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path: root/src/backend/storage/lmgr/predicate.c
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* Prevent excess SimpleLruTruncate() deletion.Noah Misch2021-01-16
| | | | | | | | | | | | | | | | | Every core SLRU wraps around. With the exception of pg_notify, the wrap point can fall in the middle of a page. Account for this in the PagePrecedes callback specification and in SimpleLruTruncate()'s use of said callback. Update each callback implementation to fit the new specification. This changes SerialPagePrecedesLogically() from the style of asyncQueuePagePrecedes() to the style of CLOGPagePrecedes(). (Whereas pg_clog and pg_serial share a key space, pg_serial is nothing like pg_notify.) The bug fixed here has the same symptoms and user followup steps as 592a589a04bd456410b853d86bd05faa9432cbbb. Back-patch to 9.5 (all supported versions). Reviewed by Andrey Borodin and (in earlier versions) by Tom Lane. Discussion: https://postgr.es/m/20190202083822.GC32531@gust.leadboat.com
* Improve comments for [Heap]CheckForSerializableConflictOut().Thomas Munro2020-06-12
| | | | | | | | | | | | Rewrite the documentation of these functions, in light of recent bug fix commit 5940ffb2. Back-patch to 13 where the check-for-conflict-out code was split up into AM-specific and generic parts, and new documentation was added that now looked wrong. Reviewed-by: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/db7b729d-0226-d162-a126-8a8ab2dc4443%40jepsen.io
* Rename assorted LWLock tranches.Tom Lane2020-05-15
| | | | | | | | | | | | | | | | Choose names that fit into the conventions for wait event names (particularly, that multi-word names are in the style MultiWordName) and hopefully convey more information to non-hacker users than the previous names did. Also rename SerializablePredicateLockListLock to SerializablePredicateListLock; the old name was long enough to cause table formatting problems, plus the double occurrence of "Lock" seems confusing/error-prone. Also change a couple of particularly opaque LWLock field names. Discussion: https://postgr.es/m/28683.1589405363@sss.pgh.pa.us
* Rename SLRU structures and associated LWLocks.Tom Lane2020-05-15
| | | | | | | | | | | | | | | | | | | | | | | | | | Originally, the names assigned to SLRUs had no purpose other than being shmem lookup keys, so not a lot of thought went into them. As of v13, though, we're exposing them in the pg_stat_slru view and the pg_stat_reset_slru function, so it seems advisable to take a bit more care. Rename them to names based on the associated on-disk storage directories (which fortunately we *did* think about, to some extent; since those are also visible to DBAs, consistency seems like a good thing). Also rename the associated LWLocks, since those names are likewise user-exposed now as wait event names. For the most part I only touched symbols used in the respective modules' SimpleLruInit() calls, not the names of other related objects. This renaming could have been taken further, and maybe someday we will do so. But for now it seems undesirable to change the names of any globally visible functions or structs, so some inconsistency is unavoidable. (But I *did* terminate "oldserxid" with prejudice, as I found that name both unreadable and not descriptive of the SLRU's contents.) Table 27.12 needs re-alphabetization now, but I'll leave that till after the other LWLock renamings I have in mind. Discussion: https://postgr.es/m/28683.1589405363@sss.pgh.pa.us
* Remove dependency on HeapTuple from predicate locking functions.Thomas Munro2020-01-28
| | | | | | | | | | | | | | | | The following changes make the predicate locking functions more generic and suitable for use by future access methods: - PredicateLockTuple() is renamed to PredicateLockTID(). It takes ItemPointer and inserting transaction ID instead of HeapTuple. - CheckForSerializableConflictIn() takes blocknum instead of buffer. - CheckForSerializableConflictOut() no longer takes HeapTuple or buffer. Author: Ashwin Agrawal Reviewed-by: Andres Freund, Kuntal Ghosh, Thomas Munro Discussion: https://postgr.es/m/CALfoeiv0k3hkEb3Oqk%3DziWqtyk2Jys1UOK5hwRBNeANT_yX%2Bng%40mail.gmail.com
* Update copyrights for 2020Bruce Momjian2020-01-01
| | | | Backpatch-through: update all files in master, backpatch legal files through 9.4
* Optimize PredicateLockTuple().Thomas Munro2019-11-11
| | | | | | | | | | | | PredicateLockTuple() has a fast exit if tuple was written by the current transaction, as in that case it already has a lock. This check can be performed using TransactionIdIsCurrentTransactionId() instead of SubTransGetTopmostTransaction(), to avoid any chance of having to hit the disk. Author: Ashwin Agrawal, based on a suggestion from Andres Freund Reviewed-by: Thomas Munro Discussion: https://postgr.es/m/CALfoeiv0k3hkEb3Oqk%3DziWqtyk2Jys1UOK5hwRBNeANT_yX%2Bng%40mail.gmail.com
* Fix inconsistencies and typos in the tree, take 10Michael Paquier2019-08-13
| | | | | | | | | This addresses some issues with unnecessary code comments, fixes various typos in docs and comments, and removes some orphaned structures and definitions. Author: Alexander Lakhin Discussion: https://postgr.es/m/9aabc775-5494-b372-8bcb-4dfc0bd37c68@gmail.com
* Fix inconsistencies and typos in the tree, take 9Michael Paquier2019-08-05
| | | | | | | | This addresses more issues with code comments, variable names and unreferenced variables. Author: Alexander Lakhin Discussion: https://postgr.es/m/7ab243e0-116d-3e44-d120-76b3df7abefd@gmail.com
* Fix inconsistencies and typos in the treeMichael Paquier2019-07-16
| | | | | | | | | | | This is numbered take 7, and addresses a set of issues around: - Fixes for typos and incorrect reference names. - Removal of unneeded comments. - Removal of unreferenced functions and structures. - Fixes regarding variable name consistency. Author: Alexander Lakhin Discussion: https://postgr.es/m/10bfd4ac-3e7c-40ab-2b2e-355ed15495e8@gmail.com
* Fix inconsistencies in the codeMichael Paquier2019-07-08
| | | | | | | | | | | This addresses a couple of issues in the code: - Typos and inconsistencies in comments and function declarations. - Removal of unreferenced function declarations. - Removal of unnecessary compile flags. - A cleanup error in regressplans.sh. Author: Alexander Lakhin Discussion: https://postgr.es/m/0c991fdf-2670-1997-c027-772a420c4604@gmail.com
* Phase 2 pgindent run for v12.Tom Lane2019-05-22
| | | | | | | | | Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
* Fix SxactGlobalXmin tracking.Thomas Munro2019-05-09
| | | | | | | | | | | | | | | | Commit bb16aba50 broke the code that maintains SxactGlobalXmin. It could get stuck when a well-timed READ ONLY transaction runs. If SxactGlobalXmin stops advancing, transactions on the FinishedSerializableTransactions queue are never cleaned up, so resources are effectively leaked. Revert that hunk of the commit. Also revert another similar hunk that was probably harmless, but unnecessary and unjustified, relating to the DOOMED flag in case of RO_SAFE early release. Author: Thomas Munro Reported-by: Tom Lane Discussion: https://postgr.es/m/16170.1557251214%40sss.pgh.pa.us
* Add basic infrastructure for 64 bit transaction IDs.Thomas Munro2019-03-28
| | | | | | | | | | | | | | | | | | | | | | | | Instead of inferring epoch progress from xids and checkpoints, introduce a 64 bit FullTransactionId type and use it to track xid generation. This fixes an unlikely bug where the epoch is reported incorrectly if the range of active xids wraps around more than once between checkpoints. The only user-visible effect of this commit is to correct the epoch used by txid_current() and txid_status(), also visible with pg_controldata, in those rare circumstances. It also creates some basic infrastructure so that later patches can use 64 bit transaction IDs in more places. The new type is a struct that we pass by value, as a form of strong typedef. This prevents the sort of accidental confusion between TransactionId and FullTransactionId that would be possible if we were to use a plain old uint64. Author: Thomas Munro Reported-by: Amit Kapila Reviewed-by: Andres Freund, Tom Lane, Heikki Linnakangas Discussion: https://postgr.es/m/CAA4eK1%2BMv%2Bmb0HFfWM9Srtc6MVe160WFurXV68iAFMcagRZ0dQ%40mail.gmail.com
* Enable parallel query with SERIALIZABLE isolation.Thomas Munro2019-03-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, the SERIALIZABLE isolation level prevented parallel query from being used. Allow the two features to be used together by sharing the leader's SERIALIZABLEXACT with parallel workers. An extra per-SERIALIZABLEXACT LWLock is introduced to make it safe to share, and new logic is introduced to coordinate the early release of the SERIALIZABLEXACT required for the SXACT_FLAG_RO_SAFE optimization, as follows: The first backend to observe the SXACT_FLAG_RO_SAFE flag (set by some other transaction) will 'partially release' the SERIALIZABLEXACT, meaning that the conflicts and locks it holds are released, but the SERIALIZABLEXACT itself will remain active because other backends might still have a pointer to it. Whenever any backend notices the SXACT_FLAG_RO_SAFE flag, it clears its own MySerializableXact variable and frees local resources so that it can skip SSI checks for the rest of the transaction. In the special case of the leader process, it transfers the SERIALIZABLEXACT to a new variable SavedSerializableXact, so that it can be completely released at the end of the transaction after all workers have exited. Remove the serializable_okay flag added to CreateParallelContext() by commit 9da0cc35, because it's now redundant. Author: Thomas Munro Reviewed-by: Haribabu Kommi, Robert Haas, Masahiko Sawada, Kevin Grittner Discussion: https://postgr.es/m/CAEepm=0gXGYhtrVDWOTHS8SQQy_=S9xo+8oCxGLWZAOoeJ=yzQ@mail.gmail.com
* Move remaining code from tqual.[ch] to heapam.h / heapam_visibility.c.Andres Freund2019-01-21
| | | | | | | | | | | | | | Given these routines are heap specific, and that there will be more generic visibility support in via table AM, it makes sense to move the prototypes to heapam.h (routines like HeapTupleSatisfiesVacuum will not be exposed in a generic fashion, because they are too storage specific). Similarly, the code in tqual.c is specific to heap, so moving it into access/heap/ makes sense. Author: Andres Freund Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Remove obsolete SLRU wrapping and warnings from predicate.c.Tom Lane2018-03-30
| | | | | | | | | | | | | | | | When SSI was developed, slru.c was limited to segment files with names in the range 0000-FFFF. This didn't allow enough space for predicate.c to store every possible XID when spilling old transactions to disk, so it would wrap around sooner and print warnings. Since commits 638cf09e and 73c986ad increased the number of segment files slru.c could manage, that behavior is unnecessary. Therefore remove that code. Also remove the macro OldSerXidSegment, which has been unused since 4cd3fb6e. Thomas Munro, reviewed by Anastasia Lubennikova Discussion: https://postgr.es/m/CAEepm=3XfsTSxgEbEOmxu0QDiXy0o18NUg2nC89JZcCGE+XFPA@mail.gmail.com
* Remove extra words.Robert Haas2018-02-22
| | | | | | Thomas Munro Discussion: http://postgr.es/m/CAEepm=2x3NUSPed6=-wDYs39KtUU5Dw3mK_NAMWps+18FmkApQ@mail.gmail.com
* Update copyright for 2018Bruce Momjian2018-01-02
| | | | Backpatch-through: certain files through 9.3
* Message style fixesPeter Eisentraut2017-09-11
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* Fix outdated commentPeter Eisentraut2017-08-23
| | | | Author: Thomas Munro <thomas.munro@enterprisedb.com>
* Fix race condition in predicate-lock init code in EXEC_BACKEND builds.Tom Lane2017-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trading a little too heavily on letting the code path be the same whether we were creating shared data structures or only attaching to them, InitPredicateLocks() inserted the "scratch" PredicateLockTargetHash entry unconditionally. This is just wrong if we're in a postmaster child, which would only reach this code in EXEC_BACKEND builds. Most of the time, the hash_search(HASH_ENTER) call would simply report that the entry already existed, causing no visible effect since the code did not bother to check for that possibility. However, if this happened while some other backend had transiently removed the "scratch" entry, then that other backend's eventual RestoreScratchTarget would suffer an assert failure; this appears to be the explanation for a recent failure on buildfarm member culicidae. In non-assert builds, there would be no visible consequences there either. But nonetheless this is a pretty bad bug for EXEC_BACKEND builds, for two reasons: 1. Each new backend would perform the hash_search(HASH_ENTER) call without holding any lock that would prevent concurrent access to the PredicateLockTargetHash hash table. This creates a low but certainly nonzero risk of corruption of that hash table. 2. In the event that the race condition occurred, by reinserting the scratch entry too soon, we were defeating the entire purpose of the scratch entry, namely to guarantee that transaction commit could move hash table entries around with no risk of out-of-memory failure. The odds of an actual OOM failure are quite low, but not zero, and if it did happen it would again result in corruption of the hash table. The user-visible symptoms of such corruption are a little hard to predict, but would presumably amount to misbehavior of SERIALIZABLE transactions that'd require a crash or postmaster restart to fix. To fix, just skip the hash insertion if IsUnderPostmaster. I also inserted a bunch of assertions that the expected things happen depending on whether IsUnderPostmaster is true. That might be overkill, since most comparable code in other functions isn't quite that paranoid, but once burnt twice shy. In passing, also move a couple of lines to places where they seemed to make more sense. Diagnosis of problem by Thomas Munro, patch by me. Back-patch to all supported branches. Discussion: https://postgr.es/m/10593.1500670709@sss.pgh.pa.us
* Phase 3 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Phase 2 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Initial pgindent run with pg_bsd_indent version 2.0.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new indent version includes numerous fixes thanks to Piotr Stefaniak. The main changes visible in this commit are: * Nicer formatting of function-pointer declarations. * No longer unexpectedly removes spaces in expressions using casts, sizeof, or offsetof. * No longer wants to add a space in "struct structname *varname", as well as some similar cases for const- or volatile-qualified pointers. * Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely. * Fixes bug where comments following declarations were sometimes placed with no space separating them from the code. * Fixes some odd decisions for comments following case labels. * Fixes some cases where comments following code were indented to less than the expected column 33. On the less good side, it now tends to put more whitespace around typedef names that are not listed in typedefs.list. This might encourage us to put more effort into typedef name collection; it's not really a bug in indent itself. There are more changes coming after this round, having to do with comment indentation and alignment of lines appearing within parentheses. I wanted to limit the size of the diffs to something that could be reviewed without one's eyes completely glazing over, so it seemed better to split up the changes as much as practical. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Final pgindent run with old pg_bsd_indent (version 1.3).Tom Lane2017-06-21
| | | | | | | | | This is just to have a clean basis for comparison with the results of the new version (which will indeed end up reverting some of these changes...) Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Don't force-assign transaction id when exporting a snapshot.Andres Freund2017-06-14
| | | | | | | | | | | | | | | | | | | | | | Previously we required every exported transaction to have an xid assigned. That was used to check that the exporting transaction is still running, which in turn is needed to guarantee that that necessary rows haven't been removed in between exporting and importing the snapshot. The exported xid caused unnecessary problems with logical decoding, because slot creation has to wait for all concurrent xid to finish, which in turn serializes concurrent slot creation. It also prohibited snapshots to be exported on hot-standby replicas. Instead export the virtual transactionid, which avoids the unnecessary serialization and the inability to export snapshots on standbys. This changes the file name of the exported snapshot, but since we never documented what that one means, that seems ok. Author: Petr Jelinek, slightly editorialized by me Reviewed-By: Andres Freund Discussion: https://postgr.es/m/f598b4b8-8cd7-0d54-0939-adda763d8c34@2ndquadrant.com
* Fix typo in commentMagnus Hagander2017-06-02
| | | | Masahiko Sawada
* Move isolationtester's is-blocked query into C code for speed.Tom Lane2017-04-10
| | | | | | | | | | | | | | | | | | | Commit 4deb41381 modified isolationtester's query to see whether a session is blocked to also check for waits occurring in GetSafeSnapshot. However, it did that in a way that enormously increased the query's runtime under CLOBBER_CACHE_ALWAYS, causing the buildfarm members that use that to run about four times slower than before, and in some cases fail entirely. To fix, push the entire logic into a dedicated backend function. This should actually reduce the CLOBBER_CACHE_ALWAYS runtime from what it was previously, though I've not checked that. In passing, expose a SQL function to check for safe-snapshot blockage, comparable to pg_blocking_pids. This is more or less free given the infrastructure built to solve the other problem, so we might as well. Thomas Munro Discussion: https://postgr.es/m/20170407165749.pstcakbc637opkax@alap3.anarazel.de
* Add GUCs for predicate lock promotion thresholds.Kevin Grittner2017-04-07
| | | | | | | | | | Defaults match the fixed behavior of prior releases, but now DBAs have better options to tune serializable workloads. It might be nice to be able to set this per relation, but that part will need to wait for another release. Author: Dagfinn Ilmari Mannsåker
* Fix typos in comments.Heikki Linnakangas2017-02-06
| | | | | | | | | Backpatch to all supported versions, where applicable, to make backpatching of future fixes go more smoothly. Josh Soref Discussion: https://www.postgresql.org/message-id/CACZqfqCf+5qRztLPgmmosr-B0Ye4srWzzw_mo4c_8_B_mtjmJQ@mail.gmail.com
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Extend framework from commit 53be0b1ad to report latch waits.Robert Haas2016-10-04
| | | | | | | | | | | | | | | | | | | | | | WaitLatch, WaitLatchOrSocket, and WaitEventSetWait now taken an additional wait_event_info parameter; legal values are defined in pgstat.h. This makes it possible to uniquely identify every point in the core code where we are waiting for a latch; extensions can pass WAIT_EXTENSION. Because latches were the major wait primitive not previously covered by this patch, it is now possible to see information in pg_stat_activity on a large number of important wait events not previously addressed, such as ClientRead, ClientWrite, and SyncRep. Unfortunately, many of the wait events added by this patch will fail to appear in pg_stat_activity because they're only used in background processes which don't currently appear in pg_stat_activity. We should fix this either by creating a separate view for such information, or else by deciding to include them in pg_stat_activity after all. Michael Paquier and Robert Haas, reviewed by Alexander Korotkov and Thomas Munro.
* Change API of ShmemAlloc() so it throws error rather than returning NULL.Tom Lane2016-09-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | A majority of callers seem to have believed that this was the API spec already, because they omitted any check for a NULL result, and hence would crash on an out-of-shared-memory failure. The original proposal was to just add such error checks everywhere, but that does nothing to prevent similar omissions in future. Instead, let's make ShmemAlloc() throw the error (so we can remove the caller-side checks that do exist), and introduce a new function ShmemAllocNoError() that has the previous behavior of returning NULL, for the small number of callers that need that and are prepared to do the right thing. This also lets us remove the rather wishy-washy behavior of printing a WARNING for out-of-shmem, which never made much sense: either the caller has a strategy for dealing with that, or it doesn't. It's not ShmemAlloc's business to decide whether a warning is appropriate. The v10 release notes will need to call this out as a significant source-code change. It's likely that it will be a bug fix for extension callers too, but if not, they'll need to change to using ShmemAllocNoError(). This is nominally a bug fix, but the odds that it's fixing any live bug are actually rather small, because in general the requests being made by the unchecked callers were already accounted for in determining the overall shmem size, so really they ought not fail. Between that and the possible impact on extensions, no back-patch. Discussion: <24843.1472563085@sss.pgh.pa.us>
* Copyedit comments and documentation.Noah Misch2016-04-01
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* Make all built-in lwlock tranche IDs fixed.Robert Haas2016-02-02
| | | | | | | This makes the values more stable, which seems like a good thing for anybody who needs to look at at them. Alexander Korotkov and Amit Kapila
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Move each SLRU's lwlocks to a separate tranche.Robert Haas2015-11-12
| | | | | | | | | | This makes it significantly easier to identify these lwlocks in LWLOCK_STATS or Trace_lwlocks output. It's also arguably better from a modularity standpoint, since lwlock.c no longer needs to know anything about the LWLock needs of the higher-level SLRU facility. Ildus Kurbangaliev, reviewd by Álvaro Herrera and by me.
* Fix serialization anomalies due to race conditions on INSERT.Kevin Grittner2015-10-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On insert the CheckForSerializableConflictIn() test was performed before the page(s) which were going to be modified had been locked (with an exclusive buffer content lock). If another process acquired a relation SIReadLock on the heap and scanned to a page on which an insert was going to occur before the page was so locked, a rw-conflict would be missed, which could allow a serialization anomaly to be missed. The window between the check and the page lock was small, so the bug was generally not noticed unless there was high concurrency with multiple processes inserting into the same table. This was reported by Peter Bailis as bug #11732, by Sean Chittenden as bug #13667, and by others. The race condition was eliminated in heap_insert() by moving the check down below the acquisition of the buffer lock, which had been the very next statement. Because of the loop locking and unlocking multiple buffers in heap_multi_insert() a check was added after all inserts were completed. The check before the start of the inserts was left because it might avoid a large amount of work to detect a serialization anomaly before performing the all of the inserts and the related WAL logging. While investigating this bug, other SSI bugs which were even harder to hit in practice were noticed and fixed, an unnecessary check (covered by another check, so redundant) was removed from heap_update(), and comments were improved. Back-patch to all supported branches. Kevin Grittner and Thomas Munro
* Collection of typo fixes.Heikki Linnakangas2015-05-20
| | | | | | | | | | | | | | | Use "a" and "an" correctly, mostly in comments. Two error messages were also fixed (they were just elogs, so no translation work required). Two function comments in pg_proc.h were also fixed. Etsuro Fujita reported one of these, but I found a lot more with grep. Also fix a few other typos spotted while grepping for the a/an typos. For example, "consists out of ..." -> "consists of ...". Plus a "though"/ "through" mixup reported by Euler Taveira. Many of these typos were in old code, which would be nice to backpatch to make future backpatching easier. But much of the code was new, and I didn't feel like crafting separate patches for each branch. So no backpatching.
* Create an infrastructure for parallel computation in PostgreSQL.Robert Haas2015-04-30
| | | | | | | | | | | | | | | | | This does four basic things. First, it provides convenience routines to coordinate the startup and shutdown of parallel workers. Second, it synchronizes various pieces of state (e.g. GUCs, combo CID mappings, transaction snapshot) from the parallel group leader to the worker processes. Third, it prohibits various operations that would result in unsafe changes to that state while parallelism is active. Finally, it propagates events that would result in an ErrorResponse, NoticeResponse, or NotifyResponse message being sent to the client from the parallel workers back to the master, from which they can then be sent on to the client. Robert Haas, Amit Kapila, Noah Misch, Rushabh Lathia, Jeevan Chalke. Suggestions and review from Andres Freund, Heikki Linnakangas, Noah Misch, Simon Riggs, Euler Taveira, and Jim Nasby.
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* Improve hash_create's API for selecting simple-binary-key hash functions.Tom Lane2014-12-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, if you wanted anything besides C-string hash keys, you had to specify a custom hashing function to hash_create(). Nearly all such callers were specifying tag_hash or oid_hash; which is tedious, and rather error-prone, since a caller could easily miss the opportunity to optimize by using hash_uint32 when appropriate. Replace this with a design whereby callers using simple binary-data keys just specify HASH_BLOBS and don't need to mess with specific support functions. hash_create() itself will take care of optimizing when the key size is four bytes. This nets out saving a few hundred bytes of code space, and offers a measurable performance improvement in tidbitmap.c (which was not exploiting the opportunity to use hash_uint32 for its 4-byte keys). There might be some wins elsewhere too, I didn't analyze closely. In future we could look into offering a similar optimized hashing function for 8-byte keys. Under this design that could be done in a centralized and machine-independent fashion, whereas getting it right for keys of platform-dependent sizes would've been notationally painful before. For the moment, the old way still works fine, so as not to break source code compatibility for loadable modules. Eventually we might want to remove tag_hash and friends from the exported API altogether, since there's no real need for them to be explicitly referenced from outside dynahash.c. Teodor Sigaev and Tom Lane
* Move the backup-block logic from XLogInsert to a new file, xloginsert.c.Heikki Linnakangas2014-11-06
| | | | | | | | | | | | xlog.c is huge, this makes it a little bit smaller, which is nice. Functions related to putting together the WAL record are in xloginsert.c, and the lower level stuff for managing WAL buffers and such are in xlog.c. Also move the definition of XLogRecord to a separate header file. This causes churn in the #includes of all the files that write WAL records, and redo routines, but it avoids pulling in xlog.h into most places. Reviewed by Michael Paquier, Alvaro Herrera, Andres Freund and Amit Kapila.
* pgindent run for 9.4Bruce Momjian2014-05-06
| | | | | This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
* Fix misc typos in comments.Heikki Linnakangas2014-04-09
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* Relax the requirement that all lwlocks be stored in a single array.Robert Haas2014-01-27
| | | | | | | | | | | | | | This makes it possible to store lwlocks as part of some other data structure in the main shared memory segment, or in a dynamic shared memory segment. There is still a main LWLock array and this patch does not move anything out of it, but it provides necessary infrastructure for doing that in the future. This change is likely to increase the size of LWLockPadded on some platforms, especially 32-bit platforms where it was previously only 16 bytes. Patch by me. Review by Andres Freund and KaiGai Kohei.
* Allow use of "z" flag in our printf calls, and use it where appropriate.Tom Lane2014-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | Since C99, it's been standard for printf and friends to accept a "z" size modifier, meaning "whatever size size_t has". Up to now we've generally dealt with printing size_t values by explicitly casting them to unsigned long and using the "l" modifier; but this is really the wrong thing on platforms where pointers are wider than longs (such as Win64). So let's start using "z" instead. To ensure we can do that on all platforms, teach src/port/snprintf.c to understand "z", and add a configure test to force use of that implementation when the platform's version doesn't handle "z". Having done that, modify a bunch of places that were using the unsigned-long hack to use "z" instead. This patch doesn't pretend to have gotten everyplace that could benefit, but it catches many of them. I made an effort in particular to ensure that all uses of the same error message text were updated together, so as not to increase the number of translatable strings. It's possible that this change will result in format-string warnings from pre-C99 compilers. We might have to reconsider if there are any popular compilers that will warn about this; but let's start by seeing what the buildfarm thinks. Andres Freund, with a little additional work by me
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.