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2020-11-30Remove leftover comments, left behind by removal of WITH OIDS.Heikki Linnakangas
Author: Amit Langote Discussion: https://www.postgresql.org/message-id/CA%2BHiwqGaRoF3XrhPW-Y7P%2BG7bKo84Z_h%3DkQHvMh-80%3Dav3wmOw%40mail.gmail.com
2020-11-28Fix a recently-introduced race condition in LISTEN/NOTIFY handling.Tom Lane
Commit 566372b3d fixed some race conditions involving concurrent SimpleLruTruncate calls, but it introduced new ones in async.c. A newly-listening backend could attempt to read Notify SLRU pages that were in process of being truncated, possibly causing an error. Also, the QUEUE_TAIL pointer could become set to a value that's not equal to the queue position of any backend. While that's fairly harmless in v13 and up (thanks to commit 51004c717), in older branches it resulted in near-permanent disabling of the queue truncation logic, so that continued use of NOTIFY led to queue-fill warnings and eventual inability to send any more notifies. (A server restart is enough to make that go away, but it's still pretty unpleasant.) The core of the problem is confusion about whether QUEUE_TAIL represents the "logical" tail of the queue (i.e., the oldest still-interesting data) or the "physical" tail (the oldest data we've not yet truncated away). To fix, split that into two variables. QUEUE_TAIL regains its definition as the logical tail, and we introduce a new variable to track the oldest un-truncated page. Per report from Mikael Gustavsson. Like the previous patch, back-patch to all supported branches. Discussion: https://postgr.es/m/1b8561412e8a4f038d7a491c8b922788@smhi.se
2020-11-16Use "true" not "TRUE" in one ICU function call.Tom Lane
This was evidently missed in commit 6337865f3, which generally did s/TRUE/true/ everywhere. It escaped notice up to now because ICU versions before ICU 68 provided definitions of "TRUE" and "FALSE" regardless. With ICU 68, it fails to compile. Per report from Condor. Back-patch to v11 where 6337865f3 came in. (I've not tested v10, where this call originated, but I imagine it's fine since we defined TRUE in c.h back then.) Discussion: https://postgr.es/m/7a6f3336165bfe3ca66abcda7966f9d0@stz-bg.com
2020-11-15Fix fuzzy thinking about amcanmulticol versus amcaninclude.Tom Lane
These flags should be independent: in particular an index AM should be able to say that it supports include columns without necessarily supporting multiple key columns. The included-columns patch got this wrong, possibly aided by the fact that it didn't bother to update the documentation. While here, clarify some text about amcanreturn, which was a little vague about what should happen when amcanreturn reports that only some of the index columns are returnable. Noted while reviewing the SP-GiST included-columns patch, which quite incorrectly (and unsafely) changed SP-GiST to claim amcanmulticol = true as a workaround for this bug. Backpatch to v11 where included columns were introduced.
2020-11-09In security-restricted operations, block enqueue of at-commit user code.Noah Misch
Specifically, this blocks DECLARE ... WITH HOLD and firing of deferred triggers within index expressions and materialized view queries. An attacker having permission to create non-temp objects in at least one schema could execute arbitrary SQL functions under the identity of the bootstrap superuser. One can work around the vulnerability by disabling autovacuum and not manually running ANALYZE, CLUSTER, REINDEX, CREATE INDEX, VACUUM FULL, or REFRESH MATERIALIZED VIEW. (Don't restore from pg_dump, since it runs some of those commands.) Plain VACUUM (without FULL) is safe, and all commands are fine when a trusted user owns the target object. Performance may degrade quickly under this workaround, however. Back-patch to 9.5 (all supported versions). Reviewed by Robert Haas. Reported by Etienne Stalmans. Security: CVE-2020-25695
2020-11-08In INSERT/UPDATE, use the table's real tuple descriptor as target.Tom Lane
This back-patches commit 20d3fe900 into the v12 and v13 branches. At the time I thought that commit was not fixing any observable bug, but Bertrand Drouvot showed otherwise: adding a dropped column to the previously-considered scenario crashes v12 and v13, unless the dropped column happens to be an integer. That is, of course, because the tupdesc we derive from the plan output tlist fails to describe the dropped column accurately, so that we'll do the wrong thing with a tuple in which that column isn't NULL. There is no bug in pre-v12 branches because they already did use the table's real tuple descriptor for any trigger-returned tuple. It seems that this set of bugs can be blamed on the changes that removed es_trig_tuple_slot, though I've not attempted to pin that down precisely. Although there's no code change needed in HEAD, update the test case to include a dropped column there too. Discussion: https://postgr.es/m/db5d97c8-f48a-51e2-7b08-b73d5434d425@amazon.com Discussion: https://postgr.es/m/16644-5da7ef98a7ac4545@postgresql.org
2020-11-06Revert "Accept relations of any kind in LOCK TABLE".Tom Lane
Revert 59ab4ac32, as well as the followup fix 33862cb9c, in all branches. We need to think a bit harder about what the behavior of LOCK TABLE on views should be, and there's no time for that before next week's releases. We'll take another crack at this later. Discussion: https://postgr.es/m/16703-e348f58aab3cf6cc@postgresql.org
2020-11-05Don't throw an error for LOCK TABLE on a self-referential view.Tom Lane
LOCK TABLE has complained about "infinite recursion" when applied to a self-referential view, ever since we made it recurse into views in v11. However, that breaks pg_dump's new assumption that it's okay to lock every relation. There doesn't seem to be any good reason to throw an error: if we just abandon the recursion, we've still satisfied the requirement of locking every referenced relation. Per bug #16703 from Andrew Bille (via Alexander Lakhin). Discussion: https://postgr.es/m/16703-e348f58aab3cf6cc@postgresql.org
2020-11-03Allow users with BYPASSRLS to alter their own passwords.Tom Lane
The intention in commit 491c029db was to require superuserness to change the BYPASSRLS property, but the actual effect of the coding in AlterRole() was to require superuserness to change anything at all about a BYPASSRLS role. Other properties of a BYPASSRLS role should be changeable under the same rules as for a normal role, though. Fix that, and also take care of some documentation omissions related to BYPASSRLS and REPLICATION role properties. Tom Lane and Stephen Frost, per bug report from Wolfgang Walther. Back-patch to all supported branches. Discussion: https://postgr.es/m/a5548a9f-89ee-3167-129d-162b5985fcf8@technowledgy.de
2020-10-27Fix use-after-free bug with event triggers and ALTER TABLE.Tom Lane
EventTriggerAlterTableEnd neglected to make sure that it built its output list in the right context. In simple cases this was masked because the function is called in PortalContext which will be sufficiently long-lived anyway; but that doesn't make it not a bug. Commit ced138e8c fixed this in HEAD and v13, but mistakenly chose not to back-patch further. Back-patch the same code change all the way (I didn't bother with the test case though, as it would prove nothing in pre-v13 branches). Per report from Arseny Sher. Original fix by Jehan-Guillaume de Rorthais. Discussion: https://postgr.es/m/877drcyprb.fsf@ars-thinkpad Discussion: https://postgr.es/m/20200902193715.6e0269d4@firost
2020-10-27Accept relations of any kind in LOCK TABLEAlvaro Herrera
The restriction that only tables and views can be locked by LOCK TABLE is quite arbitrary, since the underlying mechanism can lock any relation type. Drop the restriction so that programs such as pg_dump can lock all relations they're interested in, preventing schema changes that could cause a dump to fail after expending much effort. Backpatch to 9.5. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reported-by: Wells Oliver <wells.oliver@gmail.com> Discussion: https://postgr.es/m/20201021200659.GA32358@alvherre.pgsql
2020-10-25Fix corner case for a BEFORE ROW UPDATE trigger returning OLD.Tom Lane
If the old row has any "missing" attributes that are supposed to be retrieved from an associated tuple descriptor, the wrong things happened because the trigger result is shoved directly into an executor slot that lacks the missing-attribute data. Notably, CHECK-constraint verification would incorrectly see those columns as NULL, and so would RETURNING-list evaluation. Band-aid around this by forcibly expanding the tuple before passing it to the trigger function. (IMO it was a fundamental misdesign to put the missing-attribute data into tuple constraints, which so much of the system considers to be optional. But we're probably stuck with that now, and will have to continue to apply band-aids as we find other places with similar issues.) Back-patch to v12. v11 would also have the issue, except that commit 920311ab1 already applied a similar band-aid. That forced expansion in more cases than seem really necessary, though, so this isn't a directly equivalent fix. Amit Langote, with some cosmetic changes by me Discussion: https://postgr.es/m/16644-5da7ef98a7ac4545@postgresql.org
2020-10-20Fix ALTER TABLE .. ENABLE/DISABLE TRIGGER recursionAlvaro Herrera
More precisely, correctly handle the ONLY flag indicating not to recurse. This was implemented in 86f575948c77 by recursing in trigger.c, but that's the wrong place; use ATSimpleRecursion instead, which behaves properly. However, because legacy inheritance has never recursed in that situation, make sure to do that only for new-style partitioning. I noticed this problem while testing a fix for another bug in the vicinity. This has been wrong all along, so backpatch to 11. Discussion: https://postgr.es/m/20201016235925.GA29829@alvherre.pgsql
2020-09-30Reword partitioning error messageAlvaro Herrera
The error message about columns in the primary key not including all of the partition key was unclear; reword it. Backpatch all the way to pg11, where it appeared. Reported-by: Nagaraj Raj <nagaraj.sf@yahoo.com> Discussion: https://postgr.es/m/64062533.78364.1601415362244@mail.yahoo.com
2020-09-29Fix progress reporting of REINDEX CONCURRENTLYMichael Paquier
This addresses a couple of issues with the so-said subject: - Report the correct parent relation with the index actually being rebuilt or validated. Previously, the command status remained set to the last index created for the progress of the index build and validation, which would be incorrect when working on a table that has more than one index. - Use the correct phase when waiting before the drop of the old indexes. Previously, this was reported with the same status as when waiting before the old indexes are marked as dead. Author: Matthias van de Meent, Michael Paquier Discussion: https://postgr.es/m/CAEze2WhqFgcwe1_tv=sFYhLWV2AdpfukumotJ6JNcAOQs3jufg@mail.gmail.com Backpatch-through: 12
2020-09-26Revise RelationBuildRowSecurity() to avoid memory leaks.Tom Lane
This function leaked some memory while loading qual clauses for an RLS policy. While ordinarily negligible, that could build up in some repeated-reload cases, as reported by Konstantin Knizhnik. We can improve matters by borrowing the coding long used in RelationBuildRuleLock: build stringToNode's result directly in the target context, and remember to explicitly pfree the input string. This patch by no means completely guarantees zero leaks within this function, since we have no real guarantee that the catalog- reading subroutines it calls don't leak anything. However, practical tests suggest that this is enough to resolve the issue. In any case, any remaining leaks are similar to those risked by RelationBuildRuleLock and other relcache-loading subroutines. If we need to fix them, we should adopt a more global approach such as that used by the RECOVER_RELATION_BUILD_MEMORY hack. While here, let's remove the need for an expensive PG_TRY block by using MemoryContextSetParent to reparent an initially-short-lived context for the RLS data. Back-patch to all supported branches. Discussion: https://postgr.es/m/21356c12-8917-8249-b35f-1c447231922b@postgrespro.ru
2020-09-16Avoid unnecessary recursion to child tables in ALTER TABLE SET NOT NULL.Tom Lane
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
2020-09-01Raise error on concurrent drop of partitioned indexAlvaro Herrera
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
2020-08-21Fix handling of CREATE TABLE LIKE with inheritance.Tom Lane
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
2020-08-15Prevent concurrent SimpleLruTruncate() for any given SLRU.Noah Misch
The SimpleLruTruncate() header comment states the new coding rule. To achieve this, add locktype "frozenid" and two LWLocks. This closes a rare opportunity for data loss, which manifested as "apparent wraparound" or "could not access status of transaction" errors. Data loss is more likely in pg_multixact, due to released branches' thin margin between multiStopLimit and multiWrapLimit. If a user's physical replication primary logged ": apparent wraparound" messages, the user should rebuild standbys of that primary regardless of symptoms. At less risk is a cluster having emitted "not accepting commands" errors or "must be vacuumed" warnings at some point. One can test a cluster for this data loss by running VACUUM FREEZE in every database. Back-patch to 9.5 (all supported versions). Discussion: https://postgr.es/m/20190218073103.GA1434723@rfd.leadboat.com
2020-08-10Make contrib modules' installation scripts more secure.Tom Lane
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
2020-07-14Fix timing issue with ALTER TABLE's validate constraintDavid Rowley
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)
2020-07-03Fix temporary tablespaces for shared filesets some more.Tom Lane
Commit ecd9e9f0b fixed the problem in the wrong place, causing unwanted side-effects on the behavior of GetNextTempTableSpace(). Instead, let's make SharedFileSetInit() responsible for subbing in the value of MyDatabaseTableSpace when the default tablespace is called for. The convention about what is in the tempTableSpaces[] array is evidently insufficiently documented, so try to improve that. It also looks like SharedFileSetInit() is doing the wrong thing in the case where temp_tablespaces is empty. It was hard-wiring use of the pg_default tablespace, but it seems like using MyDatabaseTableSpace is more consistent with what happens for other temp files. Back-patch the reversion of PrepareTempTablespaces()'s behavior to 9.5, as ecd9e9f0b was. The changes in SharedFileSetInit() go back to v11 where that was introduced. (Note there is net zero code change before v11 from these two patch sets, so nothing to release-note.) Magnus Hagander and Tom Lane Discussion: https://postgr.es/m/CABUevExg5YEsOvqMxrjoNvb3ApVyH+9jggWGKwTDFyFCVWczGQ@mail.gmail.com
2020-07-03Fix temporary tablespaces for shared filesetsMagnus Hagander
A likely copy/paste error in 98e8b480532 from back in 2004 would cause temp tablespace to be reset to InvalidOid if temp_tablespaces was set to the same value as the primary tablespace in the database. This would cause shared filesets (such as for parallel hash joins) to ignore them, putting the temporary files in the default tablespace instead of the configured one. The bug is in the old code, but it appears to have been exposed only once we had shared filesets. Reviewed-By: Daniel Gustafsson Discussion: https://postgr.es/m/CABUevExg5YEsOvqMxrjoNvb3ApVyH+9jggWGKwTDFyFCVWczGQ@mail.gmail.com Backpatch-through: 9.5
2020-06-22Undo double-quoting of index names in non-text EXPLAIN output formats.Tom Lane
explain_get_index_name() applied quote_identifier() to the index name. This is fine for text output, but the non-text output formats all have their own quoting conventions and would much rather start from the actual index name. For example in JSON you'd get something like "Index Name": "\"My Index\"", which is surely not desirable, especially when the same does not happen for table names. Hence, move the responsibility for applying quoting out to the callers, where it can go into already-existing special code paths for text format. This changes the API spec for users of explain_get_index_name_hook: before, they were supposed to apply quote_identifier() if necessary, now they should not. Research suggests that the only publicly available user of the hook is hypopg, and it actually forgot to apply quoting anyway, so it's fine. (In any case, there's no behavioral change for the output of a hook as seen in non-text EXPLAIN formats, so this won't break any case that programs should be relying on.) Digging in the commit logs, it appears that quoting was included in explain_get_index_name's duties when commit 604ffd280 invented it; and that was fine at the time because we only had text output format. This should have been rethought when non-text formats were invented, but it wasn't. This is a fairly clear bug for users of non-text EXPLAIN formats, so back-patch to all supported branches. Per bug #16502 from Maciek Sakrejda. Patch by me (based on investigation by Euler Taveira); thanks to Julien Rouhaud for review. Discussion: https://postgr.es/m/16502-57bd1c9f913ed1d1@postgresql.org
2020-05-28Add missing error code to "cannot attach index ..." error.Heikki Linnakangas
ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE was used in an ereport with the same message but different errdetail a few lines earlier, so use that here as well. Backpatch-through: 11
2020-05-08Fix several DDL issues of generated columns versus inheritancePeter Eisentraut
Several combinations of generated columns and inheritance in CREATE TABLE were not handled correctly. Specifically: - Disallow a child column specifying a generation expression if the parent column is a generated column. The child column definition must be unadorned and the parent column's generation expression will be copied. - Prohibit a child column of a generated parent column specifying default values or identity. - Allow a child column of a not-generated parent column specifying itself as a generated column. This previously did not work, but it was possible to arrive at the state via other means (involving ALTER TABLE), so it seems sensible to support it. Add tests for each case. Also add documentation about the rules involving generated columns and inheritance. Discussion: https://www.postgresql.org/message-id/flat/15830.1575468847%40sss.pgh.pa.us https://www.postgresql.org/message-id/flat/2678bad1-048f-519a-ef24-b12962f41807%40enterprisedb.com https://www.postgresql.org/message-id/flat/CAJvUf_u4h0DxkCMCeEKAWCuzGUTnDP-G5iVmSwxLQSXn0_FWNQ%40mail.gmail.com
2020-05-08Propagate ALTER TABLE ... SET STORAGE to indexesPeter Eisentraut
When creating a new index, the attstorage setting of the table column is copied to regular (non-expression) index columns. But a later ALTER TABLE ... SET STORAGE is not propagated to indexes, thus creating an inconsistent and undumpable state. Discussion: https://www.postgresql.org/message-id/flat/9765d72b-37c0-06f5-e349-2a580aafd989%402ndquadrant.com
2020-05-06Heed lock protocol in DROP OWNED BYAlvaro Herrera
We were acquiring object locks then deleting objects one by one, instead of acquiring all object locks first, ignoring those that did not exist, and then deleting all objects together. The latter is the correct protocol to use, and what this commits changes to code to do. Failing to follow that leads to "cache lookup failed for relation XYZ" error reports when DROP OWNED runs concurrently with other DDL -- for example, a session termination that removes some temp tables. Author: Álvaro Herrera Reported-by: Mithun Chicklore Yogendra (Mithun CY) Reviewed-by: Ahsan Hadi, Tom Lane Discussion: https://postgr.es/m/CADq3xVZTbzK4ZLKq+dn_vB4QafXXbmMgDP3trY-GuLnib2Ai1w@mail.gmail.com
2020-04-25Fix error case for CREATE ROLE ... IN ROLE.Andrew Gierth
CreateRole() was passing a Value node, not a RoleSpec node, for the newly-created role name when adding the role as a member of existing roles for the IN ROLE syntax. This mistake went unnoticed because the node in question is used only for error messages and is not accessed on non-error paths. In older pg versions (such as 9.5 where this was found), this results in an "unexpected node type" error in place of the real error. That node type check was removed at some point, after which the code would accidentally fail to fail on 64-bit platforms (on which accessing the Value node as if it were a RoleSpec would be mostly harmless) or give an "unexpected role type" error on 32-bit platforms. Fix the code to pass the correct node type, and add an lfirst_node assertion just in case. Per report on irc from user m1chelangelo. Backpatch all the way, because this error has been around for a long time.
2020-04-21Fix detaching partitions with cloned row triggersAlvaro Herrera
When a partition is detached, any triggers that had been cloned from its parent were not properly disentangled from its parent triggers. This resulted in triggers that could not be dropped because they depended on the trigger in the trigger in the no-longer-parent table: ALTER TABLE t DETACH PARTITION t1; DROP TRIGGER trig ON t1; ERROR: cannot drop trigger trig on table t1 because trigger trig on table t requires it HINT: You can drop trigger trig on table t instead. Moreover the table can no longer be re-attached to its parent, because the trigger name is already taken: ALTER TABLE t ATTACH PARTITION t1 FOR VALUES FROM (1)TO(2); ERROR: trigger "trig" for relation "t1" already exists The former is a bug introduced in commit 86f575948c77. (The latter is not necessarily a bug, but it makes the bug more uncomfortable.) To avoid the complexity that would be needed to tell whether the trigger has a local definition that has to be merged with the one coming from the parent table, establish the behavior that the trigger is removed when the table is detached. Backpatch to pg11. Author: Justin Pryzby <pryzby@telsasoft.com> Reviewed-by: Amit Langote <amitlangote09@gmail.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://www.postgresql.org/message-id/flat/20200408152412.GZ2228@telsasoft.com
2020-04-06Preserve clustered index after rewrites with ALTER TABLEMichael Paquier
A table rewritten by ALTER TABLE would lose tracking of an index usable for CLUSTER. This setting is tracked by pg_index.indisclustered and is controlled by ALTER TABLE, so some extra work was needed to restore it properly. Note that ALTER TABLE only marks the index that can be used for clustering, and does not do the actual operation. Author: Amit Langote, Justin Pryzby Reviewed-by: Ibrar Ahmed, Michael Paquier Discussion: https://postgr.es/m/20200202161718.GI13621@telsasoft.com Backpatch-through: 9.5
2020-04-03Fix bogus CALLED_AS_TRIGGER() defenses.Tom Lane
contrib/lo's lo_manage() thought it could use trigdata->tg_trigger->tgname in its error message about not being called as a trigger. That naturally led to a core dump. unique_key_recheck() figured it could Assert that fcinfo->context is a TriggerData node in advance of having checked that it's being called as a trigger. That's harmless in production builds, and perhaps not that easy to reach in any case, but it's logically wrong. The first of these per bug #16340 from William Crowell; the second from manual inspection of other CALLED_AS_TRIGGER call sites. Back-patch the lo.c change to all supported branches, the other to v10 where the thinko crept in. Discussion: https://postgr.es/m/16340-591c7449dc7c8c47@postgresql.org
2020-04-01Check equality semantics for unique indexes on partitioned tables.Tom Lane
We require the partition key to be a subset of the set of columns being made unique, so that physically-separate indexes on the different partitions are sufficient to enforce the uniqueness constraint. The existing code checked that the listed columns appear, but did not inquire into the index semantics, which is a serious oversight given that different index opclasses might enforce completely different notions of uniqueness. Ideally, perhaps, we'd just match the partition key opfamily to the index opfamily. But hash partitioning uses hash opfamilies which we can't directly match to btree opfamilies. Hence, look up the equality operator in each family, and accept if it's the same operator. This should be okay in a fairly general sense, since the equality operator ought to precisely represent the opfamily's notion of uniqueness. A remaining weak spot is that we don't have a cross-index-AM notion of which opfamily member is "equality". But we know which one to use for hash and btree AMs, and those are the only two that are relevant here at present. (Any non-core AMs that know how to enforce equality are out of luck, for now.) Back-patch to v11 where this feature was introduced. Guancheng Luo, revised a bit by me Discussion: https://postgr.es/m/D9C3CEF7-04E8-47A1-8300-CA1DCD5ED40D@gmail.com
2020-03-22Revert "Skip WAL for new relfilenodes, under wal_level=minimal."Noah Misch
This reverts commit cb2fd7eac285b1b0a24eeb2b8ed4456b66c5a09f. Per numerous buildfarm members, it was incompatible with parallel query, and a test case assumed LP64. Back-patch to 9.5 (all supported versions). Discussion: https://postgr.es/m/20200321224920.GB1763544@rfd.leadboat.com
2020-03-21Skip WAL for new relfilenodes, under wal_level=minimal.Noah Misch
Until now, only selected bulk operations (e.g. COPY) did this. If a given relfilenode received both a WAL-skipping COPY and a WAL-logged operation (e.g. INSERT), recovery could lose tuples from the COPY. See src/backend/access/transam/README section "Skipping WAL for New RelFileNode" for the new coding rules. Maintainers of table access methods should examine that section. To maintain data durability, just before commit, we choose between an fsync of the relfilenode and copying its contents to WAL. A new GUC, wal_skip_threshold, guides that choice. If this change slows a workload that creates small, permanent relfilenodes under wal_level=minimal, try adjusting wal_skip_threshold. Users setting a timeout on COMMIT may need to adjust that timeout, and log_min_duration_statement analysis will reflect time consumption moving to COMMIT from commands like COPY. Internally, this requires a reliable determination of whether RollbackAndReleaseCurrentSubTransaction() would unlink a relation's current relfilenode. Introduce rd_firstRelfilenodeSubid. Amend the specification of rd_createSubid such that the field is zero when a new rel has an old rd_node. Make relcache.c retain entries for certain dropped relations until end of transaction. Back-patch to 9.5 (all supported versions). This introduces a new WAL record type, XLOG_GIST_ASSIGN_LSN, without bumping XLOG_PAGE_MAGIC. As always, update standby systems before master systems. This changes sizeof(RelationData) and sizeof(IndexStmt), breaking binary compatibility for affected extensions. (The most recent commit to affect the same class of extensions was 089e4d405d0f3b94c74a2c6a54357a84a681754b.) Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert Haas. Heikki Linnakangas and Michael Paquier implemented earlier designs that materially clarified the problem. Reviewed, in earlier designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane, Fujii Masao, and Simon Riggs. Reported by Martijn van Oosterhout. Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org
2020-03-21During heap rebuild, lock any TOAST index until end of transaction.Noah Misch
swap_relation_files() calls toast_get_valid_index() to find and lock this index, just before swapping with the rebuilt TOAST index. The latter function releases the lock before returning. Potential for mischief is low; a concurrent session can issue ALTER INDEX ... SET (fillfactor = ...), which is not alarming. Nonetheless, changing pg_class.relfilenode without a lock is unconventional. Back-patch to 9.5 (all supported versions), because another fix needs this. Discussion: https://postgr.es/m/20191226001521.GA1772687@rfd.leadboat.com
2020-03-18Fix typo in indexcmds.cMichael Paquier
Introduced by 61d7c7b. Backpatch-through: 12
2020-03-13Preserve replica identity index across ALTER TABLE rewritePeter Eisentraut
If an index was explicitly set as replica identity index, this setting was lost when a table was rewritten by ALTER TABLE. Because this setting is part of pg_index but actually controlled by ALTER TABLE (not part of CREATE INDEX, say), we have to do some extra work to restore it. Based-on-patch-by: Quan Zongliang <quanzongliang@gmail.com> Reviewed-by: Euler Taveira <euler.taveira@2ndquadrant.com> Discussion: https://www.postgresql.org/message-id/flat/c70fcab2-4866-0d9f-1d01-e75e189db342@gmail.com
2020-03-11Avoid duplicates in ALTER ... DEPENDS ON EXTENSIONAlvaro Herrera
If the command is attempted for an extension that the object already depends on, silently do nothing. In particular, this means that if a database containing multiple such entries is dumped, the restore will silently do the right thing and record just the first one. (At least, in a world where pg_dump does dump such entries -- which it doesn't currently, but it will.) Backpatch to 9.6, where this kind of dependency was introduced. Reviewed-by: Ibrar Ahmed, Tom Lane (offlist) Discussion: https://postgr.es/m/20200217225333.GA30974@alvherre.pgsql
2020-03-10Prevent reindex of invalid indexes on TOAST tablesMichael Paquier
Such indexes can only be duplicated leftovers of a previously failed REINDEX CONCURRENTLY command, and a valid equivalent is guaranteed to exist. As toast indexes can only be dropped if invalid, reindexing these would lead to useless duplicated indexes that can't be dropped anymore, except if the parent relation is dropped. Thanks to Justin Pryzby for reminding that this problem was reported long ago during the review of the original patch of REINDEX CONCURRENTLY, but the issue was never addressed. Reported-by: Sergei Kornilov, Justin Pryzby Author: Julien Rouhaud Reviewed-by: Michael Paquier Discussion: https://postgr.es/m/36712441546604286%40sas1-890ba5c2334a.qloud-c.yandex.net Discussion: https://postgr.es/m/20200216190835.GA21832@telsasoft.com Backpatch-through: 12
2020-02-10Fix priv checks for ALTER <object> DEPENDS ON EXTENSIONAlvaro Herrera
Marking an object as dependant on an extension did not have any privilege check whatsoever; this allowed any user to mark objects as droppable by anyone able to DROP EXTENSION, which could be used to cause system-wide havoc. Disallow by checking that the calling user owns the mentioned object. (No constraints are placed on the extension.) Security: CVE-2020-1720 Reported-by: Tom Lane Discussion: 31605.1566429043@sss.pgh.pa.us
2020-02-07Fix failure to create FKs correctly in partitionsAlvaro Herrera
On a multi-level partioned table, when adding a partition not directly connected to the root table, foreign key constraints referencing the root were not cloned to the new partition, leading to the FK being possibly inadvertently violated later on. This was caused by fuzzy thinking in CloneFkReferenced (commit f56f8f8da6af): it was skipping constraints marked as having parents on the theory that cloning those would create duplicates; but that's only correct for the top level of the partitioning hierarchy. For levels below that one, such constraints must still be considered and only skipped if later on we see that we'd create duplicates. Apparently, I (Álvaro) wrote the comments right but the code implemented something slightly different. Author: Jehan-Guillaume de Rorthais Discussion: https://postgr.es/m/20200206004948.238352db@firost
2020-02-04Fix handling of "Subplans Removed" field in EXPLAIN output.Tom Lane
Commit 499be013d added this field in a rather poorly-thought-through manner, with the result being that rather than being a field of the Append or MergeAppend plan node as intended (and as it seems to be, in text format), it was actually an element of the "Plans" subgroup. At least in JSON format, that's flat out invalid syntax, because "Plans" is an array not an object. While it's not hard to move the generation of the field so that it appears where it's supposed to, this does result in a visible change in field order in text format, in cases where a Append or MergeAppend plan node has any InitPlans attached. That's slightly annoying to do in stable branches; but the alternative of continuing to emit broken non-text formats seems worse. Also, since the set of fields emitted is not supposed to be data-dependent in non-text formats, make sure that "Subplans Removed" appears in Append and MergeAppend nodes even when it's zero, in those formats. (The previous coding made it look like it could appear in some other node types such as BitmapAnd, but we don't actually support runtime pruning there, so don't emit it in those cases.) Per bug #16171 from Mahadevan Ramachandran. Fix by Daniel Gustafsson and Tom Lane, reviewed by Hamid Akhtar. Back-patch to v11 where this code came in. Discussion: https://postgr.es/m/16171-b72259ab75505fa2@postgresql.org
2020-02-03Revert commit de0177788b.Fujii Masao
This commit reverts the fix "Make inherited TRUNCATE perform access permission checks on parent table only" only in the back branches. It's not hard to imagine that there are some applications expecting the old behavior and the fix breaks their security. To avoid this compatibility problem, we decided to apply the fix only in HEAD and revert it in all supported back branches. Discussion: https://postgr.es/m/21015.1580400165@sss.pgh.pa.us
2020-01-31Make inherited TRUNCATE perform access permission checks on parent table only.Fujii Masao
Previously, TRUNCATE command through a parent table checked the permissions on not only the parent table but also the children tables inherited from it. This was a bug and inherited queries should perform access permission checks on the parent table only. This commit fixes that bug. Back-patch to all supported branches. Author: Amit Langote Reviewed-by: Fujii Masao Discussion: https://postgr.es/m/CAHGQGwFHdSvifhJE+-GSNqUHSfbiKxaeQQ7HGcYz6SC2n_oDcg@mail.gmail.com
2020-01-26Fix EXPLAIN (SETTINGS) to follow policy about when to print empty fields.Tom Lane
In non-TEXT output formats, the "Settings" field should appear when requested, even if it would be empty. Also, get rid of the premature optimization of counting all the GUC_EXPLAIN variables at startup. Since there was no provision for adjusting that count later, all it'd take would be some extension marking a parameter as GUC_EXPLAIN to risk an assertion failure or memory stomp. We could make get_explain_guc_options() count those variables on-the-fly, or dynamically resize its array ... but TBH I do not think that making a transient array of pointers a bit smaller is worth any extra complication, especially when you consider all the other transient space EXPLAIN eats. So just allocate that array at the max possible size. In HEAD, also add some regression test coverage for this feature. Because of the memory-stomp hazard, back-patch to v12 where this feature was added. Discussion: https://postgr.es/m/19416.1580069629@sss.pgh.pa.us
2020-01-22Fix concurrent indexing operations with temporary tablesMichael Paquier
Attempting to use CREATE INDEX, DROP INDEX or REINDEX with CONCURRENTLY on a temporary relation with ON COMMIT actions triggered unexpected errors because those operations use multiple transactions internally to complete their work. Here is for example one confusing error when using ON COMMIT DELETE ROWS: ERROR: index "foo" already contains data Issues related to temporary relations and concurrent indexing are fixed in this commit by enforcing the non-concurrent path to be taken for temporary relations even if using CONCURRENTLY, transparently to the user. Using a non-concurrent path does not matter in practice as locks cannot be taken on a temporary relation by a session different than the one owning the relation, and the non-concurrent operation is more effective. The problem exists with REINDEX since v12 with the introduction of CONCURRENTLY, and with CREATE/DROP INDEX since CONCURRENTLY exists for those commands. In all supported versions, this caused only confusing error messages to be generated. Note that with REINDEX, it was also possible to issue a REINDEX CONCURRENTLY for a temporary relation owned by a different session, leading to a server crash. The idea to enforce transparently the non-concurrent code path for temporary relations comes originally from Andres Freund. Reported-by: Manuel Rigger Author: Michael Paquier, Heikki Linnakangas Reviewed-by: Andres Freund, Álvaro Herrera, Heikki Linnakangas Discussion: https://postgr.es/m/CA+u7OA6gP7YAeCguyseusYcc=uR8+ypjCcgDDCTzjQ+k6S9ksQ@mail.gmail.com Backpatch-through: 9.4
2020-01-08Fix handling of generated columns in ALTER TABLE.Tom Lane
ALTER TABLE failed if a column referenced in a GENERATED expression had been added or changed in type earlier in the ALTER command. That's because the GENERATED expression needs to be evaluated against the table's updated tuples, but it was being evaluated against the original tuples. (Fortunately the executor has adequate cross-checks to notice the mismatch, so we just got an obscure error message and not anything more dangerous.) Per report from Andreas Joseph Krogh. Back-patch to v12 where GENERATED was added. Discussion: https://postgr.es/m/VisenaEmail.200.231b0a41523275d0.16ea7f800c7@tc7-visena
2020-01-08Revert "Forbid DROP SCHEMA on temporary namespaces"Michael Paquier
This reverts commit a052f6c, following complains from Robert Haas and Tom Lane. Backpatch down to 9.4, like the previous commit. Discussion: https://postgr.es/m/CA+TgmobL4npEX5=E5h=5Jm_9mZun3MT39Kq2suJFVeamc9skSQ@mail.gmail.com Backpatch-through: 9.4