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* 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
* Fix SQL-style substring() to have spec-compliant greediness behavior.Tom Lane2019-05-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SQL's regular-expression substring() function is defined to have a pattern argument that's separated into three subpatterns by escape- double-quote markers; the function result is the part of the input matching the second subpattern. The standard makes it clear that if there is ambiguity about how to match the input to the subpatterns, the first and third subpatterns should be taken to match the smallest possible amount of text (i.e., they're "non greedy", in the terms of our regex code). We were not doing it that way: the first subpattern would eat the largest possible amount of text, causing the function result to be shorter than what the spec requires. Fix that by attaching explicit greediness quantifiers to the subpatterns. (This depends on the regex fix in commit 8a29ed053; before that, this didn't reliably change the regex engine's behavior.) Also, by adding parentheses around each subpattern, we ensure that "|" (OR) in the subpatterns behave sanely. Previously, "|" in the first or third subpatterns didn't work. This patch also makes the function throw error if you write more than two escape-double-quote markers, and do something sane if you write just one, and document that behavior. Previously, an odd number of markers led to a confusing complaint about unbalanced parentheses, while extra pairs of markers were just ignored. (Note that the spec requires exactly two markers, but we've historically allowed there to be none, and this patch preserves the old behavior for that case.) In passing, adjust some substring() test cases that didn't really prove what they said they were testing for: they used patterns that didn't match the data string, so that the output would be NULL whether or not the function was really strict. Although this is certainly a bug fix, changing the behavior in back branches seems undesirable: applications could perhaps be depending on the old behavior, since it's not obviously wrong unless you read the spec very closely. Hence, no back-patch. Discussion: https://postgr.es/m/5bb27a41-350d-37bf-901e-9d26f5592dd0@charter.net
* In bootstrap mode, use default signal handling for SIGINT etc.Tom Lane2019-05-14
| | | | | | | | | | | | | | | | | | | | Previously, the code pointed the standard process-termination signals to postgres.c's die(). That would typically result in an attempt to execute a transaction abort, which is not possible in bootstrap mode, leading to PANIC. This choice seems to be a leftover from an old code structure in which the same signal-assignment code was used for many sorts of auxiliary processes, including interactive standalone backends. It's not very sensible for bootstrap mode, which has no interest in either interactivity or continuing after an error. We can get better behavior with less effort by just letting normal process termination happen, after which the parent initdb process will clean up. This is basically cosmetic in any case, since initdb will react the same way whether bootstrap dies on a signal or abort(). Given the lack of previous complaints, I don't feel a need to back-patch, even though the behavior is old. Discussion: https://postgr.es/m/3850b11a.5121.16aaf827e4a.Coremail.thunder1@126.com
* Update SQL features/conformance information to SQL:2016Peter Eisentraut2019-05-14
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* Update information_schema for SQL:2016Peter Eisentraut2019-05-14
| | | | | This is mainly a light renumbering to match the sections in the standard.
* 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.
* Fix typo.Etsuro Fujita2019-05-14
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* Fix duplicated words in commentsMichael Paquier2019-05-14
| | | | | Author: Stephen Amell Discussion: https://postgr.es/m/539fa271-21b3-777e-a468-d96cffe9c768@gmail.com
* 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
* Fix logical replication's ideas about which type OIDs are built-in.Tom Lane2019-05-13
| | | | | | | | | | | | | | | | | | Only hand-assigned type OIDs should be presumed to match across different PG servers; those assigned during genbki.pl or during initdb are likely to change due to addition or removal of unrelated objects. This means that the cutoff should be FirstGenbkiObjectId (in HEAD) or FirstBootstrapObjectId (before that), not FirstNormalObjectId. Compare postgres_fdw's is_builtin() test. It's likely that this error has no observable consequence in a normally-functioning system, since ATM the only affected type OIDs are system catalog rowtypes and information_schema types, which would not typically be interesting for logical replication. But you could probably break it if you tried hard, so back-patch. Discussion: https://postgr.es/m/15150.1557257111@sss.pgh.pa.us
* Improve commentary about hack in is_publishable_class().Tom Lane2019-05-13
| | | | | | | | | The FirstNormalObjectId test here is a kluge that needs to go away, but the only substitute we can think of is to add a column to pg_class, which will take more work than can be handled right now. Add some commentary in the meanwhile. Discussion: https://postgr.es/m/15150.1557257111@sss.pgh.pa.us
* 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.
* Fix incorrect return value in JSON equality function for scalarsMichael Paquier2019-05-13
| | | | | | | | | | | | equalsJsonbScalarValue() uses a boolean as return type, however for one code path -1 gets returned, which is confusing. The origin of the confusion is visibly that this code got copy-pasted from compareJsonbScalarValue() since it has been introduced in d1d50bf. No backpatch, as this is only cosmetic. Author: Rikard Falkeborn Discussion: https://postgr.es/m/CADRDgG7mJnek6HNW13f+LF6V=6gag9PM+P7H5dnyWZAv49aBGg@mail.gmail.com
* Fix misoptimization of "{1,1}" quantifiers in regular expressions.Tom Lane2019-05-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A bounded quantifier with m = n = 1 might be thought a no-op. But according to our documentation (which traces back to Henry Spencer's original man page) it still imposes greediness, or non-greediness in the case of the non-greedy variant "{1,1}?", on whatever it's attached to. This turns out not to work though, because parseqatom() optimizes away the m = n = 1 case without regard for whether it's supposed to change the greediness of the argument RE. We can fix this by just not applying the optimization when the greediness needs to change; the subsequent general cases handle it fine. The three cases in which we can still apply the optimization are (a) no quantifier, or quantifier does not impose a preference; (b) atom has no greediness property, implying it cannot match a variable amount of text anyway; or (c) quantifier's greediness is same as atom's. Note that in most cases where one of these applies, we'd have exited earlier in the "not a messy case" fast path. I think it's now only possible to get to the optimization when the atom involves capturing parentheses or a non-top-level backref. Back-patch to all supported branches. I'd ordinarily be hesitant to put a subtle behavioral change into back branches, but in this case it's very hard to see a reason why somebody would write "{1,1}?" unless they're trying to get the documented change-of-greediness behavior. Discussion: https://postgr.es/m/5bb27a41-350d-37bf-901e-9d26f5592dd0@charter.net
* Fail pgwin32_message_to_UTF16() for SQL_ASCII messages.Noah Misch2019-05-12
| | | | | | | | | | | | The function had been interpreting SQL_ASCII messages as UTF8, throwing an error when they were invalid UTF8. The new behavior is consistent with pg_do_encoding_conversion(). This affects LOG_DESTINATION_STDERR and LOG_DESTINATION_EVENTLOG, which will send untranslated bytes to write() and ReportEventA(). On buildfarm member bowerbird, enabling log_connections caused an error whenever the role name was not valid UTF8. Back-patch to 9.4 (all supported versions). Discussion: https://postgr.es/m/20190512015615.GD1124997@rfd.leadboat.com
* Rearrange pgstat_bestart() to avoid failures within its critical section.Tom Lane2019-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We long ago decided to design the shared PgBackendStatus data structure to minimize the cost of writing status updates, which means that writers just have to increment the st_changecount field twice. That isn't hooked into any sort of resource management mechanism, which means that if something were to throw error between the two increments, the st_changecount field would be left odd indefinitely. That would cause readers to lock up. Now, since it's also a bad idea to leave the field odd for longer than absolutely necessary (because readers will spin while we have it set), the expectation was that we'd treat these segments like spinlock critical sections, with only short, more or less straight-line, code in them. That was fine as originally designed, but commit 9029f4b37 broke it by inserting a significant amount of non-straight-line code into pgstat_bestart(), code that is very capable of throwing errors, not to mention taking a significant amount of time during which readers will spin. We have a report from Neeraj Kumar of readers actually locking up, which I suspect was due to an encoding conversion error in X509_NAME_to_cstring, though conceivably it was just a garden-variety OOM failure. Subsequent commits have loaded even more dubious code into pgstat_bestart's critical section (and commit fc70a4b0d deserves some kind of booby prize for managing to miss the critical section entirely, although the negative consequences seem minimal given that the PgBackendStatus entry should be seen by readers as inactive at that point). The right way to fix this mess seems to be to compute all these values into a local copy of the process' PgBackendStatus struct, and then just copy the data back within the critical section proper. This plan can't be implemented completely cleanly because of the struct's heavy reliance on out-of-line strings, which we must initialize separately within the critical section. But still, the critical section is far smaller and safer than it was before. In hopes of forestalling future errors of the same ilk, rename the macros for st_changecount management to make it more apparent that the writer-side macros create a critical section. And to prevent the worst consequences if we nonetheless manage to mess it up anyway, adjust those macros so that they really are a critical section, ie they now bump CritSectionCount. That doesn't add much overhead, and it guarantees that if we do somehow throw an error while the counter is odd, it will lead to PANIC and a database restart to reset shared memory. Back-patch to 9.5 where the problem was introduced. In HEAD, also fix an oversight in commit b0b39f72b: it failed to teach pgstat_read_current_status to copy st_gssstatus data from shared memory to local memory. Hence, subsequent use of that data within the transaction would potentially see changing data that it shouldn't see. Discussion: https://postgr.es/m/CAPR3Wj5Z17=+eeyrn_ZDG3NQGYgMEOY6JV6Y-WRRhGgwc16U3Q@mail.gmail.com
* Cope with EINVAL and EIDRM shmat() failures in PGSharedMemoryAttach.Tom Lane2019-05-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a very old race condition in our code to see whether a pre-existing shared memory segment is still in use by a conflicting postmaster: it's possible for the other postmaster to remove the segment in between our shmctl() and shmat() calls. It's a narrow window, and there's no risk unless both postmasters are using the same port number, but that's possible during parallelized "make check" tests. (Note that while the TAP tests take some pains to choose a randomized port number, pg_regress doesn't.) If it does happen, we treated that as an unexpected case and errored out. To fix, allow EINVAL to be treated as segment-not-present, and the same for EIDRM on Linux. AFAICS, the considerations here are basically identical to the checks for acceptable shmctl() failures, so I documented and coded it that way. While at it, adjust PGSharedMemoryAttach's API to remove its undocumented dependency on UsedShmemSegAddr in favor of passing the attach address explicitly. This makes it easier to be sure we're using a null shmaddr when probing for segment conflicts (thus avoiding questions about what EINVAL means). I don't think there was a bug there, but it required fragile assumptions about the state of UsedShmemSegAddr during PGSharedMemoryIsInUse. Commit c09850992 may have made this failure more probable by applying the conflicting-segment tests more often. Hence, back-patch to all supported branches, as that was. Discussion: https://postgr.es/m/22224.1557340366@sss.pgh.pa.us
* Improve and fix some error handling for REINDEX INDEX/TABLE CONCURRENTLYMichael Paquier2019-05-10
| | | | | | | | | | | | | | | | | | | This improves the user experience when it comes to restrict several flavors of REINDEX CONCURRENTLY. First, for INDEX, remove a restriction on shared relations as we already check after catalog relations. Then, for TABLE, add a proper error message when attempting to run the command on system catalogs. The code path of CREATE INDEX CONCURRENTLY already complains about that, but if a REINDEX is issued then then the error generated is confusing. While on it, add more tests to check restrictions on catalog indexes and on toast table/index for catalogs. Some error messages are improved, with wording suggestion coming from Tom Lane. Reported-by: Tom Lane Author: Michael Paquier Reviewed-by: Tom Lane Discussion: https://postgr.es/m/23694.1556806002@sss.pgh.pa.us
* Repair issues with faulty generation of merge-append plans.Tom Lane2019-05-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | create_merge_append_plan failed to honor the CP_EXACT_TLIST flag: it would generate the expected targetlist but then it felt free to add resjunk sort targets to it. This demonstrably leads to assertion failures in v11 and HEAD, and it's probably just accidental that we don't see the same in older branches. I've not looked into whether there would be any real-world consequences in non-assert builds. In HEAD, create_append_plan has sprouted the same problem, so fix that too (although we do not have any test cases that seem able to reach that bug). This is an oversight in commit 3fc6e2d7f which invented the CP_EXACT_TLIST flag, so back-patch to 9.6 where that came in. convert_subquery_pathkeys would create pathkeys for subquery output values if they match any EquivalenceClass known in the outer query and are available in the subquery's syntactic targetlist. However, the second part of that condition is wrong, because such values might not appear in the subquery relation's reltarget list, which would mean that they couldn't be accessed above the level of the subquery scan. We must check that they appear in the reltarget list, instead. This can lead to dropping knowledge about the subquery's sort ordering, but I believe it's okay, because any sort key that the outer query actually has any interest in would appear in the reltarget list. This second issue is of very long standing, but right now there's no evidence that it causes observable problems before 9.6, so I refrained from back-patching further than that. We can revisit that choice if somebody finds a way to make it cause problems in older branches. (Developing useful test cases for these issues is really problematic; fixing convert_subquery_pathkeys removes the only known way to exhibit the create_merge_append_plan bug, and neither of the test cases added by this patch causes a problem in all branches, even when considering the issues separately.) The second issue explains bug #15795 from Suresh Kumar R ("could not find pathkey item to sort" with nested DISTINCT queries). I stumbled across the first issue while investigating that. Discussion: https://postgr.es/m/15795-fadb56c8e44ee73c@postgresql.org
* postgres_fdw: Fix cost estimation for aggregate pushdown.Etsuro Fujita2019-05-09
| | | | | | | | | | | | | | | | | In commit 7012b132d0, which added support for aggregate pushdown in postgres_fdw, the expense of evaluating the final scan/join target computed by make_group_input_target() was not accounted for at all in costing aggregate pushdown paths with local statistics. The right fix for this would be to have a separate upper stage to adjust the final scan/join relation (see comments for apply_scanjoin_target_to_paths()); but for now, fix by adding the tlist eval cost when costing aggregate pushdown paths with local statistics. Apply this to HEAD only to avoid destabilizing existing plan choices. Author: Etsuro Fujita Reviewed-By: Antonin Houska Discussion: https://postgr.es/m/5C66A056.60007%40lab.ntt.co.jp
* 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
* 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.
* Fix error messagesAlvaro Herrera2019-05-08
| | | | | | | | | | Some messages related to foreign servers were reporting the server name without quotes, or not at all; our style is to have all names be quoted, and the server name already appears quoted in a few other messages, so just add quotes and make them all consistent. Remove an extra "s" in other messages (typos introduced by myself in f56f8f8da6af).
* Fix table lock levels for REINDEX INDEX CONCURRENTLYPeter Eisentraut2019-05-08
| | | | | | | | | | | | | REINDEX CONCURRENTLY locks tables with ShareUpdateExclusiveLock rather than the ShareLock used by a plain REINDEX. However, RangeVarCallbackForReindexIndex() was not updated for that and still used the ShareLock only. This would lead to lock upgrades later, leading to possible deadlocks. Reported-by: Andres Freund <andres@anarazel.de> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/20190430151735.wi52sxjvxsjvaxxt%40alap3.anarazel.de
* 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.
* Improve error reporting in jsonpathAlexander Korotkov2019-05-08
| | | | | | | | | | | | | | | This commit contains multiple improvements to error reporting in jsonpath including but not limited to getting rid of following things: * definition of error messages in macros, * errdetail() when valueable information could fit to errmsg(), * word "singleton" which is not properly explained anywhere, * line breaks in error messages. Reported-by: Tom Lane Discussion: https://postgr.es/m/14890.1555523005%40sss.pgh.pa.us Author: Alexander Korotkov Reviewed-by: Tom Lane
* 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
* Fix typos and clarify a commentMagnus Hagander2019-05-07
| | | | Author: Daniel Gustafsson <daniel@yesql.se>
* Avoid "invalid memory alloc request size" while reading pg_stat_activity.Tom Lane2019-05-07
| | | | | | | | | | | | | | | | | | | On a 64-bit machine, if you set track_activity_query_size and max_connections such that their product exceeds 1GB, shared memory setup will still succeed (given enough RAM), but attempts to read pg_stat_activity fail with "invalid memory alloc request size". Work around that by using MemoryContextAllocHuge to allocate the local copy of the activity strings. Using the "huge" API costs us nothing extra in normal cases, and it seems better than throwing an error and/or explaining to people why they can't do this. This situation seems insanely profligate today, but who knows what people will consider normal in ten or twenty years? So let's fix it in HEAD but not worry about a back-patch. Per report from James Tomson. Discussion: https://postgr.es/m/1CFDCCD6-B268-48D8-85C8-400D2790B2C3@pushd.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
* Use checkAsUser for selectivity estimator checks, if it's set.Dean Rasheed2019-05-06
| | | | | | | | | | | | | | | | | | | | | | | | | In examine_variable() and examine_simple_variable(), when checking the user's table and column privileges to determine whether to grant access to the pg_statistic data, use checkAsUser for the privilege checks, if it's set. This will be the case if we're accessing the table via a view, to indicate that we should perform privilege checks as the view owner rather than the current user. This change makes this planner check consistent with the check in the executor, so the planner will be able to make use of statistics if the table is accessible via the view. This fixes a performance regression introduced by commit e2d4ef8de8, which affects queries against non-security barrier views in the case where the user doesn't have privileges on the underlying table, but the view owner does. Note that it continues to provide the same safeguards controlling access to pg_statistic for direct table access (in which case checkAsUser won't be set) and for security barrier views, because of the nearby checks on rte->security_barrier and rte->securityQuals. Back-patch to all supported branches because e2d4ef8de8 was. Dean Rasheed, reviewed by Jonathan Katz and Stephen Frost.
* Fix security checks for selectivity estimation functions with RLS.Dean Rasheed2019-05-06
| | | | | | | | | | | | | | | | | | | | | | In commit e2d4ef8de8, security checks were added to prevent user-supplied operators from running over data from pg_statistic unless the user has table or column privileges on the table, or the operator is leakproof. For a table with RLS, however, checking for table or column privileges is insufficient, since that does not guarantee that the user has permission to view all of the column's data. Fix this by also checking for securityQuals on the RTE, and insisting that the operator be leakproof if there are any. Thus the leakproofness check will only be skipped if there are no securityQuals and the user has table or column privileges on the table -- i.e., only if we know that the user has access to all the data in the column. Back-patch to 9.5 where RLS was added. Dean Rasheed, reviewed by Jonathan Katz and Stephen Frost. Security: CVE-2019-10130
* Bring pg_nextoid()'s error messages into line with message style guide.Tom Lane2019-05-05
| | | | | | | Noticed while reviewing nearby code. Given all the disclaimers about this not being meant as user-facing code, I wonder whether we should make these non-translatable? But in any case there's little excuse for them not to be good English.
* Fix style violations in syscache lookups.Tom Lane2019-05-05
| | | | | | | | | | | | | | | | | Project style is to check the success of SearchSysCacheN and friends by applying HeapTupleIsValid to the result. A tiny minority of calls creatively did it differently. Bring them into line with the rest. This is just cosmetic, since HeapTupleIsValid is indeed just a null check at the moment ... but that may not be true forever, and in any case it puts a mental burden on readers who may wonder why these call sites are not like the rest. Back-patch to v11 just to keep the branches in sync. (The bulk of these errors seem to have originated in v11 or v12, though a few are old.) Per searching to see if anyplace else had made the same error repaired in 62148c352.
* Add check for syscache lookup failure in update_relispartition().Tom Lane2019-05-05
| | | | | | | | Omitted in commit 05b38c7e6 (though it looks like the original blame belongs to 9e9befac4). A failure is admittedly unlikely, but if it did happen, SIGSEGV is not the approved method of reporting it. Per Coverity. Back-patch to v11 where the broken code originated.
* 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.
* Remove RelationSetIndexList().Tom Lane2019-05-03
| | | | | | | | In the wake of commit f912d7dec, RelationSetIndexList isn't used any more. It was always a horrid wart, so getting rid of it is very nice. We can also convert rd_indexvalid back to a plain boolean. Discussion: https://postgr.es/m/28926.1556664156@sss.pgh.pa.us
* Fix reindexing of pg_class indexes some more.Tom Lane2019-05-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commits 3dbb317d3 et al failed under CLOBBER_CACHE_ALWAYS testing. Investigation showed that to reindex pg_class_oid_index, we must suppress accesses to the index (via SetReindexProcessing) before we call RelationSetNewRelfilenode, or at least before we do CommandCounterIncrement therein; otherwise, relcache reloads happening within the CCI may try to fetch pg_class rows using the index's new relfilenode value, which is as yet an empty file. Of course, the point of 3dbb317d3 was that that ordering didn't work either, because then RelationSetNewRelfilenode's own update of the index's pg_class row cannot access the index, should it need to. There are various ways we might have got around that, but Andres Freund came up with a brilliant solution: for a mapped index, we can really just skip the pg_class update altogether. The only fields it was actually changing were relpages etc, but it was just setting them to zeroes which is useless make-work. (Correct new values will be installed at the end of index build.) All pg_class indexes are mapped and probably always will be, so this eliminates the problem by removing work rather than adding it, always a pleasant outcome. Having taught RelationSetNewRelfilenode to do it that way, we can revert the code reordering in reindex_index. (But I left the moved setup code where it was; there seems no reason why it has to run without use of the old index. If you're trying to fix a busted pg_class index, you'll have had to disable system index use altogether to get this far.) Moreover, this means we don't need RelationSetIndexList at all, because reindex_relation's hacking to make "REINDEX TABLE pg_class" work is likewise now unnecessary. We'll leave that code in place in the back branches, but a follow-on patch will remove it in HEAD. In passing, do some minor cleanup for commit 5c1560606 (in HEAD only), notably removing a duplicate newrnode assignment. Patch by me, using a core idea due to Andres Freund. Back-patch to all supported branches, as 3dbb317d3 was. Discussion: https://postgr.es/m/28926.1556664156@sss.pgh.pa.us
* 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.
* Fix union for pgstat message typesMagnus Hagander2019-05-01
| | | | | | | | | | | | The message type for temp files and for checksum failures were missing from the union. Due to the coding style used there was no compiler error when this happend. So change the code to actively use the union thereby producing a compiler error if the same mistake happens again, suggested by Tom Lane. Author: Julien Rouhaud Reported-By: Tomas Vondra Discussion: https://postgr.es/m/20190430163328.zd4rrlnbvgaqlcdz@development
* Fix unused variable compiler warning in !debug builds.Andres Freund2019-04-30
| | | | | | | | Introduced in 3dbb317d3. Fix by using the new local variable in more places. Reported-By: Bruce Momjian (off-list) Backpatch: 9.4-, like 3dbb317d3
* Improve comment spelling and style in llvmjit_deform.c.Andres Freund2019-04-30
| | | | | | | Author: Justin Pryzby Discussion: https://postgr.es/m/20190408141828.GE10080@telsasoft.com https://postgr.es/m/20181127184133.GM10913@telsasoft.com
* Improve code inferring length of bitmap for JITed tuple deforming.Andres Freund2019-04-30
| | | | | | | | | | | | | | | | | | | | | | While discussing comment improvements (see next commit) by Justin Pryzby, Tom complained about a few details of the logic to infer the length of the NULL bitmap when building the JITed tuple deforming function. That bitmap allows to avoid checking the tuple header's natts, a check which often causes a pipeline stall Improvements: a) As long as missing columns aren't taken into account, we can continue to infer the length of the NULL bitmap from NOT NULL columns following it. Previously we stopped at the first missing column. It's unlikely to matter much in practice, but the alternative would have been to document why we stop. b) For robustness reasons it seems better to also check against attisdropped - RemoveAttributeById() sets attnotnull to false, but an additional check is trivial. c) Improve related comments Discussion: https://postgr.es/m/20637.1555957068@sss.pgh.pa.us Backpatch: -