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2020-08-15Move new LOCKTAG_DATABASE_FROZEN_IDS to end of enum LockTagType.Noah Misch
Several PGXN modules reference LockTagType values; renumbering would force a recompile of those modules. Oversight in back-patch of today's commit 566372b3d6435639e4cc4476d79b8505a0297c87. Back-patch to released branches, v12 through 9.5. Reported by Tom Lane. Discussion: https://postgr.es/m/921383.1597523945@sss.pgh.pa.us
2020-08-15Prevent concurrent SimpleLruTruncate() for any given SLRU.Noah Misch
The SimpleLruTruncate() header comment states the new coding rule. To achieve this, add locktype "frozenid" and two LWLocks. This closes a rare opportunity for data loss, which manifested as "apparent wraparound" or "could not access status of transaction" errors. Data loss is more likely in pg_multixact, due to released branches' thin margin between multiStopLimit and multiWrapLimit. If a user's physical replication primary logged ": apparent wraparound" messages, the user should rebuild standbys of that primary regardless of symptoms. At less risk is a cluster having emitted "not accepting commands" errors or "must be vacuumed" warnings at some point. One can test a cluster for this data loss by running VACUUM FREEZE in every database. Back-patch to 9.5 (all supported versions). Discussion: https://postgr.es/m/20190218073103.GA1434723@rfd.leadboat.com
2020-08-14Fix postmaster's behavior during smart shutdown.Tom Lane
Up to now, upon receipt of a SIGTERM ("smart shutdown" command), the postmaster has immediately killed all "optional" background processes, and subsequently refused to launch new ones while it's waiting for foreground client processes to exit. No doubt this seemed like an OK policy at some point; but it's a pretty bad one now, because it makes for a seriously degraded environment for the remaining clients: * Parallel queries are killed, and new ones fail to launch. (And our parallel-query infrastructure utterly fails to deal with the case in a reasonable way --- it just hangs waiting for workers that are not going to arrive. There is more work needed in that area IMO.) * Autovacuum ceases to function. We can tolerate that for awhile, but if bulk-update queries continue to run in the surviving client sessions, there's eventually going to be a mess. In the worst case the system could reach a forced shutdown to prevent XID wraparound. * The bgwriter and walwriter are also stopped immediately, likely resulting in performance degradation. Hence, let's rearrange things so that the only immediate change in behavior is refusing to let in new normal connections. Once the last normal connection is gone, shut everything down as though we'd received a "fast" shutdown. To implement this, remove the PM_WAIT_BACKUP and PM_WAIT_READONLY states, instead staying in PM_RUN or PM_HOT_STANDBY while normal connections remain. A subsidiary state variable tracks whether or not we're letting in new connections in those states. This also allows having just one copy of the logic for killing child processes in smart and fast shutdown modes. I moved that logic into PostmasterStateMachine() by inventing a new state PM_STOP_BACKENDS. Back-patch to 9.6 where parallel query was added. In principle this'd be a good idea in 9.5 as well, but the risk/reward ratio is not as good there, since lack of autovacuum is not a problem during typical uses of smart shutdown. Per report from Bharath Rupireddy. Patch by me, reviewed by Thomas Munro Discussion: https://postgr.es/m/CALj2ACXAZ5vKxT9P7P89D87i3MDO9bfS+_bjMHgnWJs8uwUOOw@mail.gmail.com
2020-07-31Fix recently-introduced performance problem in ts_headline().Tom Lane
The new hlCover() algorithm that I introduced in commit c9b0c678d turns out to potentially take O(N^2) or worse time on long documents, if there are many occurrences of individual query words but few or no substrings that actually satisfy the query. (One way to hit this behavior is with a "common_word & rare_word" type of query.) This seems unavoidable given the original goal of checking every substring of the document, so we have to back off that idea. Fortunately, it seems unlikely that anyone would really want headlines spanning all of a long document, so we can avoid the worse-than-linear behavior by imposing a maximum length of substring that we'll consider. For now, just hard-wire that maximum length as a multiple of max_words times max_fragments. Perhaps at some point somebody will argue for exposing it as a ts_headline parameter, but I'm hesitant to make such a feature addition in a back-patched bug fix. I also noted that the hlFirstIndex() function I'd added in that commit was unnecessarily stupid: it really only needs to check whether a HeadlineWordEntry's item pointer is null or not. This wouldn't make all that much difference in typical cases with queries having just a few terms, but a cycle shaved is a cycle earned. In addition, add a CHECK_FOR_INTERRUPTS call in TS_execute_recurse. This ensures that hlCover's loop is cancellable if it manages to take a long time, and it may protect some other TS_execute callers as well. Back-patch to 9.6 as the previous commit was. I also chose to add the CHECK_FOR_INTERRUPTS call to 9.5. The old hlCover() algorithm seems to avoid the O(N^2) behavior, at least on the test case I tried, but nonetheless it's not very quick on a long document. Per report from Stephen Frost. Discussion: https://postgr.es/m/20200724160535.GW12375@tamriel.snowman.net
2020-07-29Backpatch tuplesort.c assertion.Peter Geoghegan
Backpatch an assertion (that was originally added to Postgres 12 by commit dd299df8189) that seems broadly useful. The assertion can detect violations of the HOT invariant (i.e. no two index tuples can point to the same heap TID) when CREATE INDEX somehow incorrectly allows that to take place. For example, a IndexBuildHeapScan/heapam_index_build_range_scan bug might result in two tuples that both point to the same heap TID. If these two tuples also happen to be duplicates, the assertion will fail. Discussion: https://postgr.es/m/CAH2-WzmBxu4o=pMsniur+bwHqCGCmV_AOLkuK6BuU7ngA6evqw@mail.gmail.com Backpatch: 9.5-11 only
2020-06-16Fix buffile.c error handling.Thomas Munro
Convert buffile.c error handling to use ereport. This fixes cases where I/O errors were indistinguishable from EOF or not reported. Also remove "%m" from error messages where errno would be bogus. While we're modifying those strings, add block numbers and short read byte counts where appropriate. Back-patch to all supported releases. Reported-by: Amit Khandekar <amitdkhan.pg@gmail.com> Reviewed-by: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Ibrar Ahmed <ibrar.ahmad@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/CA%2BhUKGJE04G%3D8TLK0DLypT_27D9dR8F1RQgNp0jK6qR0tZGWOw%40mail.gmail.com
2020-06-11Fix mishandling of NaN counts in numeric_[avg_]combine.Tom Lane
When merging two NumericAggStates, the code missed adding the new state's NaNcount unless its N was also nonzero; since those counts are independent, this is wrong. This would only have visible effect if some partial aggregate scans found only NaNs while earlier ones found only non-NaNs; then we could end up falsely deciding that there were no NaNs and fail to return a NaN final result as expected. That's pretty improbable, so it's no surprise this hasn't been reported from the field. Still, it's a bug. I didn't try to produce a regression test that would show the bug, but I did notice that these functions weren't being reached at all in our regression tests, so I improved the tests to at least exercise them. With these additions, I see pretty complete code coverage on the aggregation-related functions in numeric.c. Back-patch to 9.6 where this code was introduced. (I only added the improved test case as far back as v10, though, since the relevant part of aggregates.sql isn't there at all in 9.6.)
2020-06-01Fix use-after-release mistake in currtid() and currtid2() for viewsMichael Paquier
This issue has been present since the introduction of this code as of a3519a2 from 2002, and has been found by buildfarm member prion that uses RELCACHE_FORCE_RELEASE via the tests introduced recently in e786be5. Discussion: https://postgr.es/m/20200601022055.GB4121@paquier.xyz Backpatch-through: 9.5
2020-05-28Add CHECK_FOR_INTERRUPTS() to the repeat() functionJoe Conway
The repeat() function loops for potentially a long time without ever checking for interrupts. This prevents, for example, a query cancel from interrupting until the work is all done. Fix by inserting a CHECK_FOR_INTERRUPTS() into the loop. Backpatch to all supported versions. Discussion: https://www.postgresql.org/message-id/flat/8692553c-7fe8-17d9-cbc1-7cddb758f4c6%40joeconway.com
2020-05-14Fix the MSVC build for versions 2015 and later.Amit Kapila
Visual Studio 2015 and later versions should still be able to do the same as Visual Studio 2012, but the declaration of locale_name is missing in _locale_t, causing the code compilation to fail, hence this falls back instead on to enumerating all system locales by using EnumSystemLocalesEx to find the required locale name.  If the input argument is in Unix-style then we can get ISO Locale name directly by using GetLocaleInfoEx() with LCType as LOCALE_SNAME. In passing, change the documentation references of the now obsolete links. Note that this problem occurs only with NLS enabled builds. Author: Juan José Santamaría Flecha, Davinder Singh and Amit Kapila Reviewed-by: Ranier Vilela and Amit Kapila Backpatch-through: 9.5 Discussion: https://postgr.es/m/CAHzhFSFoJEWezR96um4-rg5W6m2Rj9Ud2CNZvV4NWc9tXV7aXQ@mail.gmail.com
2020-05-07Fix YA text phrase search bug.Tom Lane
checkcondition_str() failed to report multiple matches for a prefix pattern correctly: it would dutifully merge the match positions, but then after exiting that loop, if the last prefix-matching word had had no suitable positions, it would report there were no matches. The upshot would be failing to recognize a match that the query should match. It looks like you need all of these conditions to see the bug: * a phrase search (else we don't ask for match position details) * a prefix search item (else we don't get to this code) * a weight restriction (else checkclass_str won't fail) Noted while investigating a problem report from Pavel Borisov, though this is distinct from the issue he was on about. Back-patch to 9.6 where phrase search was added.
2020-05-01Get rid of trailing semicolons in C macro definitions.Tom Lane
Writing a trailing semicolon in a macro is almost never the right thing, because you almost always want to write a semicolon after each macro call instead. (Even if there was some reason to prefer not to, pgindent would probably make a hash of code formatted that way; so within PG the rule should basically be "don't do it".) Thus, if we have a semi inside the macro, the compiler sees "something;;". Much of the time the extra empty statement is harmless, but it could lead to mysterious syntax errors at call sites. In perhaps an overabundance of neatnik-ism, let's run around and get rid of the excess semicolons whereever possible. The only thing worse than a mysterious syntax error is a mysterious syntax error that only happens in the back branches; therefore, backpatch these changes where relevant, which is most of them because most of these mistakes are old. (The lack of reported problems shows that this is largely a hypothetical issue, but still, it could bite us in some future patch.) John Naylor and Tom Lane Discussion: https://postgr.es/m/CACPNZCs0qWTqJ2QUSGJ07B7uvAvzMb-KbG2q+oo+J3tsWN5cqw@mail.gmail.com
2020-04-27Fix full text search to handle NOT above a phrase search correctly.Tom Lane
Queries such as '!(foo<->bar)' failed to find matching rows when implemented as a GiST or GIN index search. That's because of failing to handle phrase searches as tri-valued when considering a query without any position information for the target tsvector. We can only say that the phrase operator might match, not that it does match; and therefore its NOT also might match. The previous coding incorrectly inverted the approximate phrase result to decide that there was certainly no match. To fix, we need to make TS_phrase_execute return a real ternary result, and then bubble that up accurately in TS_execute. As long as we have to do that anyway, we can simplify the baroque things TS_phrase_execute was doing internally to manage tri-valued searching with only a bool as explicit result. For now, I left the externally-visible result of TS_execute as a plain bool. There do not appear to be any outside callers that need to distinguish a three-way result, given that they passed in a flag saying what to do in the absence of position data. This might need to change someday, but we wouldn't want to back-patch such a change. Although tsginidx.c has its own TS_execute_ternary implementation for use at upper index levels, that sadly managed to get this case wrong as well :-(. Fixing it is a lot easier fortunately. Per bug #16388 from Charles Offenbacher. Back-patch to 9.6 where phrase search was introduced. Discussion: https://postgr.es/m/16388-98cffba38d0b7e6e@postgresql.org
2020-04-07Fix circle_in to accept "(x,y),r" as it's advertised to do.Tom Lane
Our documentation describes four allowed input syntaxes for circles, but the regression tests tried only three ... with predictable consequences. Remarkably, this has been wrong since the circle datatype was added in 1997, but nobody noticed till now. David Zhang, with some help from me Discussion: https://postgr.es/m/332c47fa-d951-7574-b5cc-a8f7f7201202@highgo.ca
2020-04-07Adjust bytea get_bit/set_bit to cope with bytea strings > 256MB.Tom Lane
Since the existing bit number argument can't exceed INT32_MAX, it's not possible for these functions to manipulate bits beyond the first 256MB of a bytea value. However, it'd be good if they could do at least that much, and not fall over entirely for longer bytea values. Adjust the comparisons to be done in int64 arithmetic so that works. Also tweak the error reports to show sane values in case of overflow. Also add some test cases to improve the miserable code coverage of these functions. Apply patch to back branches only; HEAD has a better solution as of commit 26a944cf2. Extracted from a much larger patch by Movead Li Discussion: https://postgr.es/m/20200312115135445367128@highgo.ca
2020-04-06Preserve clustered index after rewrites with ALTER TABLEMichael Paquier
A table rewritten by ALTER TABLE would lose tracking of an index usable for CLUSTER. This setting is tracked by pg_index.indisclustered and is controlled by ALTER TABLE, so some extra work was needed to restore it properly. Note that ALTER TABLE only marks the index that can be used for clustering, and does not do the actual operation. Author: Amit Langote, Justin Pryzby Reviewed-by: Ibrar Ahmed, Michael Paquier Discussion: https://postgr.es/m/20200202161718.GI13621@telsasoft.com Backpatch-through: 9.5
2020-03-28Ensure snapshot is registered within ScanPgRelation().Andres Freund
In 9.4 I added support to use a historical snapshot in ScanPgRelation(), while adding logical decoding. Unfortunately a conflict with the concurrent removal of SnapshotNow was incorrectly resolved, leading to an unregistered snapshot being used. It is not correct to use an unregistered (or non-active) snapshot for anything non-trivial, because catalog invalidations can cause the snapshot to be invalidated. Luckily it seems unlikely to actively cause problems in practice, as ScanPgRelation() requires that we already have a lock on the relation, we only look for a single row, and we don't appear to rely on the result's tid to be correct. It however is clearly wrong and potential negative consequences would likely be hard to find. So it seems worth backpatching the fix, even without a concrete hazard. Discussion: https://postgr.es/m/20200229052459.wzhqnbhrriezg4v2@alap3.anarazel.de Backpatch: 9.5-
2020-03-22Revert "Skip WAL for new relfilenodes, under wal_level=minimal."Noah Misch
This reverts commit cb2fd7eac285b1b0a24eeb2b8ed4456b66c5a09f. Per numerous buildfarm members, it was incompatible with parallel query, and a test case assumed LP64. Back-patch to 9.5 (all supported versions). Discussion: https://postgr.es/m/20200321224920.GB1763544@rfd.leadboat.com
2020-03-21Skip WAL for new relfilenodes, under wal_level=minimal.Noah Misch
Until now, only selected bulk operations (e.g. COPY) did this. If a given relfilenode received both a WAL-skipping COPY and a WAL-logged operation (e.g. INSERT), recovery could lose tuples from the COPY. See src/backend/access/transam/README section "Skipping WAL for New RelFileNode" for the new coding rules. Maintainers of table access methods should examine that section. To maintain data durability, just before commit, we choose between an fsync of the relfilenode and copying its contents to WAL. A new GUC, wal_skip_threshold, guides that choice. If this change slows a workload that creates small, permanent relfilenodes under wal_level=minimal, try adjusting wal_skip_threshold. Users setting a timeout on COMMIT may need to adjust that timeout, and log_min_duration_statement analysis will reflect time consumption moving to COMMIT from commands like COPY. Internally, this requires a reliable determination of whether RollbackAndReleaseCurrentSubTransaction() would unlink a relation's current relfilenode. Introduce rd_firstRelfilenodeSubid. Amend the specification of rd_createSubid such that the field is zero when a new rel has an old rd_node. Make relcache.c retain entries for certain dropped relations until end of transaction. Back-patch to 9.5 (all supported versions). This introduces a new WAL record type, XLOG_GIST_ASSIGN_LSN, without bumping XLOG_PAGE_MAGIC. As always, update standby systems before master systems. This changes sizeof(RelationData) and sizeof(IndexStmt), breaking binary compatibility for affected extensions. (The most recent commit to affect the same class of extensions was 089e4d405d0f3b94c74a2c6a54357a84a681754b.) Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert Haas. Heikki Linnakangas and Michael Paquier implemented earlier designs that materially clarified the problem. Reviewed, in earlier designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane, Fujii Masao, and Simon Riggs. Reported by Martijn van Oosterhout. Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
2020-03-21Fix cosmetic blemishes involving rd_createSubid.Noah Misch
Remove an obsolete comment from AtEOXact_cleanup(). Restore formatting of a comment in struct RelationData, mangled by the pgindent run in commit 9af4159fce6654aa0e081b00d02bca40b978745c. Back-patch to 9.5 (all supported versions), because another fix stacks on this.
2020-03-16Avoid holding a directory FD open across assorted SRF calls.Tom Lane
This extends the fixes made in commit 085b6b667 to other SRFs with the same bug, namely pg_logdir_ls(), pgrowlocks(), pg_timezone_names(), pg_ls_dir(), and pg_tablespace_databases(). Also adjust various comments and documentation to warn against expecting to clean up resources during a ValuePerCall SRF's final call. Back-patch to all supported branches, since these functions were all born broken. Justin Pryzby, with cosmetic tweaks by me Discussion: https://postgr.es/m/20200308173103.GC1357@telsasoft.com
2020-03-14Restructure polymorphic-type resolution in funcapi.c.Tom Lane
resolve_polymorphic_tupdesc() and resolve_polymorphic_argtypes() failed to cover the case of having to resolve anyarray given only an anyrange input. The bug was masked if anyelement was also used (as either input or output), which probably helps account for our not having noticed. While looking at this I noticed that resolve_generic_type() would produce the wrong answer if asked to make that same resolution. ISTM that resolve_generic_type() is confusingly defined and overly complex, so rather than fix it, let's just make funcapi.c do the specific lookups it requires for itself. With this change, resolve_generic_type() is not used anywhere, so remove it in HEAD. In the back branches, leave it alone (complete with bug) just in case any external code is using it. While we're here, make some other refactoring adjustments in funcapi.c with an eye to upcoming future expansion of the set of polymorphic types: * Simplify quick-exit tests by adding an overall have_polymorphic_result flag. This is about a wash now but will be a win when there are more flags. * Reduce duplication of code between resolve_polymorphic_tupdesc() and resolve_polymorphic_argtypes(). * Don't bother to validate correct matching of anynonarray or anyenum; the parser should have done that, and even if it didn't, just doing "return false" here would lead to a very confusing, off-point error message. (Really, "return false" in these two functions should only occur if the call_expr isn't supplied or we can't obtain data type info from it.) * For the same reason, throw an elog rather than "return false" if we fail to resolve a polymorphic type. The bug's been there since we added anyrange, so back-patch to all supported branches. Discussion: https://postgr.es/m/6093.1584202130@sss.pgh.pa.us
2020-03-13Preserve replica identity index across ALTER TABLE rewritePeter Eisentraut
If an index was explicitly set as replica identity index, this setting was lost when a table was rewritten by ALTER TABLE. Because this setting is part of pg_index but actually controlled by ALTER TABLE (not part of CREATE INDEX, say), we have to do some extra work to restore it. Based-on-patch-by: Quan Zongliang <quanzongliang@gmail.com> Reviewed-by: Euler Taveira <euler.taveira@2ndquadrant.com> Discussion: https://www.postgresql.org/message-id/flat/c70fcab2-4866-0d9f-1d01-e75e189db342@gmail.com
2020-01-31Fix CheckAttributeType's handling of collations for ranges.Tom Lane
Commit fc7695891 changed CheckAttributeType to recurse into ranges, but made it pass down the wrong collation (always InvalidOid, since ranges as such have no collation). This would result in guaranteed failure when considering a range type whose subtype is collatable. Embarrassingly, we lack any regression tests that would expose such a problem (but fortunately, somebody noticed before we shipped this bug in any release). Fix it to pass down the range's subtype collation property instead, and add some regression test cases to exercise collatable-subtype ranges a bit more. Back-patch to all supported branches, as the previous patch was. Report and patch by Julien Rouhaud, test cases tweaked by me Discussion: https://postgr.es/m/CAOBaU_aBWqNweiGUFX0guzBKkcfJ8mnnyyGC_KBQmO12Mj5f_A@mail.gmail.com
2020-01-23Fix an oversight in commit 4c70098ff.Tom Lane
I had supposed that the from_char_seq_search() call sites were all passing the constant arrays you'd expect them to pass ... but on looking closer, the one for DY format was passing the days[] array not days_short[]. This accidentally worked because the day abbreviations in English are all the same as the first three letters of the full day names. However, once we took out the "maximum comparison length" logic, it stopped working. As penance for that oversight, add regression test cases covering this, as well as every other switch case in DCH_from_char() that was not reached according to the code coverage report. Also, fold the DCH_RM and DCH_rm cases into one --- now that seq_search is case independent, there's no need to pass different comparison arrays for those cases. Back-patch, as the previous commit was.
2020-01-23Clean up formatting.c's logic for matching constant strings.Tom Lane
seq_search(), which is used to match input substrings to constants such as month and day names, had a lot of bizarre and unnecessary behaviors. It was mostly possible to avert our eyes from that before, but we don't want to duplicate those behaviors in the upcoming patch to allow recognition of non-English month and day names. So it's time to clean this up. In particular: * seq_search scribbled on the input string, which is a pretty dangerous thing to do, especially in the badly underdocumented way it was done here. Fortunately the input string is a temporary copy, but that was being made three subroutine levels away, making it something easy to break accidentally. The behavior is externally visible nonetheless, in the form of odd case-folding in error reports about unrecognized month/day names. The scribbling is evidently being done to save a few calls to pg_tolower, but that's such a cheap function (at least for ASCII data) that it's pretty pointless to worry about. In HEAD I switched it to be pg_ascii_tolower to ensure it is cheap in all cases; but there are corner cases in Turkish where this'd change behavior, so leave it as pg_tolower in the back branches. * seq_search insisted on knowing the case form (all-upper, all-lower, or initcap) of the constant strings, so that it didn't have to case-fold them to perform case-insensitive comparisons. This likewise seems like excessive micro-optimization, given that pg_tolower is certainly very cheap for ASCII data. It seems unsafe to assume that we know the case form that will come out of pg_locale.c for localized month/day names, so it's better just to define the comparison rule as "downcase all strings before comparing". (The choice between downcasing and upcasing is arbitrary so far as English is concerned, but it might not be in other locales, so follow citext's lead here.) * seq_search also had a parameter that'd cause it to report a match after a maximum number of characters, even if the constant string were longer than that. This was not actually used because no caller passed a value small enough to cut off a comparison. Replicating that behavior for localized month/day names seems expensive as well as useless, so let's get rid of that too. * from_char_seq_search used the maximum-length parameter to truncate the input string in error reports about not finding a matching name. This leads to rather confusing reports in many cases. Worse, it is outright dangerous if the input string isn't all-ASCII, because we risk truncating the string in the middle of a multibyte character. That'd lead either to delivering an illegible error message to the client, or to encoding-conversion failures that obscure the actual data problem. Get rid of that in favor of truncating at whitespace if any (a suggestion due to Alvaro Herrera). In addition to fixing these things, I const-ified the input string pointers of DCH_from_char and its subroutines, to make sure there aren't any other scribbling-on-input problems. The risk of generating a badly-encoded error message seems like enough of a bug to justify back-patching, so patch all supported branches. Discussion: https://postgr.es/m/29432.1579731087@sss.pgh.pa.us
2020-01-12Fix edge-case crashes and misestimation in range containment selectivity.Tom Lane
When estimating the selectivity of "range_var <@ range_constant" or "range_var @> range_constant", if the upper (or respectively lower) bound of the range_constant was above the last bin of the range_var's histogram, the code would access uninitialized memory and potentially crash (though it seems the probability of a crash is quite low). Handle the endpoint cases explicitly to fix that. While at it, be more paranoid about the possibility of getting NaN or other silly results from the range type's subdiff function. And improve some comments. Ordinarily we'd probably add a regression test case demonstrating the bug in unpatched code. But it's too hard to get it to crash reliably because of the uninitialized-memory dependence, so skip that. Per bug #16122 from Adam Scott. It's been broken from the beginning, apparently, so backpatch to all supported branches. Diagnosis by Michael Paquier, patch by Andrey Borodin and Tom Lane. Discussion: https://postgr.es/m/16122-eb35bc248c806c15@postgresql.org
2019-12-12Fix EXTRACT(ISOYEAR FROM timestamp) for years BC.Tom Lane
The test cases added by commit 26ae3aa80 exposed an old oversight in timestamp[tz]_part: they didn't correct the result of date2isoyear() for BC years, so that we produced an off-by-one answer for such years. Fix that, and back-patch to all supported branches. Discussion: https://postgr.es/m/SG2PR06MB37762CAE45DB0F6CA7001EA9B6550@SG2PR06MB3776.apcprd06.prod.outlook.com
2019-12-12Remove redundant function calls in timestamp[tz]_part().Tom Lane
The DTK_DOW/DTK_ISODOW and DTK_DOY switch cases in timestamp_part() and timestamptz_part() contained calls of timestamp2tm() that were fully redundant with the ones done just above the switch. This evidently crept in during commit 258ee1b63, which relocated that code from another place where the calls were indeed needed. Just delete the redundant calls. I (tgl) noted that our test coverage of these functions left quite a bit to be desired, so extend timestamp.sql and timestamptz.sql to cover all the branches. Back-patch to all supported branches, as the previous commit was. There's no real issue here other than some wasted cycles in some not-too-heavily-used code paths, but the test coverage seems valuable. Report and patch by Li Japin; test case adjustments by me. Discussion: https://postgr.es/m/SG2PR06MB37762CAE45DB0F6CA7001EA9B6550@SG2PR06MB3776.apcprd06.prod.outlook.com
2019-12-01Fix misbehavior with expression indexes on ON COMMIT DELETE ROWS tables.Tom Lane
We implement ON COMMIT DELETE ROWS by truncating tables marked that way, which requires also truncating/rebuilding their indexes. But RelationTruncateIndexes asks the relcache for up-to-date copies of any index expressions, which may cause execution of eval_const_expressions on them, which can result in actual execution of subexpressions. This is a bad thing to have happening during ON COMMIT. Manuel Rigger reported that use of a SQL function resulted in crashes due to expectations that ActiveSnapshot would be set, which it isn't. The most obvious fix perhaps would be to push a snapshot during PreCommit_on_commit_actions, but I think that would just open the door to more problems: CommitTransaction explicitly expects that no user-defined code can be running at this point. Fortunately, since we know that no tuples exist to be indexed, there seems no need to use the real index expressions or predicates during RelationTruncateIndexes. We can set up dummy index expressions instead (we do need something that will expose the right data type, as there are places that build index tupdescs based on this), and just ignore predicates and exclusion constraints. In a green field it'd likely be better to reimplement ON COMMIT DELETE ROWS using the same "init fork" infrastructure used for unlogged relations. That seems impractical without catalog changes though, and even without that it'd be too big a change to back-patch. So for now do it like this. Per private report from Manuel Rigger. This has been broken forever, so back-patch to all supported branches.
2019-11-21Defend against self-referential views in relation_is_updatable().Tom Lane
While a self-referential view doesn't actually work, it's possible to create one, and it turns out that this breaks some of the information_schema views. Those views call relation_is_updatable(), which neglected to consider the hazards of being recursive. In older PG versions you get a "stack depth limit exceeded" error, but since v10 it'd recurse to the point of stack overrun and crash, because commit a4c35ea1c took out the expression_returns_set() call that was incidentally checking the stack depth. Since this function is only used by information_schema views, it seems like it'd be better to return "not updatable" than suffer an error. Hence, add tracking of what views we're examining, in just the same way that the nearby fireRIRrules() code detects self-referential views. I added a check_stack_depth() call too, just to be defensive. Per private report from Manuel Rigger. Back-patch to all supported versions.
2019-11-16Further fix dumping of views that contain just VALUES(...).Tom Lane
It turns out that commit e9f1c01b7 missed a case: we must print a VALUES clause in long format if get_query_def is given a resultDesc that would require the query's output column name(s) to be different from what the bare VALUES clause would produce. This applies in case an ALTER ... RENAME COLUMN has been done to a view that formerly could be printed in simple format, as shown in the added regression test case. It also explains bug #16119 from Dmitry Telpt, because it turns out that (unlike CREATE VIEW) CREATE MATERIALIZED VIEW fails to apply any column aliases it's given to the stored ON SELECT rule. So to get them to be printed, we have to account for the resultDesc renaming. It might be worth changing the matview code so that it creates the ON SELECT rule with the correct aliases; but we'd still need these messy checks in get_simple_values_rte to handle the case of a subsequent column rename, so any such change would be just neatnik-ism not a bug fix. Like the previous patch, back-patch to all supported branches. Discussion: https://postgr.es/m/16119-e64823f30a45a754@postgresql.org
2019-11-07Fix integer-overflow edge case detection in interval_mul and pgbench.Tom Lane
This patch adopts the overflow check logic introduced by commit cbdb8b4c0 into two more places. interval_mul() failed to notice if it computed a new microseconds value that was one more than INT64_MAX, and pgbench's double-to-int64 logic had the same sorts of edge-case problems that cbdb8b4c0 fixed in the core code. To make this easier to get right in future, put the guts of the checks into new macros in c.h, and add commentary about how to use the macros correctly. Back-patch to all supported branches, as we did with the previous fix. Yuya Watari Discussion: https://postgr.es/m/CAJ2pMkbkkFw2hb9Qb1Zj8d06EhWAQXFLy73St4qWv6aX=vqnjw@mail.gmail.com
2019-11-04Catch invalid typlens in a couple of placesPeter Eisentraut
Rearrange the logic in record_image_cmp() and record_image_eq() to error out on unexpected typlens (either not supported there or completely invalid due to corruption). Barring corruption, this is not possible today but it seems more future-proof and robust to fix this. Reported-by: Peter Geoghegan <pg@bowt.ie>
2019-10-17When restoring GUCs in parallel workers, show an error context.Thomas Munro
Otherwise it can be hard to see where an error is coming from, when the parallel worker sets all the GUCs that it received from the leader. Bug #15726. Back-patch to 9.5, where RestoreGUCState() appeared. Reported-by: Tiago Anastacio Reviewed-by: Daniel Gustafsson, Tom Lane Discussion: https://postgr.es/m/15726-6d67e4fa14f027b3%40postgresql.org
2019-10-04Fix bitshiftright()'s zero-padding some more.Tom Lane
Commit 5ac0d9360 failed to entirely fix bitshiftright's habit of leaving one-bits in the pad space that should be all zeroes, because in a moment of sheer brain fade I'd concluded that only the code path used for not-a-multiple-of-8 shift distances needed to be fixed. Of course, a multiple-of-8 shift distance can also cause the problem, so we need to forcibly zero the extra bits in both cases. Per bug #16037 from Alexander Lakhin. As before, back-patch to all supported branches. Discussion: https://postgr.es/m/16037-1d1ebca564db54f4@postgresql.org
2019-10-03Avoid unnecessary out-of-memory errors during encoding conversion.Tom Lane
Encoding conversion uses the very simplistic rule that the output can't be more than 4X longer than the input, and palloc's a buffer of that size. This results in failure to convert any string longer than 1/4 GB, which is becoming an annoying limitation. As a band-aid to improve matters, allow the allocated output buffer size to exceed 1GB. We still insist that the final result fit into MaxAllocSize (1GB), though. Perhaps it'd be safe to relax that restriction, but it'd require close analysis of all callers, which is daunting (not least because external modules might call these functions). For the moment, this should allow a 2X to 4X improvement in the longest string we can convert, which is a useful gain in return for quite a simple patch. Also, once we have successfully converted a long string, repalloc the output down to the actual string length, returning the excess to the malloc pool. This seems worth doing since we can usually expect to give back several MB if we take this path at all. This still leaves much to be desired, most notably that the assumption that MAX_CONVERSION_GROWTH == 4 is very fragile, and yet we have no guard code verifying that the output buffer isn't overrun. Fixing that would require significant changes in the encoding conversion APIs, so it'll have to wait for some other day. The present patch seems safely back-patchable, so patch all supported branches. Alvaro Herrera and Tom Lane Discussion: https://postgr.es/m/20190816181418.GA898@alvherre.pgsql Discussion: https://postgr.es/m/3614.1569359690@sss.pgh.pa.us
2019-10-03Allow repalloc() to give back space when a large chunk is downsized.Tom Lane
Up to now, if you resized a large (>8K) palloc chunk down to a smaller size, aset.c made no attempt to return any space to the malloc pool. That's unpleasant if a really large allocation is resized to a significantly smaller size. I think no such cases existed when this code was designed, and I'm not sure whether they're common even yet, but an upcoming fix to encoding conversion will certainly create such cases. Therefore, fix AllocSetRealloc so that it gives realloc() a chance to do something with the block. This doesn't noticeably increase complexity, we mostly just have to change the order in which the cases are considered. Back-patch to all supported branches. Discussion: https://postgr.es/m/20190816181418.GA898@alvherre.pgsql Discussion: https://postgr.es/m/3614.1569359690@sss.pgh.pa.us
2019-09-22Fix failure to zero-pad the result of bitshiftright().Tom Lane
If the bitstring length is not a multiple of 8, we'd shift the rightmost bits into the pad space, which must be zeroes --- bit_cmp, for one, depends on that. This'd lead to the result failing to compare equal to what it should compare equal to, as reported in bug #16013 from Daryl Waycott. This is, if memory serves, not the first such bug in the bitstring functions. In hopes of making it the last one, do a bit more work than minimally necessary to fix the bug: * Add assertion checks to bit_out() and varbit_out() to complain if they are given incorrectly-padded input. This will improve the odds that manual testing of any new patch finds problems. * Encapsulate the padding-related logic in macros to make it easier to use. Also, remove unnecessary padding logic from bit_or() and bitxor(). Somebody had already noted that we need not re-pad the result of bit_and() since the inputs are required to be the same length, but failed to extrapolate that to the other two. Also, move a comment block that once was near the head of varbit.c (but people kept putting other stuff in front of it), to put it in the header block. Note for the release notes: if anyone has inconsistent data as a result of saving the output of bitshiftright() in a table, it's possible to fix it with something like UPDATE mytab SET bitcol = ~(~bitcol) WHERE bitcol != ~(~bitcol); This has been broken since day one, so back-patch to all supported branches. Discussion: https://postgr.es/m/16013-c2765b6996aacae9@postgresql.org
2019-08-27Reject empty names and recursion in config-file include directives.Tom Lane
An empty file name or subdirectory name leads join_path_components() to just produce the parent directory name, which leads to weird failures or recursive inclusions. Let's throw a specific error for that. It takes only slightly more code to detect all-blank names, so do so. Also, detect direct recursion, ie a file calling itself. As coded this will also detect recursion via "include_dir '.'", which is perhaps more likely than explicitly including the file itself. Detecting indirect recursion would require API changes for guc-file.l functions, which seems not worth it since extensions might call them. The nesting depth limit will catch such cases eventually, just not with such an on-point error message. In passing, adjust the example usages in postgresql.conf.sample to perhaps eliminate the problem at the source: there's no reason for the examples to suggest that an empty value is valid. Per a trouble report from Brent Bates. Back-patch to 9.5; the issue is old, but the code in 9.4 is enough different that the patch doesn't apply easily, and it doesn't seem worth the trouble to fix there. Ian Barwick and Tom Lane Discussion: https://postgr.es/m/8c8bcbca-3bd9-dc6e-8986-04a5abdef142@2ndquadrant.com
2019-08-14Fix ALTER SYSTEM to cope with duplicate entries in postgresql.auto.conf.Tom Lane
ALTER SYSTEM itself normally won't make duplicate entries (although up till this patch, it was possible to confuse it by writing case variants of a GUC's name). However, if some external tool has appended entries to the file, that could result in duplicate entries for a single GUC name. In such a situation, ALTER SYSTEM did exactly the wrong thing, because it replaced or removed only the first matching entry, leaving the later one(s) still there and hence still determining the active value. This patch fixes that by making ALTER SYSTEM sweep through the file and remove all matching entries, then (if not ALTER SYSTEM RESET) append the new setting to the end. This means entries will be in order of last setting rather than first setting, but that shouldn't hurt anything. Also, make the comparisons case-insensitive so that the right things happen if you do, say, ALTER SYSTEM SET "TimeZone" = 'whatever'. This has been broken since ALTER SYSTEM was invented, so back-patch to all supported branches. Ian Barwick, with minor mods by me Discussion: https://postgr.es/m/aed6cc9f-98f3-2693-ac81-52bb0052307e@2ndquadrant.com
2019-08-07Fix some incorrect parsing of time with time zone stringsMichael Paquier
When parsing a timetz string with a dynamic timezone abbreviation or a timezone not specified, it was possible to generate incorrect timestamps based on a date which uses some non-initialized variables if the input string did not specify fully a date to parse. This is already checked when a full timezone spec is included in the input string, but the two other cases mentioned above missed the same checks. This gets fixed by generating an error as this input is invalid, or in short when a date is not fully specified. Valgrind was complaining about this problem. Bug: #15910 Author: Alexander Lakhin Discussion: https://postgr.es/m/15910-2eba5106b9aa0c61@postgresql.org Backpatch-through: 9.4
2019-08-05Require the schema qualification in pg_temp.type_name(arg).Noah Misch
Commit aa27977fe21a7dfa4da4376ad66ae37cb8f0d0b5 introduced this restriction for pg_temp.function_name(arg); do likewise for types created in temporary schemas. Programs that this breaks should add "pg_temp." schema qualification or switch to arg::type_name syntax. Back-patch to 9.4 (all supported versions). Reviewed by Tom Lane. Reported by Tom Lane. Security: CVE-2019-10208
2019-07-26Tweak our special-case logic for the IANA "Factory" timezone.Tom Lane
pg_timezone_names() tries to avoid showing the "Factory" zone in the view, mainly because that has traditionally had a very long "abbreviation" such as "Local time zone must be set--see zic manual page", so that showing it messes up psql's formatting of the whole view. Since tzdb version 2016g, IANA instead uses the abbreviation "-00", which is sane enough that there's no reason to discriminate against it. On the other hand, it emerges that FreeBSD and possibly other packagers are so wedded to backwards compatibility that they hack the IANA data to keep the old spelling --- and not just that old spelling, but even older spellings that IANA used back in the stone age. This caused the filter logic to fail to suppress "Factory" at all on such platforms, though the formatting problem is definitely real in that case. To solve both problems, get rid of the hard-wired assumption about exactly what Factory's abbreviation is, and instead reject abbreviations exceeding 31 characters. This will allow Factory to appear in the view if and only if it's using the modern abbreviation. In passing, simplify the code we add to zic.c to support "zic -P" to remove its now-obsolete hacks to not print the Factory zone's abbreviation. Unlike pg_timezone_names(), there's no reason for that code to support old/nonstandard timezone data. Since we generally prefer to keep timezone-related behavior the same in all branches, and since this is arguably a bug fix, back-patch to all supported branches. Discussion: https://postgr.es/m/3961.1564086915@sss.pgh.pa.us
2019-07-26Fix loss of fractional digits for large values in cash_numeric().Tom Lane
Money values exceeding about 18 digits (depending on lc_monetary) could be inaccurately converted to numeric, due to select_div_scale() deciding it didn't need to compute any fractional digits. Force its hand by setting the dscale of one division input to equal the number of fractional digits we need. In passing, rearrange the logic to not do useless work in locales where money values are considered integral. Per bug #15925 from Slawomir Chodnicki. Back-patch to all supported branches. Discussion: https://postgr.es/m/15925-da9953e2674bb5c8@postgresql.org
2019-07-18Fix error in commit e6feef57.Jeff Davis
I was careless passing a datum directly to DATE_NOT_FINITE without calling DatumGetDateADT() first. Backpatch-through: 9.4
2019-07-18Fix daterange canonicalization for +/- infinity.Jeff Davis
The values 'infinity' and '-infinity' are a part of the DATE type itself, so a bound of the date 'infinity' is not the same as an unbounded/infinite range. However, it is still wrong to try to canonicalize such values, because adding or subtracting one has no effect. Fix by treating 'infinity' and '-infinity' the same as unbounded ranges for the purposes of canonicalization (but not other purposes). Backpatch to all versions because it is inconsistent with the documented behavior. Note that this could be an incompatibility for applications relying on the behavior contrary to the documentation. Author: Laurenz Albe Reviewed-by: Thomas Munro Discussion: https://postgr.es/m/77f24ea19ab802bc9bc60ddbb8977ee2d646aec1.camel%40cybertec.at Backpatch-through: 9.4
2019-06-30Don't read fields of a misaligned ExpandedObjectHeader or AnyArrayType.Noah Misch
UBSan complains about this. Instead, cast to a suitable type requiring only 4-byte alignment. DatumGetAnyArrayP() already assumes one can cast between AnyArrayType and ArrayType, so this doesn't introduce a new assumption. Back-patch to 9.5, where AnyArrayType was introduced. Reviewed by Tom Lane. Discussion: https://postgr.es/m/20190629210334.GA1244217@rfd.leadboat.com
2019-06-12Fix incorrect printing of queries with duplicated join names.Tom Lane
Given a query in which multiple JOIN nodes used the same alias (which'd necessarily be in different sub-SELECTs), ruleutils.c would assign the JOIN nodes distinct aliases for clarity ... but then it forgot to print the modified aliases when dumping the JOIN nodes themselves. This results in a dump/reload hazard for views, because the emitted query is flat-out incorrect: Vars will be printed with table names that have no referent. This has been wrong for a long time, so back-patch to all supported branches. Philip Dubé Discussion: https://postgr.es/m/CY4PR2101MB080246F2955FF58A6ED1FEAC98140@CY4PR2101MB0802.namprd21.prod.outlook.com
2019-06-10Don't access catalogs to validate GUCs when not connected to a DB.Andres Freund
Vignesh found this bug in the check function for default_table_access_method's check hook, but that was just copied from older GUCs. Investigation by Michael and me then found the bug in further places. When not connected to a database (e.g. in a walsender connection), we cannot perform (most) GUC checks that need database access. Even when only shared tables are needed, unless they're nailed (c.f. RelationCacheInitializePhase2()), they cannot be accessed without pg_class etc. being present. Fix by extending the existing IsTransactionState() checks to also check for MyDatabaseOid. Reported-By: Vignesh C, Michael Paquier, Andres Freund Author: Vignesh C, Andres Freund Discussion: https://postgr.es/m/CALDaNm1KXK9gbZfY-p_peRFm_XrBh1OwQO1Kk6Gig0c0fVZ2uw%40mail.gmail.com Backpatch: 9.4-