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* Fix typos.Amit Kapila2019-05-26
| | | | | | | Reported-by: Alexander Lakhin Author: Alexander Lakhin Reviewed-by: Amit Kapila and Tom Lane Discussion: https://postgr.es/m/7208de98-add8-8537-91c0-f8b089e2928c@gmail.com
* tableam: Rename wrapper functions to match callback names.Andres Freund2019-05-23
| | | | | | | | | | | | | | | | Some of the wrapper functions didn't match the callback names. Many of them due to staying "consistent" with historic naming of the wrapped functionality. We decided that for most cases it's more important to be for tableam to be consistent going forward, than with the past. The one exception is beginscan/endscan/... because it'd have looked odd to have systable_beginscan/endscan/... with a different naming scheme, and changing the systable_* APIs would have caused way too much churn (including breaking a lot of external users). Author: Ashwin Agrawal, with some small additions by Andres Freund Reviewed-By: Andres Freund Discussion: https://postgr.es/m/CALfoeiugyrXZfX7n0ORCa4L-m834dzmaE8eFdbNR6PMpetU4Ww@mail.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
* Initial pgindent run for v12.Tom Lane2019-05-22
| | | | | | | | This is still using the 2.0 version of pg_bsd_indent. I thought it would be good to commit this separately, so as to document the differences between 2.0 and 2.1 behavior. Discussion: https://postgr.es/m/16296.1558103386@sss.pgh.pa.us
* tableam: Move heap-specific logic from needs_toast_table below tableam.Robert Haas2019-05-21
| | | | | | | | | This allows table AMs to completely suppress TOAST table creation, or to modify the conditions under which they are created. Patch by me. Reviewed by Andres Freund. Discussion: http://postgr.es/m/CA+Tgmoa4O2n=yphqD2pERUnYmUO84bH1SqMsA-nSxBGsZ7gWfA@mail.gmail.com
* Fix comment for issue_xlog_fsync().Fujii Masao2019-05-21
| | | | | | | "segno" is the argument for the function, not "log" and "seg". Author: Antonin Houska Discussion: https://postgr.es/m/11863.1558361020@spoje.net
* Don't to predicate lock for analyze scans, refactor scan option passing.Andres Freund2019-05-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before this commit, when ANALYZE was run on a table and serializable was used (either by virtue of an explicit BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE, or default_transaction_isolation being set to serializable) a null pointer dereference lead to a crash. The analyze scan doesn't need a snapshot (nor predicate locking), but before this commit a scan only contained information about being a bitmap or sample scan. Refactor the option passing to the scan_begin callback to use a bitmask instead. Alternatively we could have added a new boolean parameter, but that seems harder to read. Even before this issue various people (Heikki, Tom, Robert) suggested doing so. These changes don't change the scan APIs outside of tableam. The flags argument could be exposed, it's not necessary to fix this problem. Also the wrapper table_beginscan* functions encapsulate most of that complexity. After these changes fixing the bug is trivial, just don't acquire predicate lock for analyze style scans. That was already done for bitmap heap scans. Add an assert that a snapshot is passed when acquiring the predicate lock, so this kind of bug doesn't require running with serializable. Also add a comment about sample scans currently requiring predicate locking the entire relation, that previously wasn't remarked upon. Reported-By: Joe Wildish Author: Andres Freund Discussion: https://postgr.es/m/4EA80A20-E9BF-49F1-9F01-5B66CAB21453@elusive.cx https://postgr.es/m/20190411164947.nkii4gaeilt4bui7@alap3.anarazel.de https://postgr.es/m/20190518203102.g7peu2fianukjuxm@alap3.anarazel.de
* "A void function may not return a value".Tom Lane2019-05-18
| | | | Per buildfarm.
* tableam: Avoid relying on relation size to determine validity of tids.Andres Freund2019-05-17
| | | | | | | | | | | Instead add a tableam callback to do so. To avoid adding per validation overhead, pass a scan to tuple_tid_valid. In heap's case we'd otherwise incurred a RelationGetNumberOfBlocks() call for each tid - which'd have added noticable overhead to nodeTidscan.c. Author: Andres Freund Reviewed-By: Ashwin Agrawal Discussion: https://postgr.es/m/20190515185447.gno2jtqxyktylyvs@alap3.anarazel.de
* tableam: Don't assume that every AM uses md.c style storage.Andres Freund2019-05-17
| | | | | | | | | | | | | | | | | | | | | | Previously various parts of the code routed size requests through RelationGetNumberOfBlocks[InFork]. That works if md.c is used by the AM, but not otherwise. Add a tableam callback to return the size of the table. As not every AM will use postgres' BLCKSZ, have it return bytes, and have RelationGetNumberOfBlocksInFork() round the byte size up into blocks. To allow code outside of the AM to determine the actual relation size map InvalidForkNumber the total size of a relation, as not every AM might just need the postgres defined forks. A few users of RelationGetNumberOfBlocks() ought to be converted away from that. One case, the use of it to determine whether a tid is valid, will be fixed in a follow up commit. Others will have to wait for v13. Author: Andres Freund Discussion: https://postgr.es/m/20190423225201.3bbv6tbqzkb5w7cw@alap3.anarazel.de
* Remove extra nbtree half-dead internal page check.Peter Geoghegan2019-05-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's not safe for nbtree VACUUM to attempt to delete a target page whose right sibling is already half-dead, since that would fail the cross-check when VACUUM attempts to re-find a downlink to the right sibling in the parent page. Logic to prevent this from happening was added by commit 8da31837803, which addressed a bug in the overhaul of page deletion that went into PostgreSQL 9.4 (commit efada2b8e92). VACUUM was made to check the right sibling page, and back off when it happened to be half-dead already. However, it is only truly necessary to do the right sibling check on the leaf level, since that transitively determines if the deletion target's parent's right sibling page is itself undergoing deletion. Remove the internal page level check, and add a comment explaining why the leaf level check alone suffices. The extra check is also unnecessary due to the fact that internal pages that are marked half-dead are generally considered corrupt. Commit efada2b8e92 established the principle that there should never be half-dead internal pages (internal pages pending deletion are possible, but that status is never directly represented in the internal page). VACUUM will complain about corruption when it encounters half-dead internal pages, so VACUUM is bound to raise an error one way or another when an nbtree index has a half-dead internal page (contrib/amcheck will also report that the page is corrupt). It's possible that a pg_upgrade'd 9.3 database will still have half-dead internal pages, so it may seem like there is an argument for leaving the check in place to reliably get a cleaner error message that advises the user to REINDEX. However, leaf pages are also deleted in the first phase of deletion prior to PostgreSQL 9.4, so I believe we won't even attempt to re-find the parent page anyway (we won't have the fully deleted leaf page as the right sibling of our target page, so we won't even try to find a downlink for it). Discussion: https://postgr.es/m/CAH2-Wzm_ntmqJjWLRyKzimFmFvk+BnVAvUpaA4s1h9Ja58woaQ@mail.gmail.com
* Remove obsolete nbtree insertion comment.Peter Geoghegan2019-05-15
| | | | | | | | | | | | | | | | | | Remove a Berkeley-era comment above _bt_insertonpg() that admonishes the reader to grok Lehman and Yao's paper before making any changes. This made a certain amount of sense back when _bt_insertonpg() was responsible for most of the things that are now spread across _bt_insertonpg(), _bt_findinsertloc(), _bt_insert_parent(), and _bt_split(), but it doesn't work like that anymore. I believe that this comment alludes to the need to "couple" or "crab" buffer locks as we ascend the tree as page splits cascade upwards. The nbtree README already explains this in detail, which seems sufficient. Besides, the changes to page splits made by commit 40dae7ec537 altered the exact details of how buffer locks are retained during splits; Lehman and Yao's original algorithm seems to release the lock on the left child page/buffer slightly earlier than _bt_insertonpg()/_bt_insert_parent() can.
* Reverse order of newitem nbtree candidate splits.Peter Geoghegan2019-05-15
| | | | | | | | | | | | | | | | | | | | | | | | | | Commit fab25024, which taught nbtree to choose candidate split points more carefully, had _bt_findsplitloc() record all possible split points in an initial pass over a page that is about to be split. The order that candidate split points were processed and stored in was assumed to match the offset number order of split points on an imaginary version of the page that contains the same items as the original, but also fits newitem (the item that provoked the split precisely because it didn't fit). However, the order of split points in the final array was not quite what was expected: the split point that makes newitem the firstright item came after the split point that makes newitem the lastleft item -- not before. As a result, _bt_findsplitloc() could get confused about the leftmost and rightmost tuples among all possible split points recorded for the page. This seems to have no appreciable impact on the quality of the final split point chosen by _bt_findsplitloc(), but it's still wrong. To fix, switch the order in which newitem candidate splits are recorded in. This also makes it possible to describe candidate split points in terms of which pair of adjoining tuples enclose the split point within _bt_findsplitloc(), making it clearer why it's generally safe for _bt_split() to expect lastleft and firstright tuples.
* Handle table_complete_speculative's succeeded argument as documented.Andres Freund2019-05-14
| | | | | | | | | | | | | | | | For some reason both callsite and the implementation for heapam had the meaning inverted (i.e. succeeded == true was passed in case of conflict). That's confusing. I (Andres) briefly pondered whether it'd be better to rename table_complete_speculative's argument to 'bool specConflict' or such, but decided not to. The 'complete' in the function name for me makes `succeeded` sound a bit better. Reported-By: Ashwin Agrawal, Melanie Plageman, Heikki Linnakangas Discussion: https://postgr.es/m/CALfoeitk7-TACwYv3hCw45FNPjkA86RfXg4iQ5kAOPhR+F1Y4w@mail.gmail.com https://postgr.es/m/97673451-339f-b21e-a781-998d06b1067c@iki.fi
* Detect internal GiST page splits correctly during index build.Heikki Linnakangas2019-05-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As we descend the GiST tree during insertion, we modify any downlinks on the way down to include the new tuple we're about to insert (if they don't cover it already). Modifying an existing downlink might cause an internal page to split, if the new downlink tuple is larger than the old one. If that happens, we need to back up to the parent and re-choose a page to insert to. We used to detect that situation, thanks to the NSN-LSN interlock normally used to detect concurrent page splits, but that got broken by commit 9155580fd5. With that commit, we now use a dummy constant LSN value for every page during index build, so the LSN-NSN interlock no longer works. I thought that was OK because there can't be any other backends modifying the index during index build, but missed that the insertion itself can modify the page we're inserting to. The consequence was that we would sometimes insert the new tuple to an incorrect page, one whose downlink doesn't cover the new tuple. To fix, add a flag to the stack that keeps track of the state while descending tree, to indicate that a page was split, and that we need to retry the descend from the parent. Thomas Munro first reported that the contrib/intarray regression test was failing occasionally on the buildfarm after commit 9155580fd5. The failure was intermittent, because the gistchoose() function is not deterministic, and would only occasionally create the right circumstances for this bug to cause the failure. Patch by Anastasia Lubennikova, with some changes by me to make it work correctly also when the internal page split also causes the "grandparent" to be split. Discussion: https://www.postgresql.org/message-id/CA%2BhUKGJRzLo7tZExWfSbwM3XuK7aAK7FhdBV0FLkbUG%2BW0v0zg%40mail.gmail.com
* Fix comment on when HOT update is possible.Heikki Linnakangas2019-05-14
| | | | | | | | The conditions listed in this comment have changed several times, and at some point the thing that the "if so" referred to was negated. The text was OK up to 9.6. It was differently wrong in v10, v11 and master, so fix in all those versions.
* Standardize ItemIdData terminology.Peter Geoghegan2019-05-13
| | | | | | | | | | | | | The term "item pointer" should not be used to refer to ItemIdData variables, since that is needlessly ambiguous. Only ItemPointerData/ItemPointer variables should be called item pointers. To fix, establish the convention that ItemIdData variables should always be referred to either as "item identifiers" or "line pointers". The term "item identifier" already predominates in docs and translatable messages, and so should be the preferred alternative there. Discussion: https://postgr.es/m/CAH2-Wz=c=MZQjUzde3o9+2PLAPuHTpVZPPdYxN=E4ndQ2--8ew@mail.gmail.com
* Don't leave behind junk nbtree pages during split.Peter Geoghegan2019-05-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 8fa30f906be reduced the elevel of a number of "can't happen" _bt_split() errors from PANIC to ERROR. At the same time, the new right page buffer for the split could continue to be acquired well before the critical section. This was possible because it was relatively straightforward to make sure that _bt_split() could not throw an error, with a few specific exceptions. The exceptional cases were safe because they involved specific, well understood errors, making it possible to consistently zero the right page before actually raising an error using elog(). There was no danger of leaving around a junk page, provided _bt_split() stuck to this coding rule. Commit 8224de4f, which introduced INCLUDE indexes, added code to make _bt_split() truncate away non-key attributes. This happened at a point that broke the rule around zeroing the right page in _bt_split(). If truncation failed (perhaps due to palloc() failure), that would result in an errant right page buffer with junk contents. This could confuse VACUUM when it attempted to delete the page, and should be avoided on general principle. To fix, reorganize _bt_split() so that truncation occurs before the new right page buffer is even acquired. A junk page/buffer will not be left behind if _bt_nonkey_truncate()/_bt_truncate() raise an error. Discussion: https://postgr.es/m/CAH2-WzkcWT_-NH7EeL=Az4efg0KCV+wArygW8zKB=+HoP=VWMw@mail.gmail.com Backpatch: 11-, where INCLUDE indexes were introduced.
* Clean up the behavior and API of catalog.c's is-catalog-relation tests.Tom Lane2019-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The right way for IsCatalogRelation/Class to behave is to return true for OIDs less than FirstBootstrapObjectId (not FirstNormalObjectId), without any of the ad-hoc fooling around with schema membership. The previous code was wrong because (1) it claimed that information_schema tables were not catalog relations but their toast tables were, which is silly; and (2) if you dropped and recreated information_schema, which is a supported operation, the behavior changed. That's even sillier. With this definition, "catalog relations" are exactly the ones traceable to the postgres.bki data, which seems like what we want. With this simplification, we don't actually need access to the pg_class tuple to identify a catalog relation; we only need its OID. Hence, replace IsCatalogClass with "IsCatalogRelationOid(oid)". But keep IsCatalogRelation as a convenience function. This allows fixing some arguably-wrong semantics in contrib/sepgsql and ReindexRelationConcurrently, which were using an IsSystemNamespace test where what they really should be using is IsCatalogRelationOid. The previous coding failed to protect toast tables of system catalogs, and also was not on board with the general principle that user-created tables do not become catalogs just by virtue of being renamed into pg_catalog. We can also get rid of a messy hack in ReindexMultipleTables. While we're at it, also rename IsSystemNamespace to IsCatalogNamespace, because the previous name invited confusion with the more expansive semantics used by IsSystemRelation/Class. Also improve the comments in catalog.c. There are a few remaining places in replication-related code that are special-casing OIDs below FirstNormalObjectId. I'm inclined to think those are wrong too, and if there should be any special case it should just extend to FirstBootstrapObjectId. But first we need to debate whether a FOR ALL TABLES publication should include information_schema. Discussion: https://postgr.es/m/21697.1557092753@sss.pgh.pa.us Discussion: https://postgr.es/m/15150.1557257111@sss.pgh.pa.us
* Remove obsolete nbtree split REDO routine comment.Peter Geoghegan2019-05-08
| | | | | | | | | Commit dd299df8189, which added suffix truncation to nbtree, simplified the WAL record format used by page splits. It became necessary to explicitly WAL-log the new high key for the left half of a split in all cases, which relieved the REDO routine from having to reconstruct a new high key for the left page by copying the first item from the right page. Remove a comment that referred to the previous practice.
* Remove leftover reference to old "flat file" mechanism in a comment.Heikki Linnakangas2019-05-08
| | | | The flat file mechanism was removed in PostgreSQL 9.0.
* Correct obsolete nbtsort.c minimum key comment.Peter Geoghegan2019-05-07
| | | | | | | It is no longer possible under any circumstances for nbtree code to reconstruct a strict lower bound key (parent page's pivot tuple key) for a right sibling page by retrieving the first item in the right sibling page.
* Add TRUNCATE parameter to VACUUM.Fujii Masao2019-05-08
| | | | | | | | | | | | | | | This commit adds new parameter to VACUUM command, TRUNCATE, which specifies that VACUUM should attempt to truncate off any empty pages at the end of the table and allow the disk space for the truncated pages to be returned to the operating system. This parameter, if specified, overrides the vacuum_truncate reloption. If neither the reloption nor the VACUUM option is used, the default is true, as before. Author: Fujii Masao Reviewed-by: Julien Rouhaud, Masahiko Sawada Discussion: https://postgr.es/m/CAD21AoD+qtrSDL=GSma4Wd3kLYLeRC0hPna-YAdkDeV4z156vg@mail.gmail.com
* Revert "Avoid the creation of the free space map for small heap relations".Amit Kapila2019-05-07
| | | | | | | | | | | | | | | | | | | | | This feature was using a process local map to track the first few blocks in the relation. The map was reset each time we get the block with enough freespace. It was discussed that it would be better to track this map on a per-relation basis in relcache and then invalidate the same whenever vacuum frees up some space in the page or when FSM is created. The new design would be better both in terms of API design and performance. List of commits reverted, in reverse chronological order: 06c8a5090e Improve code comments in b0eaa4c51b. 13e8643bfc During pg_upgrade, conditionally skip transfer of FSMs. 6f918159a9 Add more tests for FSM. 9c32e4c350 Clear the local map when not used. 29d108cdec Update the documentation for FSM behavior.. 08ecdfe7e5 Make FSM test portable. b0eaa4c51b Avoid creation of the free space map for small heap relations. Discussion: https://postgr.es/m/20190416180452.3pm6uegx54iitbt5@alap3.anarazel.de
* Correct more obsolete nbtree page split comments.Peter Geoghegan2019-05-03
| | | | | | | | | | | | Commit 3f342839 corrected obsolete comments about buffer locks at the main _bt_insert_parent() call site, but missed similar obsolete comments above _bt_insert_parent() itself. Both sets of comments were rendered obsolete by commit 40dae7ec537, which made the nbtree page split algorithm more robust. Fix the comments that were missed the first time around now. In passing, refine a related _bt_insert_parent() comment about re-finding the parent page to insert new downlink.
* heap_prepare_freeze_tuple: Simplify codingAlvaro Herrera2019-05-02
| | | | | | | | | | Commit d2599ecfcc74 introduced some contorted, confused code around: readers would think that it's possible for HeapTupleHeaderGetXmin return a non-frozen value for some frozen tuples, which would be disastrous. There's no actual bug, but it seems better to make it clearer. Per gripe from Tom Lane and Andres Freund. Discussion: https://postgr.es/m/30116.1555430496@sss.pgh.pa.us
* Fix nbtsort.c's page space accounting.Peter Geoghegan2019-05-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit dd299df8189, which made heap TID a tiebreaker nbtree index column, introduced new rules on page space management to make suffix truncation safe. In general, suffix truncation needs to have a small amount of extra space available on the new left page when splitting a leaf page. This is needed in case it turns out that truncation cannot even "truncate away the heap TID column", resulting in a larger-than-firstright leaf high key with an explicit heap TID representation. Despite all this, CREATE INDEX/nbtsort.c did not account for the possible need for extra heap TID space on leaf pages when deciding whether or not a new item could fit on current page. This could lead to "failed to add item to the index page" errors when CREATE INDEX/nbtsort.c tried to finish off a leaf page that lacked space for a larger-than-firstright leaf high key (it only had space for firstright tuple, which was just short of what was needed following "truncation"). Several conditions needed to be met all at once for CREATE INDEX to fail. The problem was in the hard limit on what will fit on a page, which tends to be masked by the soft fillfactor-wise limit. The easiest way to recreate the problem seems to be a CREATE INDEX on a low cardinality text column, with tuples that are of non-uniform width, using a fillfactor of 100. To fix, bring nbtsort.c in line with nbtsplitloc.c, which already pessimistically assumes that all leaf page splits will have high keys that have a heap TID appended. Reported-By: Andreas Joseph Krogh Discussion: https://postgr.es/m/VisenaEmail.c5.3ee7fe277d514162.16a6d785bea@tc7-visena
* Fix some problems with VACUUM (INDEX_CLEANUP FALSE).Robert Haas2019-05-02
| | | | | | | | | | | | | | | | | | | | The new nleft_dead_tuples and nleft_dead_itemids fields are confusing and do not seem like the correct way forward. One of them is tested via an assertion that can fail, as it has already done on buildfarm member topminnow. Remove the assertion and the fields. Change the logic for the case where a tuple is not initially pruned by heap_page_prune but later diagnosed HEAPTUPLE_DEAD by HeapTupleSatisfiesVacuum. Previously, tupgone = true was set in that case, which leads to treating the tuple as one that will be removed. In a normal vacuum, that's OK, because we'll remove index entries for it and then the second heap pass will remove the tuple itself, but when index cleanup is disabled, those things don't happen, so we must instead treat it as a recently-dead tuple that we have voluntarily chosen to keep. Report and analysis by Tom Lane. This patch loosely based on one from Masahiko Sawada, but I changed most of it.
* Message style fixesAlvaro Herrera2019-04-30
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* Widen tuple counter variables from long to int64Alvaro Herrera2019-04-30
| | | | | | | | Mistake in ab0dfc961b6a; progress reporting would have wrapped around for indexes created with more than 2^31 tuples. Reported-by: Peter Geoghegan Discussion: https://postgr.es/m/CAH2-Wz=WbNxc5ob5NJ9yqo2RMJ0q4HXDS30GVCobeCvC9A1L9A@mail.gmail.com
* Fix several recently introduced issues around handling new relation forks.Andres Freund2019-04-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most of these stem from d25f519107 "tableam: relation creation, VACUUM FULL/CLUSTER, SET TABLESPACE.". 1) To pass data to the relation_set_new_filenode() RelationSetNewRelfilenode() was made to update RelationData.rd_rel directly. That's not OK however, as it makes the relcache entries temporarily inconsistent. Which among other scenarios is a problem if a REINDEX targets an index on pg_class - the CatalogTupleUpdate() in RelationSetNewRelfilenode(). Presumably that was introduced because other places in the code do so - while those aren't "good practice" they don't appear to be actively buggy (e.g. because system tables may not be targeted). I (Andres) should have caught this while reviewing and signficantly evolving the code in that commit, mea culpa. Fix that by instead passing in the new RelFileNode as separate argument to relation_set_new_filenode() and rely on the relcache to update the catalog entry. Also revert that the RelationMapUpdateMap() call was changed to immediate, and undo some other more unnecessary changes. 2) Document that the relation_set_new_filenode cannot rely on the whole relcache entry to be valid. It might be worthwhile to refactor the code to never have to rely on that, but given the way heap_create() is currently coded, that'd be a large change. 3) ATExecSetTableSpace() shouldn't do FlushRelationBuffers() itself. A table AM might not use shared buffers at all. Move to index_copy_data() and heapam_relation_copy_data(). 4) heapam_relation_set_new_filenode() previously sometimes accessed rel->rd_rel->relpersistence rather than the `persistence` argument. Code movement mistake. 5) Previously heapam_relation_set_new_filenode() re-opened the smgr relation to create the init for, if necesary. Instead have RelationCreateStorage() return the SMgrRelation and use it to create the init fork. 6) Add a note about the danger of modifying the relcache directly to ATExecSetTableSpace() - it's currently not a bug because there's a check ERRORing for catalog tables. Regression tests and assertion improvements that together trigger the bug described in 1) will be added in a later commit, as there is a related bug on all branches. Reported-By: Michael Paquier Diagnosed-By: Tom Lane and Andres Freund Author: Andres Freund Reviewed-By: Tom Lane Discussion: https://postgr.es/m/20190418011430.GA19133@paquier.xyz
* Remove obsolete _bt_insert_parent() comment.Peter Geoghegan2019-04-29
| | | | | | | Remove a comment that refers to a coding practice that was fully removed by commit a8b8f4db, which introduced MarkBufferDirty(). It looks like the comment was even obsolete before then, since it concerns write-ordering dependencies with synchronous buffer writes.
* Allow pg_class xid & multixid horizons to not be set.Andres Freund2019-04-23
| | | | | | | | | | | | | | | | | | | | | | | This allows table AMs that don't need these horizons. This was already documented in the tableam relation_set_new_filenode callback, but an assert prevented if from actually working (the test AM code contained the change itself). Defang the asserts in the general code, and move the stronger ones into heap AM. Relatedly, after CLUSTER/VACUUM, we'd always assign a relfrozenxid / relminmxid. Change the table_relation_copy_for_cluster() interface to allow the AM to overwrite the horizons that get set on the pg_class entry. This'd also in the future allow AMs like heap to compute a relfrozenxid during rewrite that's the table's actual minimum rather than a pre-determined value. Arguably it'd have been better to move the whole computation / setting of those values into the callback, but it seems likely that for other reasons it'd be better to be able to use one value to vacuum/cluster multiple tables (e.g. a toast's horizon shouldn't be different than the table's). Reported-By: Heikki Linnakangas Author: Andres Freund Discussion: https://postgr.es/m/9a7fb9cc-2419-5db7-8840-ddc10c93f122@iki.fi
* Prevent O(N^2) unique index insertion edge case.Peter Geoghegan2019-04-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit dd299df8 made nbtree treat heap TID as a tiebreaker column, establishing the principle that there is only one correct location (page and page offset number) for every index tuple, no matter what. Insertions of tuples into non-unique indexes proceed as if heap TID (scan key's scantid) is just another user-attribute value, but insertions into unique indexes are more delicate. The TID value in scantid must initially be omitted to ensure that the unique index insertion visits every leaf page that duplicates could be on. The scantid is set once again after unique checking finishes successfully, which can force _bt_findinsertloc() to step right one or more times, to locate the leaf page that the new tuple must be inserted on. Stepping right within _bt_findinsertloc() was assumed to occur no more frequently than stepping right within _bt_check_unique(), but there was one important case where that assumption was incorrect: inserting a "duplicate" with NULL values. Since _bt_check_unique() didn't do any real work in this case, it wasn't appropriate for _bt_findinsertloc() to behave as if it was finishing off a conventional unique insertion, where any existing physical duplicate must be dead or recently dead. _bt_findinsertloc() might have to grovel through a substantial portion of all of the leaf pages in the index to insert a single tuple, even when there were no dead tuples. To fix, treat insertions of tuples with NULLs into a unique index as if they were insertions into a non-unique index: never unset scantid before calling _bt_search() to descend the tree, and bypass _bt_check_unique() entirely. _bt_check_unique() is no longer responsible for incoming tuples with NULL values. Discussion: https://postgr.es/m/CAH2-Wzm08nr+JPx4jMOa9CGqxWYDQ-_D4wtPBiKghXAUiUy-nQ@mail.gmail.com
* Convert gist to compute page level xid horizon on primary.Andres Freund2019-04-22
| | | | | | | | | | | | | | | | | Due to parallel development, gist added the missing conflict information in c952eae52a3, while 558a9165e08 moved that computation to the primary for the index types that already had it. Thus adapt gist to also compute on the primary, using index_compute_xid_horizon_for_tuples() instead of its own copy of the logic. This also adds pg_waldump support for XLOG_GIST_DELETE records, which previously was not properly present. Bumps WAL version. Author: Andres Freund Discussion: https://postgr.es/m/20190406050243.bszosdg4buvabfrt@alap3.anarazel.de
* Simplify some ERROR paths clearing wait events and transient filesMichael Paquier2019-04-17
| | | | | | | | | | | | | | Transient files and wait events get normally cleaned up when seeing an exception (be it in the context of a transaction for a backend or another process like the checkpointer), hence there is little point in complicating error code paths to do this work. This shaves a bit of code, and removes some extra handling with errno which needed to be preserved during the cleanup steps done. Reported-by: Masahiko Sawada Author: Michael Paquier Reviewed-by: Tom Lane, Masahiko Sawada Discussion: https://postgr.es/m/CAD21AoDhHYVq5KkXfkaHhmjA-zJYj-e4teiRAJefvXuKJz1tKQ@mail.gmail.com
* Fix division by zero in _bt_vacuum_needs_cleanup()Alexander Korotkov2019-04-15
| | | | | | | | | | | Checks inside _bt_vacuum_needs_cleanup() allow division by zero to happen when metad->btm_last_cleanup_num_heap_tuples == 0. This commit adjusts the expression so that no division by zero might happen. Reported-by: Piotr Stefaniak Discussion: https://postgr.es/m/DB8PR03MB5931C41F7787A95313F08322F22A0%40DB8PR03MB5931.eurprd03.prod.outlook.com Reviewed-by: Masahiko Sawada Backpatch-through: 11
* Fix GetNewTransactionId()'s interaction with xidVacLimit.Thomas Munro2019-04-12
| | | | | | | | | | | | | | | Commit ad308058 switched to returning a FullTransactionId, but failed to load the potentially updated value in the case where xidVacLimit is reached and we release and reacquire the lock. Repair, closing bug #15727. While reviewing that commit, also fix the size computation used by EstimateTransactionStateSize() and switch to the mul_size() macro traditionally used in such expressions. Author: Thomas Munro Reported-by: Roman Zharkov Discussion: https://postgr.es/m/15727-0be246e7d852d229%40postgresql.org
* Fix typos in reloptions.cMichael Paquier2019-04-12
| | | | | Author: Kirk Jamison Discussion: https://postgr.es/m/D09B13F772D2274BB348A310EE3027C6493463@g01jpexmbkw24
* Avoid counting transaction stats for parallel worker cooperatingAmit Kapila2019-04-10
| | | | | | | | | | | | | | | | | | | | | | transaction. The transaction that is initiated by the parallel worker to cooperate with the actual transaction started by the main backend to complete the query execution should not be counted as a separate transaction. The other internal transactions started and committed by the parallel worker are still counted as separate transactions as we that is what we do in other places like autovacuum. This will partially fix the bloat in transaction stats due to additional transactions performed by parallel workers. For a complete fix, we need to decide how we want to show all the transactions that are started internally for various operations and that is a matter of separate patch. Reported-by: Haribabu Kommi Author: Haribabu Kommi Reviewed-by: Amit Kapila, Jamison Kirk and Rahila Syed Backpatch-through: 9.6 Discussion: https://postgr.es/m/CAJrrPGc9=jKXuScvNyQ+VNhO0FZk7LLAShAJRyZjnedd2D61EQ@mail.gmail.com
* Add vacuum_truncate reloption.Fujii Masao2019-04-08
| | | | | | | | | | | | | | | vacuum_truncate controls whether vacuum tries to truncate off any empty pages at the end of the table. Previously vacuum always tried to do the truncation. However, the truncation could cause some problems; for example, ACCESS EXCLUSIVE lock needs to be taken on the table during the truncation and can cause the query cancellation on the standby even if hot_standby_feedback is true. Setting this reloption to false can be helpful to avoid such problems. Author: Tsunakawa Takayuki Reviewed-By: Julien Rouhaud, Masahiko Sawada, Michael Paquier, Kirk Jamison and Fujii Masao Discussion: https://postgr.es/m/CAHGQGwE5UqFqSq1=kV3QtTUtXphTdyHA-8rAj4A=Y+e4kyp3BQ@mail.gmail.com
* Fix a number of issues around modifying a previously updated row.Andres Freund2019-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit fixes three, unfortunately related, issues: 1) Since 5db6df0c01, the introduction of DML via tableam, it was possible to trigger "ERROR: unexpected table_lock_tuple status: 1" when updating a row that was previously updated in the same transaction - but only when the previously updated row was before updated in a concurrent transaction (and READ COMMITTED was used). The reason for that was that that case simply wasn't expected. Fixing that lead to: 2) Even before the above commit, there were error checks (introduced in 6868ed7491b7) preventing a row being updated by different commands within the same statement (say in a function called by an UPDATE) - but that check wasn't performed when the row was first updated in a concurrent transaction - instead the second update was silently skipped in that case. After this change we throw the same error as we'd without the concurrent transaction. 3) The error messages (introduced in 6868ed7491b7) preventing such updates emitted the same error message for both DELETE and UPDATE ("tuple to be updated was already modified by an operation triggered by the current command"). While that could be changed separately, it made it hard to write tests that verify the correct correct behavior of the code. This commit changes heap's implementation of table_lock_tuple() to return TM_SelfModified instead of TM_Invisible (previously loosely modeled after EvalPlanQualFetch), and teaches nodeModifyTable.c to handle that in response to table_lock_tuple() and not just in response to table_(delete|update). Additionally it fixes the wrong error message (see 3 above). The comment for table_lock_tuple() is also adjusted to state that TM_Deleted won't return information in TM_FailureData - it'll not always be available. This also adds tests to ensure that DELETE/UPDATE correctly error out when affecting a row that concurrently was modified by another transaction. Author: Andres Freund Reported-By: Tom Lane, when investigating a bug bug fix to another bug by Amit Langote Discussion: https://postgr.es/m/19321.1554567786@sss.pgh.pa.us
* Remove unused struct member, enforce multi_insert callback presence.Andres Freund2019-04-04
| | | | | Author: David Rowley, Andres Freund Discussion: https://postgr.es/m/CAKJS1f9=9phmm66diAji4gvHnWSrK7BGFoNct+mEUT_c8pPOjw@mail.gmail.com
* Harden tableam against nonexistant / wrong kind of AMs.Andres Freund2019-04-04
| | | | | | | | | | | | | | | | | Previously it was allowed to set default_table_access_method to an empty string. That makes sense for default_tablespace, where that was copied from, as it signals falling back to the database's default tablespace. As there is no equivalent for table AMs, forbid that. Also make sure to throw a usable error when creating a table using an index AM, by using get_am_type_oid() to implement get_table_am_oid() instead of a separate copy. Previously we'd error out only later, in GetTableAmRoutine(). Thirdly remove GetTableAmRoutineByAmId() - it was only used in an earlier version of 8586bf7ed8. Add tests for the above (some for index AMs as well).
* tableam: Add table_multi_insert() and revamp/speed-up COPY FROM buffering.Andres Freund2019-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | This adds table_multi_insert(), and converts COPY FROM, the only user of heap_multi_insert, to it. A simple conversion of COPY FROM use slots would have yielded a slowdown when inserting into a partitioned table for some workloads. Different partitions might need different slots (both slot types and their descriptors), and dropping / creating slots when there's constant partition changes is measurable. Thus instead revamp the COPY FROM buffering for partitioned tables to allow to buffer inserts into multiple tables, flushing only when limits are reached across all partition buffers. By only dropping slots when there've been inserts into too many different partitions, the aforementioned overhead is gone. By allowing larger batches, even when there are frequent partition changes, we actuall speed such cases up significantly. By using slots COPY of very narrow rows into unlogged / temporary might slow down very slightly (due to the indirect function calls). Author: David Rowley, Andres Freund, Haribabu Kommi Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de https://postgr.es/m/20190327054923.t3epfuewxfqdt22e@alap3.anarazel.de
* Make queries' locking of indexes more consistent.Tom Lane2019-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The assertions added by commit b04aeb0a0 exposed that there are some code paths wherein the executor will try to open an index without holding any lock on it. We do have some lock on the index's table, so it seems likely that there's no fatal problem with this (for instance, the index couldn't get dropped from under us). Still, it's bad practice and we should fix it. To do so, remove the optimizations in ExecInitIndexScan and friends that tried to avoid taking a lock on an index belonging to a target relation, and just take the lock always. In non-bug cases, this will result in no additional shared-memory access, since we'll find in the local lock table that we already have a lock of the desired type; hence, no significant performance degradation should occur. Also, adjust the planner and executor so that the type of lock taken on an index is always identical to the type of lock taken for its table, by relying on the recently added RangeTblEntry.rellockmode field. This avoids some corner cases where that might not have been true before (possibly resulting in extra locking overhead), and prevents future maintenance issues from having multiple bits of logic that all needed to be in sync. In addition, this change removes all core calls to ExecRelationIsTargetRelation, which avoids a possible O(N^2) startup penalty for queries with large numbers of target relations. (We'd probably remove that function altogether, were it not that we advertise it as something that FDWs might want to use.) Also adjust some places in selfuncs.c to not take any lock on indexes they are transiently opening, since we can assume that plancat.c did that already. In passing, change gin_clean_pending_list() to take RowExclusiveLock not AccessShareLock on its target index. Although it's not clear that that's actually a bug, it seemed very strange for a function that's explicitly going to modify the index to use only AccessShareLock. David Rowley, reviewed by Julien Rouhaud and Amit Langote, a bit of further tweaking by me Discussion: https://postgr.es/m/19465.1541636036@sss.pgh.pa.us
* Allow VACUUM to be run with index cleanup disabled.Robert Haas2019-04-04
| | | | | | | | | | | | | | | This commit adds a new reloption, vacuum_index_cleanup, which controls whether index cleanup is performed for a particular relation by default. It also adds a new option to the VACUUM command, INDEX_CLEANUP, which can be used to override the reloption. If neither the reloption nor the VACUUM option is used, the default is true, as before. Masahiko Sawada, reviewed and tested by Nathan Bossart, Alvaro Herrera, Kyotaro Horiguchi, Darafei Praliaskouski, and me. The wording of the documentation is mostly due to me. Discussion: http://postgr.es/m/CAD21AoAt5R3DNUZSjOoXDUY=naYPUOuffVsRzuTYMz29yLzQCA@mail.gmail.com
* Invalidate binary search bounds consistently.Peter Geoghegan2019-04-04
| | | | | | | | | | | | | | | | | _bt_check_unique() failed to invalidate binary search bounds in the event of a live conflict following commit e5adcb78. This resulted in problems after waiting for the conflicting xact to commit or abort. The subsequent call to _bt_check_unique() would restore the initial binary search bounds, rather than starting a new search. Fix by explicitly invalidating bounds when it becomes clear that there is a live conflict that insertion will have to wait to resolve. Ashutosh Sharma, with a few additional tweaks by me. Author: Ashutosh Sharma Reported-By: Ashutosh Sharma Diagnosed-By: Ashutosh Sharma Discussion: https://postgr.es/m/CAE9k0PnQp-qr-UYKMSCzdC2FBzdE4wKP41hZrZvvP26dKLonLg@mail.gmail.com
* Refactor the fsync queue for wider use.Thomas Munro2019-04-04
| | | | | | | | | | | | | | | | | | | | | | | Previously, md.c and checkpointer.c were tightly integrated so that fsync calls could be handed off and processed in the background. Introduce a system of callbacks and file tags, so that other modules can hand off fsync work in the same way. For now only md.c uses the new interface, but other users are being proposed. Since there may be use cases that are not strictly SMGR implementations, use a new function table for sync handlers rather than extending the traditional SMGR one. Instead of using a bitmapset of segment numbers for each RelFileNode in the checkpointer's hash table, make the segment number part of the key. This requires sending explicit "forget" requests for every segment individually when relations are dropped, but suits the file layout schemes of proposed future users better (ie sparse or high segment numbers). Author: Shawn Debnath and Thomas Munro Reviewed-by: Thomas Munro, Andres Freund Discussion: https://postgr.es/m/CAEepm=2gTANm=e3ARnJT=n0h8hf88wqmaZxk0JYkxw+b21fNrw@mail.gmail.com
* Log all statements from a sample of transactionsAlvaro Herrera2019-04-03
| | | | | | | | This is useful to obtain a view of the different transaction types in an application, regardless of the durations of the statements each runs. Author: Adrien Nayrat Reviewed-by: Masahiko Sawada, Hayato Kuroda, Andres Freund