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* Fix underqualified cast-target type names in pg_dump and psql queries.Tom Lane2017-10-31
| | | | | | | | | | | | | | | | | | | | Queries running with some non-pg_catalog schema frontmost in their search path need to be careful to schema-qualify type names that should be sought in pg_catalog. Vitaly Burovoy reported an oversight of this sort in pg_dump's dumpSequence, and grepping detected another one in psql's describeOneTableDetails, both introduced by sequence-related changes in v10. In pg_dump, we can fix things by removing the cast altogether, since it doesn't really matter what data types are reported for these query result columns. Likewise in psql, the query seemed to be working unduly hard to get a result that's guaranteed to be exactly 'bigint'. I also changed a couple of occurrences of "::char" similarly. These are not bugs, since "char" is a typename keyword and not subject to search_path rules, but it seems better to use uniform style. Vitaly Burovoy and Tom Lane Discussion: https://postgr.es/m/CAKOSWN=ds66zLw2SqkLTM8wbXFgDbc_OdkmT3dJfPT2mE5kipA@mail.gmail.com
* Fix autovacuum work item error handlingAlvaro Herrera2017-10-30
| | | | | | | | | | | | | | | | | In autovacuum's "work item" processing, a few strings were allocated in the current transaction's memory context, which goes away during error handling; if an error happened during execution of the work item, the pfree() calls to clean up afterwards would try to release already-released memory, possibly leading to a crash. In branch master, this was already fixed by commit 335f3d04e4c8, so backpatch that to REL_10_STABLE to fix the problem there too. As a secondary problem, verify that the autovacuum worker is connected to the right database for each work item; otherwise some items would be discarded by workers in other databases. Reported-by: Justin Pryzby Discussion: https://postgr.es/m/20171014035732.GB31726@telsasoft.com
* Allow parallel query for prepared statements with generic plans.Robert Haas2017-10-29
| | | | | | | | | | | | | | This was always intended to work, but due to an oversight in max_parallel_hazard_walker, it didn't. In testing, we missed the fact that it was only working for custom plans, where the parameter value has been substituted for the parameter itself early enough that everything worked. In a generic plan, the Param node survives and must be treated as parallel-safe. SerializeParamList provides for the transmission of parameter values to workers. Amit Kapila with help from Kuntal Ghosh. Some changes by me. Discussion: http://postgr.es/m/CAA4eK1+_BuZrmVCeua5Eqnm4Co9DAXdM5HPAOE2J19ePbR912Q@mail.gmail.com
* Fix problems with the "role" GUC and parallel query.Robert Haas2017-10-29
| | | | | | | | | | Without this fix, dropping a role can sometimes result in parallel query failures in sessions that have used "SET ROLE" to assume the dropped role, even if that setting isn't active any more. Report by Pavan Deolasee. Patch by Amit Kapila, reviewed by me. Discussion: http://postgr.es/m/CABOikdOomRcZsLsLK+Z+qENM1zxyaWnAvFh3MJZzZnnKiF+REg@mail.gmail.com
* Dept of second thoughts: keep aliasp_item in sync with tlistitem.Tom Lane2017-10-27
| | | | | | | | Commit d5b760ecb wasn't quite right, on second thought: if the caller didn't ask for column names then it would happily emit more Vars than if the caller did ask for column names. This is surely not a good idea. Advance the aliasp_item whether or not we're preparing a colnames list.
* Fix crash when columns have been added to the end of a view.Tom Lane2017-10-27
| | | | | | | | | | | | | | | | | | | | | | | expandRTE() supposed that an RTE_SUBQUERY subquery must have exactly as many non-junk tlist items as the RTE has column aliases for it. This was true at the time the code was written, and is still true so far as parse analysis is concerned --- but when the function is used during planning, the subquery might have appeared through insertion of a view that now has more columns than it did when the outer query was parsed. This results in a core dump if, for instance, we have to expand a whole-row Var that references the subquery. To avoid crashing, we can either stop expanding the RTE when we run out of aliases, or invent new aliases for the added columns. While the latter might be more useful, the former is consistent with what expandRTE() does for composite-returning functions in the RTE_FUNCTION case, so it seems like we'd better do it that way. Per bug #14876 from Samuel Horwitz. This has been busted since commit ff1ea2173 allowed views to acquire more columns, so back-patch to all supported branches. Discussion: https://postgr.es/m/20171026184035.1471.82810@wrigleys.postgresql.org
* Rethink the dependencies recorded for FieldSelect/FieldStore nodes.Tom Lane2017-10-27
| | | | | | | | | | | | | | | | | | | | | On closer investigation, commits f3ea3e3e8 et al were a few bricks shy of a load. What we need is not so much to lock down the result type of a FieldSelect, as to lock down the existence of the column it's trying to extract. Otherwise, we can break it by dropping that column. The dependency on the result type is then held indirectly through the column, and doesn't need to be recorded explicitly. Out of paranoia, I left in the code to record a dependency on the result type, but it's used only if we can't identify the pg_class OID for the column. That shouldn't ever happen right now, AFAICS, but it seems possible that in future the input node could be marked as being of type RECORD rather than some specific composite type. Likewise for FieldStore. Like the previous patch, back-patch to all supported branches. Discussion: https://postgr.es/m/22571.1509064146@sss.pgh.pa.us
* Move new structure member to the end.Robert Haas2017-10-27
| | | | | | Reduces ABI breakage. Per Tom Lane. Discussion: http://postgr.es/m/4035.1509113974@sss.pgh.pa.us
* Fix mistaken failure to allow parallelism in corner case.Robert Haas2017-10-27
| | | | | | | | | | | | | | | If we try to run a parallel plan in serial mode because, for example, it's going to be scanned via a cursor, but for some reason we're already in parallel mode (for example because an outer query is running in parallel), we'd incorrectly try to launch workers. Fix by adding a flag to the EState, so that we can be certain that ExecutePlan() and ExecGather()/ExecGatherMerge() will have the same idea about whether we are executing serially or in parallel. Report and fix by Amit Kapila with help from Kuntal Ghosh. A few tweaks by me. Discussion: http://postgr.es/m/CAA4eK1+_BuZrmVCeua5Eqnm4Co9DAXdM5HPAOE2J19ePbR912Q@mail.gmail.com
* Make setrefs.c match by ressortgroupref even for plain Vars.Tom Lane2017-10-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, we skipped using search_indexed_tlist_for_sortgroupref() if the tlist expression being sought in the child plan node was merely a Var. This is purely an optimization, based on the theory that search_indexed_tlist_for_var() is faster, and one copy of a Var should be as good as another. However, the GROUPING SETS patch broke the latter assumption: grouping columns containing the "same" Var can sometimes have different outputs, as shown in the test case added here. So do it the hard way whenever a ressortgroupref marking exists. (If this seems like a bottleneck, we could imagine building a tlist index data structure for ressortgroupref values, as we do for Vars. But I'll let that idea go until there's some evidence it's worthwhile.) Back-patch to 9.6. The problem also exists in 9.5 where GROUPING SETS came in, but this patch is insufficient to resolve the problem in 9.5: there is some obscure dependency on the upper-planner-pathification work that happened in 9.6. Given that this is such a weird corner case, and no end users have complained about it, it doesn't seem worth the work to develop a fix for 9.5. Patch by me, per a report from Heikki Linnakangas. (This does not fix Heikki's original complaint, just the follow-on one.) Discussion: https://postgr.es/m/aefc657e-edb2-64d5-6df1-a0828f6e9104@iki.fi
* Improve gendef.pl diagnostic on failure to open sym fileAndrew Dunstan2017-10-26
| | | | | | | | There have been numerous buildfarm failures but the diagnostic is currently silent about the reason for failure to open the file. Let's see if we can get to the bottom of it. Backpatch to all live branches.
* Undo inadvertent change in capitalization in commit 18fc4ec.Andrew Dunstan2017-10-26
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* Fixed handling of escape character in libecpg.Michael Meskes2017-10-26
| | | | Patch by Tsunakawa Takayuki <tsunakawa.takay@jp.fujitsu.com>
* Fix libpq to not require user's home directory to exist.Tom Lane2017-10-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some people like to run libpq-using applications in environments where there's no home directory. We've broken that scenario before (cf commits 5b4067798 and bd58d9d88), and commit ba005f193 broke it again, by making it a hard error if we fail to get the home directory name while looking for ~/.pgpass. The previous precedent is that if we can't get the home directory name, we should just silently act as though the file we hoped to find there doesn't exist. Rearrange the new code to honor that. Looking around, the service-file code added by commit 41a4e4595 had the same disease. Apparently, that escaped notice because it only runs when a service name has been specified, which I guess the people who use this scenario don't do. Nonetheless, it's wrong too, so fix that case as well. Add a comment about this policy to pqGetHomeDirectory, in the probably vain hope of forestalling the same error in future. And upgrade the rather miserable commenting in parseServiceInfo, too. In passing, also back off parseServiceInfo's assumption that only ENOENT is an ignorable error from stat() when checking a service file. We would need to ignore at least ENOTDIR as well (cf 5b4067798), and seeing that the far-better-tested code for ~/.pgpass treats all stat() failures alike, I think this code ought to as well. Per bug #14872 from Dan Watson. Back-patch the .pgpass change to v10 where ba005f193 came in. The service-file bugs are far older, so back-patch the other changes to all supported branches. Discussion: https://postgr.es/m/20171025200457.1471.34504@wrigleys.postgresql.org
* Process variadic arguments consistently in json functionsAndrew Dunstan2017-10-25
| | | | | | | | | | | | json_build_object and json_build_array and the jsonb equivalents did not correctly process explicit VARIADIC arguments. They are modified to use the new extract_variadic_args() utility function which abstracts away the details of the call method. Michael Paquier, reviewed by Tom Lane and Dmitry Dolgov. Backpatch to 9.5 for the jsonb fixes and 9.4 for the json fixes, as that's where they originated.
* Add a utility function to extract variadic function argumentsAndrew Dunstan2017-10-25
| | | | | | | | | | | This is epecially useful in the case or "VARIADIC ANY" functions. The caller can get the artguments and types regardless of whether or not and explicit VARIADIC array argument has been used. The function also provides an option to convert arguments on type "unknown" to to "text". Michael Paquier and me, reviewed by Tom Lane. Backpatch to 9.4 in order to support the following json bug fix.
* In the planner, delete joinaliasvars lists after we're done with them.Tom Lane2017-10-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although joinaliasvars lists coming out of the parser are quite simple, those lists can contain arbitrarily complex expressions after subquery pullup. We do not perform expression preprocessing on them, meaning that expressions in those lists will not meet the expectations of later phases of the planner (for example, that they do not contain SubLinks). This had been thought pretty harmless, since we don't intentionally touch those lists in later phases --- but Andreas Seltenreich found a case in which adjust_appendrel_attrs() could recurse into a joinaliasvars list and then die on its assertion that it never sees a SubLink. We considered a couple of localized fixes to prevent that specific case from looking at the joinaliasvars lists, but really this seems like a generic hazard for all expression processing in the planner. Therefore, probably the best answer is to delete the joinaliasvars lists from the parsetree at the end of expression preprocessing, so that there are no reachable expressions that haven't been through preprocessing. The case Andreas found seems to be harmless in non-Assert builds, and so far there are no field reports suggesting that there are user-visible effects in other cases. I considered back-patching this anyway, but it turns out that Andreas' test doesn't fail at all in 9.4-9.6, because in those versions adjust_appendrel_attrs contains code (added in commit 842faa714 and removed again in commit 215b43cdc) to process SubLinks rather than complain about them. Barring discovery of another path by which unprocessed joinaliasvars lists can cause trouble, the most prudent compromise seems to be to patch this into v10 but not further. Patch by me, with thanks to Amit Langote for initial investigation and review. Discussion: https://postgr.es/m/87r2tvt9f1.fsf@ansel.ydns.eu
* Update time zone data files to tzdata release 2017c.Tom Lane2017-10-23
| | | | | | DST law changes in Fiji, Namibia, Northern Cyprus, Sudan, Tonga, and Turks & Caicos Islands. Historical corrections for Alaska, Apia, Burma, Calcutta, Detroit, Ireland, Namibia, and Pago Pago.
* Sync our copy of the timezone library with IANA release tzcode2017c.Tom Lane2017-10-23
| | | | | | | This is a trivial update containing only cosmetic changes. The point is just to get back to being synced with an official release of tzcode, rather than some ad-hoc point in their commit history, which is where commit 47f849a3c left it.
* Fix some oversights in expression dependency recording.Tom Lane2017-10-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | find_expr_references() neglected to record a dependency on the result type of a FieldSelect node, allowing a DROP TYPE to break a view or rule that contains such an expression. I think we'd omitted this case intentionally, reasoning that there would always be a related dependency ensuring that the DROP would cascade to the view. But at least with nested field selection expressions, that's not true, as shown in bug #14867 from Mansur Galiev. Add the dependency, and for good measure a dependency on the node's exposed collation. Likewise add a dependency on the result type of a FieldStore. I think here the reasoning was that it'd only appear within an assignment to a field, and the dependency on the field's column would be enough ... but having seen this example, I think that's wrong for nested-composites cases. Looking at nearby code, I notice we're not recording a dependency on the exposed collation of CoerceViaIO, which seems inconsistent with our choices for related node types. Maybe that's OK but I'm feeling suspicious of this code today, so let's add that; it certainly can't hurt. This patch does not do anything to protect already-existing views, only views created after it's installed. But seeing that the issue has been there a very long time and nobody noticed till now, that's probably good enough. Back-patch to all supported branches. Discussion: https://postgr.es/m/20171023150118.1477.19174@wrigleys.postgresql.org
* Adjust psql \d query to avoid use of @> operator.Tom Lane2017-10-22
| | | | | | | | | | | | | | | | | | It seems that the parray_gin extension has seen fit to introduce a "text[] @> text[]" operator, which conflicts with the core "anyarray @> anyarray" operator, causing ambiguous-operator failures if the input arguments are coercible to text[] without being exactly that type. This strikes me as a bad idea, but it's out there and people use it. As of v10, that breaks psql's query that tries to test "pg_statistic_ext.stxkind @> '{d}'", since stxkind is char[]. The best workaround seems to be to avoid use of that operator. We can use a scalar-vs-array test "'d' = any(stxkind)" instead; that's arguably more readable anyway. Per report from Justin Pryzby. Backpatch to v10 where this query was added. Discussion: https://postgr.es/m/20171022181525.GA21884@telsasoft.com
* Fix typcache's failure to treat ranges as container types.Tom Lane2017-10-20
| | | | | | | | | | | | | | | | | Like the similar logic for arrays and records, it's necessary to examine the range's subtype to decide whether the range type can support hashing. We can omit checking the subtype for btree-defined operations, though, since range subtypes are required to have those operations. (Possibly that simplification for btree cases led us to overlook that it does not apply for hash cases.) This is only an issue if the subtype lacks hash support, which is not true of any built-in range type, but it's easy to demonstrate a problem with a range type over, eg, money: you can get a "could not identify a hash function" failure when the planner is misled into thinking that hash join or aggregation would work. This was born broken, so back-patch to all supported branches.
* Fix typoMagnus Hagander2017-10-19
| | | | David Rowley
* Fix incorrect handling of CTEs and ENRs as DML target relations.Tom Lane2017-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | setTargetTable threw an error if the proposed target RangeVar's relname matched any visible CTE or ENR. This breaks backwards compatibility in the CTE case, since pre-v10 we never looked for a CTE here at all, so that CTE names did not mask regular tables. It does seem like a good idea to throw an error for the ENR case, though, thus causing ENRs to mask tables for this purpose; ENRs are new in v10 so we're not breaking existing code, and we may someday want to allow them to be the targets of DML. To fix that, replace use of getRTEForSpecialRelationTypes, which was overkill anyway, with use of scanNameSpaceForENR. A second problem was that the check neglected to verify null schemaname, so that a CTE or ENR could incorrectly be thought to match a qualified RangeVar. That happened because getRTEForSpecialRelationTypes relied on its caller to have checked for null schemaname. Even though the one remaining caller got it right, this is obviously bug-prone, so move the check inside getRTEForSpecialRelationTypes. Also, revert commit 18ce3a4ab's extremely poorly thought out decision to add a NULL return case to parserOpenTable --- without either documenting that or adjusting any of the callers to check for it. The current bug seems to have arisen in part due to working around that bad idea. In passing, remove the one-line shim functions transformCTEReference and transformENRReference --- they don't seem to be adding any clarity or functionality. Per report from Hugo Mercier (via Julien Rouhaud). Back-patch to v10 where the bug was introduced. Thomas Munro, with minor editing by me Discussion: https://postgr.es/m/CAOBaU_YdPVH+PTtiKSSLOiiW3mVDYsnNUekK+XPbHXiP=wrFLA@mail.gmail.com
* Repair breakage of aggregate FILTER option.Tom Lane2017-10-16
| | | | | | | | | | | | | | | | | An aggregate's input expression(s) are not supposed to be evaluated at all for a row where its FILTER test fails ... but commit 8ed3f11bb overlooked that requirement. Reshuffle so that aggregates having a filter clause evaluate their arguments separately from those without. This still gets the benefit of doing only one ExecProject in the common case of multiple Aggrefs, none of which have filters. While at it, arrange for filter clauses to be included in the common ExecProject evaluation, thus perhaps buying a little bit even when there are filters. Back-patch to v10 where the bug was introduced. Discussion: https://postgr.es/m/30065.1508161354@sss.pgh.pa.us
* Restore nodeAgg.c's ability to check for improperly-nested aggregates.Tom Lane2017-10-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | While poking around in the aggregate logic, I noticed that commit 8ed3f11bb broke the logic in nodeAgg.c that purports to detect nested aggregates, by moving initialization of regular aggregate argument expressions out of the code segment that checks for that. You could argue that this check is unnecessary, but it's not much code so I'm inclined to keep it as a backstop against parser and planner bugs. However, there's certainly zero value in checking only some of the subexpressions. We can make the check complete again, and as a bonus make it a good deal more bulletproof against future mistakes of the same ilk, by moving it out to the outermost level of ExecInitAgg. This means we need to check only once per Agg node not once per aggregate, which also seems like a good thing --- if the check does find something wrong, it's not urgent that we report it before the plan node initialization finishes. Since this requires remembering the original length of the aggs list, I deleted a long-obsolete stanza that changed numaggs from 0 to 1. That's so old it predates our decision that palloc(0) is a valid operation, in (digs...) 2004, see commit 24a1e20f1. In passing improve a few comments. Back-patch to v10, just in case.
* Fix possible crash with Parallel Bitmap Heap Scan.Robert Haas2017-10-13
| | | | | | | | | | | If a Parallel Bitmap Heap scan's chain of leftmost descendents includes a BitmapOr whose first child is a BitmapAnd, the prior coding would mistakenly create a non-shared TIDBitmap and then try to perform shared iteration. Report by Tomas Vondra. Patch by Dilip Kumar. Discussion: http://postgr.es/m/50e89684-8ad9-dead-8767-c9545bafd3b6@2ndquadrant.com
* Fix AggGetAggref() so it won't lie to aggregate final functions.Tom Lane2017-10-12
| | | | | | | | | | | | | | | | | | | | | | If we merge the transition calculations for two different aggregates, it's reasonable to assume that the transition function should not care which of those Aggref structs it gets from AggGetAggref(). It is not reasonable to make the same assumption about an aggregate final function, however. Commit 804163bc2 broke this, as it will pass whichever Aggref was first associated with the transition state in both cases. This doesn't create an observable bug so far as the core system is concerned, because the only existing uses of AggGetAggref() are in ordered-set aggregates that happen to not pay attention to anything but the input properties of the Aggref; and besides that, we disabled sharing of transition calculations for OSAs yesterday. Nonetheless, if some third-party code were using AggGetAggref() in a normal aggregate, they would be entitled to call this a bug. Hence, back-patch the fix to 9.6 where the problem was introduced. In passing, improve some of the comments about transition state sharing. Discussion: https://postgr.es/m/CAB4ELO5RZhOamuT9Xsf72ozbenDLLXZKSk07FiSVsuJNZB861A@mail.gmail.com
* Infer functional dependency past RelabelTypeAlvaro Herrera2017-10-12
| | | | | | | | | | Vars hidden within a RelabelType would not be detected as compatible with some functional dependency. Repair by properly ignoring the RelabelType. Author: David Rowley Reviewed-by: Tomas Vondra Discussion: https://postgr.es/m/CAKJS1f-y-UEy=rsBXynBOgiW1fKMr_LVoYSGL9QOc36mLEC-ww@mail.gmail.com
* Fix logical replication to fire BEFORE ROW DELETE triggers.Robert Haas2017-10-12
| | | | | | | | | | Before, that would fail to happen unless a BEFORE ROW UPDATE trigger was also present. Noted by me while reviewing a patch from Masahiko Sawada, who also wrote this patch. Reviewed by Petr Jelinek. Discussion: http://postgr.es/m/CA+TgmobAZvCxduG8y_mQKBK7nz-vhbdLvjM354KEFozpuzMN5A@mail.gmail.com
* Prevent sharing transition states between ordered-set aggregates.Tom Lane2017-10-11
| | | | | | | | | | | | | | | | | | | | | | | | This ought to work, but the built-in OSAs are not capable of coping, because their final-functions destructively modify their transition state (specifically, the contained tuplesort object). That was fine when those functions were written, but commit 804163bc2 moved the goalposts without telling orderedsetaggs.c. We should fix the built-in OSAs to support this, but it will take a little work, especially if we don't want to sacrifice performance in the normal non-shared-state case. Given that it took a year after 9.6 release for anyone to notice this bug, we should not prioritize sharable-state over nonsharable-state performance. And a proper fix is likely to be more complicated than we'd want to back-patch, too. Therefore, let's just put in this stop-gap patch to prevent nodeAgg.c from choosing to use shared state for OSAs. We can revert it in HEAD when we get a better fix. Report from Lukas Eder, diagnosis by me, patch by David Rowley. Back-patch to 9.6 where the problem was introduced. Discussion: https://postgr.es/m/CAB4ELO5RZhOamuT9Xsf72ozbenDLLXZKSk07FiSVsuJNZB861A@mail.gmail.com
* Prevent idle in transaction session timeout from sometimes being ignored.Andres Freund2017-10-11
| | | | | | | | | | | | | | | | | | | | | | | The previous coding in ProcessInterrupts() could lead to idle_in_transaction_session_timeout being ignored, when statement_timeout occurred earlier. The problem was that ProcessInterrupts() would return before processing the transaction timeout if QueryCancelPending was set while QueryCancelHoldoffCount != 0 - which is the case when reading new commands from the client. Ergo when the idle transaction timeout would hit. Fix that by removing the early return. Alternatively the transaction timeout code could have been moved up, but that early return seems like an issue that could hit other cases too. Author: Lukas Fittl Bug: #14821 Discussion: https://www.postgresql.org/message-id/20170921010956.17345.61461%40wrigleys.postgresql.org https://www.postgresql.org/message-id/CAP53PkxQnv3OWJpyNPGJYT62uY=n1=2CF_Lpc6gVOFnc0-gazw@mail.gmail.com Backpatch: 9.6-, where idle_in_transaction_session_timeout was introduced.
* Doc: fix missing explanation of default object privileges.Tom Lane2017-10-11
| | | | | | | | | | | | | | The GRANT reference page, which lists the default privileges for new objects, failed to mention that USAGE is granted by default for data types and domains. As a lesser sin, it also did not specify anything about the initial privileges for sequences, FDWs, foreign servers, or large objects. Fix that, and add a comment to acldefault() in the probably vain hope of getting people to maintain this list in future. Noted by Laurenz Albe, though I editorialized on the wording a bit. Back-patch to all supported branches, since they all have this behavior. Discussion: https://postgr.es/m/1507620895.4152.1.camel@cybertec.at
* Fix mistakes in comments.Robert Haas2017-10-11
| | | | | | Masahiko Sawada Discussion: http://postgr.es/m/CAD21AoBsfYsMHD6_SL9iN3n_Foaa+oPbL5jG55DxU1ChaujqwQ@mail.gmail.com
* Fix low-probability loss of NOTIFY messages due to XID wraparound.Tom Lane2017-10-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now async.c has used TransactionIdIsInProgress() to detect whether a notify message's source transaction is still running. However, that function has a quick-exit path that reports that XIDs before RecentXmin are no longer running. If a listening backend is doing nothing but listening, and not running any queries, there is nothing that will advance its value of RecentXmin. Once 2 billion transactions elapse, the RecentXmin check causes active transactions to be reported as not running. If they aren't committed yet according to CLOG, async.c decides they aborted and discards their messages. The timing for that is a bit tight but it can happen when multiple backends are sending notifies concurrently. The net symptom therefore is that a sufficiently-long-surviving listen-only backend starts to miss some fraction of NOTIFY traffic, but only under heavy load. The only function that updates RecentXmin is GetSnapshotData(). A brute-force fix would therefore be to take a snapshot before processing incoming notify messages. But that would add cycles, as well as contention for the ProcArrayLock. We can be smarter: having taken the snapshot, let's use that to check for running XIDs, and not call TransactionIdIsInProgress() at all. In this way we reduce the number of ProcArrayLock acquisitions from one per message to one per notify interrupt; that's the same under light load but should be a benefit under heavy load. Light testing says that this change is a wash performance-wise for normal loads. I looked around for other callers of TransactionIdIsInProgress() that might be at similar risk, and didn't find any; all of them are inside transactions that presumably have already taken a snapshot. Problem report and diagnosis by Marko Tiikkaja, patch by me. Back-patch to all supported branches, since it's been like this since 9.0. Discussion: https://postgr.es/m/20170926182935.14128.65278@wrigleys.postgresql.org
* Add missing clean step to src/test/modules/brin/Makefile.Tom Lane2017-10-10
| | | | | | | | I noticed the tmp_check subdirectory wasn't getting cleaned up after a check-world run. Apparently pgxs.mk will only do this for you if you've defined REGRESS. The only other src/test/modules Makefile that does not set that is snapshot_too_old, and it does it like this.
* Increase distance between flush requests during bulk file copies.Tom Lane2017-10-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | copy_file() reads and writes data 64KB at a time (with default BLCKSZ), and historically has issued a pg_flush_data request after each write. This turns out to interact really badly with macOS's new APFS file system: a large file copy takes over 100X longer than it ought to on APFS, as reported by Brent Dearth. While that's arguably a macOS bug, it's not clear whether Apple will do anything about it in the near future, and in any case experimentation suggests that issuing flushes a bit less often can be helpful on other platforms too. Hence, rearrange the logic in copy_file() so that flush requests are issued once per N writes rather than every time through the loop. I set the FLUSH_DISTANCE to 32MB on macOS (any less than that still results in a noticeable speed degradation on APFS), but 1MB elsewhere. In limited testing on Linux and FreeBSD, this seems slightly faster than the previous code, and certainly no worse. It helps noticeably on macOS even with the older HFS filesystem. A simpler change would have been to just increase the size of the copy buffer without changing the loop logic, but that seems likely to trash the processor cache without really helping much. Back-patch to 9.6 where we introduced msync() as an implementation option for pg_flush_data(). The problem seems specific to APFS's mmap/msync support, so I don't think we need to go further back. Discussion: https://postgr.es/m/CADkxhTNv-j2jw2g8H57deMeAbfRgYBoLmVuXkC=YCFBXRuCOww@mail.gmail.com
* Fix crash when logical decoding is invoked from a PL function.Tom Lane2017-10-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The logical decoding functions do BeginInternalSubTransaction and RollbackAndReleaseCurrentSubTransaction to clean up after themselves. It turns out that AtEOSubXact_SPI has an unrecognized assumption that we always need to cancel the active SPI operation in the SPI context that surrounds the subtransaction (if there is one). That's true when the RollbackAndReleaseCurrentSubTransaction call is coming from the SPI-using function itself, but not when it's happening inside some unrelated function invoked by a SPI query. In practice the affected callers are the various PLs. To fix, record the current subtransaction ID when we begin a SPI operation, and clean up only if that ID is the subtransaction being canceled. Also, remove AtEOSubXact_SPI's assertion that it must have cleaned up the surrounding SPI context's active tuptable. That's proven wrong by the same test case. Also clarify (or, if you prefer, reinterpret) the calling conventions for _SPI_begin_call and _SPI_end_call. The memory context cleanup in the latter means that these have always had the flavor of a matched resource-management pair, but they weren't documented that way before. Per report from Ben Chobot. Back-patch to 9.4 where logical decoding came in. In principle, the SPI changes should go all the way back, since the problem dates back to commit 7ec1c5a86. But given the lack of field complaints it seems few people are using internal subtransactions in this way. So I don't feel a need to take any risks in 9.2/9.3. Discussion: https://postgr.es/m/73FBA179-C68C-4540-9473-71E865408B15@silentmedia.com
* Fix intra-query memory leakage in nodeProjectSet.c.Tom Lane2017-10-06
| | | | | | | | | | | | Both ExecMakeFunctionResultSet() and evaluation of simple expressions need to be done in the per-tuple memory context, not per-query, else we leak data until end of query. This is a consideration that was missed while refactoring code in the ProjectSet patch (note that in pre-v10, ExecMakeFunctionResult is called in the per-tuple context). Per bug #14843 from Ben M. Diagnosed independently by Andres and myself. Discussion: https://postgr.es/m/20171005230321.28561.15927@wrigleys.postgresql.org
* Fix access-off-end-of-array in clog.c.Tom Lane2017-10-06
| | | | | | | | | | | | | Sloppy loop coding in set_status_by_pages() resulted in fetching one array element more than it should from the subxids[] array. The odds of this resulting in SIGSEGV are pretty small, but we've certainly seen that happen with similar mistakes elsewhere. While at it, we can get rid of an extra TransactionIdToPage() calculation per loop. Per report from David Binderman. Back-patch to all supported branches, since this code is quite old. Discussion: https://postgr.es/m/HE1PR0802MB2331CBA919CBFFF0C465EB429C710@HE1PR0802MB2331.eurprd08.prod.outlook.com
* Fix traversal of half-frozen update chainsAlvaro Herrera2017-10-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When some tuple versions in an update chain are frozen due to them being older than freeze_min_age, the xmax/xmin trail can become broken. This breaks HOT (and probably other things). A subsequent VACUUM can break things in more serious ways, such as leaving orphan heap-only tuples whose root HOT redirect items were removed. This can be seen because index creation (or REINDEX) complain like ERROR: XX000: failed to find parent tuple for heap-only tuple at (0,7) in table "t" Because of relfrozenxid contraints, we cannot avoid the freezing of the early tuples, so we must cope with the results: whenever we see an Xmin of FrozenTransactionId, consider it a match for whatever the previous Xmax value was. This problem seems to have appeared in 9.3 with multixact changes, though strictly speaking it seems unrelated. Since 9.4 we have commit 37484ad2a "Change the way we mark tuples as frozen", so the fix is simple: just compare the raw Xmin (still stored in the tuple header, since freezing merely set an infomask bit) to the Xmax. But in 9.3 we rewrite the Xmin value to FrozenTransactionId, so the original value is lost and we have nothing to compare the Xmax with. To cope with that case we need to compare the Xmin with FrozenXid, assume it's a match, and hope for the best. Sadly, since you can pg_upgrade a 9.3 instance containing half-frozen pages to newer releases, we need to keep the old check in newer versions too, which seems a bit brittle; I hope we can somehow get rid of that. I didn't optimize the new function for performance. The new coding is probably a bit slower than before, since there is a function call rather than a straight comparison, but I'd rather have it work correctly than be fast but wrong. This is a followup after 20b655224249 fixed a few related problems. Apparently, in 9.6 and up there are more ways to get into trouble, but in 9.3 - 9.5 I cannot reproduce a problem anymore with this patch, so there must be a separate bug. Reported-by: Peter Geoghegan Diagnosed-by: Peter Geoghegan, Michael Paquier, Daniel Wood, Yi Wen Wong, Álvaro Discussion: https://postgr.es/m/CAH2-Wznm4rCrhFAiwKPWTpEw2bXDtgROZK7jWWGucXeH3D1fmA@mail.gmail.com
* Fix more user-visible elog() calls.Robert Haas2017-10-05
| | | | | | | | | Michael Paquier discovered that this could be triggered via SQL; give a nicer message instead. Patch by Michael Paquier, reviewed by Masahiko Sawada. Discussion: http://postgr.es/m/CAB7nPqQtPg+LKKtzdKN26judHcvPZ0s1gNigzOT4j8CYuuuBYg@mail.gmail.com
* Fix race condition with unprotected use of a latch pointer variable.Tom Lane2017-10-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 597a87ccc introduced a latch pointer variable to replace use of a long-lived shared latch in the shared WalRcvData structure. This was not well thought out, because there are now hazards of the pointer variable changing while it's being inspected by another process. This could obviously lead to a core dump in code like if (WalRcv->latch) SetLatch(WalRcv->latch); and there's a more remote risk of a torn read, if we have any platforms where reading/writing a pointer is not atomic. An actual problem would occur only if the walreceiver process exits (gracefully) while the startup process is trying to signal it, but that seems well within the realm of possibility. To fix, treat the pointer variable (not the referenced latch) as being protected by the WalRcv->mutex spinlock. There remains a race condition that we could apply SetLatch to a process latch that no longer belongs to the walreceiver, but I believe that's harmless: at worst it'd cause an extra wakeup of the next process to use that PGPROC structure. Back-patch to v10 where the faulty code was added. Discussion: https://postgr.es/m/22735.1507048202@sss.pgh.pa.us
* Fix coding rules violations in walreceiver.cAlvaro Herrera2017-10-03
| | | | | | | | | | | | | | | | | | | | | 1. Since commit b1a9bad9e744 we had pstrdup() inside a spinlock-protected critical section; reported by Andreas Seltenreich. Turn those into strlcpy() to stack-allocated variables instead. Backpatch to 9.6. 2. Since commit 9ed551e0a4fd we had a pfree() uselessly inside a spinlock-protected critical section. Tom Lane noticed in code review. Move down. Backpatch to 9.6. 3. Since commit 64233902d22b we had GetCurrentTimestamp() (a kernel call) inside a spinlock-protected critical section. Tom Lane noticed in code review. Move it up. Backpatch to 9.2. 4. Since commit 1bb2558046cc we did elog(PANIC) while holding spinlock. Tom Lane noticed in code review. Release spinlock before dying. Backpatch to 9.2. Discussion: https://postgr.es/m/87h8vhtgj2.fsf@ansel.ydns.eu
* Stamp 10.0.REL_10_0Tom Lane2017-10-02
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* Translation updatesPeter Eisentraut2017-10-02
| | | | | Source-Git-URL: git://git.postgresql.org/git/pgtranslation/messages.git Source-Git-Hash: 4eb5acee0bc0ba7b40220367dfc44bb4af188c88
* Use a longer connection timeout in pg_isready test.Tom Lane2017-10-01
| | | | | | | | | | | Buildfarm members skink and sungazer have both recently failed this test, with symptoms indicating that the default 3-second timeout isn't quite enough for those very slow systems. There's no reason to be miserly with this timeout, so boost it to 60 seconds. Back-patch to all versions containing this test. That may be overkill, because the failure has only been observed in the v10 branch, but I don't feel like having to revisit this later.
* Fix busy-wait in pgbench, with --rate.Heikki Linnakangas2017-10-01
| | | | | | | | | | | If --rate was used to throttle pgbench, it failed to sleep when it had nothing to do, leading to a busy-wait with 100% CPU usage. This bug was introduced in the refactoring in v10. Before that, sleep() was called with a timeout, even when there were no file descriptors to wait for. Reported by Jeff Janes, patch by Fabien COELHO. Backpatch to v10. Discussion: https://www.postgresql.org/message-id/CAMkU%3D1x5hoX0pLLKPRnXCy0T8uHoDvXdq%2B7kAM9eoC9_z72ucw%40mail.gmail.com
* Fix inadequate locking during get_rel_oids().Tom Lane2017-09-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_rel_oids used to not take any relation locks at all, but that stopped being a good idea with commit 3c3bb9933, which inserted a syscache lookup into the function. A concurrent DROP TABLE could now produce "cache lookup failed", which we don't want to have happen in normal operation. The best solution seems to be to transiently take a lock on the relation named by the RangeVar (which also makes the result of RangeVarGetRelid a lot less spongy). But we shouldn't hold the lock beyond this function, because we don't want VACUUM to lock more than one table at a time. (That would not be a big problem right now, but it will become one after the pending feature patch to allow multiple tables to be named in VACUUM.) In passing, adjust vacuum_rel and analyze_rel to document that we don't trust the passed RangeVar to be accurate, and allow the RangeVar to possibly be NULL --- which it is anyway for a whole-database VACUUM, though we accidentally didn't crash for that case. The passed RangeVar is in fact inaccurate when dealing with a child partition, as of v10, and it has been wrong for a whole long time in the case of vacuum_rel() recursing to a TOAST table. None of these things present visible bugs up to now, because the passed RangeVar is in fact only consulted for autovacuum logging, and in that particular context it's always accurate because autovacuum doesn't let vacuum.c expand partitions nor recurse to toast tables. Still, this seems like trouble waiting to happen, so let's nail the door at least partly shut. (Further cleanup is planned, in HEAD only, as part of the pending feature patch.) Fix some sadly inaccurate/obsolete comments too. Back-patch to v10. Michael Paquier and Tom Lane Discussion: https://postgr.es/m/25023.1506107590@sss.pgh.pa.us
* pgbench: If we fail to send a command to the server, fail.Robert Haas2017-09-29
| | | | | | | | | | | This beats the old behavior of busy-waiting hands down. Oversight in commit 12788ae49e1933f463bc59a6efe46c4a01701b76. Report by Pavan Deolasee. Patch by Fabien Coelho. Reviewed by Pavan Deolasee. Discussion: http://postgr.es/m/CABOikdPhfXTypckMC1Ux6Ko+hKBWwUBA=EXsvamXYSg8M9J94w@mail.gmail.com