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* Avoid unnecessary recursion to child tables in ALTER TABLE SET NOT NULL.Tom Lane2020-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a partitioned table's column is already marked NOT NULL, there is no need to examine its partitions, because we can rely on previous DDL to have enforced that the child columns are NOT NULL as well. (Unfortunately, the same cannot be said for traditional inheritance, so for now we have to restrict the optimization to partitioned tables.) Hence, we may skip recursing to child tables in this situation. The reason this case is worth worrying about is that when pg_dump dumps a partitioned table having a primary key, it will include the requisite NOT NULL markings in the CREATE TABLE commands, and then add the primary key as a separate step. The primary key addition generates a SET NOT NULL as a subcommand, just to be sure. So the situation where a SET NOT NULL is redundant does arise in the real world. Skipping the recursion does more than just save a few cycles: it means that a command such as "ALTER TABLE ONLY partition_parent ADD PRIMARY KEY" will take locks only on the partition parent table, not on the partitions. It turns out that parallel pg_restore is effectively assuming that that's true, and has little choice but to do so because the dependencies listed for such a TOC entry don't include the partitions. pg_restore could thus issue this ALTER while data restores on the partitions are still in progress. Taking unnecessary locks on the partitions not only hurts concurrency, but can lead to actual deadlock failures, as reported by Domagoj Smoljanovic. (A contributing factor in the deadlock is that TRUNCATE on a child partition wants a non-exclusive lock on the parent. This seems likewise unnecessary, but the fix for it is more invasive so we won't consider back-patching it. Fortunately, getting rid of one of these two poor behaviors is enough to remove the deadlock.) Although support for partitioned primary keys came in with v11, this patch is dependent on the SET NOT NULL refactoring done by commit f4a3fdfbd, so we can only patch back to v12. Patch by me; thanks to Alvaro Herrera and Amit Langote for review. Discussion: https://postgr.es/m/VI1PR03MB31670CA1BD9625C3A8C5DD05EB230@VI1PR03MB3167.eurprd03.prod.outlook.com
* Fix bogus cache-invalidation logic in logical replication worker.Tom Lane2020-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | The code recorded cache invalidation events by zeroing the "localreloid" field of affected cache entries. However, it's possible for an inval event to occur even while we have the entry open and locked. So an ill-timed inval could result in "cache lookup failed for relation 0" errors, if the worker's code tried to use the cleared field. We can fix that by creating a separate bool field to record whether the entry needs to be revalidated. (In the back branches, cram the bool into what had been padding space, to avoid an ABI break in the somewhat unlikely event that any extension is looking at this struct.) Also, rearrange the logic in logicalrep_rel_open so that it does the right thing in cases where table_open would fail. We should retry the lookup by name in that case, but we didn't. The real-world impact of this is probably small. In the first place, the error conditions are very low probability, and in the second place, the worker would just exit and get restarted. We only noticed because in a CLOBBER_CACHE_ALWAYS build, the failure can occur repeatedly, preventing the worker from making progress. Nonetheless, it's clearly a bug, and it impedes a useful type of testing; so back-patch to v10 where this code was introduced. Discussion: https://postgr.es/m/1032727.1600096803@sss.pgh.pa.us
* Use the properly transformed RangeVar for expandTableLikeClause().Tom Lane2020-09-13
| | | | | | | | | | | | | | | transformCreateStmt() adjusts the transformed statement's RangeVar to specify the target schema explicitly, for the express reason of making sure that auxiliary statements derived by parse transformation operate on the right table. But the refactoring I did in commit 502898192 got this wrong and passed the untransformed RangeVar to expandTableLikeClause(). This could lead to assertion failures or weird misbehavior if the wrong table was accessed. Per report from Alexander Lakhin. Like the previous patch, back-patch to all supported branches. Discussion: https://postgr.es/m/05051f9d-b32b-cb35-6735-0e9f2ab86b5f@gmail.com
* Use _exit(2) for SIGQUIT during ProcessStartupPacket, too.Tom Lane2020-09-10
| | | | | | | | | | | | | | | | | | | | | Bring the signal handling for startup-packet collection into line with the policy established in commits bedadc732 and 8e19a8264, namely don't risk running atexit callbacks when handling SIGQUIT. Ideally, we'd not do so for SIGTERM or timeout interrupts either, but that change seems a bit too risky for the back branches. For now, just improve the comments in this area to describe the risk. Also relocate where BackendInitialize re-disables these interrupts, to minimize the code span where they're active. This doesn't buy a whole lot of safety, but it can't hurt. In passing, rename startup_die() to remove confusion about whether it is for the startup process. Like the previous commits, back-patch to all supported branches. Discussion: https://postgr.es/m/1850884.1599601164@sss.pgh.pa.us
* doc: Fix some grammar and inconsistenciesMichael Paquier2020-09-10
| | | | | | | | Some comments are fixed while on it. Author: Justin Pryzby Discussion: https://postgr.es/m/20200818171702.GK17022@telsasoft.com Backpatch-through: 9.6
* Make archiver's SIGQUIT handler exit via _exit().Tom Lane2020-09-09
| | | | | | | | | | | | | | | | | | Commit 8e19a8264 changed the SIGQUIT handlers of almost all server processes not to run atexit callbacks. The archiver process was skipped, perhaps because it's not connected to shared memory; but it's just as true here that running atexit callbacks in a signal handler is unsafe. So let's make it work like the rest. In HEAD and v13, we can use the common SignalHandlerForCrashExit handler. Before that, just tweak pgarch_exit to use _exit(2) explicitly. Like the previous commit, back-patch to all supported branches. Kyotaro Horiguchi, back-patching by me Discussion: https://postgr.es/m/1850884.1599601164@sss.pgh.pa.us
* Check default partitions constraints while descendingAlvaro Herrera2020-09-08
| | | | | | | | | | | | | | | | | | | | | | | Partitioning tuple route code assumes that the partition chosen while descending the partition hierarchy is always the correct one. This is true except when the partition is the default partition and another partition has been added concurrently: the partition constraint changes and we don't recheck it. This can lead to tuples mistakenly being added to the default partition that should have been rejected. Fix by rechecking the default partition constraint while descending the hierarchy. An isolation test based on the reproduction steps described by Hao Wu (with tweaks for extra coverage) is included. Backpatch to 12, where this bug came in with 898e5e3290a7. Reported by: Hao Wu <hawu@vmware.com> Author: Amit Langote <amitlangote09@gmail.com> Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/CA+HiwqFqBmcSSap4sFnCBUEL_VfOMmEKaQ3gwUhyfa4c7J_-nA@mail.gmail.com Discussion: https://postgr.es/m/DM5PR0501MB3910E97A9EDFB4C775CF3D75A42F0@DM5PR0501MB3910.namprd05.prod.outlook.com
* Fix misleading error message about inconsistent moving-aggregate types.Tom Lane2020-09-06
| | | | | | | | | | | | | We reported the wrong types when complaining that an aggregate's moving-aggregate implementation is inconsistent with its regular implementation. This was wrong since the feature was introduced, so back-patch to all supported branches. Jeff Janes Discussion: https://postgr.es/m/CAMkU=1x808LH=LPhZp9mNSP0Xd1xDqEd+XeGcvEe48dfE6xV=A@mail.gmail.com
* Fix over-eager ping'ing in logical replication receiver.Tom Lane2020-09-04
| | | | | | | | | | | Commit 3f60f690f only partially fixed the broken-status-tracking issue in LogicalRepApplyLoop: we need ping_sent to have the same lifetime as last_recv_timestamp. The effects are much less serious than what that commit fixed, though. AFAICS this would just lead to extra ping requests being sent, once per second until the sender responds. Still, it's a bug, so backpatch to v10 as before. Discussion: https://postgr.es/m/959627.1599248476@sss.pgh.pa.us
* Avoid lockup of a parallel worker when reporting a long error message.Tom Lane2020-09-03
| | | | | | | | | | | | | | | | | | | | | Because sigsetjmp() will restore the initial state with signals blocked, the code path in bgworker.c for reporting an error and exiting would execute that way. Usually this is fairly harmless; but if a parallel worker had an error message exceeding the shared-memory communication buffer size (16K) it would lock up, because it would wait for a resume-sending signal from its parallel leader which it would never detect. To fix, just unblock signals at the appropriate point. This can be shown to fail back to 9.6. The lack of parallel query infrastructure makes it difficult to provide a simple test case for 9.5; but I'm pretty sure the issue exists in some form there as well, so apply the code change there too. Vignesh C, reviewed by Bharath Rupireddy, Robert Haas, and myself Discussion: https://postgr.es/m/CALDaNm1d1hHPZUg3xU4XjtWBOLCrA+-2cJcLpw-cePZ=GgDVfA@mail.gmail.com
* Raise error on concurrent drop of partitioned indexAlvaro Herrera2020-09-01
| | | | | | | | | | | | | | | | | | We were already raising an error for DROP INDEX CONCURRENTLY on a partitioned table, albeit a different and confusing one: ERROR: DROP INDEX CONCURRENTLY must be first action in transaction Change that to throw a more comprehensible error: ERROR: cannot drop partitioned index \"%s\" concurrently Michael Paquier authored the test case for indexes on temporary partitioned tables. Backpatch to 11, where indexes on partitioned tables were added. Reported-by: Jan Mussler <jan.mussler@zalando.de> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/16594-d2956ca909585067@postgresql.org
* Fix code for re-finding scan position in a multicolumn GIN index.Tom Lane2020-08-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | collectMatchBitmap() needs to re-find the index tuple it was previously looking at, after transiently dropping lock on the index page it's on. The tuple should still exist and be at its prior position or somewhere to the right of that, since ginvacuum never removes tuples but concurrent insertions could add one. However, there was a thinko in that logic, to the effect of expecting any inserted tuples to have the same index "attnum" as what we'd been scanning. Since there's no physical separation of tuples with different attnums, it's not terribly hard to devise scenarios where this fails, leading to transient "lost saved point in index" errors. (While I've duplicated this with manual testing, it seems impossible to make a reproducible test case with our available testing technology.) Fix by just continuing the scan when the attnum doesn't match. While here, improve the error message used if we do fail, so that it matches the wording used in btree for a similar case. collectMatchBitmap()'s posting-tree code path was previously not exercised at all by our regression tests. While I can't make a regression test that exhibits the bug, I can at least improve the code coverage here, so do that. The test case I made for this is an extension of one added by 4b754d6c1, so it only works in HEAD and v13; didn't seem worth trying hard to back-patch it. Per bug #16595 from Jesse Kinkead. This has been broken since multicolumn capability was added to GIN (commit 27cb66fdf), so back-patch to all supported branches. Discussion: https://postgr.es/m/16595-633118be8eef9ce2@postgresql.org
* Avoid pushing quals down into sub-queries that have grouping sets.Tom Lane2020-08-22
| | | | | | | | | | | | | | | | | | | | | | | | | | The trouble with doing this is that an apparently-constant subquery output column isn't really constant if it is a grouping column that appears in only some of the grouping sets. A qual using such a column would be subject to incorrect const-folding after push-down, as seen in bug #16585 from Paul Sivash. To fix, just disable qual pushdown altogether if the sub-query has nonempty groupingSets. While we could imagine far less restrictive solutions, there is not much point in working harder right now, because subquery_planner() won't move HAVING clauses to WHERE within such a subquery. If the qual stays in HAVING it's not going to be a lot more useful than if we'd kept it at the outer level. Having said that, this restriction could be removed if we used a parsetree representation that distinguished such outputs from actual constants, which is something I hope to do in future. Hence, make the patch a minimal addition rather than integrating it more tightly (e.g. by renumbering the existing items in subquery_is_pushdown_safe's comment). Back-patch to 9.5 where grouping sets were introduced. Discussion: https://postgr.es/m/16585-9d8c340d23ade8c1@postgresql.org
* Fix handling of CREATE TABLE LIKE with inheritance.Tom Lane2020-08-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a CREATE TABLE command uses both LIKE and traditional inheritance, Vars in CHECK constraints and expression indexes that are absorbed from a LIKE parent table tended to get mis-numbered, resulting in wrong answers and/or bizarre error messages (though probably not any actual crashes, thanks to validation occurring in the executor). In v12 and up, the same could happen to Vars in GENERATED expressions, even in cases with no LIKE clause but multiple traditional-inheritance parents. The cause of the problem for LIKE is that parse_utilcmd.c supposed it could renumber such Vars correctly during transformCreateStmt(), which it cannot since we have not yet accounted for columns added via inheritance. Fix that by postponing processing of LIKE INCLUDING CONSTRAINTS, DEFAULTS, GENERATED, INDEXES till after we've performed DefineRelation(). The error with GENERATED and multiple inheritance is a simple oversight in MergeAttributes(); it knows it has to renumber Vars in inherited CHECK constraints, but forgot to apply the same processing to inherited GENERATED expressions (a/k/a defaults). Per bug #16272 from Tom Gottfried. The non-GENERATED variants of the issue are ancient, presumably dating right back to the addition of CREATE TABLE LIKE; hence back-patch to all supported branches. Discussion: https://postgr.es/m/16272-6e32da020e9a9381@postgresql.org
* Fix a few typos in JIT comments and READMEDavid Rowley2020-08-21
| | | | | | | Reviewed-by: Abhijit Menon-Sen Reviewed-by: Andres Freund Discussion: https://postgr.es/m/CAApHDvobgmCs6CohqhKTUf7D8vffoZXQTCBTERo9gbOeZmvLTw%40mail.gmail.com Backpatch-through: 11, where JIT was added
* Suppress unnecessary RelabelType nodes in yet more cases.Tom Lane2020-08-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a477bfc1d fixed eval_const_expressions() to ensure that it didn't generate unnecessary RelabelType nodes, but I failed to notice that some other places in the planner had the same issue. Really noplace in the planner should be using plain makeRelabelType(), for fear of generating expressions that should be equal() to semantically equivalent trees, but aren't. An example is that because canonicalize_ec_expression() failed to be careful about this, we could end up with an equivalence class containing both a plain Const, and a Const-with-RelabelType representing exactly the same value. So far as I can tell this led to no visible misbehavior, but we did waste a bunch of cycles generating and evaluating "Const = Const-with-RelabelType" to prove such entries are redundant. Hence, move the support function added by a477bfc1d to where it can be more generally useful, and use it in the places where planner code previously used makeRelabelType. Back-patch to v12, like the previous patch. While I have no concrete evidence of any real misbehavior here, it's certainly possible that I overlooked a case where equivalent expressions that aren't equal() could cause a user-visible problem. In any case carrying extra RelabelType nodes through planning to execution isn't very desirable. Discussion: https://postgr.es/m/1311836.1597781384@sss.pgh.pa.us
* Move new LOCKTAG_DATABASE_FROZEN_IDS to end of enum LockTagType.Noah Misch2020-08-15
| | | | | | | | | | | 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
* Prevent concurrent SimpleLruTruncate() for any given SLRU.Noah Misch2020-08-15
| | | | | | | | | | | | | | | | | 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
* Be more careful about the shape of hashable subplan clauses.Tom Lane2020-08-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nodeSubplan.c expects that the testexpr for a hashable ANY SubPlan has the form of one or more OpExprs whose LHS is an expression of the outer query's, while the RHS is an expression over Params representing output columns of the subquery. However, the planner only went as far as verifying that the clauses were all binary OpExprs. This works 99.99% of the time, because the clauses have the right shape when emitted by the parser --- but it's possible for function inlining to break that, as reported by PegoraroF10. To fix, teach the planner to check that the LHS and RHS contain the right things, or more accurately don't contain the wrong things. Given that this has been broken for years without anyone noticing, it seems sufficient to just give up hashing when it happens, rather than go to the trouble of commuting the clauses back again (which wouldn't necessarily work anyway). While poking at that, I also noticed that nodeSubplan.c had a baked-in assumption that the number of hash clauses is identical to the number of subquery output columns. Again, that's fine as far as parser output goes, but it's not hard to break it via function inlining. There seems little reason for that assumption though --- AFAICS, the only thing it's buying us is not having to store the number of hash clauses explicitly. Adding code to the planner to reject such cases would take more code than getting nodeSubplan.c to cope, so I fixed it that way. This has been broken for as long as we've had hashable SubPlans, so back-patch to all supported branches. Discussion: https://postgr.es/m/1549209182255-0.post@n3.nabble.com
* Fix postmaster's behavior during smart shutdown.Tom Lane2020-08-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Handle new HOT chains in index-build table scansAlvaro Herrera2020-08-13
| | | | | | | | | | | | | | | | | | | | | | | | | | When a table is scanned by heapam_index_build_range_scan (née IndexBuildHeapScan) and the table lock being held allows concurrent data changes, it is possible for new HOT chains to sprout in a page that were unknown when the scan of a page happened. This leads to an error such as ERROR: failed to find parent tuple for heap-only tuple at (X,Y) in table "tbl" because the root tuple was not present when we first obtained the list of the page's root tuples. This can be fixed by re-obtaining the list of root tuples, if we see that a heap-only tuple appears to point to a non-existing root. This was reported by Anastasia as occurring for BRIN summarization (which exists since 9.5), but I think it could theoretically also happen with CREATE INDEX CONCURRENTLY (much older) or REINDEX CONCURRENTLY (very recent). It seems a happy coincidence that BRIN forces us to backpatch this all the way to 9.5. Reported-by: Anastasia Lubennikova <a.lubennikova@postgrespro.ru> Diagnosed-by: Anastasia Lubennikova <a.lubennikova@postgrespro.ru> Co-authored-by: Anastasia Lubennikova <a.lubennikova@postgrespro.ru> Co-authored-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/602d8487-f0b2-5486-0088-0f372b2549fa@postgrespro.ru Backpatch: 9.5 - master
* BRIN: Handle concurrent desummarization properlyAlvaro Herrera2020-08-12
| | | | | | | | | | | | | | | If a page range is desummarized at just the right time concurrently with an index walk, BRIN would raise an error indicating index corruption. This is scary and unhelpful; silently returning that the page range is not summarized is sufficient reaction. This bug was introduced by commit 975ad4e602ff as additional protection against a bug whose actual fix was elsewhere. Backpatch equally. Reported-By: Anastasia Lubennikova <a.lubennikova@postgrespro.ru> Diagnosed-By: Alexander Lakhin <exclusion@gmail.com> Discussion: https://postgr.es/m/2588667e-d07d-7e10-74e2-7e1e46194491@postgrespro.ru Backpatch: 9.5 - master
* Empty search_path in logical replication apply worker and walsender.Noah Misch2020-08-10
| | | | | | | | | | | | | | This is like CVE-2018-1058 commit 582edc369cdbd348d68441fc50fa26a84afd0c1a. Today, a malicious user of a publisher or subscriber database can invoke arbitrary SQL functions under an identity running replication, often a superuser. This fix may cause "does not exist" or "no schema has been selected to create in" errors in a replication process. After upgrading, consider watching server logs for these errors. Objects accruing schema qualification in the wake of the earlier commit are unlikely to need further correction. Back-patch to v10, which introduced logical replication. Security: CVE-2020-14349
* Make contrib modules' installation scripts more secure.Tom Lane2020-08-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hostile objects located within the installation-time search_path could capture references in an extension's installation or upgrade script. If the extension is being installed with superuser privileges, this opens the door to privilege escalation. While such hazards have existed all along, their urgency increases with the v13 "trusted extensions" feature, because that lets a non-superuser control the installation path for a superuser-privileged script. Therefore, make a number of changes to make such situations more secure: * Tweak the construction of the installation-time search_path to ensure that references to objects in pg_catalog can't be subverted; and explicitly add pg_temp to the end of the path to prevent attacks using temporary objects. * Disable check_function_bodies within installation/upgrade scripts, so that any security gaps in SQL-language or PL-language function bodies cannot create a risk of unwanted installation-time code execution. * Adjust lookup of type input/receive functions and join estimator functions to complain if there are multiple candidate functions. This prevents capture of references to functions whose signature is not the first one checked; and it's arguably more user-friendly anyway. * Modify various contrib upgrade scripts to ensure that catalog modification queries are executed with secure search paths. (These are in-place modifications with no extension version changes, since it is the update process itself that is at issue, not the end result.) Extensions that depend on other extensions cannot be made fully secure by these methods alone; therefore, revert the "trusted" marking that commit eb67623c9 applied to earthdistance and hstore_plperl, pending some better solution to that set of issues. Also add documentation around these issues, to help extension authors write secure installation scripts. Patch by me, following an observation by Andres Freund; thanks to Noah Misch for review. Security: CVE-2020-14350
* Translation updatesPeter Eisentraut2020-08-10
| | | | | Source-Git-URL: https://git.postgresql.org/git/pgtranslation/messages.git Source-Git-Hash: 444a6779aafc552ac452715caa65cfca0e723073
* walsnd: Don't set waiting_for_ping_response spuriouslyAlvaro Herrera2020-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ashutosh Bapat noticed that when logical walsender needs to wait for WAL, and it realizes that it must send a keepalive message to walreceiver to update the sent-LSN, which *does not* request a reply from walreceiver, it wrongly sets the flag that it's going to wait for that reply. That means that any future would-be sender of feedback messages ends up not sending a feedback message, because they all believe that a reply is expected. With built-in logical replication there's not much harm in this, because WalReceiverMain will send a ping-back every wal_receiver_timeout/2 anyway; but with other logical replication systems (e.g. pglogical) it can cause significant pain. This problem was introduced in commit 41d5f8ad734, where the request-reply flag was changed from true to false to WalSndKeepalive, without at the same time removing the line that sets waiting_for_ping_response. Just removing that line would be a sufficient fix, but it seems better to shift the responsibility of setting the flag to WalSndKeepalive itself instead of requiring caller to do it; this is clearly less error-prone. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reported-by: Ashutosh Bapat <ashutosh.bapat@2ndquadrant.com> Backpatch: 9.5 and up Discussion: https://postgr.es/m/20200806225558.GA22401@alvherre.pgsql
* Fix yet another issue with step generation in partition pruning.Etsuro Fujita2020-08-07
| | | | | | | | | | | | | | | | Commit 13838740f fixed some issues with step generation in partition pruning, but there was yet another one: get_steps_using_prefix() assumes that clauses in the passed-in prefix list are sorted in ascending order of their partition key numbers, but the caller failed to ensure this for range partitioning, which led to an assertion failure in debug builds. Adjust the caller function to arrange the clauses in the prefix list in the required order for range partitioning. Back-patch to v11, like the previous commit. Patch by me, reviewed by Amit Langote. Discussion: https://postgr.es/m/CAPmGK16jkXiFG0YqMbU66wte-oJTfW6D1HaNvQf%3D%2B5o9%3Dm55wQ%40mail.gmail.com
* Fix typo.Robert Haas2020-08-06
| | | | | Per report from Tom Lane. Previously fixed in master by commit f057980149ddccd4b862d2c6b3920ed498b0d7ec.
* Fix minor problems with non-exclusive backup cleanup.Robert Haas2020-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The previous coding imagined that it could call before_shmem_exit() when a non-exclusive backup began and then remove the previously-added handler by calling cancel_before_shmem_exit() when that backup ended. However, this only works provided that nothing else in the system has registered a before_shmem_exit() hook in the interim, because cancel_before_shmem_exit() is documented to remove a callback only if it is the latest callback registered. It also only works if nothing can ERROR out between the time that sessionBackupState is reset and the time that cancel_before_shmem_exit(), which doesn't seem to be strictly true. To fix, leave the handler installed for the lifetime of the session, arrange to install it just once, and teach it to quietly do nothing if there isn't a non-exclusive backup in process. This was originally committed to master as 303640199d0436c5e7acdf50b837a027b5726594, but I did not back-patch at the time because the consequences were minor. However, now there's been a second report of this causing trouble with a slightly different test case than the one I reported originally, so now I'm back-patching as far as v11 where JIT was introduced. Patch by me, reviewed by Kyotaro Horiguchi, Michael Paquier (who preferred a different approach, but got outvoted), Fujii Masao, and Tom Lane, and with comments by various others. New problem report from Bharath Rupireddy. Discussion: http://postgr.es/m/CA+TgmobMjnyBfNhGTKQEDbqXYE3_rXWpc4CM63fhyerNCes3mA@mail.gmail.com Discussion: http://postgr.es/m/CALj2ACWk7j4F2v2fxxYfrroOF=AdFNPr1WsV+AGtHAFQOqm_pw@mail.gmail.com
* Fix matching of sub-partitions when a partitioned plan is stale.Tom Lane2020-08-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we no longer require AccessExclusiveLock to add a partition, the executor may see that a partitioned table has more partitions than the planner saw. ExecCreatePartitionPruneState's code for matching up the partition lists in such cases was faulty, and would misbehave if the planner had successfully pruned any partitions from the query. (Thus, trouble would occur only if a partition addition happens concurrently with a query that uses both static and dynamic partition pruning.) This led to an Assert failure in debug builds, and probably to crashes or query misbehavior in production builds. To repair the bug, just explicitly skip zeroes in the plan's relid_map[] list. I also made some cosmetic changes to make the code more readable (IMO anyway). Also, convert the cross-checking Assert to a regular test-and-elog, since it's now apparent that this logic is more fragile than one would like. Currently, there's no way to repeatably exercise this code, except with manual use of a debugger to stop the backend between planning and execution. Hence, no test case in this patch. We oughta do something about that testability gap, but that's for another day. Amit Langote and Tom Lane, per report from Justin Pryzby. Oversight in commit 898e5e329; backpatch to v12 where that appeared. Discussion: https://postgr.es/m/20200802181131.GA27754@telsasoft.com
* Fix recently-introduced performance problem in ts_headline().Tom Lane2020-07-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Fix some issues with step generation in partition pruning.Etsuro Fujita2020-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the case of range partitioning, get_steps_using_prefix() assumes that the passed-in prefix list contains at least one clause for each of the partition keys earlier than one specified in the passed-in step_lastkeyno, but the caller (ie, gen_prune_steps_from_opexps()) didn't take it into account, which led to a server crash or incorrect results when the list contained no clauses for such partition keys, as reported in bug #16500 and #16501 from Kobayashi Hisanori. Update the caller to call that function only when the list created there contains at least one clause for each of the earlier partition keys in the case of range partitioning. While at it, fix some other issues: * The list to pass to get_steps_using_prefix() is allowed to contain multiple clauses for the same partition key, as described in the comment for that function, but that function actually assumed that the list contained just a single clause for each of middle partition keys, which led to an assertion failure when the list contained multiple clauses for such partition keys. Update that function to match the comment. * In the case of hash partitioning, partition keys are allowed to be NULL, in which case the list to pass to get_steps_using_prefix() contains no clauses for NULL partition keys, but that function treats that case as like the case of range partitioning, which led to the assertion failure. Update the assertion test to take into account NULL partition keys in the case of hash partitioning. * Fix a typo in a comment in get_steps_using_prefix_recurse(). * gen_partprune_steps() failed to detect self-contradiction from strict-qual clauses and an IS NULL clause for the same partition key in some cases, producing incorrect partition-pruning steps, which led to incorrect results of partition pruning, but didn't cause any user-visible problems fortunately, as the self-contradiction is detected later in the query planning. Update that function to detect the self-contradiction. Per bug #16500 and #16501 from Kobayashi Hisanori. Patch by me, initial diagnosis for the reported issue and review by Dmitry Dolgov. Back-patch to v11, where partition pruning was introduced. Discussion: https://postgr.es/m/16500-d1613f2a78e1e090%40postgresql.org Discussion: https://postgr.es/m/16501-5234a9a0394f6754%40postgresql.org
* Fix buffer usage stats for nodes above Gather Merge.Amit Kapila2020-07-25
| | | | | | | | | | | | | | | Commit 85c9d347 addressed a similar problem for Gather and Gather Merge nodes but forgot to account for nodes above parallel nodes. This still works for nodes above Gather node because we shut down the workers for Gather node as soon as there are no more tuples. We can do a similar thing for Gather Merge as well but it seems better to account for stats during nodes shutdown after completing the execution. Reported-by: Stéphane Lorek, Jehan-Guillaume de Rorthais Author: Jehan-Guillaume de Rorthais <jgdr@dalibo.com> Reviewed-by: Amit Kapila Backpatch-through: 10, where it was introduced Discussion: https://postgr.es/m/20200718160206.584532a2@firost
* Fix error message.Thomas Munro2020-07-23
| | | | | | | Remove extra space. Back-patch to all releases, like commit 7897e3bb. Author: Lu, Chenyang <lucy.fnst@cn.fujitsu.com> Discussion: https://postgr.es/m/795d03c6129844d3803e7eea48f5af0d%40G08CNEXMBPEKD04.g08.fujitsu.local
* neqjoinsel must now pass through collation to eqjoinsel.Tom Lane2020-07-21
| | | | | | | | | | | | | Since commit 044c99bc5, eqjoinsel passes the passed-in collation to any operators it invokes. However, neqjoinsel failed to pass on whatever collation it got, so that if we invoked a collation-dependent operator via that code path, we'd get "could not determine which collation to use for string comparison" or the like. Per report from Justin Pryzby. Back-patch to v12, like the previous commit. Discussion: https://postgr.es/m/20200721191606.GL5748@telsasoft.com
* Assert that we don't insert nulls into attnotnull catalog columns.Tom Lane2020-07-21
| | | | | | | | | | | | | | | | | | | | | The executor checks for this error, and so does the bootstrap catalog loader, but we never checked for it in retail catalog manipulations. The folly of that has now been exposed, so let's add assertions checking it. Checking in CatalogTupleInsert[WithInfo] and CatalogTupleUpdate[WithInfo] should be enough to cover this. Back-patch to v10; the aforesaid functions didn't exist before that, and it didn't seem worth adapting the patch to the oldest branches. But given the risk of JIT crashes, I think we certainly need this as far back as v11. Pre-v13, we have to explicitly exclude pg_subscription.subslotname and pg_subscription_rel.srsublsn from the checks, since they are mismarked. (Even if we change our mind about applying BKI_FORCE_NULL in the branch tips, it doesn't seem wise to have assertions that would fire in existing databases.) Discussion: https://postgr.es/m/298837.1595196283@sss.pgh.pa.us
* Avoid direct C access to possibly-null pg_subscription_rel.srsublsn.Tom Lane2020-07-21
| | | | | | | | | | | | | | | | | | | | | | This coding technique is unsafe, since we'd be accessing off the end of the tuple if the field is null. SIGSEGV is pretty improbable, but perhaps not impossible. Also, returning garbage for the LSN doesn't seem like a great idea, even if callers aren't looking at it today. Also update docs to point out explicitly that pg_subscription.subslotname and pg_subscription_rel.srsublsn can be null. Perhaps we should mark these two fields BKI_FORCE_NULL, so that they'd be correctly labeled in databases that are initdb'd in the future. But we can't force that for existing databases, and on balance it's not too clear that having a mix of different catalog contents in the field would be wise. Apply to v10 (where this code came in) through v12. Already fixed in v13 and HEAD. Discussion: https://postgr.es/m/732838.1595278439@sss.pgh.pa.us
* Kluge slot_compile_deform() to ignore incorrect attnotnull markings.Tom Lane2020-07-20
| | | | | | | | | | | | | | | | | | | | | | Since we mustn't force an initdb in released branches, there is no simple way to correct the markings of pg_subscription.subslotname and pg_subscription_rel.srsublsn as attnotnull in existing pre-v13 installations. Fortunately, released branches don't rely on attnotnull being correct for much. The planner looks at it in relation_excluded_by_constraints, but it'd be difficult to get that to matter for a query on a system catalog. The only place where it's really problematic is in JIT's slot_compile_deform(), which can produce incorrect code that crashes if there are NULLs in an allegedly not-null column. Hence, hack up slot_compile_deform() to be specifically aware of these two incorrect markings and not trust them. This applies to v11 and v12; the JIT code didn't exist before that, and we've fixed the markings in v13. Discussion: https://postgr.es/m/229396.1595191345@sss.pgh.pa.us
* Fix construction of updated-columns bitmap in logical replication.Tom Lane2020-07-20
| | | | | | | | | | | | | | | | | | | Commit b9c130a1f failed to apply the publisher-to-subscriber column mapping while checking which columns were updated. Perhaps less significantly, it didn't exclude dropped columns either. This could result in an incorrect updated-columns bitmap and thus wrong decisions about whether to fire column-specific triggers on the subscriber while applying updates. In HEAD (since commit 9de77b545), it could also result in accesses off the end of the colstatus array, as detected by buildfarm member skink. Fix the logic, and adjust 003_constraints.pl so that the problem is exposed in unpatched code. In HEAD, also add some assertions to check that we don't access off the ends of these newly variable-sized arrays. Back-patch to v10, as b9c130a1f was. Discussion: https://postgr.es/m/CAH2-Wz=79hKQ4++c5A060RYbjTHgiYTHz=fw6mptCtgghH2gJA@mail.gmail.com
* Fix whitespacePeter Eisentraut2020-07-17
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* Fix bitmap AND/OR scans on the inside of a nestloop partition-wise join.Tom Lane2020-07-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | reparameterize_path_by_child() failed to reparameterize BitmapAnd and BitmapOr paths. This matters only if such a path is chosen as the inside of a nestloop partition-wise join, where we have to pass in parameters from the outside of the nestloop. If that did happen, we generated a bad plan that would likely lead to crashes at execution. This is not entirely reparameterize_path_by_child()'s fault though; it's the victim of an ancient decision (my ancient decision, I think) to not bother filling in param_info in BitmapAnd/Or path nodes. That caused the function to believe that such nodes and their children contain no parameter references and so need not be processed. In hindsight that decision looks pretty penny-wise and pound-foolish: while it saves a few cycles during path node setup, we do commonly need the information later. In particular, by reversing the decision and requiring valid param_info data in all nodes of a bitmap path tree, we can get rid of indxpath.c's get_bitmap_tree_required_outer() function, which computed the data on-demand. It's not unlikely that that nets out as a savings of cycles in many scenarios. A couple of other things in indxpath.c can be simplified as well. While here, get rid of some cases in reparameterize_path_by_child() that are visibly dead or useless, given that we only care about reparameterizing paths that can be on the inside of a parameterized nestloop. This case reminds one of the maxim that untested code probably does not work, so I'm unwilling to leave unreachable code in this function. (I did leave the T_Gather case in place even though it's not reached in the regression tests. It's not very clear to me when the planner might prefer to put Gather below rather than above a nestloop, but at least in principle the case might be interesting.) Per bug #16536, originally from Arne Roland but with a test case by Andrew Gierth. Back-patch to v11 where this code came in. Discussion: https://postgr.es/m/16536-2213ee0b3aad41fd@postgresql.org
* Fix timing issue with ALTER TABLE's validate constraintDavid Rowley2020-07-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | An ALTER TABLE to validate a foreign key in which another subcommand already caused a pending table rewrite could fail due to ALTER TABLE attempting to validate the foreign key before the actual table rewrite takes place. This situation could result in an error such as: ERROR: could not read block 0 in file "base/nnnnn/nnnnn": read only 0 of 8192 bytes The failure here was due to the SPI call which validates the foreign key trying to access an index which is yet to be rebuilt. Similarly, we also incorrectly tried to validate CHECK constraints before the heap had been rewritten. The fix for both is to delay constraint validation until phase 3, after the table has been rewritten. For CHECK constraints this means a slight behavioral change. Previously ALTER TABLE VALIDATE CONSTRAINT on inheritance tables would be validated from the bottom up. This was different from the order of evaluation when a new CHECK constraint was added. The changes made here aligns the VALIDATE CONSTRAINT evaluation order for inheritance tables to be the same as ADD CONSTRAINT, which is generally top-down. Reported-by: Nazli Ugur Koyluoglu, using SQLancer Discussion: https://postgr.es/m/CAApHDvp%3DZXv8wiRyk_0rWr00skhGkt8vXDrHJYXRMft3TjkxCA%40mail.gmail.com Backpatch-through: 9.5 (all supported versions)
* Fix comments related to table AMsMichael Paquier2020-07-14
| | | | | | | | | | | Incorrect function names were referenced. As this fixes some portions of tableam.h, that is mentioned in the docs as something to look at when implementing a table AM, backpatch down to 12 where this has been introduced. Author: Hironobu Suzuki Discussion: https://postgr.es/m/8fe6d672-28dd-3f1d-7aed-ac2f6d599d3f@interdb.jp Backpatch-through: 12
* Cope with lateral references in the quals of a subquery RTE.Tom Lane2020-07-13
| | | | | | | | | | | | | | | | | | | | | | The qual pushdown logic assumed that all Vars in a restriction clause must be Vars referencing subquery outputs; but since we introduced LATERAL, it's possible for such a Var to be a lateral reference instead. This led to an assertion failure in debug builds. In a non-debug build, there might be no ill effects (if qual_is_pushdown_safe decided the qual was unsafe anyway), or we could get failures later due to construction of an invalid plan. I've not gone to much length to characterize the possible failures, but at least segfaults in the executor have been observed. Given that this has been busted since 9.3 and it took this long for anybody to notice, I judge that the case isn't worth going to great lengths to optimize. Hence, fix by just teaching qual_is_pushdown_safe that such quals are unsafe to push down, matching the previous behavior when it accidentally didn't fail. Per report from Tom Ellis. Back-patch to all supported branches. Discussion: https://postgr.es/m/20200713175124.GQ8220@cloudinit-builder
* Forbid numeric NaN in jsonpathAlexander Korotkov2020-07-11
| | | | | | | | | | | | | | SQL standard doesn't define numeric Inf or NaN values. It appears even more ridiculous to support then in jsonpath assuming JSON doesn't support these values as well. This commit forbids returning NaN from .double(), which was previously allowed. NaN can't be result of inner-jsonpath computation over non-NaNs. So, we can not expect NaN in the jsonpath output. Reported-by: Tom Lane Discussion: https://postgr.es/m/203949.1591879542%40sss.pgh.pa.us Author: Alexander Korotkov Reviewed-by: Tom Lane Backpatch-through: 12
* Improve error reporting for jsonpath .double() methodAlexander Korotkov2020-07-11
| | | | | | | | | | | When jsonpath .double() method detects that numeric or string can't be converted to double precision, it throws an error. This commit makes these errors explicitly express the reason of failure. Discussion: https://postgr.es/m/CAPpHfdtqJtiSXkP7tOXez18NxhLUH_-75bL8%3DOce4Ki%2Bbv7V6Q%40mail.gmail.com Author: Alexander Korotkov Reviewed-by: Tom Lane Backpatch-through: 12
* Remove WARNING message from brin_desummarize_rangeAlvaro Herrera2020-07-09
| | | | | | | | | | This message was being emitted on the grounds that only crashed summarization could cause it, but in reality even an aborted vacuum could do it ... which makes it way too noisy, particularly since it shows up in regression tests and makes them die. Reported by Tom Lane. Discussion: https://postgr.es/m/489091.1593534251@sss.pgh.pa.us
* Fix pg_current_logfile() to not emit a carriage return on Windows.Tom Lane2020-07-09
| | | | | | | | | | | | | | | | | | | | Due to not having our signals straight about CRLF vs. LF line termination, the output of pg_current_logfile() included a trailing \r on Windows. To fix, force the file descriptor it uses into text mode. While here, move a couple of local variable declarations to make the function's logic clearer. In v12 and v13, also back-patch the test added by 1c4e88e2f so that this function has some test coverage. However, the 004_logrotate.pl test script doesn't exist before v12, and it didn't seem worth adding to older branches just for this. Per report from Thomas Kellerer. Back-patch to v10 where this function was added. Discussion: https://postgr.es/m/412ae8da-76bb-640f-039a-f3513499e53d@gmx.net
* Fix "ignoring return value" complaints from commit 96d1f423f9Joe Conway2020-07-04
| | | | | | | | | | | | | | | The cfbot and some BF animals are complaining about the previous read_binary_file commit because of ignoring return value of ‘fread’. So let's make everyone happy by testing the return value even though not strictly needed. Reported by Justin Pryzby, and suggested patch by Tom Lane. Backpatched to v11 same as the previous commit. Reported-By: Justin Pryzby Reviewed-By: Tom Lane Discussion: https://postgr.es/m/flat/969b8d82-5bb2-5fa8-4eb1-f0e685c5d736%40joeconway.com Backpatch-through: 11
* Read until EOF vice stat-reported size in read_binary_fileJoe Conway2020-07-04
| | | | | | | | | | | | | | | | | | read_binary_file(), used by SQL functions pg_read_file() and friends, uses stat to determine file length to read, when not passed an explicit length as an argument. This is problematic, for example, if the file being read is a virtual file with a stat-reported length of zero. Arrange to read until EOF, or StringInfo data string lenth limit, is reached instead. Original complaint and patch by me, with significant review, corrections, advice, and code optimizations by Tom Lane. Backpatched to v11. Prior to that only paths relative to the data and log dirs were allowed for files, so no "zero length" files were reachable anyway. Reviewed-By: Tom Lane Discussion: https://postgr.es/m/flat/969b8d82-5bb2-5fa8-4eb1-f0e685c5d736%40joeconway.com Backpatch-through: 11
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