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* Assorted code review for recent ProcArrayLock patch.Robert Haas2015-09-03
| | | | | | | | | | | | | | | Post-commit review by Andres Freund discovered a couple of concurrency bugs in the original patch: specifically, if the leader cleared a follower's XID before it reached PGSemaphoreLock, the semaphore would be left in the wrong state; and if another process did PGSemaphoreUnlock for some unrelated reason, we might resume execution before the fact that our XID was cleared was globally visible. Also, improve the wording of some comments, rename nextClearXidElem to firstClearXidElem in PROC_HDR for clarity, and drop some volatile qualifiers that aren't necessary. Amit Kapila, reviewed and slightly revised by me.
* Document that max_worker_processes must be high enough in standby.Fujii Masao2015-09-03
| | | | | | | | | The setting values of some parameters including max_worker_processes must be equal to or higher than the values on the master. However, previously max_worker_processes was not listed as such parameter in the document. So this commit adds it to that list. Back-patch to 9.4 where max_worker_processes was added.
* Allow usage of huge maintenance_work_mem for GIN build.Teodor Sigaev2015-09-02
| | | | | | | | | | | | | Currently, in-memory posting list during GIN build process is limited 1GB because of using repalloc. The patch replaces call of repalloc to repalloc_huge. It increases limit of posting list from 180 millions (1GB / sizeof(ItemPointerData)) to 4 billions limited by maxcount/count fields in GinEntryAccumulator and subsequent calls. Check added. Also, fix accounting of allocatedMemory during build to prevent integer overflow with maintenance_work_mem > 4GB. Robert Abraham <robert.abraham86@googlemail.com> with additions by me
* Allow notifications to bgworkers without database connections.Robert Haas2015-09-01
| | | | | | | | | | | | | | | | | | Previously, if one background worker registered another background worker and set bgw_notify_pid while for the second background worker, it would not receive notifications from the postmaster unless, at the time the "parent" was registered, BGWORKER_BACKEND_DATABASE_CONNECTION was set. To fix, instead instead of including only those background workers that requested database connections in the postmater's BackendList, include them all. There doesn't seem to be any reason not do this, and indeed it removes a significant amount of duplicated code. The other option is to make PostmasterMarkPIDForWorkerNotify look at BackgroundWorkerList in addition to BackendList, but that adds more code duplication instead of getting rid of it. Patch by me. Review and testing by Ashutosh Bapat.
* Clean up icc + ia64 situation.Tom Lane2015-08-31
| | | | | | | | | | | | | | Some googling turned up multiple sources saying that older versions of icc do not accept gcc-compatible asm blocks on IA64, though asm does work on x86[_64]. This is apparently fixed as of icc version 12.0 or so, but that doesn't help us much; if we have to carry the extra implementation anyway, we may as well just use it for icc rather than add a compiler version test. Hence, revert commit 2c713d6ea29c91cd2cbd92fa801a61e55ea2a3c4 (though I separated the icc code from the gcc code completely, producing what seems cleaner code). Document the state of affairs more explicitly, both in s_lock.h and postgres.c, and make some cosmetic adjustments around the IA64 code in s_lock.h.
* Actually, it's not that hard to merge the Windows pqsignal code ...Tom Lane2015-08-31
| | | | | ... just need to typedef sigset_t and provide sigemptyset/sigfillset, which are easy enough.
* Remove theoretically-unnecessary special case for icc.Tom Lane2015-08-31
| | | | | | | | Intel's icc is generally able to swallow asm blocks written for gcc. We have a few places that don't seem to know that, though. Experiment with removing the special case for icc in ia64_get_bsp(); if the buildfarm likes this, I'll try more cleanup. This is a good test case because it involves a "stop" notation that seems like it might not be very portable.
* Remove support for Unix systems without the POSIX signal APIs.Tom Lane2015-08-31
| | | | | | | | | | | | | | | | | | | Remove configure's checks for HAVE_POSIX_SIGNALS, HAVE_SIGPROCMASK, and HAVE_SIGSETJMP. These APIs are required by the Single Unix Spec v2 (POSIX 1997), which we generally consider to define our minimum required set of Unix APIs. Moreover, no buildfarm member has reported not having them since 2012 or before, which means that even if the code is still live somewhere, it's untested --- and we've made plenty of signal-handling changes of late. So just take these APIs as given and save the cycles for configure probes for them. However, we can't remove as much C code as I'd hoped, because the Windows port evidently still uses the non-POSIX code paths for signal masking. Since we're largely emulating these BSD-style APIs for Windows anyway, it might be a good thing to switch over to POSIX-like notation and thereby remove a few more #ifdefs. But I'm not in a position to code or test that. In the meantime, we can at least make things a bit more transparent by testing for WIN32 explicitly in these places.
* Ensure locks are acquired on RLS-added relationsStephen Frost2015-08-28
| | | | | | | | During fireRIRrules(), get_row_security_policies can add to securityQuals and withCheckOptions. Make sure to lock any relations added at that point and before firing RIR rules on those expressions. Back-patch to 9.5 where RLS was added.
* Clarify what some historic terms in rewriteHandler.c mean.Andres Freund2015-08-28
| | | | Discussion: 20150827131352.GF2435@awork2.anarazel.de
* Speed up HeapTupleSatisfiesMVCC() by replacing the XID-in-progress test.Tom Lane2015-08-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than consulting TransactionIdIsInProgress to see if an in-doubt transaction is still running, consult XidInMVCCSnapshot. That requires the same or fewer cycles as TransactionIdIsInProgress, and what's far more important, it does not access shared data structures (at least in the no-subxip-overflow case) so it incurs no contention. Furthermore, we would have had to check XidInMVCCSnapshot anyway before deciding that we were allowed to see the tuple. There should never be a case where XidInMVCCSnapshot says a transaction is done while TransactionIdIsInProgress says it's still running. The other way around is quite possible though. The result of that difference is that HeapTupleSatisfiesMVCC will no longer set hint bits on tuples whose source transactions recently finished but are still running according to our snapshot. The main cost of delaying the hint-bit setting is that repeated visits to a just-committed tuple, by transactions none of which have snapshots new enough to see the source transaction as done, will each execute TransactionIdIsCurrentTransactionId, which they need not have done before. However, that's normally just a small overhead, and no contention costs are involved; so it seems well worth the benefit of removing TransactionIdIsInProgress calls during the life of the source transaction. The core idea for this patch is due to Jeff Janes, who also did the legwork proving its performance benefits. His original proposal was to swap the order of TransactionIdIsInProgress and XidInMVCCSnapshot calls in some cases within HeapTupleSatisfiesMVCC. That was a bit messy though. The idea that we could dispense with calling TransactionIdIsInProgress altogether was mine, as is the final patch.
* Limit the verbosity of memory context statistics dumps.Tom Lane2015-08-25
| | | | | | | | | | | | | | | | | | | | | We had a report from Stefan Kaltenbrunner of a case in which postmaster log files overran available disk space because multiple backends spewed enormous context stats dumps upon hitting an out-of-memory condition. Given the lack of similar reports, this isn't a common problem, but it still seems worth doing something about. However, we don't want to just blindly truncate the output, because that might prevent diagnosis of OOM problems. What seems like a workable compromise is to limit the dump to 100 child contexts per parent, and summarize the space used within any additional child contexts. That should help because practical cases where the dump gets long will typically be huge numbers of siblings under the same parent context; while the additional debugging value from seeing details about individual siblings beyond 100 will not be large, we hope. Anyway it doesn't take much code or memory space to do this, so let's try it like this and see how things go. Since the summarization mechanism requires passing totals back up anyway, I took the opportunity to add a "grand total" line to the end of the printout.
* Reduce number of bytes examined by convert_one_string_to_scalar().Tom Lane2015-08-23
| | | | | | | | | | | | | | | | | | | | | Previously, convert_one_string_to_scalar() would examine up to 20 bytes of the input string, producing a scalar conversion with theoretical precision far greater than is of any possible use considering the other limitations on the accuracy of the resulting selectivity estimate. (I think this choice might pre-date the caller-level logic that strips any common prefix of the strings; before that, there could have been value in scanning the strings far enough to use all the precision available in a double.) Aside from wasting cycles to little purpose, this choice meant that the "denom" variable could grow to as much as 256^21 = 3.74e50, which could overflow in some non-IEEE float arithmetics. While we don't really support any machines with non-IEEE arithmetic anymore, this still seems like quite an unnecessary platform dependency. Limit the scan to 12 bytes instead, thus limiting "denom" to 256^13 = 2.03e31, a value more likely to be computable everywhere. Per testing by Greg Stark, which showed overflow failures in our standard regression tests on VAX.
* Avoid use of float arithmetic in bipartite_match.c.Tom Lane2015-08-23
| | | | | | | | | | | | | | | Since the distances used in this algorithm are small integers (not more than the size of the U set, in fact), there is no good reason to use float arithmetic for them. Use short ints instead: they're smaller, faster, and require no special portability assumptions. Per testing by Greg Stark, which disclosed that the code got into an infinite loop on VAX for lack of IEEE-style float infinities. We don't really care all that much whether Postgres can run on a VAX anymore, but there seems sufficient reason to change this code anyway. In passing, make a few other small adjustments to make the code match usual Postgres coding style a bit better.
* Fix typo in C comment.Kevin Grittner2015-08-23
| | | | | Merlin Moncure Backpatch to 9.5, where the misspelling was introduced
* Improve whitespacePeter Eisentraut2015-08-22
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* Avoid O(N^2) behavior when enlarging SPI tuple table in spi_printtup().Tom Lane2015-08-21
| | | | | | | | | | | | | For no obvious reason, spi_printtup() was coded to enlarge the tuple pointer table by just 256 slots at a time, rather than doubling the size at each reallocation, as is our usual habit. For very large SPI results, this makes for O(N^2) time spent in repalloc(), which of course soon comes to dominate the runtime. Use the standard doubling approach instead. This is a longstanding performance bug, so back-patch to all active branches. Neil Conway
* Do not allow *timestamp to be passed as NULLAlvaro Herrera2015-08-21
| | | | | | | | | | | | | The code had bugs that would cause crashes if NULL was passed as that argument (originally intended to mean not to bother returning its value), and after inspection it turns out that nothing seems interested in the case that *ts is NULL anyway. Therefore, remove the partial checks intended to support that case. Author: Michael Paquier though I didn't include a proposed Assert. Backpatch to 9.5.
* Remove ExecGetScanType functionAlvaro Herrera2015-08-21
| | | | This became unused in a191a169d6d0b9558da4519e66510c4540204a51.
* Allow record_in() and record_recv() to work for transient record types.Tom Lane2015-08-21
| | | | | | | | | | | | | | | | | | If we have the typmod that identifies a registered record type, there's no reason that record_in() should refuse to perform input conversion for it. Now, in direct SQL usage, record_in() will always be passed typmod = -1 with type OID RECORDOID, because no typmodin exists for type RECORD, so the case can't arise. However, some InputFunctionCall users such as PLs may be able to supply the right typmod, so we should allow this to support them. Note: the previous coding and comment here predate commit 59c016aa9f490b53. There has been no case since 8.1 in which the passed type OID wouldn't be valid; and if it weren't, this error message wouldn't be apropos anyway. Better to let lookup_rowtype_tupdesc complain about it. Back-patch to 9.1, as this is necessary for my upcoming plpython fix. I'm committing it separately just to make it a bit more visible in the commit history.
* Rename 'cmd' to 'cmd_name' in CreatePolicyStmtStephen Frost2015-08-21
| | | | | | | | | | | To avoid confusion, rename CreatePolicyStmt's 'cmd' to 'cmd_name', parse_policy_command's 'cmd' to 'polcmd', and AlterPolicy's 'cmd_datum' to 'polcmd_datum', per discussion with Noah and as a follow-up to his correction of copynodes/equalnodes handling of the CreatePolicyStmt 'cmd' field. Back-patch to 9.5 where the CreatePolicyStmt was introduced, as we are still only in alpha.
* In AlterRole, make bypassrls an intStephen Frost2015-08-21
| | | | | | | | | | | | | | | | When reworking bypassrls in AlterRole to operate the same way the other attribute handling is done, I missed that the variable was incorrectly a bool rather than an int. This meant that on platforms with an unsigned char, we could end up with incorrect behavior during ALTER ROLE. Pointed out by Andres thanks to tests he did changing our bool to be the one from stdbool.h which showed this and a number of other issues. Add regression tests to test CREATE/ALTER role for the various role attributes. Arrange to leave roles behind for testing pg_dumpall, but none which have the LOGIN attribute. Back-patch to 9.5 where the AlterRole bug exists.
* Fix bug in calculations of hash join buckets.Kevin Grittner2015-08-19
| | | | | | | | | | | | | | Commit 8cce08f168481c5fc5be4e7e29b968e314f1b41e used a left-shift on a literal of 1 that could (in large allocations) be shifted by 31 or more bits. This was assigned to a local variable that was already declared to be a long to protect against overruns of int, but the literal in this shift needs to be declared long to allow it to work correctly in some compilers. Backpatch to 9.5, where the bug was introduced. Report and patch by KaiGai Kohei, slighly modified based on discussion.
* Don't use function definitions looking like old-style ones.Andres Freund2015-08-15
| | | | | | | This fixes a bunch of somewhat pedantic warnings with new compilers. Since by far the majority of other functions definitions use the (void) style it just seems to be consistent to do so as well in the remaining few places.
* Correct type of waitMode variable in ExecInsertIndexTuples().Andres Freund2015-08-15
| | | | | | | | | It was a bool, even though it should be CEOUC_WAIT_MODE. That's unlikely to have a negative effect with the current definition of bool (char), but it's definitely wrong. Discussion: 20150812084351.GD8470@awork2.anarazel.de Backpatch: 9.5, where ON CONFLICT was merged
* Don't use 'bool' as a struct member name in help_config.c.Andres Freund2015-08-15
| | | | | | | | | | | | Doing so doesn't work if bool is a macro rather than a typedef. Although c.h spends some effort to support configurations where bool is a preexisting macro, help_config.c has existed this way since 2003 (b700a6), and there have not been any reports of problems. Backpatch anyway since this is as riskless as it gets. Discussion: 20150812084351.GD8470@awork2.anarazel.de Backpatch: 9.0-master
* Encoding PG_UHC is code page 949.Noah Misch2015-08-14
| | | | | | | | | | | This fixes presentation of non-ASCII messages to the Windows event log and console in rare cases involving Korean locale. Processes like the postmaster and checkpointer, but not processes attached to databases, were affected. Back-patch to 9.4, where MessageEncoding was introduced. The problem exists in all supported versions, but this change has no effect in the absence of the code recognizing PG_UHC MessageEncoding. Noticed while investigating bug #13427 from Dmitri Bourlatchkov.
* Restore old pgwin32_message_to_UTF16() behavior outside transactions.Noah Misch2015-08-14
| | | | | | | | | | | Commit 49c817eab78c6f0ce8c3bf46766b73d6cf3190b7 replaced with a hard error the dubious pg_do_encoding_conversion() behavior when outside a transaction. Reintroduce the historic soft failure locally within pgwin32_message_to_UTF16(). This fixes errors when writing messages in less-common encodings to the Windows event log or console. Back-patch to 9.4, where the aforementioned commit first appeared. Per bug #13427 from Dmitri Bourlatchkov.
* Reduce lock levels for ALTER TABLE SET autovacuum storage optionsSimon Riggs2015-08-14
| | | | | | | | | | | | Reduce lock levels down to ShareUpdateExclusiveLock for all autovacuum-related relation options when setting them using ALTER TABLE. Add infrastructure to allow varying lock levels for relation options in later patches. Setting multiple options together uses the highest lock level required for any option. Works for both main and toast tables. Fabrízio Mello, reviewed by Michael Paquier, mild edit and additional regression tests from myself
* Fix unitialized variablesAlvaro Herrera2015-08-13
| | | | | | | | | As complained by clang, reported by Andres Freund. Brown paper bag bug in ccc4c074994d. Add some comments, too. Backpatch to 9.5, like that one.
* Undo mistaken tightening in join_is_legal().Tom Lane2015-08-12
| | | | | | | | | | | | | | | | | | | One of the changes I made in commit 8703059c6b55c427 turns out not to have been such a good idea: we still need the exception in join_is_legal() that allows a join if both inputs already overlap the RHS of the special join we're checking. Otherwise we can miss valid plans, and might indeed fail to find a plan at all, as in recent report from Andreas Seltenreich. That code was added way back in commit c17117649b9ae23d, but I failed to include a regression test case then; my bad. Put it back with a better explanation, and a test this time. The logic does end up a bit different than before though: I now believe it's appropriate to make this check first, thereby allowing such a case whether or not we'd consider the previous SJ(s) to commute with this one. (Presumably, we already decided they did; but it was confusing to have this consideration in the middle of the code that was handling the other case.) Back-patch to all active branches, like the previous patch.
* Close some holes in BRIN page assignmentAlvaro Herrera2015-08-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In some corner cases, it is possible for the BRIN index relation to be extended by brin_getinsertbuffer but the new page not be used immediately for anything by its callers; when this happens, the page is initialized and the FSM is updated (by brin_getinsertbuffer) with the info about that page, but these actions are not WAL-logged. A later index insert/update can use the page, but since the page is already initialized, the initialization itself is not WAL-logged then either. Replay of this sequence of events causes recovery to fail altogether. There is a related corner case within brin_getinsertbuffer itself, in which we extend the relation to put a new index tuple there, but later find out that we cannot do so, and do not return the buffer; the page obtained from extension is not even initialized. The resulting page is lost forever. To fix, shuffle the code so that initialization is not the responsibility of brin_getinsertbuffer anymore, in normal cases; instead, the initialization is done by its callers (brin_doinsert and brin_doupdate) once they're certain that the page is going to be used. When either those functions determine that the new page cannot be used, before bailing out they initialize the page as an empty regular page, enter it in FSM and WAL-log all this. This way, the page is usable for future index insertions, and WAL replay doesn't find trying to insert tuples in pages whose initialization didn't make it to the WAL. The same strategy is used in brin_getinsertbuffer when it cannot return the new page. Additionally, add a new step to vacuuming so that all pages of the index are scanned; whenever an uninitialized page is found, it is initialized as empty and WAL-logged. This closes the hole that the relation is extended but the system crashes before anything is WAL-logged about it. We also take this opportunity to update the FSM, in case it has gotten out of date. Thanks to Heikki Linnakangas for finding the problem that kicked some additional analysis of BRIN page assignment code. Backpatch to 9.5, where BRIN was introduced. Discussion: https://www.postgresql.org/message-id/20150723204810.GY5596@postgresql.org
* Remove duplicated assignment in pg_create_physical_replication_slot.Andres Freund2015-08-12
| | | | Reported-By: Gurjeet Singh
* Fix two off-by-one errors in bufmgr.c.Andres Freund2015-08-12
| | | | | | | | | | | | | | | | | | | In 4b4b680c I passed a buffer index number (starting from 0) instead of a proper Buffer id (which start from 1 for shared buffers) in two places. This wasn't noticed so far as one of those locations isn't compiled at all (PrintPinnedBufs) and the other one (InvalidBuffer) requires a unlikely, but possible, set of circumstances to trigger a symptom. To reduce the likelihood of such incidents a bit also convert existing open coded mappings from buffer descriptors to buffer ids with BufferDescriptorGetBuffer(). Author: Qingqing Zhou Reported-By: Qingqing Zhou Discussion: CAJjS0u2ai9ooUisKtkV8cuVUtEkMTsbK8c7juNAjv8K11zeCQg@mail.gmail.com Backpatch: 9.5 where the private ref count infrastructure was introduced
* Fix some possible low-memory failures in regexp compilation.Tom Lane2015-08-12
| | | | | | | | | newnfa() failed to set the regex error state when malloc() fails. Several places in regcomp.c failed to check for an error after calling subre(). Each of these mistakes could lead to null-pointer-dereference crashes in memory-starved backends. Report and patch by Andreas Seltenreich. Back-patch to all branches.
* Postpone extParam/allParam calculations until the very end of planning.Tom Lane2015-08-11
| | | | | | | | | | | | | | | | | | | | | | | | Until now we computed these Param ID sets at the end of subquery_planner, but that approach depends on subquery_planner returning a concrete Plan tree. We would like to switch over to returning one or more Paths for a subquery, and in that representation the necessary details aren't fully fleshed out (not to mention that we don't really want to do this work for Paths that end up getting discarded). Hence, refactor so that we can compute the param ID sets at the end of planning, just before set_plan_references is run. The main change necessary to make this work is that we need to capture the set of outer-level Param IDs available to the current query level before exiting subquery_planner, since the outer levels' plan_params lists are transient. (That's not going to pose a problem for returning Paths, since all the work involved in producing that data is part of expression preprocessing, which will continue to happen before Paths are produced.) On the plus side, this change gets rid of several existing kluges. Eventually I'd like to get rid of SS_finalize_plan altogether in favor of doing this work during set_plan_references, but that will require some complex rejiggering because SS_finalize_plan needs to visit subplans and initplans before the main plan. So leave that idea for another day.
* Don't include rel.h when relcache.h is sufficientAlvaro Herrera2015-08-11
| | | | Trivial change to reduce exposure of rel.h.
* Allow pg_create_physical_replication_slot() to reserve WAL.Andres Freund2015-08-11
| | | | | | | | | | | | | | | | When creating a physical slot it's often useful to immediately reserve the current WAL position instead of only doing after the first feedback message arrives. That e.g. allows slots to guarantee that all the WAL for a base backup will be available afterwards. Logical slots already have to reserve WAL during creation, so generalize that logic into being usable for both physical and logical slots. Catversion bump because of the new parameter. Author: Gurjeet Singh Reviewed-By: Andres Freund Discussion: CABwTF4Wh_dBCzTU=49pFXR6coR4NW1ynb+vBqT+Po=7fuq5iCw@mail.gmail.com
* Introduce macros determining if a replication slot is physical or logical.Andres Freund2015-08-11
| | | | | | | | These make the code a bit easier to read, and make it easier to add a more explicit notion of a slot's type at some point in the future. Author: Gurjeet Singh Discussion: CABwTF4Wh_dBCzTU=49pFXR6coR4NW1ynb+vBqT+Po=7fuq5iCw@mail.gmail.com
* Minor cleanups in slot related code.Andres Freund2015-08-11
| | | | | | | | Fix a bunch of typos, and remove two superflous includes. Author: Gurjeet Singh Discussion: CABwTF4Wh_dBCzTU=49pFXR6coR4NW1ynb+vBqT+Po=7fuq5iCw@mail.gmail.com Backpatch: 9.4
* Further mucking with PlaceHolderVar-related restrictions on join order.Tom Lane2015-08-10
| | | | | | | | | | | | | | | | | | | Commit 85e5e222b1dd02f135a8c3bf387d0d6d88e669bd turns out not to have taken care of all cases of the partially-evaluatable-PlaceHolderVar problem found by Andreas Seltenreich's fuzz testing. I had set it up to check for risky PHVs only in the event that we were making a star-schema-based exception to the param_source_rels join ordering heuristic. However, it turns out that the problem can occur even in joins that satisfy the param_source_rels heuristic, in which case allow_star_schema_join() isn't consulted. Refactor so that we check for risky PHVs whenever the proposed join has any remaining parameterization. Back-patch to 9.2, like the previous patch (except for the regression test case, which only works back to 9.3 because it uses LATERAL). Note that this discovery implies that problems of this sort could've occurred in 9.2 and up even before the star-schema patch; though I've not tried to prove that experimentally.
* Add confirmed_flush column to pg_replication_slots.Andres Freund2015-08-10
| | | | | | | | | | | | | There's no reason not to expose both restart_lsn and confirmed_flush since they have rather distinct meanings. The former is the oldest WAL still required and valid for both physical and logical slots, whereas the latter is the location up to which a logical slot's consumer has confirmed receiving data. Most of the time a slot will require older WAL (i.e. restart_lsn) than the confirmed position (i.e. confirmed_flush_lsn). Author: Marko Tiikkaja, editorialized by me Discussion: 559D110B.1020109@joh.to
* Fix copy & paste mistake in pg_get_replication_slots().Andres Freund2015-08-10
| | | | | | | | XLogRecPtr was compared with InvalidTransactionId instead of InvalidXLogRecPtr. As both are defined to the same value this doesn't cause any actual problems, but it's still wrong. Backpatch: 9.4-master, bug was introduced in 9.4
* Remove gram.y's precedence declaration for OVERLAPS.Tom Lane2015-08-09
| | | | | | | | | | | | | | | | | The allowed syntax for OVERLAPS, viz "row OVERLAPS row", is sufficiently constrained that we don't actually need a precedence declaration for OVERLAPS; indeed removing this declaration does not change the generated gram.c file at all. Let's remove it to avoid confusion about whether OVERLAPS has precedence or not. If we ever generalize what we allow for OVERLAPS, we might need to put back a precedence declaration for it, but we might want some other level than what it has today --- and leaving the declaration there would just risk confusion about whether that would be an incompatible change. Likewise, remove OVERLAPS from the documentation's precedence table. Per discussion with Noah Misch. Back-patch to 9.5 where we hacked up some nearby precedence decisions.
* Further adjustments to PlaceHolderVar removal.Tom Lane2015-08-07
| | | | | | | | | | | | | | | | | | | | | | | | A new test case from Andreas Seltenreich showed that we were still a bit confused about removing PlaceHolderVars during join removal. Specifically, remove_rel_from_query would remove a PHV that was used only underneath the removable join, even if the place where it's used was the join partner relation and not the join clause being deleted. This would lead to a "too late to create a new PlaceHolderInfo" error later on. We can defend against that by checking ph_eval_at to see if the PHV could possibly be getting used at some partner rel. Also improve some nearby LATERAL-related logic. I decided that the check on ph_lateral needed to take precedence over the check on ph_needed, in case there's a lateral reference underneath the join being considered. (That may be impossible, but I'm not convinced of it, and it's easy enough to defend against the case.) Also, I realized that remove_rel_from_query's logic for updating LateralJoinInfos is dead code, because we don't build those at all until after join removal. Back-patch to 9.3. Previous versions didn't have the LATERAL issues, of course, and they also didn't attempt to remove PlaceHolderInfos during join removal. (I'm starting to wonder if changing that was really such a great idea.)
* Fix attach-related race condition in shm_mq_send_bytes.Robert Haas2015-08-07
| | | | Spotted by Antonin Houska.
* Don't include low level locking code from frontend code.Andres Freund2015-08-07
| | | | | | | | | | | | | | | | | | | | | | Some frontend code like e.g. pg_xlogdump or pg_resetxlog, has to use backend headers. Unfortunately until now that code includes most of the locking code. It's generally not nice to expose such low level details, but de6fd1c898 made that a hard problem. We fall back to defining 'inline' away if the compiler doesn't support it - that can cause linker errors like on buildfarm animal pademelon if a inline function references backend only code. To fix that problem separate definitions from lock.h that are required from frontend code into lockdefs.h and use it in the relevant places. I've only removed the minimal amount of necessary definitions for now - it might turn out that we want more for other reasons. To avoid such details being exposed again put some checks against being included from frontend code into atomics.h, lock.h, lwlock.h and s_lock.h. It's otherwise fairly easy to indirectly include these headers. Discussion: 20150806070902.GE12214@awork2.anarazel.de
* Address points made in post-commit review of replication origins.Andres Freund2015-08-07
| | | | | | | | | | Amit reviewed the replication origins patch and made some good points. Address them. This fixes typos in error messages, docs and comments and adds a missing error check (although in a should-never-happen scenario). Discussion: CAA4eK1JqUBVeWWKwUmBPryFaje4190ug0y-OAUHWQ6tD83V4xg@mail.gmail.com Backpatch: 9.5, where replication origins were introduced.
* Fix old oversight in join removal logic.Tom Lane2015-08-06
| | | | | | | | | | | | | Commit 9e7e29c75ad441450f9b8287bd51c13521641e3b introduced an Assert that join removal didn't reduce the eval_at set of any PlaceHolderVar to empty. At first glance it looks like join_is_removable ensures that's true --- but actually, the loop in join_is_removable skips PlaceHolderVars that are not referenced above the join due to be removed. So, if we don't want any empty eval_at sets, the right thing to do is to delete any now-unreferenced PlaceHolderVars from the data structure entirely. Per fuzz testing by Andreas Seltenreich. Back-patch to 9.3 where the aforesaid Assert was added.
* Fix eclass_useful_for_merging to give valid results for appendrel children.Tom Lane2015-08-06
| | | | | | | | | | | | | | | | | | | | Formerly, this function would always return "true" for an appendrel child relation, because it would think that the appendrel parent was a potential join target for the child. In principle that should only lead to some inefficiency in planning, but fuzz testing by Andreas Seltenreich disclosed that it could lead to "could not find pathkey item to sort" planner errors in odd corner cases. Specifically, we would think that all columns of a child table's multicolumn index were interesting pathkeys, causing us to generate a MergeAppend path that sorts by all the columns. However, if any of those columns weren't actually used above the level of the appendrel, they would not get added to that rel's targetlist, which would result in being unable to resolve the MergeAppend's sort keys against its targetlist during createplan.c. Backpatch to 9.3. In older versions, columns of an appendrel get added to its targetlist even if they're not mentioned above the scan level, so that the failure doesn't occur. It might be worth back-patching this fix to older versions anyway, but I'll refrain for the moment.