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path: root/src/backend/commands/vacuumlazy.c
AgeCommit message (Collapse)Author
2017-08-14Final pgindent + perltidy run for v10.Tom Lane
2017-07-22Fix typo in commentAlvaro Herrera
Commit fd31cd265138 renamed the variable to skipping_blocks, but forgot to update this comment. Noticed while inspecting code.
2017-07-07Fix typoAlvaro Herrera
Noticed while reviewing code.
2017-06-22Update out-of-date comment in vacuumlazy.cRobert Haas
Commit 15c121b3ed7eb2f290e19533e41ccca734d23574 seems to have overlooked the need to trim this part of the comment. Pavan Deolasee Discussion: http://postgr.es/m/CABOikdPq_9+cWRNZ0RLKTwuZyj=uL85X=Usifa-CbPee1ZCM5A@mail.gmail.com
2017-06-21Phase 3 of pgindent updates.Tom Lane
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/[email protected] Discussion: https://postgr.es/m/[email protected]
2017-06-21Phase 2 of pgindent updates.Tom Lane
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/[email protected] Discussion: https://postgr.es/m/[email protected]
2017-06-21Initial pgindent run with pg_bsd_indent version 2.0.Tom Lane
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/[email protected] Discussion: https://postgr.es/m/[email protected]
2017-06-13Re-run pgindent.Tom Lane
This is just to have a clean base state for testing of Piotr Stefaniak's latest version of FreeBSD indent. I fixed up a couple of places where pgindent would have changed format not-nicely. perltidy not included. Discussion: https://postgr.es/m/VI1PR03MB119959F4B65F000CA7CD9F6BF2CC0@VI1PR03MB1199.eurprd03.prod.outlook.com
2017-06-04Assorted translatable string fixesAlvaro Herrera
Mark our rusage reportage string translatable; remove quotes from type names; unify formatting of very similar messages.
2017-05-17Post-PG 10 beta1 pgindent runBruce Momjian
perltidy run not included.
2017-03-24Make VACUUM VERBOSE report the number of skipped frozen pages.Fujii Masao
Previously manual VACUUM did not report the number of skipped frozen pages even when VERBOSE option is specified. But this information is helpful to monitor the VACUUM activity, and also autovacuum reports that number in the log file when the condition of log_autovacuum_min_duration is met. This commit changes VACUUM VERBOSE so that it reports the number of frozen pages that it skips. Author: Masahiko Sawada Reviewed-by: Yugo Nagata and Jim Nasby Discussion: http://postgr.es/m/CAD21AoDZQKCxo0L39Mrq08cONNkXQKXuh=2DP1Q8ebmt35SoaA@mail.gmail.com
2017-03-16Avoid having vacuum set reltuples to 0 on non-empty relations in theAndrew Gierth
presence of page pins, which leads to serious estimation errors in the planner. This particularly affects small heavily-accessed tables, especially where locking (e.g. from FK constraints) forces frequent vacuums for mxid cleanup. Fix by keeping separate track of pages whose live tuples were actually counted vs. pages that were only scanned for freezing purposes. Thus, reltuples can only be set to 0 if all pages of the relation were actually counted. Backpatch to all supported versions. Per bug #14057 from Nicolas Baccelli, analyzed by me. Discussion: https://postgr.es/m/[email protected]
2017-03-03Allow vacuums to report oldestxminSimon Riggs
Allow VACUUM and Autovacuum to report the oldestxmin value they used while cleaning tables, helping to make better sense out of the other statistics we report in various cases.
2017-01-23Prefetch blocks during lazy vacuum's truncation scanAlvaro Herrera
Vacuum truncation scan can be sped up on rotating media by prefetching blocks in forward direction. That makes the blocks already present in memory by the time they are needed, while also letting OS read-ahead kick in. The truncate scan has been measured to be five times faster than without this patch (that was on a slow disk, but it shouldn't hurt on fast disks.) Author: Álvaro Herrera, loosely based on a submission by Claudio Freire Discussion: https://postgr.es/m/CAGTBQpa6NFGO_6g_y_7zQx8L9GcHDSQKYdo1tGuh791z6PYgEg@mail.gmail.com
2017-01-03Update copyright via script for 2017Bruce Momjian
2016-09-06Fix VACUUM_TRUNCATE_LOCK_WAIT_INTERVALSimon Riggs
lazy_truncate_heap() was waiting for VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL, but in microseconds not milliseconds as originally intended. Found by code inspection. Simon Riggs
2016-07-19Add comment & docs about no vacuum truncation with sto.Kevin Grittner
Omission noted by Andres Freund.
2016-07-18Clear all-frozen visibilitymap status when locking tuples.Andres Freund
Since a892234 & fd31cd265 the visibilitymap's freeze bit is used to avoid vacuuming the whole relation in anti-wraparound vacuums. Doing so correctly relies on not adding xids to the heap without also unsetting the visibilitymap flag. Tuple locking related code has not done so. To allow selectively resetting all-frozen - to avoid pessimizing heap_lock_tuple - allow to selectively reset the all-frozen with visibilitymap_clear(). To avoid having to use visibilitymap_get_status (e.g. via VM_ALL_FROZEN) inside a critical section, have visibilitymap_clear() return whether any bits have been reset. There's a remaining issue (denoted by XXX): After the PageIsAllVisible() check in heap_lock_tuple() and heap_lock_updated_tuple_rec() the page status could theoretically change. Practically that currently seems impossible, because updaters will hold a page level pin already. Due to the next beta coming up, it seems better to get the required WAL magic bump done before resolving this issue. The added flags field fields to xl_heap_lock and xl_heap_lock_updated require bumping the WAL magic. Since there's already been a catversion bump since the last beta, that's not an issue. Reviewed-By: Robert Haas, Amit Kapila and Andres Freund Author: Masahiko Sawada, heavily revised by Andres Freund Discussion: CAEepm=3fWAbWryVW9swHyLTY4sXVf0xbLvXqOwUoDiNCx9mBjQ@mail.gmail.com Backpatch: -
2016-06-17Add VACUUM (DISABLE_PAGE_SKIPPING) for emergencies.Robert Haas
If you really want to vacuum every single page in the relation, regardless of apparent visibility status or anything else, you can use this option. In previous releases, this behavior could be achieved using VACUUM (FREEZE), but because we can now recognize all-frozen pages as not needing to be frozen again, that no longer works. There should be no need for routine use of this option, but maybe bugs or disaster recovery will necessitate its use. Patch by me, reviewed by Andres Freund.
2016-06-15Fix lazy_scan_heap so that it won't mark pages all-frozen too soon.Robert Haas
Commit a892234f830e832110f63fc0a2afce2fb21d1584 added a new bit per page to the visibility map fork indicating whether the page is all-frozen, but incorrectly assumed that if lazy_scan_heap chose to freeze a tuple then that tuple would not need to later be frozen again. This turns out to be false, because xmin and xmax (and conceivably xvac, if dealing with tuples from very old releases) could be frozen at separate times. Thanks to Andres Freund for help in uncovering and tracking down this issue.
2016-06-09pgindent run for 9.6Robert Haas
2016-06-03Fix comment to be more accurate.Robert Haas
Now that we skip vacuuming all-frozen pages, this comment needs updating. Masahiko Sawada
2016-06-03Cosmetic improvements to freeze map code.Robert Haas
Per post-commit review comments from Andres Freund, improve variable names, comments, and in one place, slightly improve the code structure. Masahiko Sawada
2016-04-20Revert no-op changes to BufferGetPage()Kevin Grittner
The reverted changes were intended to force a choice of whether any newly-added BufferGetPage() calls needed to be accompanied by a test of the snapshot age, to support the "snapshot too old" feature. Such an accompanying test is needed in about 7% of the cases, where the page is being used as part of a scan rather than positioning for other purposes (such as DML or vacuuming). The additional effort required for back-patching, and the doubt whether the intended benefit would really be there, have indicated it is best just to rely on developers to do the right thing based on comments and existing usage, as we do with many other conventions. This change should have little or no effect on generated executable code. Motivated by the back-patching pain of Tom Lane and Robert Haas
2016-04-08Add the "snapshot too old" featureKevin Grittner
This feature is controlled by a new old_snapshot_threshold GUC. A value of -1 disables the feature, and that is the default. The value of 0 is just intended for testing. Above that it is the number of minutes a snapshot can reach before pruning and vacuum are allowed to remove dead tuples which the snapshot would otherwise protect. The xmin associated with a transaction ID does still protect dead tuples. A connection which is using an "old" snapshot does not get an error unless it accesses a page modified recently enough that it might not be able to produce accurate results. This is similar to the Oracle feature, and we use the same SQLSTATE and error message for compatibility.
2016-04-08Modify BufferGetPage() to prepare for "snapshot too old" featureKevin Grittner
This patch is a no-op patch which is intended to reduce the chances of failures of omission once the functional part of the "snapshot too old" patch goes in. It adds parameters for snapshot, relation, and an enum to specify whether the snapshot age check needs to be done for the page at this point. This initial patch passes NULL for the first two new parameters and BGP_NO_SNAPSHOT_TEST for the third. The follow-on patch will change the places where the test needs to be made.
2016-03-16Fix problems in commit c16dc1aca5e01e6acaadfcf38f5fc964a381dc62.Robert Haas
Vinayak Pokale provided a patch for a copy-and-paste error in a comment. I noticed that I'd use the word "automatically" nearby where I meant to talk about things being "atomic". Rahila Syed spotted a misplaced counter update. Fix all that stuff.
2016-03-15Add simple VACUUM progress reporting.Robert Haas
There's a lot more that could be done here yet - in particular, this reports only very coarse-grained information about the index vacuuming phase - but even as it stands, the new pg_stat_progress_vacuum can tell you quite a bit about what a long-running vacuum is actually doing. Amit Langote and Robert Haas, based on earlier work by Vinayak Pokale and Rahila Syed.
2016-03-10Don't vacuum all-frozen pages.Robert Haas
Commit a892234f830e832110f63fc0a2afce2fb21d1584 gave us enough infrastructure to avoid vacuuming pages where every tuple on the page is already frozen. So, replace the notion of a scan_all or whole-table vacuum with the less onerous notion of an "aggressive" vacuum, which will pages that are all-visible, but still skip those that are all-frozen. This should greatly reduce the cost of anti-wraparound vacuuming on large clusters where the majority of data is never touched between one cycle and the next, because we'll no longer have to read all of those pages only to find out that we don't need to do anything with them. Patch by me, reviewed by Masahiko Sawada.
2016-03-09Re-pgindent vacuumlazy.c.Robert Haas
2016-03-09Add a generic command progress reporting facility.Robert Haas
Using this facility, any utility command can report the target relation upon which it is operating, if there is one, and up to 10 64-bit counters; the intent of this is that users should be able to figure out what a utility command is doing without having to resort to ugly hacks like attaching strace to a backend. As a demonstration, this adds very crude reporting to lazy vacuum; we just report the target relation and nothing else. A forthcoming patch will make VACUUM report a bunch of additional data that will make this much more interesting. But this gets the basic framework in place. Vinayak Pokale, Rahila Syed, Amit Langote, Robert Haas, reviewed by Kyotaro Horiguchi, Jim Nasby, Thom Brown, Masahiko Sawada, Fujii Masao, and Masanori Oyama.
2016-03-08Department of second thoughts: remove PD_ALL_FROZEN.Robert Haas
Commit a892234f830e832110f63fc0a2afce2fb21d1584 added a second bit per page to the visibility map, which still seems like a good idea, but it also added a second page-level bit alongside PD_ALL_VISIBLE to track whether the visibility map bit was set. That no longer seems like a clever plan, because we don't really need that bit for anything. We always clear both bits when the page is modified anyway. Patch by me, reviewed by Kyotaro Horiguchi and Masahiko Sawada.
2016-03-02Change the format of the VM fork to add a second bit per page.Robert Haas
The new bit indicates whether every tuple on the page is already frozen. It is cleared only when the all-visible bit is cleared, and it can be set only when we vacuum a page and find that every tuple on that page is both visible to every transaction and in no need of any future vacuuming. A future commit will use this new bit to optimize away full-table scans that would otherwise be triggered by XID wraparound considerations. A page which is merely all-visible must still be scanned in that case, but a page which is all-frozen need not be. This commit does not attempt that optimization, although that optimization is the goal here. It seems better to get the basic infrastructure in place first. Per discussion, it's very desirable for pg_upgrade to automatically migrate existing VM forks from the old format to the new format. That, too, will be handled in a follow-on patch. Masahiko Sawada, reviewed by Kyotaro Horiguchi, Fujii Masao, Amit Kapila, Simon Riggs, Andres Freund, and others, and substantially revised by me.
2016-01-02Update copyright for 2016Bruce Momjian
Backpatch certain files through 9.1
2015-12-30Dept of second thoughts: the !scan_all exit mustn't increase scanned_pages.Tom Lane
In the extreme edge case where contended pages are the only ones that escape being scanned, the previous commit would have allowed us to think that relfrozenxid could be advanced, which is exactly wrong.
2015-12-30Avoid useless truncation attempts during VACUUM.Tom Lane
VACUUM can skip heap pages altogether when there's a run of consecutive pages that are all-visible according to the visibility map. This causes it to not update its nonempty_pages count, just as if those pages were empty, which means that at the end we will think they are candidates for deletion. Thus, we may take the table's AccessExclusive lock only to find that no pages are really truncatable. This usually causes no real problems on a master server, thanks to the lock being acquired only conditionally; but on hot-standby servers, the same lock must be acquired unconditionally which can result in unnecessary query cancellations. To improve matters, force examination of the table's last page whenever we reach there with a nonempty_pages count that would allow a truncation attempt. If it's not empty, we'll advance nonempty_pages and thereby prevent the truncation attempt. If we are unable to acquire cleanup lock on that page, there's no need to force it, unless we're doing an anti-wraparound vacuum. We can just check for tuples with a shared buffer lock and then give up. (When we are doing an anti-wraparound vacuum, and decide it's okay to skip the page because it contains no freezable tuples, this patch still improves matters because nonempty_pages is properly updated, which it was not before.) Since only the last page is special-cased in this way, we might attempt a truncation that will release many fewer pages than the normal heuristic would suggest; at worst, only one page would be truncated. But that seems all right, because the situation won't repeat during the next vacuum. The real problem with the old logic is that the useless truncation attempt happens every time we vacuum, so long as the state of the last few dozen pages doesn't change. This is a longstanding deficiency, but since the consequences aren't very severe in most scenarios, I'm not going to risk a back-patch. Jeff Janes and Tom Lane
2015-10-29Message style improvementsPeter Eisentraut
Message style, plurals, quoting, spelling, consistency with similar messages
2015-05-24pgindent run for 9.5Bruce Momjian
2015-05-20Fix more typos in comments.Heikki Linnakangas
Patch by CharSyam, plus a few more I spotted with grep.
2015-04-03Add log_min_autovacuum_duration per-table optionAlvaro Herrera
This is useful to control autovacuum log volume, for situations where monitoring only a set of tables is necessary. Author: Michael Paquier Reviewed by: A team led by Naoya Anzai (also including Akira Kurosawa, Taiki Kondo, Huong Dangminh), Fujii Masao.
2015-03-18Rationalize vacuuming options and parametersAlvaro Herrera
We were involving the parser too much in setting up initial vacuuming parameters. This patch moves that responsibility elsewhere to simplify code, and also to make future additions easier. To do this, create a new struct VacuumParams which is filled just prior to vacuum execution, instead of at parse time; for user-invoked vacuuming this is set up in a new function ExecVacuum, while autovacuum sets it up by itself. While at it, add a new member VACOPT_SKIPTOAST to enum VacuumOption, only set by autovacuum, which is used to disable vacuuming of the toast table instead of the old do_toast parameter; this relieves the argument list of vacuum() and some callees a bit. This partially makes up for having added more arguments in an effort to avoid having autovacuum from constructing a VacuumStmt parse node. Author: Michael Paquier. Some tweaks by Álvaro Reviewed by: Robert Haas, Stephen Frost, Álvaro Herrera
2015-01-08Fix logging of pages skipped due to pins during vacuum.Andres Freund
The new logging introduced in 35192f06 made the incorrect assumption that scan_all vacuums would always wait for buffer pins; but they only do so if the page actually needs to be frozen. Fix that inaccuracy by removing the difference in log output based on scan_all and just always remove the same message. I chose to keep the split log message from the original commit for now, it seems likely that it'll be of use in the future. Also merge the line about buffer pins in autovacuum's log output into the existing "pages: ..." line. It seems odd to have a separate line about pins, without the "topic: " prefix others have. Also rename the new 'pinned_pages' variable to 'pinskipped_pages' because it actually tracks the number of pages that could *not* be pinned. Discussion: [email protected]
2015-01-06Update copyright for 2015Bruce Momjian
Backpatch certain files through 9.0
2014-12-18Use %u to print out BlockNumber variablesAlvaro Herrera
Per Tom Lane
2014-12-18Have VACUUM log number of skipped pages due to pinsAlvaro Herrera
Author: Jim Nasby, some kibitzing by Heikki Linnankangas. Discussion leading to current behavior and precise wording fueled by thoughts from Robert Haas and Andres Freund.
2014-11-14Move BufferGetBlockNumber() out of heap_page_is_all_visible()'s inner loop.Andres Freund
In some workloads BufferGetBlockNumber() shows up in profiles due to the sheer number of calls to it (and because it causes cache misses). The compiler can't move it out of the loop because it's a full extern function call...
2014-11-06Move the backup-block logic from XLogInsert to a new file, xloginsert.c.Heikki Linnakangas
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.
2014-10-30Test IsInTransactionChain, not IsTransactionBlock, in vac_update_relstats.Tom Lane
As noted by Noah Misch, my initial cut at fixing bug #11638 didn't cover all cases where ANALYZE might be invoked in an unsafe context. We need to test the result of IsInTransactionChain not IsTransactionBlock; which is notationally a pain because IsInTransactionChain requires an isTopLevel flag, which would have to be passed down through several levels of callers. I chose to pass in_outer_xact (ie, the result of IsInTransactionChain) rather than isTopLevel per se, as that seemed marginally more apropos for the intermediate functions to know about.
2014-06-20Do all-visible handling in lazy_vacuum_page() outside its critical section.Andres Freund
Since fdf9e21196a lazy_vacuum_page() rechecks the all-visible status of pages in the second pass over the heap. It does so inside a critical section, but both visibilitymap_test() and heap_page_is_all_visible() perform operations that should not happen inside one. The former potentially performs IO and both potentially do memory allocations. To fix, simply move all the all-visible handling outside the critical section. Doing so means that the PD_ALL_VISIBLE on the page won't be included in the full page image of the HEAP2_CLEAN record anymore. But that's fine, the flag will be set by the HEAP2_VISIBLE logged later. Backpatch to 9.3 where the problem was introduced. The bug only came to light due to the assertion added in 4a170ee9 and isn't likely to cause problems in production scenarios. The worst outcome is a avoidable PANIC restart. This also gets rid of the difference in the order of operations between master and standby mentioned in 2a8e1ac5. Per reports from David Leverton and Keith Fiske in bug #10533.
2014-05-06pgindent run for 9.4Bruce Momjian
This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.