila
* printf("%lf") is not portable, so omit the "l".Tom Lane2018-05-20
| | | | | | | | | | | | The "l" (ell) width spec means something in the corresponding scanf usage, but not here. While modern POSIX says that applying "l" to "f" and other floating format specs is a no-op, SUSv2 says it's undefined. Buildfarm experience says that some old compilers emit warnings about it, and at least one old stdio implementation (mingw's "ANSI" option) actually produces wrong answers and/or crashes. Discussion: https://postgr.es/m/21670.1526769114@sss.pgh.pa.us Discussion: https://postgr.es/m/c085e1da-0d64-1c15-242d-c921f32e0d5c@dunslane.net
* Fix error message on short read of pg_controlMagnus Hagander2018-05-18
| | | | | Instead of saying "error: success", indicate that we got a working read but it was too short.
* Message wording and pluralization improvementsPeter Eisentraut2018-05-17
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* Various improvements of skipping index scan during vacuum technicsTeodor Sigaev2018-05-10
| | | | | | | | | | | | | | | | | - Change vacuum_cleanup_index_scale_factor GUC to PGC_USERSET. vacuum_cleanup_index_scale_factor GUC was defined as PGC_SIGHUP. But this GUC affects not only autovacuum. So it might be useful to change it from user session in order to influence manually runned VACUUM. - Add missing tab-complete support for vacuum_cleanup_index_scale_factor reloption. - Fix condition for B-tree index cleanup. Zero value of vacuum_cleanup_index_scale_factor means that user wants B-tree index cleanup to be never skipped. - Documentation and comment improvements Authors: Justin Pryzby, Alexander Korotkov, Liudmila Mantrova Reviewed by: all authors and Robert Haas Discussion: https://www.postgresql.org/message-id/flat/20180502023025.GD7631%40telsasoft.com
* Fix scenario where streaming standby gets stuck at a continuation record.Heikki Linnakangas2018-05-05
| | | | | | | | | | | | | | | | | | | | | If a continuation record is split so that its first half has already been removed from the master, and is only present in pg_wal, and there is a recycled WAL segment in the standby server that looks like it would contain the second half, recovery would get stuck. The code in XLogPageRead() incorrectly started streaming at the beginning of the WAL record, even if we had already read the first page. Backpatch to 9.4. In principle, older versions have the same problem, but without replication slots, there was no straightforward mechanism to prevent the master from recycling old WAL that was still needed by standby. Without such a mechanism, I think it's reasonable to assume that there's enough slack in how many old segments are kept around to not run into this, or you have a WAL archive. Reported by Jonathon Nelson. Analysis and patch by Kyotaro HORIGUCHI, with some extra comments by me. Discussion: https://www.postgresql.org/message-id/CACJqAM3xVz0JY1XFDKPP%2BJoJAjoGx%3DGNuOAshEDWCext7BFvCQ%40mail.gmail.com
* Don't mark pages all-visible spuriouslyAlvaro Herrera2018-05-04
| | | | | | | | | | | | | | | | | | | | | | | | | Dan Wood diagnosed a long-standing problem that pages containing tuples that are locked by multixacts containing live lockers may spuriously end up as candidates for getting their all-visible flag set. This has the long-term effect that multixacts remain unfrozen; this may previously pass undetected, but since commit XYZ it would be reported as "ERROR: found multixact 134100944 from before relminmxid 192042633" because when a later vacuum tries to freeze the page it detects that a multixact that should have gotten frozen, wasn't. Dan proposed a (correct) patch that simply sets a variable to its correct value, after a bogus initialization. But, per discussion, it seems better coding to avoid the bogus initializations altogether, since they could give rise to more bugs later. Therefore this fix rewrites the logic a little bit to avoid depending on the bogus initializations. This bug was part of a family introduced in 9.6 by commit a892234f830e; later, commit 38e9f90a227d fixed most of them, but this one was unnoticed. Authors: Dan Wood, Pavan Deolasee, Álvaro Herrera Reviewed-by: Masahiko Sawada, Pavan Deolasee, Álvaro Herrera Discussion: https://postgr.es/m/84EBAC55-F06D-4FBE-A3F3-8BDA093CE3E3@amazon.com
* Don't truncate away non-key attributes for leftmost downlinks.Teodor Sigaev2018-05-04
| | | | | | | | | | | | nbtsort.c does not need to truncate away non-key attributes for the minimum key of the leftmost page on a level, since this is only used to build a minus infinity downlink for the level's leftmost page. Truncating away non-key attributes in advance of truncating away all attributes in _bt_sortaddtup() does not affect the correctness of CREATE INDEX, but it is misleading. Author: Peter Geoghegan Discussion: https://www.postgresql.org/message-id/CAH2-WzkAS2M3ussHG-s_Av=Zo6dPjOxyu5fNRkYnxQV+YzGQ4w@mail.gmail.com
* Re-think predicate locking on GIN indexes.Teodor Sigaev2018-05-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The principle behind the locking was not very well thought-out, and not documented. Add a section in the README to explain how it's supposed to work, and change the code so that it actually works that way. This fixes two bugs: 1. If fast update was turned on concurrently, subsequent inserts to the pending list would not conflict with predicate locks that were acquired earlier, on entry pages. The included 'predicate-gin-fastupdate' test demonstrates that. To fix, make all scans acquire a predicate lock on the metapage. That lock represents a scan of the pending list, whether or not there is a pending list at the moment. Forget about the optimization to skip locking/checking for locks, when fastupdate=off. 2. If a scan finds no match, it still needs to lock the entry page. The point of predicate locks is to lock the gabs between values, whether or not there is a match. The included 'predicate-gin-nomatch' test tests that case. In addition to those two bug fixes, this removes some unnecessary locking, following the principle laid out in the README. Because all items in a posting tree have the same key value, a lock on the posting tree root is enough to cover all the items. (With a very large posting tree, it would possibly be better to lock the posting tree leaf pages instead, so that a "skip scan" with a query like "A & B", you could avoid unnecessary conflict if a new tuple is inserted with A but !B. But let's keep this simple.) Also, some spelling fixes. Author: Heikki Linnakangas with some editorization by me Review: Andrey Borodin, Alexander Korotkov Discussion: https://www.postgresql.org/message-id/0b3ad2c2-2692-62a9-3a04-5724f2af9114@iki.fi
* Add HOLD_INTERRUPTS section into FinishPreparedTransaction.Teodor Sigaev2018-05-03
| | | | | | | | | | | | | If an interrupt arrives in the middle of FinishPreparedTransaction and any callback decide to call CHECK_FOR_INTERRUPTS (e.g. RemoveTwoPhaseFile can write a warning with ereport, which checks for interrupts) then it's possible to leave current GXact undeleted. Backpatch to all supported branches Stas Kelvich Discussion: ihttps://www.postgresql.org/message-id/3AD85097-A3F3-4EBA-99BD-C38EDF8D2949@postgrespro.ru
* Clean up warnings from -Wimplicit-fallthrough.Tom Lane2018-05-01
| | | | | | | | | | | | | | | | | | | | | | | | | Recent gcc can warn about switch-case fall throughs that are not explicitly labeled as intentional. This seems like a good thing, so clean up the warnings exposed thereby by labeling all such cases with comments that gcc will recognize. In files that already had one or more suitable comments, I generally matched the existing style of those. Otherwise I went with /* FALLTHROUGH */, which is one of the spellings approved at the more-restrictive-than-default level -Wimplicit-fallthrough=4. (At the default level you can also spell it /* FALL ?THRU */, and it's not picky about case. What you can't do is include additional text in the same comment, so some existing comments containing versions of this aren't good enough.) Testing with gcc 8.0.1 (Fedora 28's current version), I found that I also had to put explicit "break"s after elog(ERROR) or ereport(ERROR); apparently, for this purpose gcc doesn't recognize that those don't return. That seems like possibly a gcc bug, but it's fine because in most places we did that anyway; so this amounts to a visit from the style police. Discussion: https://postgr.es/m/15083.1525207729@sss.pgh.pa.us
* In AtEOXact_Files, complain if any files remain unclosed at commit.Tom Lane2018-04-28
| | | | | | | | | | | This change makes this module act more like most of our other low-level resource management modules. It's a caller error if something is not explicitly closed by the end of a successful transaction, so issue a WARNING about it. This would not actually have caught the file leak bug fixed in commit 231bcd080, because that was in a transaction-abort path; but it still seems like a good, and pretty cheap, cross-check. Discussion: https://postgr.es/m/152056616579.4966.583293218357089052@wrigleys.postgresql.org
* Post-feature-freeze pgindent run.Tom Lane2018-04-26
| | | | Discussion: https://postgr.es/m/15719.1523984266@sss.pgh.pa.us
* Fix wrong validation of top-parent pointer during page deletion in Btree.Teodor Sigaev2018-04-23
| | | | | | | | | | | | | | | | | | | | | After introducing usage of t_tid of inner or page high key for storing number of attributes of tuple, validation of tuple's ItemPointer with ItemPointerIsValid becomes incorrect, it's need to validate only blocknumber of ItemPointer. Missing this causes a incorrect page deletion, fix that. Test is added. BTW, current contrib/amcheck doesn't fail on index corrupted by this way. Also introduce BTreeTupleGetTopParent/BTreeTupleSetTopParent macroses to improve code readability and to avoid possible confusion with page high key: high key is used to store top-parent link for branch to remove. Bug found by Michael Paquier, but bug doesn't exist in previous versions because t_tid was set to P_HIKEY. Author: Teodor Sigaev Reviewer: Peter Geoghegan Discussion: https://www.postgresql.org/message-id/flat/20180419052436.GA16000%40paquier.xyz
* Adjust _bt_insertonpg() commentsTeodor Sigaev2018-04-19
| | | | | | | | Remove an obsolete reference to the 'afteritem' argument, which was removed by commit bc292937. Add a comment that clarifies how _bt_insertonpg() indirectly handles the insertion of high key items. Author: Peter Geoghegan
* Handle XLOG_BTREE_META_CLEANUP in btree_desc() and btree_identify()Teodor Sigaev2018-04-19
| | | | | | | | New WAL record XLOG_BTREE_META_CLEANUP introduced in 857f9c36 has no handling in btree_desc() and btree_identify(). This patch implements corresponding handling. Alexander Korotkov
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