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* Refactor sendAuthRequest.Heikki Linnakangas2016-08-18
| | | | | | | | | | This way sendAuthRequest doesn't need to know the details of all the different authentication methods. This is in preparation for adding SCRAM authentication, which will add yet another authentication request message type, with different payload. Reviewed-By: Michael Paquier Discussion: <CAB7nPqQvO4sxLFeS9D+NM3wpy08ieZdAj_6e117MQHZAfxBFsg@mail.gmail.com>
* Fix deletion of speculatively inserted TOAST on conflictAndres Freund2016-08-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | INSERT .. ON CONFLICT runs a pre-check of the possible conflicting constraints before performing the actual speculative insertion. In case the inserted tuple included TOASTed columns the ON CONFLICT condition would be handled correctly in case the conflict was caught by the pre-check, but if two transactions entered the speculative insertion phase at the same time, one would have to re-try, and the code for aborting a speculative insertion did not handle deleting the speculatively inserted TOAST datums correctly. TOAST deletion would fail with "ERROR: attempted to delete invisible tuple" as we attempted to remove the TOAST tuples using simple_heap_delete which reasoned that the given tuples should not be visible to the command that wrote them. This commit updates the heap_abort_speculative() function which aborts the conflicting tuple to use itself, via toast_delete, for deleting associated TOAST datums. Like before, the inserted toast rows are not marked as being speculative. This commit also adds a isolationtester spec test, exercising the relevant code path. Unfortunately 9.5 cannot handle two waiting sessions, and thus cannot execute this test. Reported-By: Viren Negi, Oskari Saarenmaa Author: Oskari Saarenmaa, edited a bit by me Bug: #14150 Discussion: <20160519123338.12513.20271@wrigleys.postgresql.org> Backpatch: 9.5, where ON CONFLICT was introduced
* Implement regexp_match(), a simplified alternative to regexp_matches().Tom Lane2016-08-17
| | | | | | | | | | | | | | | | | | regexp_match() is like regexp_matches(), but it disallows the 'g' flag and in consequence does not need to return a set. Instead, it returns a simple text array value, or NULL if there's no match. Previously people usually got that behavior with a sub-select, but this way is considerably more efficient. Documentation adjusted so that regexp_match() is presented first and then regexp_matches() is introduced as a more complicated version. This is a bit historically revisionist but seems pedagogically better. Still TODO: extend contrib/citext to support this function. Emre Hasegeli, reviewed by David Johnston Discussion: <CAE2gYzy42sna2ME_e3y1KLQ-4UBrB-eVF0SWn8QG39sQSeVhEw@mail.gmail.com>
* Properly re-initialize replication slot shared memory upon creation.Andres Freund2016-08-17
| | | | | | | | | | | | | | | | | | Slot creation did not clear all fields upon creation. After start the memory is zeroed, but when a physical replication slot was created in the shared memory of a previously existing logical slot, catalog_xmin would not be cleared. That in turn would prevent vacuum from doing its duties. To fix initialize all the fields. To make similar future bugs less likely, zero all of ReplicationSlotPersistentData, and re-order the rest of the initialization to be in struct member order. Analysis: Andrew Gierth Reported-By: md@chewy.com Author: Michael Paquier Discussion: <20160705173502.1398.70934@wrigleys.postgresql.org> Backpatch: 9.4, where replication slots were introduced
* Disable update_process_title by default on WindowsMagnus Hagander2016-08-17
| | | | | | | | | | The performance overhead of this can be significant on Windows, and most people don't have the tools to view it anyway as Windows does not have native support for process titles. Discussion: <0A3221C70F24FB45833433255569204D1F5BE3E8@G01JPEXMBYT05> Takayuki Tsunakawa
* Improve parsetree representation of special functions such as CURRENT_DATE.Tom Lane2016-08-16
| | | | | | | | | | | | | | We implement a dozen or so parameterless functions that the SQL standard defines special syntax for. Up to now, that was done by converting them into more or less ad-hoc constructs such as "'now'::text::date". That's messy for multiple reasons: it exposes what should be implementation details to users, and performance is worse than it needs to be in several cases. To improve matters, invent a new expression node type SQLValueFunction that can represent any of these parameterless functions. Bump catversion because this changes stored parsetrees for rules. Discussion: <30058.1463091294@sss.pgh.pa.us>
* Suppress -Wunused-result warning for strtol().Tom Lane2016-08-16
| | | | | | | | I'm not sure which bozo thought it's a problem to use strtol() only for its endptr result, but silence the warning using same method used elsewhere. Report: <f845d3a6-5328-3e2a-924f-f8e91aa2b6d2@2ndquadrant.com>
* Fix assorted places in psql to print version numbers >= 10 in new style.Tom Lane2016-08-16
| | | | | | | | | | | | | | | | | | | This is somewhat cosmetic, since as long as you know what you are looking at, "10.0" is a serviceable substitute for "10". But there is a potential for confusion between version numbers with minor numbers and those without --- we don't want people asking "why is psql saying 10.0 when my server is 10.2". Therefore, back-patch as far as practical, which turns out to be 9.3. I could have redone the patch to use fprintf(stderr) in place of psql_error(), but it seems more work than is warranted for branches that will be EOL or nearly so by the time v10 comes out. Although only psql seems to contain any code that needs this, I chose to put the support function into fe_utils, since it seems likely we'll need it in other client programs in future. (In 9.3-9.5, use dumputils.c, the predecessor of fe_utils/string_utils.c.) In HEAD, also fix the backend code that whines about loadable-library version mismatch. I don't see much need to back-patch that.
* Fix typosPeter Eisentraut2016-08-16
| | | | From: Alexander Law <exclusion@gmail.com>
* Fix possible crash due to incorrect allocation context.Robert Haas2016-08-16
| | | | | | | | | | | | | Commit af33039317ddc4a0e38a02e2255c2bf453115fd2 aimed to reduce leakage from tqueue.c, which is good. Unfortunately, by changing the memory context in which all of gather_readnext() executes, it also changed the context in which ExecShutdownGatherWorkers executes, which is not good, because that function eventually causes a call to ExecParallelRetrieveInstrumentation, which proceeds to allocate planstate->worker_instrument in a short-lived context, causing a crash. Rushabh Lathia, reviewed by Amit Kapila and by me.
* Once again allow LWLocks to be used within DSM segments.Robert Haas2016-08-15
| | | | | | | | | | Prior to commit 7882c3b0b95640e361f1533fe0f2d02e4e5d8610, it was possible to use LWLocks within DSM segments, but that commit broke this use case by switching from a doubly linked list to a circular linked list. Switch back, using a new bit of general infrastructure for maintaining lists of PGPROCs. Thomas Munro, reviewed by me.
* Stamp HEAD as 10devel.Tom Lane2016-08-15
| | | | | | | | | | This is a good bit more complicated than the average new-version stamping commit, because it includes various adjustments in pursuit of changing from three-part to two-part version numbers. It's likely some further work will be needed around that change; but this is enough to get through the regression tests, at least in Unix builds. Peter Eisentraut and Tom Lane
* Final pgindent + perltidy run for 9.6.Tom Lane2016-08-15
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* Remove bogus dependencies on NUMERIC_MAX_PRECISION.Tom Lane2016-08-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | NUMERIC_MAX_PRECISION is a purely arbitrary constraint on the precision and scale you can write in a numeric typmod. It might once have had something to do with the allowed range of a typmod-less numeric value, but at least since 9.1 we've allowed, and documented that we allowed, any value that would physically fit in the numeric storage format; which is something over 100000 decimal digits, not 1000. Hence, get rid of numeric_in()'s use of NUMERIC_MAX_PRECISION as a limit on the allowed range of the exponent in scientific-format input. That was especially silly in view of the fact that you can enter larger numbers as long as you don't use 'e' to do it. Just constrain the value enough to avoid localized overflow, and let make_result be the final arbiter of what is too large. Likewise adjust ecpg's equivalent of this code. Also get rid of numeric_recv()'s use of NUMERIC_MAX_PRECISION to limit the number of base-NBASE digits it would accept. That created a dump/restore hazard for binary COPY without doing anything useful; the wire-format limit on number of digits (65535) is about as tight as we would want. In HEAD, also get rid of pg_size_bytes()'s unnecessary intimacy with what the numeric range limit is. That code doesn't exist in the back branches. Per gripe from Aravind Kumar. Back-patch to all supported branches, since they all contain the documentation claim about allowed range of NUMERIC (cf commit cabf5d84b). Discussion: <2895.1471195721@sss.pgh.pa.us>
* Add SQL-accessible functions for inspecting index AM properties.Tom Lane2016-08-13
| | | | | | | | | | | | | | | | | | | | | Per discussion, we should provide such functions to replace the lost ability to discover AM properties by inspecting pg_am (cf commit 65c5fcd35). The added functionality is also meant to displace any code that was looking directly at pg_index.indoption, since we'd rather not believe that the bit meanings in that field are part of any client API contract. As future-proofing, define the SQL API to not assume that properties that are currently AM-wide or index-wide will remain so unless they logically must be; instead, expose them only when inquiring about a specific index or even specific index column. Also provide the ability for an index AM to override the behavior. In passing, document pg_am.amtype, overlooked in commit 473b93287. Andrew Gierth, with kibitzing by me and others Discussion: <87mvl5on7n.fsf@news-spur.riddles.org.uk>
* Doc: clarify that DROP ... CASCADE is recursive.Tom Lane2016-08-12
| | | | | | | | | | Apparently that's not obvious to everybody, so let's belabor the point. In passing, document that DROP POLICY has CASCADE/RESTRICT options (which it does, per gram.y) but they do nothing (I assume, anyway). Also update some long-obsolete commentary in gram.y. Discussion: <20160805104837.1412.84915@wrigleys.postgresql.org>
* Fix inappropriate printing of never-measured times in EXPLAIN.Tom Lane2016-08-12
| | | | | | | | | | | | | | | | | EXPLAIN (ANALYZE, TIMING OFF) would print an elapsed time of zero for a trigger function, because no measurement has been taken but it printed the field anyway. This isn't what EXPLAIN does elsewhere, so suppress it. In the same vein, EXPLAIN (ANALYZE, BUFFERS) with non-text output format would print buffer I/O timing numbers even when no measurement has been taken because track_io_timing is off. That seems not per policy, either, so change it. Back-patch to 9.2 where these features were introduced. Maksim Milyutin Discussion: <081c0540-ecaa-bd29-3fd2-6358f3b359a9@postgrespro.ru>
* Code cleanup in SyncRepWaitForLSN()Simon Riggs2016-08-12
| | | | | | | | | | Commit 14e8803f1 removed LWLocks when accessing MyProc->syncRepState but didn't clean up the surrounding code and comments. Cleanup and backpatch to 9.5, to keep code similar. Julien Rouhaud, improved by suggestion from Michael Paquier, implemented trivially by myself.
* Fix busted Assert for CREATE MATVIEW ... WITH NO DATA.Tom Lane2016-08-11
| | | | | | | | | | | | | | | | Commit 874fe3aea changed the command tag returned for CREATE MATVIEW/CREATE TABLE AS ... WITH NO DATA, but missed that there was code in spi.c that expected the command tag to always be "SELECT". Fortunately, the consequence was only an Assert failure, so this oversight should have no impact in production builds. Since this code path was evidently un-exercised, add a regression test. Per report from Shivam Saxena. Back-patch to 9.3, like the previous commit. Michael Paquier Report: <97218716-480B-4527-B5CD-D08D798A0C7B@dresources.com>
* Fix several one-byte buffer over-reads in to_numberPeter Eisentraut2016-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | Several places in NUM_numpart_from_char(), which is called from the SQL function to_number(text, text), could accidentally read one byte past the end of the input buffer (which comes from the input text datum and is not null-terminated). 1. One leading space character would be skipped, but there was no check that the input was at least one byte long. This does not happen in practice, but for defensiveness, add a check anyway. 2. Commit 4a3a1e2cf apparently accidentally doubled that code that skips one space character (so that two spaces might be skipped), but there was no overflow check before skipping the second byte. Fix by removing that duplicate code. 3. A logic error would allow a one-byte over-read when looking for a trailing sign (S) placeholder. In each case, the extra byte cannot be read out directly, but looking at it might cause a crash. The third item was discovered by Piotr Stefaniak, the first two were found and analyzed by Tom Lane and Peter Eisentraut.
* Translation updatesPeter Eisentraut2016-08-08
| | | | | Source-Git-URL: git://git.postgresql.org/git/pgtranslation/messages.git Source-Git-Hash: cda21c1d7b160b303dc21dfe9d4169f2c8064c60
* Fix two errors with nested CASE/WHEN constructs.Tom Lane2016-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ExecEvalCase() tried to save a cycle or two by passing &econtext->caseValue_isNull as the isNull argument to its sub-evaluation of the CASE value expression. If that subexpression itself contained a CASE, then *isNull was an alias for econtext->caseValue_isNull within the recursive call of ExecEvalCase(), leading to confusion about whether the inner call's caseValue was null or not. In the worst case this could lead to a core dump due to dereferencing a null pointer. Fix by not assigning to the global variable until control comes back from the subexpression. Also, avoid using the passed-in isNull pointer transiently for evaluation of WHEN expressions. (Either one of these changes would have been sufficient to fix the known misbehavior, but it's clear now that each of these choices was in itself dangerous coding practice and best avoided. There do not seem to be any similar hazards elsewhere in execQual.c.) Also, it was possible for inlining of a SQL function that implements the equality operator used for a CASE comparison to result in one CASE expression's CaseTestExpr node being inserted inside another CASE expression. This would certainly result in wrong answers since the improperly nested CaseTestExpr would be caused to return the inner CASE's comparison value not the outer's. If the CASE values were of different data types, a crash might result; moreover such situations could be abused to allow disclosure of portions of server memory. To fix, teach inline_function to check for "bare" CaseTestExpr nodes in the arguments of a function to be inlined, and avoid inlining if there are any. Heikki Linnakangas, Michael Paquier, Tom Lane Report: https://github.com/greenplum-db/gpdb/pull/327 Report: <4DDCEEB8.50602@enterprisedb.com> Security: CVE-2016-5423
* Make format() error messages consistent againPeter Eisentraut2016-08-08
| | | | 07d25a964 changed only one occurrence. Change the other one as well.
* Correct column name in information schemaPeter Eisentraut2016-08-07
| | | | | | | | | | Although the standard has routines.result_cast_character_set_name, given the naming of the surrounding columns, we concluded that this must have been a mistake and that result_cast_char_set_name was intended, so change the implementation. The documentation was already using the new name. found by Clément Prévost <prevostclement@gmail.com>
* Fix misestimation of n_distinct for a nearly-unique column with many nulls.Tom Lane2016-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If ANALYZE found no repeated non-null entries in its sample, it set the column's stadistinct value to -1.0, intending to indicate that the entries are all distinct. But what this value actually means is that the number of distinct values is 100% of the table's rowcount, and thus it was overestimating the number of distinct values by however many nulls there are. This could lead to very poor selectivity estimates, as for example in a recent report from Andreas Joseph Krogh. We should discount the stadistinct value by whatever we've estimated the nulls fraction to be. (That is what will happen if we choose to use a negative stadistinct for a column that does have repeated entries, so this code path was just inconsistent.) In addition to fixing the stadistinct entries stored by several different ANALYZE code paths, adjust the logic where get_variable_numdistinct() forces an "all distinct" estimate on the basis of finding a relevant unique index. Unique indexes don't reject nulls, so there's no reason to assume that the null fraction doesn't apply. Back-patch to all supported branches. Back-patching is a bit of a judgment call, but this problem seems to affect only a few users (else we'd have identified it long ago), and it's bad enough when it does happen that destabilizing plan choices in a worse direction seems unlikely. Patch by me, with documentation wording suggested by Dean Rasheed Report: <VisenaEmail.26.df42f82acae38a58.156463942b8@tc7-visena> Discussion: <16143.1470350371@sss.pgh.pa.us>
* Fix crash when pg_get_viewdef_name_ext() is passed a non-view relation.Tom Lane2016-08-07
| | | | | | | | Oversight in commit 976b24fb4. Andreas Seltenreich Report: <87y448l3ag.fsf@credativ.de>
* Fix TOAST access failure in RETURNING queries.Tom Lane2016-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Discussion of commit 3e2f3c2e4 exposed a problem that is of longer standing: since we don't detoast data while sticking it into a portal's holdStore for PORTAL_ONE_RETURNING and PORTAL_UTIL_SELECT queries, and we release the query's snapshot as soon as we're done loading the holdStore, later readout of the holdStore can do TOAST fetches against data that can no longer be seen by any of the session's live snapshots. This means that a concurrent VACUUM could remove the TOAST data before we can fetch it. Commit 3e2f3c2e4 exposed the problem by showing that sometimes we had *no* live snapshots while fetching TOAST data, but we'd be at risk anyway. I believe this code was all right when written, because our management of a session's exposed xmin was such that the TOAST references were safe until end of transaction. But that's no longer true now that we can advance or clear our PGXACT.xmin intra-transaction. To fix, copy the query's snapshot during FillPortalStore() and save it in the Portal; release it only when the portal is dropped. This essentially implements a policy that we must hold a relevant snapshot whenever we access potentially-toasted data. We had already come to that conclusion in other places, cf commits 08e261cbc94ce9a7 and ec543db77b6b72f2. I'd have liked to add a regression test case for this, but I didn't see a way to make one that's not unreasonably bloated; it seems to require returning a toasted value to the client, and those will be big. In passing, improve PortalRunUtility() so that it positively verifies that its ending PopActiveSnapshot() call will pop the expected snapshot, removing a rather shaky assumption about which utility commands might do their own PopActiveSnapshot(). There's no known bug here, but now that we're actively referencing the snapshot it's almost free to make this code a bit more bulletproof. We might want to consider back-patching something like this into older branches, but it would be prudent to let it prove itself more in HEAD beforehand. Discussion: <87vazemeda.fsf@credativ.de>
* Avoid crashing in GetOldestSnapshot() if there are no known snapshots.Tom Lane2016-08-07
| | | | | | | | | | | | | The sole caller expects NULL to be returned in such a case, so make it so and document it. Per reports from Andreas Seltenreich and Regina Obe. This doesn't really fix their problem, as now their RETURNING queries will say "ERROR: no known snapshots", but in any case this function should not dump core in a reasonably-foreseeable situation. Report: <87vazemeda.fsf@credativ.de> Report: <20160807051854.1427.32414@wrigleys.postgresql.org>
* Don't propagate a null subtransaction snapshot up to parent transaction.Tom Lane2016-08-07
| | | | | | | | | This oversight could cause logical decoding to fail to decode an outer transaction containing changes, if a subtransaction had an XID but no actual changes. Per bug #14279 from Marko Tiikkaja. Patch by Marko based on analysis by Andrew Gierth. Discussion: <20160804191757.1430.39011@wrigleys.postgresql.org>
* In B-tree page deletion, clean up properly after page deletion failure.Tom Lane2016-08-06
| | | | | | | | | | | | | | | | | | | | | | In _bt_unlink_halfdead_page(), we might fail to find an immediate left sibling of the target page, perhaps because of corruption of the page sibling links. The code intends to cope with this by just abandoning the deletion attempt; but what actually happens is that it fails outright due to releasing the same buffer lock twice. (And error recovery masks a second problem, which is possible leakage of a pin on another page.) Seems to have been introduced by careless refactoring in commit efada2b8e. Since there are multiple cases to consider, let's make releasing the buffer lock in the failure case the responsibility of _bt_unlink_halfdead_page() not its caller. Also, avoid fetching the leaf page's left-link again after we've dropped lock on the page. This is probably harmless, but it's not exactly good coding practice. Per report from Kyotaro Horiguchi. Back-patch to 9.4 where the faulty code was introduced. Discussion: <20160803.173116.111915228.horiguchi.kyotaro@lab.ntt.co.jp>
* Make array_to_tsvector() sort and de-duplicate the given strings.Tom Lane2016-08-05
| | | | | | | This is required for the result to be a legal tsvector value. Noted while fooling with Andreas Seltenreich's ts_delete() crash. Discussion: <87invhoj6e.fsf@credativ.de>
* Fix ts_delete(tsvector, text[]) to cope with duplicate array entries.Tom Lane2016-08-05
| | | | | | | | | | | | | Such cases either failed an Assert, or produced a corrupt tsvector in non-Assert builds, as reported by Andreas Seltenreich. The reason is that tsvector_delete_by_indices() just assumed that its input array had no duplicates. Fix by explicitly de-duping. In passing, improve some comments, and fix a number of tests for null values to use ERRCODE_NULL_VALUE_NOT_ALLOWED not ERRCODE_INVALID_PARAMETER_VALUE. Discussion: <87invhoj6e.fsf@credativ.de>
* Re-pgindent tsvector_op.c.Tom Lane2016-08-05
| | | | | Messed up by recent commits --- this is annoying me while trying to fix some bugs here.
* Change InitToastSnapshot to a macro.Robert Haas2016-08-05
| | | | | | | | | tqual.h is included in some front-end compiles, and a static inline breaks on buildfarm member castoroides. Since the macro is never referenced, it should dodge that problem, although this doesn't seem like the cleanest way of hiding things from front-end compiles. Report and review by Tom Lane; patch by me.
* Fix hard to hit race condition in heapam's tuple locking code.Andres Freund2016-08-04
| | | | | | | | | | | | As mentioned in its commit message, eca0f1db left open a race condition, where a page could be marked all-visible, after the code checked PageIsAllVisible() to pin the VM, but before the page is locked. Plug that hole. Reviewed-By: Robert Haas, Andres Freund Author: Amit Kapila Discussion: CAEepm=3fWAbWryVW9swHyLTY4sXVf0xbLvXqOwUoDiNCx9mBjQ@mail.gmail.com Backpatch: -
* Fix bogus coding in WaitForBackgroundWorkerShutdown().Tom Lane2016-08-04
| | | | | | | | | | | | | | | | Some conditions resulted in "return" directly out of a PG_TRY block, which left the exception stack dangling, and to add insult to injury failed to restore the state of set_latch_on_sigusr1. This is a bug only in 9.5; in HEAD it was accidentally fixed by commit db0f6cad4, which removed the surrounding PG_TRY block. However, I (tgl) chose to apply the patch to HEAD as well, because the old coding was gratuitously different from WaitForBackgroundWorkerStartup(), and there would indeed have been no bug if it were done like that to start with. Dmitry Ivanov Discussion: <1637882.WfYN5gPf1A@abook>
* Prevent "snapshot too old" from trying to return pruned TOAST tuples.Robert Haas2016-08-03
| | | | | | | | | | | | | Previously, we tested for MVCC snapshots to see whether they were too old, but not TOAST snapshots, which can lead to complaints about missing TOAST chunks if those chunks are subject to early pruning. Ideally, the threshold lsn and timestamp for a TOAST snapshot would be that of the corresponding MVCC snapshot, but since we have no way of deciding which MVCC snapshot was used to fetch the TOAST pointer, use the oldest active or registered snapshot instead. Reported by Andres Freund, who also sketched out what the fix should look like. Patch by me, reviewed by Amit Kapila.
* Make INSERT-from-multiple-VALUES-rows handle targetlist indirection better.Tom Lane2016-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, if an INSERT with multiple rows of VALUES had indirection (array subscripting or field selection) in its target-columns list, the parser handled that by applying transformAssignedExpr() to each element of each VALUES row independently. This led to having ArrayRef assignment nodes or FieldStore nodes in each row of the VALUES RTE. That works for simple cases, but in bug #14265 Nuri Boardman points out that it fails if there are multiple assignments to elements/fields of the same target column. For such cases to work, rewriteTargetListIU() has to nest the ArrayRefs or FieldStores together to produce a single expression to be assigned to the column. But it failed to find them in the top-level targetlist and issued an error about "multiple assignments to same column". We could possibly fix this by teaching the rewriter to apply rewriteTargetListIU to each VALUES row separately, but that would be messy (it would change the output rowtype of the VALUES RTE, for example) and inefficient. Instead, let's fix the parser so that the VALUES RTE outputs are just the user-specified values, cast to the right type if necessary, and then the ArrayRefs or FieldStores are applied in the top-level targetlist to Vars representing the RTE's outputs. This is the same parsetree representation already used for similar cases with INSERT/SELECT syntax, so it allows simplifications in ruleutils.c, which no longer needs to treat INSERT-from-multiple-VALUES as its own special case. This implementation works by applying transformAssignedExpr to the VALUES entries as before, and then stripping off any ArrayRefs or FieldStores it adds. With lots of VALUES rows it would be noticeably more efficient to not add those nodes in the first place. But that's just an optimization not a bug fix, and there doesn't seem to be any good way to do it without significant refactoring. (A non-invasive answer would be to apply transformAssignedExpr + stripping to just the first VALUES row, and then just forcibly cast remaining rows to the same data types exposed in the first row. But this way would lead to different, not-INSERT-specific errors being reported in casting failure cases, so it doesn't seem very nice.) So leave that for later; this patch at least isn't making the per-row parsing work worse, and it does make the finished parsetree smaller, saving rewriter and planner work. Catversion bump because stored rules containing such INSERTs would need to change. Because of that, no back-patch, even though this is a very long-standing bug. Report: <20160727005725.7438.26021@wrigleys.postgresql.org> Discussion: <9578.1469645245@sss.pgh.pa.us>
* Do not let PostmasterContext survive into background workers.Tom Lane2016-08-03
| | | | | | | | | | | | | | | | | | | | | We don't want postmaster child processes to contain a copy of the postmaster's PostmasterContext. That would be a waste of memory at least, and at worst a security issue, since there are copies of the semi-sensitive pg_hba and pg_ident data in there. All other child process types delete the PostmasterContext after forking, but the original coding of the background worker patch (commit da07a1e85) did not do so. It appears that the only reason for that was to avoid copying the bgworker's MyBgworkerEntry out of that context; but the couple of additional statements needed to do so are hardly good justification for it. Hence, copy that data and then clear the context as other child processes do. Because this patch changes the memory context in which a bgworker function gains control, back-patching it would be a bit risky, so we won't fix this in back branches. The "security" complaint is pretty thin anyway for generic bgworkers; only with the introduction of parallel query is there any question of running untrusted code in a bgworker process. Discussion: <14111.1470082717@sss.pgh.pa.us>
* Add missing casts in information schemaPeter Eisentraut2016-08-03
| | | | From: Clément Prévost <prevostclement@gmail.com>
* C comment: fix typoBruce Momjian2016-08-03
| | | | Author: Amit Langote
* Remove duplicate InitPostmasterChild() call while starting a bgworker.Tom Lane2016-08-02
| | | | | | | | | | | This is apparently harmless on Windows, but on Unix it results in an assertion failure. We'd not noticed because this code doesn't get used on Unix unless you build with -DEXEC_BACKEND. Bug was evidently introduced by sloppy refactoring in commit 31c453165. Thomas Munro Discussion: <CAEepm=1VOnbVx4wsgQFvj94hu9jVt2nVabCr7QiooUSvPJXkgQ@mail.gmail.com>
* Block interrupts during HandleParallelMessages().Tom Lane2016-08-02
| | | | | | | | | | | | | | | | As noted by Alvaro, there are CHECK_FOR_INTERRUPTS() calls in the shm_mq.c functions called by HandleParallelMessages(). I believe they're all unreachable since we always pass nowait = true, but it doesn't seem like a great idea to assume that no such call will ever be reachable from HandleParallelMessages(). If that did happen, there would be a risk of a recursive call to HandleParallelMessages(), which it does not appear to be designed for --- for example, there's nothing that would prevent out-of-order processing of received messages. And certainly such cases cannot easily be tested. So let's prevent it by holding off interrupts for the duration of the function. Back-patch to 9.5 which contains identical code. Discussion: <14869.1470083848@sss.pgh.pa.us>
* Change minimum max_worker_processes from 1 to 0Peter Eisentraut2016-08-02
| | | | | Setting it to 0 is probably not useful in practice, but it allows testing of situations without available background worker slots.
* Minor cleanup for access/transam/parallel.c.Tom Lane2016-08-01
| | | | | | | | | | | | | | | | | | | | ParallelMessagePending *must* be marked volatile, because it's set by a signal handler. On the other hand, it's pointless for HandleParallelMessageInterrupt to save/restore errno; that must be, and is, done at the outer level of the SIGUSR1 signal handler. Calling CHECK_FOR_INTERRUPTS() inside HandleParallelMessages, which itself is called from CHECK_FOR_INTERRUPTS(), seems both useless and hazardous. The comment claiming that this is needed to handle the error queue going away is certainly misguided, in any case. Improve a couple of error message texts, and use ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE to report loss of parallel worker connection, since that's what's used in e.g. tqueue.c. (Maybe it would be worth inventing a dedicated ERRCODE for this type of failure? But I do not think ERRCODE_INTERNAL_ERROR is appropriate.) Minor stylistic cleanups.
* Don't CHECK_FOR_INTERRUPTS between WaitLatch and ResetLatch.Tom Lane2016-08-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | This coding pattern creates a race condition, because if an interesting interrupt happens after we've checked InterruptPending but before we reset our latch, the latch-setting done by the signal handler would get lost, and then we might block at WaitLatch in the next iteration without ever noticing the interrupt condition. You can put the CHECK_FOR_INTERRUPTS before WaitLatch or after ResetLatch, but not between them. Aside from fixing the bugs, add some explanatory comments to latch.h to perhaps forestall the next person from making the same mistake. In HEAD, also replace gather_readnext's direct call of HandleParallelMessages with CHECK_FOR_INTERRUPTS. It does not seem clean or useful for this one caller to bypass ProcessInterrupts and go straight to HandleParallelMessages; not least because that fails to consider the InterruptPending flag, resulting in useless work both here (if InterruptPending isn't set) and in the next CHECK_FOR_INTERRUPTS call (if it is). This thinko seems to have been introduced in the initial coding of storage/ipc/shm_mq.c (commit ec9037df2), and then blindly copied into all the subsequent parallel-query support logic. Back-patch relevant hunks to 9.4 to extirpate the error everywhere. Discussion: <1661.1469996911@sss.pgh.pa.us>
* Code review for tqueue.c: fix memory leaks, speed it up, other fixes.Tom Lane2016-07-31
| | | | | | | | | | | | | | | | | | | | When doing record typmod remapping, tqueue.c did fresh catalog lookups for each tuple it processed, which was pretty horrible performance-wise (it seemed to about halve the already none-too-quick speed of bulk reads in parallel mode). Worse, it insisted on putting bits of that data into TopMemoryContext, from where it never freed them, causing a session-lifespan memory leak. (I suppose this was coded with the idea that the sender process would quit after finishing the query --- but the receiver uses the same code.) Restructure to avoid repetitive catalog lookups and to keep that data in a query-lifespan context, in or below the context where the TQueueDestReceiver or TupleQueueReader itself lives. Fix some other bugs such as continuing to use a tupledesc after releasing our refcount on it. Clean up cavalier datatype choices (typmods are int32, please, not int, and certainly not Oid). Improve comments and error message wording.
* Fix worst memory leaks in tqueue.c.Tom Lane2016-07-29
| | | | | | | | | | | | | | | | | | | | | | | | | TupleQueueReaderNext() leaks like a sieve if it has to do any tuple disassembly/reconstruction. While we could try to clean up its allocations piecemeal, it seems like a better idea just to insist that it should be run in a short-lived memory context, so that any transient space goes away automatically. I chose to have nodeGather.c switch into its existing per-tuple context before the call, rather than inventing a separate context inside tqueue.c. This is sufficient to stop all leakage in the simple case I exhibited earlier today (see link below), but it does not deal with leaks induced in more complex cases by tqueue.c's insistence on using TopMemoryContext for data that it's not actually trying hard to keep track of. That issue is intertwined with another major source of inefficiency, namely failure to cache lookup results across calls, so it seems best to deal with it separately. In passing, improve some comments, and modify gather_readnext's method for deciding when it's visited all the readers so that it's more obviously correct. (I'm not actually convinced that the previous code *is* correct in the case of a reader deletion; it certainly seems fragile.) Discussion: <32763.1469821037@sss.pgh.pa.us>
* Fix tqueue.c's range-remapping code.Tom Lane2016-07-29
| | | | It's depressingly clear that nobody ever tested this.
* Eliminate a few more user-visible "cache lookup failed" errors.Robert Haas2016-07-29
| | | | Michael Paquier