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* Make real sure we don't reassociate joins into or out of SEMI/ANTI joins.Tom Lane2015-08-05
| | | | | | | | | | | | | | | | Per the discussion in optimizer/README, it's unsafe to reassociate anything into or out of the RHS of a SEMI or ANTI join. An example from Piotr Stefaniak showed that join_is_legal() wasn't sufficiently enforcing this rule, so lock it down a little harder. I couldn't find a reasonably simple example of the optimizer trying to do this, so no new regression test. (Piotr's example involved the random search in GEQO accidentally trying an invalid case and triggering a sanity check way downstream in clause selectivity estimation, which did not seem like a sequence of events that would be useful to memorialize in a regression test as-is.) Back-patch to all active branches.
* Fix debug message output when connecting to a logical slot.Andres Freund2015-08-05
| | | | | | | | | | Previously the message erroneously printed the same LSN twice as the assignment to the start_lsn variable was before the message. Correct that. Reported-By: Marko Tiikkaja Author: Marko Tiikkaja Backpatch: 9.5, where logical decoding was introduced
* Fix bogus "out of memory" reports in tuplestore.c.Tom Lane2015-08-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tuplesort/tuplestore memory management logic assumed that the chunk allocation overhead for its memtuples array could not increase when increasing the array size. This is and always was true for tuplesort, but we (I, I think) blindly copied that logic into tuplestore.c without noticing that the assumption failed to hold for the much smaller array elements used by tuplestore. Given rather small work_mem, this could result in an improper complaint about "unexpected out-of-memory situation", as reported by Brent DeSpain in bug #13530. The easiest way to fix this is just to increase tuplestore's initial array size so that the assumption holds. Rather than relying on magic constants, though, let's export a #define from aset.c that represents the safe allocation threshold, and make tuplestore's calculation depend on that. Do the same in tuplesort.c to keep the logic looking parallel, even though tuplesort.c isn't actually at risk at present. This will keep us from breaking it if we ever muck with the allocation parameters in aset.c. Back-patch to all supported versions. The error message doesn't occur pre-9.3, not so much because the problem can't happen as because the pre-9.3 tuplestore code neglected to check for it. (The chance of trouble is a great deal larger as of 9.3, though, due to changes in the array-size-increasing strategy.) However, allowing LACKMEM() to become true unexpectedly could still result in less-than-desirable behavior, so let's patch it all the way back.
* Fix a PlaceHolderVar-related oversight in star-schema planning patch.Tom Lane2015-08-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit b514a7460d9127ddda6598307272c701cbb133b7, I changed the planner so that it would allow nestloop paths to remain partially parameterized, ie the inner relation might need parameters from both the current outer relation and some upper-level outer relation. That's fine so long as we're talking about distinct parameters; but the patch also allowed creation of nestloop paths for cases where the inner relation's parameter was a PlaceHolderVar whose eval_at set included the current outer relation and some upper-level one. That does *not* work. In principle we could allow such a PlaceHolderVar to be evaluated at the lower join node using values passed down from the upper relation along with values from the join's own outer relation. However, nodeNestloop.c only supports simple Vars not arbitrary expressions as nestloop parameters. createplan.c is also a few bricks shy of being able to handle such cases; it misplaces the PlaceHolderVar parameters in the plan tree, which is why the visible symptoms of this bug are "plan should not reference subplan's variable" and "failed to assign all NestLoopParams to plan nodes" planner errors. Adding the necessary complexity to make this work doesn't seem like it would be repaid in significantly better plans, because in cases where such a PHV exists, there is probably a corresponding join order constraint that would allow a good plan to be found without using the star-schema exception. Furthermore, adding complexity to nodeNestloop.c would create a run-time penalty even for plans where this whole consideration is irrelevant. So let's just reject such paths instead. Per fuzz testing by Andreas Seltenreich; the added regression test is based on his example query. Back-patch to 9.2, like the previous patch.
* Cap wal_buffers to avoid a server crash when it's set very large.Robert Haas2015-08-04
| | | | | | | | | | It must be possible to multiply wal_buffers by XLOG_BLCKSZ without overflowing int, or calculations in StartupXLOG will go badly wrong and crash the server. Avoid that by imposing a maximum value on wal_buffers. This will be just under 2GB, assuming the usual value for XLOG_BLCKSZ. Josh Berkus, per an analysis by Andrew Gierth.
* Update comment to match behavior of latest code.Robert Haas2015-08-04
| | | | Peter Geoghegan
* RLS: Keep deny policy when only restrictive existStephen Frost2015-08-03
| | | | | | | | | | | | | | | Only remove the default deny policy when a permissive policy exists (either from the hook or defined by the user). If only restrictive policies exist then no rows will be visible, as restrictive policies shouldn't make rows visible. To address this requirement, a single "USING (true)" permissive policy can be created. Update the test_rls_hooks regression tests to create the necessary "USING (true)" permissive policy. Back-patch to 9.5 where RLS was added. Per discussion with Dean.
* Translation updatesPeter Eisentraut2015-08-03
| | | | | Source-Git-URL: git://git.postgresql.org/git/pgtranslation/messages.git Source-Git-Hash: 01a9485e7f9d18e1195250ec68634f1d3c9497f6
* Make recovery rename tablespace_map to *.old if backup_label is not present.Fujii Masao2015-08-03
| | | | | | | | | | | | | | | If tablespace_map file is present without backup_label file, there is no use of such file. There is no harm in retaining it, but it is better to get rid of the map file so that we don't have any redundant file in data directory and it will avoid any sort of confusion. It seems prudent though to just rename the file out of the way rather than delete it completely, also we ignore any error that occurs in rename operation as even if map file is present without backup_label file, it is harmless. Back-patch to 9.5 where tablespace_map file was introduced. Amit Kapila, reviewed by Robert Haas, Alvaro Herrera and me.
* Fix a number of places that produced XX000 errors in the regression tests.Tom Lane2015-08-02
| | | | | | | | | | | | | | | | | | | | It's against project policy to use elog() for user-facing errors, or to omit an errcode() selection for errors that aren't supposed to be "can't happen" cases. Fix all the violations of this policy that result in ERRCODE_INTERNAL_ERROR log entries during the standard regression tests, as errors that can reliably be triggered from SQL surely should be considered user-facing. I also looked through all the files touched by this commit and fixed other nearby problems of the same ilk. I do not claim to have fixed all violations of the policy, just the ones in these files. In a few places I also changed existing ERRCODE choices that didn't seem particularly appropriate; mainly replacing ERRCODE_SYNTAX_ERROR by something more specific. Back-patch to 9.5, but no further; changing ERRCODE assignments in stable branches doesn't seem like a good idea.
* Avoid calling memcpy() with a NULL source pointer and count == 0.Tom Lane2015-08-02
| | | | | | | | | | | | | | | | As in commit 0a52d378b03b7d5a, avoid doing something that has undefined results according to the C standard, even though in practice there does not seem to be any problem with it. This fixes two places in numeric.c that demonstrably could call memcpy() with such arguments. I looked through that file and didn't see any other places with similar hazards; this is not to claim that there are not such places in other files. Per report from Piotr Stefaniak. Back-patch to 9.5 which is where the previous commit was added. We're more or less setting a precedent that we will not worry about this type of issue in pre-9.5 branches unless someone demonstrates a problem in the field.
* Fix incorrect order of lock file removal and failure to close() sockets.Tom Lane2015-08-02
| | | | | | | | | | | | | | | | | | | | | | | | | Commit c9b0cbe98bd783e24a8c4d8d8ac472a494b81292 accidentally broke the order of operations during postmaster shutdown: it resulted in removing the per-socket lockfiles after, not before, postmaster.pid. This creates a race-condition hazard for a new postmaster that's started immediately after observing that postmaster.pid has disappeared; if it sees the socket lockfile still present, it will quite properly refuse to start. This error appears to be the explanation for at least some of the intermittent buildfarm failures we've seen in the pg_upgrade test. Another problem, which has been there all along, is that the postmaster has never bothered to close() its listen sockets, but has just allowed them to close at process death. This creates a different race condition for an incoming postmaster: it might be unable to bind to the desired listen address because the old postmaster is still incumbent. This might explain some odd failures we've seen in the past, too. (Note: this is not related to the fact that individual backends don't close their client communication sockets. That behavior is intentional and is not changed by this patch.) Fix by adding an on_proc_exit function that closes the postmaster's ports explicitly, and (in 9.3 and up) reshuffling the responsibility for where to unlink the Unix socket files. Lock file unlinking can stay where it is, but teach it to unlink the lock files in reverse order of creation.
* Fix race condition that lead to WALInsertLock deadlock with commit_delay.Heikki Linnakangas2015-08-02
| | | | | | | | | | | | | | | | | If a call to WaitForXLogInsertionsToFinish() returned a value in the middle of a page, and another backend then started to insert a record to the same page, and then you called WaitXLogInsertionsToFinish() again, the second call might return a smaller value than the first call. The problem was in GetXLogBuffer(), which always updated the insertingAt value to the beginning of the requested page, not the actual requested location. Because of that, the second call might return a xlog pointer to the beginning of the page, while the first one returned a later position on the same page. XLogFlush() performs two calls to WaitXLogInsertionsToFinish() in succession, and holds WALWriteLock on the second call, which can deadlock if the second call to WaitXLogInsertionsToFinish() blocks. Reported by Spiros Ioannou. Backpatch to 9.4, where the more scalable WALInsertLock mechanism, and this bug, was introduced.
* Micro optimize LWLockAttemptLock() a bit.Andres Freund2015-08-02
| | | | | | | | | | | | LWLockAttemptLock pointlessly read the lock's state in every loop iteration, even though pg_atomic_compare_exchange_u32() returns the old value. Instead do that only once before the loop iteration. Additionally there's no need to have the expected_state variable, old_state mostly had the same value anyway. Noticed-By: Heikki Linnakangas Backpatch: 9.5, no reason to let the branches diverge at this point
* Fix issues around the "variable" support in the lwlock infrastructure.Andres Freund2015-08-02
| | | | | | | | | | | | | | | | | | | | | | | | | The lwlock scalability work introduced two race conditions into the lwlock variable support provided for xlog.c. First, and harmlessly on most platforms, it set/read the variable without the spinlock in some places. Secondly, due to the removal of the spinlock, it was possible that a backend missed changes to the variable's state if it changed in the wrong moment because checking the lock's state, the variable's state and the queuing are not protected by a single spinlock acquisition anymore. To fix first move resetting the variable's from LWLockAcquireWithVar to WALInsertLockRelease, via a new function LWLockReleaseClearVar. That prevents issues around waiting for a variable's value to change when a new locker has acquired the lock, but not yet set the value. Secondly re-check that the variable hasn't changed after enqueing, that prevents the issue that the lock has been released and already re-acquired by the time the woken up backend checks for the lock's state. Reported-By: Jeff Janes Analyzed-By: Heikki Linnakangas Reviewed-By: Heikki Linnakangas Discussion: 5592DB35.2060401@iki.fi Backpatch: 9.5, where the lwlock scalability went in
* Fix some planner issues with degenerate outer join clauses.Tom Lane2015-08-01
| | | | | | | | | | | | | An outer join clause that didn't actually reference the RHS (perhaps only after constant-folding) could confuse the join order enforcement logic, leading to wrong query results. Also, nested occurrences of such things could trigger an Assertion that on reflection seems incorrect. Per fuzz testing by Andreas Seltenreich. The practical use of such cases seems thin enough that it's not too surprising we've not heard field reports about it. This has been broken for a long time, so back-patch to all active branches.
* Teach predtest.c that "foo" implies "foo IS NOT NULL".Tom Lane2015-08-01
| | | | | | | | | | | Per complaint from Peter Holzer. It's useful to cover this special case, since for a boolean variable "foo", earlier parts of the planner will have reduced variants like "foo = true" to just "foo", and thus we may fail to recognize the applicability of a partial index with predicate "foo IS NOT NULL". Back-patch to 9.5, but not further; given the lack of previous complaints this doesn't seem like behavior to change in stable branches.
* Fix an oversight in checking whether a join with LATERAL refs is legal.Tom Lane2015-07-31
| | | | | | | | | | | | | | | In many cases, we can implement a semijoin as a plain innerjoin by first passing the righthand-side relation through a unique-ification step. However, one of the cases where this does NOT work is where the RHS has a LATERAL reference to the LHS; that makes the RHS dependent on the LHS so that unique-ification is meaningless. joinpath.c understood this, and so would not generate any join paths of this kind ... but join_is_legal neglected to check for the case, so it would think that we could do it. The upshot would be a "could not devise a query plan for the given query" failure once we had failed to generate any join paths at all for the bogus join pair. Back-patch to 9.3 where LATERAL was added.
* Fix broken assertion in BRIN codeAlvaro Herrera2015-07-30
| | | | | | | | | | | | | | | | | | | The code was assuming that any NULL value in scan keys was due to IS NULL or IS NOT NULL, but it turns out to be possible to get them with other operators too, if they are used in contrived-enough ways. Easiest way out of the problem seems to check explicitely for the IS NOT NULL flag, instead of assuming it must be set if the IS NULL flag is not set, when a null scan key is found; if neither flag is set, follow the lead of other index AMs and assume that all indexable operators must be strict, and thus the query is never satisfiable. Also, add a comment to try and lure some future hacker into improving analysis of scan keys in brin. Per report from Andreas Seltenreich; diagnosis by Tom Lane. Backpatch to 9.5. Discussion: http://www.postgresql.org/message-id/20646.1437919632@sss.pgh.pa.us
* Use appropriate command type when retrieving relation's policies.Joe Conway2015-07-30
| | | | | | | | | | | | | When retrieving policies, if not working on the root target relation, we actually want the relation's SELECT policies, regardless of the top level query command type. For example in UPDATE t1...FROM t2 we need to apply t1's UPDATE policies and t2's SELECT policies. Previously top level query command type was applied to all relations, which was wrong. Add some regression coverage to ensure we don't violate this principle in the future. Report and patch by Dean Rasheed. Cherry picked from larger refactoring patch and tweaked by me. Back-patched to 9.5 where RLS was introduced.
* Avoid some zero-divide hazards in the planner.Tom Lane2015-07-30
| | | | | | | | | | | | | | | | | | | | | | | | | Although I think on all modern machines floating division by zero results in Infinity not SIGFPE, we still don't want infinities running around in the planner's costing estimates; too much risk of that leading to insane behavior. grouping_planner() failed to consider the possibility that final_rel might be known dummy and hence have zero rowcount. (I wonder if it would be better to set a rows estimate of 1 for dummy relations? But at least in the back branches, changing this convention seems like a bad idea, so I'll leave that for another day.) Make certain that get_variable_numdistinct() produces a nonzero result. The case that can be shown to be broken is with stadistinct < 0.0 and small ntuples; we did not prevent the result from rounding to zero. For good luck I applied clamp_row_est() to all the nonconstant return values. In ExecChooseHashTableSize(), Assert that we compute positive nbuckets and nbatch. I know of no reason to think this isn't the case, but it seems like a good safety check. Per reports from Piotr Stefaniak. Back-patch to all active branches.
* Create new ParseExprKind for use by policy expressions.Joe Conway2015-07-29
| | | | | | | | | | | Policy USING and WITH CHECK expressions were using EXPR_KIND_WHERE for parse analysis, which results in inappropriate ERROR messages when the expression contains unsupported constructs such as aggregates. Create a new ParseExprKind called EXPR_KIND_POLICY and tailor the related messages to fit. Reported by Noah Misch. Reviewed by Dean Rasheed, Alvaro Herrera, and Robert Haas. Back-patch to 9.5 where RLS was introduced.
* Add missing post create and alter hooks to policy objects.Joe Conway2015-07-29
| | | | | | AlterPolicy() and CreatePolicy() lacked their respective hook invocations. Noted by Noah Misch, review by Dean Rasheed. Back-patch to 9.5 where RLS was introduced.
* Remove outdated comment in LWLockDequeueSelf's header.Andres Freund2015-07-29
| | | | | Noticed-By: Robert Haas Backpatch: 9.5, where the function was added
* Fix typo in comment.Heikki Linnakangas2015-07-29
| | | | Amit Langote
* Suppress "variable may be used uninitialized" warning.Tom Lane2015-07-28
| | | | Also re-pgindent, just because I'm a neatnik.
* Disallow converting a table to a view if row security is present.Joe Conway2015-07-28
| | | | | | | | | | | | When DefineQueryRewrite() is about to convert a table to a view, it checks the table for features unavailable to views. For example, it rejects tables having triggers. It omits to reject tables having relrowsecurity or a pg_policy record. Fix that. To faciliate the repair, invent relation_has_policies() which indicates the presence of policies on a relation even when row security is disabled for that relation. Reported by Noah Misch. Patch by me, review by Stephen Frost. Back-patch to 9.5 where RLS was introduced.
* Create a pg_shdepend entry for each role in TO clause of policies.Joe Conway2015-07-28
| | | | | | | | | CreatePolicy() and AlterPolicy() omit to create a pg_shdepend entry for each role in the TO clause. Fix this by creating a new shared dependency type called SHARED_DEPENDENCY_POLICY and assigning it to each role. Reported by Noah Misch. Patch by me, reviewed by Alvaro Herrera. Back-patch to 9.5 where RLS was introduced.
* Only adjust negative indexes in json_get up to the length of the path.Andrew Dunstan2015-07-28
| | | | | | | | The previous code resulted in memory access beyond the path bounds. The cure is to move it into a code branch that checks the value of lex_level is within the correct bounds. Bug reported and diagnosed by Piotr Stefaniak.
* Reduce chatter from signaling of autovacuum workers.Tom Lane2015-07-28
| | | | | | | | | | | | | | | | | | | | Don't print a WARNING if we get ESRCH from a kill() that's attempting to cancel an autovacuum worker. It's possible (and has been seen in the buildfarm) that the worker is already gone by the time we are able to execute the kill, in which case the failure is harmless. About the only plausible reason for reporting such cases would be to help debug corrupted lock table contents, but this is hardly likely to be the most important symptom if that happens. Moreover issuing a WARNING might scare users more than is warranted. Also, since sending a signal to an autovacuum worker is now entirely a routine thing, and the worker will log the query cancel on its end anyway, reduce the message saying we're doing that from LOG to DEBUG1 level. Very minor cosmetic cleanup as well. Since the main practical reason for doing this is to avoid unnecessary buildfarm failures, back-patch to all active branches.
* Plug RLS related information leak in pg_stats view.Joe Conway2015-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The pg_stats view is supposed to be restricted to only show rows about tables the user can read. However, it sometimes can leak information which could not otherwise be seen when row level security is enabled. Fix that by not showing pg_stats rows to users that would be subject to RLS on the table the row is related to. This is done by creating/using the newly introduced SQL visible function, row_security_active(). Along the way, clean up three call sites of check_enable_rls(). The second argument of that function should only be specified as other than InvalidOid when we are checking as a different user than the current one, as in when querying through a view. These sites were passing GetUserId() instead of InvalidOid, which can cause the function to return incorrect results if the current user has the BYPASSRLS privilege and row_security has been set to OFF. Additionally fix a bug causing RI Trigger error messages to unintentionally leak information when RLS is enabled, and other minor cleanup and improvements. Also add WITH (security_barrier) to the definition of pg_stats. Bumped CATVERSION due to new SQL functions and pg_stats view definition. Back-patch to 9.5 where RLS was introduced. Reported by Yaroslav. Patch by Joe Conway and Dean Rasheed with review and input by Michael Paquier and Stephen Frost.
* Remove ssl renegotiation support.Andres Freund2015-07-28
| | | | | | | | | | | | | | | | | | | | | | While postgres' use of SSL renegotiation is a good idea in theory, it turned out to not work well in practice. The specification and openssl's implementation of it have lead to several security issues. Postgres' use of renegotiation also had its share of bugs. Additionally OpenSSL has a bunch of bugs around renegotiation, reported and open for years, that regularly lead to connections breaking with obscure error messages. We tried increasingly complex workarounds to get around these bugs, but we didn't find anything complete. Since these connection breakages often lead to hard to debug problems, e.g. spuriously failing base backups and significant latency spikes when synchronous replication is used, we have decided to change the default setting for ssl renegotiation to 0 (disabled) in the released backbranches and remove it entirely in 9.5 and master. Author: Andres Freund Discussion: 20150624144148.GQ4797@alap3.anarazel.de Backpatch: 9.5 and master, 9.0-9.4 get a different patch
* Remove an unsafe Assert, and explain join_clause_is_movable_into() better.Tom Lane2015-07-28
| | | | | | | | | | | | | | join_clause_is_movable_into() is approximate, in the sense that it might sometimes return "false" when actually it would be valid to push the given join clause down to the specified level. This is okay ... but there was an Assert in get_joinrel_parampathinfo() that's only safe if the answers are always exact. Comment out the Assert, and add a bunch of commentary to clarify what's going on. Per fuzz testing by Andreas Seltenreich. The added regression test is a pretty silly query, but it's based on his crasher example. Back-patch to 9.2 where the faulty logic was introduced.
* Another attempt at fixing memory leak in xlogreader.Heikki Linnakangas2015-07-28
| | | | | | max_block_id is also reset between reading records. Michael Paquier
* Improve RLS handling in copy.cStephen Frost2015-07-27
| | | | | | | | | | | | | | | To avoid a race condition where the relation being COPY'd could be changed into a view or otherwise modified, keep the original lock on the relation. Further, fully qualify the relation when building the query up. Also remove the poorly thought-out Assert() and check the entire relationOids list as, post-RLS, there can certainly be multiple relations involved and the planner does not guarantee their ordering. Per discussion with Noah and Andres. Back-patch to 9.5 where RLS was introduced.
* Further code review for pg_stat_ssl patch.Tom Lane2015-07-27
| | | | | | | | Fix additional bogosity in commit 9029f4b37406b21a. Include the BackendSslStatusBuffer in the BackendStatusShmemSize calculation, avoid ugly and error-prone casts to char* and back, put related code stanzas into a consistent order (and fix a couple of previous instances of that sin). All cosmetic except for the size oversight.
* Fix pointer-arithmetic thinko in pg_stat_ssl patch.Tom Lane2015-07-27
| | | | | Nasty memory-stomp bug in commit 9029f4b37406b21a. It's not apparent how this survived even cursory testing :-(. Per report from Peter Holzer.
* Don't assume that PageIsEmpty() returns true on an all-zeros page.Heikki Linnakangas2015-07-27
| | | | | | | | It does currently, and I don't see us changing that any time soon, but we don't make that assumption anywhere else. Per Tom Lane's suggestion. Backpatch to 9.2, like the previous patch that added this assumption.
* Fix memory leak in xlogreader facility.Heikki Linnakangas2015-07-27
| | | | | | | XLogReaderFree failed to free the per-block data buffers, when they happened to not be used by the latest read WAL record. Michael Paquier. Backpatch to 9.5, where the per-block buffers were added.
* Reuse all-zero pages in GIN.Heikki Linnakangas2015-07-27
| | | | | | | | | | In GIN, an all-zeros page would be leaked forever, and never reused. Just add them to the FSM in vacuum, and they will be reinitialized when grabbed from the FSM. On master and 9.5, attempting to access the page's opaque struct also caused an assertion failure, although that was otherwise harmless. Reported by Jeff Janes. Backpatch to all supported versions.
* Fix handling of all-zero pages in SP-GiST vacuum.Heikki Linnakangas2015-07-27
| | | | | | | | | | | | SP-GiST initialized an all-zeros page at vacuum, but that was not WAL-logged, which is not safe. You might get a torn page write, when it gets flushed to disk, and end-up with a half-initialized index page. To fix, leave it in the all-zeros state, and add it to the FSM. It will be initialized when reused. Also don't set the page-deleted flag when recycling an empty page. That was also not WAL-logged, and a torn write of that would cause the page to have an invalid checksum. Backpatch to 9.2, where SP-GiST indexes were added.
* Avoid calling PageGetSpecialPointer() on an all-zeros page.Heikki Linnakangas2015-07-27
| | | | | | | That was otherwise harmless, but tripped the new assertion in PageGetSpecialPointer(). Reported by Amit Langote. Backpatch to 9.5, where the assertion was added.
* Remove false comment about speculative insertion.Heikki Linnakangas2015-07-27
| | | | | | | | There is no full discussion of speculative insertions in the executor README. There is a high-level explanation in execIndexing.c, but it doesn't seem necessary to refer it from here. Peter Geoghegan
* Fix oversight in flattening of subqueries with empty FROM.Tom Lane2015-07-26
| | | | | | | | | | | | | | | | | I missed a restriction that commit f4abd0241de20d5d6a79b84992b9e88603d44134 should have enforced: we can't pull up an empty-FROM subquery if it's under an outer join, because then we'd need to wrap its output columns in PlaceHolderVars. As the code currently stands, the PHVs end up with empty relid sets, which doesn't work (and is correctly caught by an Assert). It's possible that this could be fixed by assigning the PHVs the relid sets of the parent FromExpr/JoinExpr, but getting that to work is more complication than I care to add right now; indeed it's likely that we'll never bother, since pulling up empty-FROM subqueries is a rather marginal optimization anyway. Per report from Andreas Seltenreich. Back-patch to 9.5 where the faulty code was added.
* Make entirely-dummy appendrels get marked as such in set_append_rel_size.Tom Lane2015-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The planner generally expects that the estimated rowcount of any relation is at least one row, *unless* it has been proven empty by constraint exclusion or similar mechanisms, which is marked by installing a dummy path as the rel's cheapest path (cf. IS_DUMMY_REL). When I split up allpaths.c's processing of base rels into separate set_base_rel_sizes and set_base_rel_pathlists steps, the intention was that dummy rels would get marked as such during the "set size" step; this is what justifies an Assert in indxpath.c's get_loop_count that other relations should either be dummy or have positive rowcount. Unfortunately I didn't get that quite right for append relations: if all the child rels have been proven empty then set_append_rel_size would come up with a rowcount of zero, which is correct, but it didn't then do set_dummy_rel_pathlist. (We would have ended up with the right state after set_append_rel_pathlist, but that's too late, if we generate indexpaths for some other rel first.) In addition to fixing the actual bug, I installed an Assert enforcing this convention in set_rel_size; that then allows simplification of a couple of now-redundant tests for zero rowcount in set_append_rel_size. Also, to cover the possibility that third-party FDWs have been careless about not returning a zero rowcount estimate, apply clamp_row_est to whatever an FDW comes up with as the rows estimate. Per report from Andreas Seltenreich. Back-patch to 9.2. Earlier branches did not have the separation between set_base_rel_sizes and set_base_rel_pathlists steps, so there was no intermediate state where an appendrel would have had inconsistent rowcount and pathlist. It's possible that adding the Assert to set_rel_size would be a good idea in older branches too; but since they're not under development any more, it's likely not worth the trouble.
* Check the relevant index element in ON CONFLICT unique index inference.Andres Freund2015-07-26
| | | | | | | | | | | | | | | | ON CONFLICT unique index inference had a thinko that could affect cases where the user-supplied inference clause required that an attribute match a particular (user specified) collation and/or opclass. infer_collation_opclass_match() has to check for opclass and/or collation matches and that the attribute is in the list of attributes or expressions known to be in the definition of the index under consideration. The bug was that these two conditions weren't necessarily evaluated for the same index attribute. Author: Peter Geoghegan Discussion: CAM3SWZR4uug=WvmGk7UgsqHn2MkEzy9YU-+8jKGO4JPhesyeWg@mail.gmail.com Backpatch: 9.5, where ON CONFLICT was introduced
* Fix flattening of nested grouping sets.Andres Freund2015-07-26
| | | | | | | | | | | | | | | Previously nested grouping set specifications accidentally weren't flattened, but instead contained the nested specification as a element in the outer list. Fix this by, as actually documented in comments, concatenating the nested set specification into the outer one. Also add tests to prevent this from breaking again. Author: Andrew Gierth, with tests from Jeevan Chalke Reported-By: Jeevan Chalke Discussion: CAM2+6=V5YvuxB+EyN4iH=GbD-XTA435TCNvnDFSD--YvXs+pww@mail.gmail.com Backpatch: 9.5, where grouping sets were introduced
* Allow to push down clauses from HAVING to WHERE when grouping sets are used.Andres Freund2015-07-26
| | | | | | | | | | | | | | | Previously we disallowed pushing down quals to WHERE in the presence of grouping sets. That's overly restrictive. We now instead copy quals to WHERE if applicable, leaving the one in HAVING in place. That's because, at that stage of the planning process, it's nontrivial to determine if it's safe to remove the one in HAVING. Author: Andrew Gierth Discussion: 874mkt3l59.fsf@news-spur.riddles.org.uk Backpatch: 9.5, where grouping sets were introduced. This isn't exactly a bugfix, but it seems better to keep the branches in sync at this point.
* Recognize GROUPING() as a aggregate expression.Andres Freund2015-07-26
| | | | | | | | | | Previously GROUPING() was not recognized as a aggregate expression, erroneously allowing the planner to move it from HAVING to WHERE. Author: Jeevan Chalke Reviewed-By: Andrew Gierth Discussion: CAM2+6=WG9omG5rFOMAYBweJxmpTaapvVp5pCeMrE6BfpCwr4Og@mail.gmail.com Backpatch: 9.5, where grouping sets were introduced
* Build column mapping for grouping sets in all required cases.Andres Freund2015-07-26
| | | | | | | | | | | The previous coding frequently failed to fail because for one it's unusual to have rollup clauses with one column, and for another sometimes the wrong mapping didn't cause obvious problems. Author: Jeevan Chalke Reviewed-By: Andrew Gierth Discussion: CAM2+6=W=9=hQOipH0HAPbkun3Z3TFWij_EiHue0_6UX=oR=1kw@mail.gmail.com Backpatch: 9.5, where grouping sets were introduced