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* 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
* 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
* 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 typosPeter Eisentraut2016-08-16
| | | | From: Alexander Law <exclusion@gmail.com>
* Disable parallel query by default.Robert Haas2016-08-16
| | | | | | Per discussion, set the default value of max_parallel_workers_per_gather to 0 in 9.6 only. We'll leave it enabled in master so that it gets more testing and in the hope that it can be enable by default in v10.
* 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>
* 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.
* Make format() error messages consistent againPeter Eisentraut2016-08-08
| | | | 07d25a964 changed only one occurrence. Change the other one as well.
* 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>
* 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.
* 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>
* C comment: fix typoBruce Momjian2016-08-03
| | | | Author: Amit Langote
* 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.
* Eliminate a few more user-visible "cache lookup failed" errors.Robert Haas2016-07-29
| | | | Michael Paquier
* Fix assorted fallout from IS [NOT] NULL patch.Tom Lane2016-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commits 4452000f3 et al established semantics for NullTest.argisrow that are a bit different from its initial conception: rather than being merely a cache of whether we've determined the input to have composite type, the flag now has the further meaning that we should apply field-by-field testing as per the standard's definition of IS [NOT] NULL. If argisrow is false and yet the input has composite type, the construct instead has the semantics of IS [NOT] DISTINCT FROM NULL. Update the comments in primnodes.h to clarify this, and fix ruleutils.c and deparse.c to print such cases correctly. In the case of ruleutils.c, this merely results in cosmetic changes in EXPLAIN output, since the case can't currently arise in stored rules. However, it represents a live bug for deparse.c, which would formerly have sent a remote query that had semantics different from the local behavior. (From the user's standpoint, this means that testing a remote nested-composite column for null-ness could have had unexpected recursive behavior much like that fixed in 4452000f3.) In a related but somewhat independent fix, make plancat.c set argisrow to false in all NullTest expressions constructed to represent "attnotnull" constructs. Since attnotnull is actually enforced as a simple null-value check, this is a more accurate representation of the semantics; we were previously overpromising what it meant for composite columns, which might possibly lead to incorrect planner optimizations. (It seems that what the SQL spec expects a NOT NULL constraint to mean is an IS NOT NULL test, so arguably we are violating the spec and should fix attnotnull to do the other thing. If we ever do, this part should get reverted.) Back-patch, same as the previous commit. Discussion: <10682.1469566308@sss.pgh.pa.us>
* Change various deparsing functions to return NULL for invalid input.Robert Haas2016-07-26
| | | | | | | | | | | Previously, some functions returned various fixed strings and others failed with a cache lookup error. Per discussion, standardize on returning NULL. Although user-exposed "cache lookup failed" error messages might normally qualify for bug-fix treatment, no back-patch; the risk of breaking user code which is accustomed to the current behavior seems too high. Michael Paquier
* Fix typoPeter Eisentraut2016-07-25
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* Message style improvementsPeter Eisentraut2016-07-25
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* Remove very-obsolete estimates of shmem usage from postgresql.conf.sample.Tom Lane2016-07-19
| | | | | | | | | | runtime.sgml used to contain a table of estimated shared memory consumption rates for max_connections and some other GUCs. Commit 390bfc643 removed that on the well-founded grounds that (a) we weren't maintaining the entries well and (b) it no longer mattered so much once we got out from under SysV shmem limits. But it missed that there were even-more-obsolete versions of some of those numbers in comments in postgresql.conf.sample. Remove those too. Back-patch to 9.3 where the aforesaid commit went in.
* Remove obsolete comment.Tom Lane2016-07-17
| | | | Peter Geoghegan
* Fix crash in close_ps() for NaN input coordinates.Tom Lane2016-07-16
| | | | | | | | | | The Assert() here seems unreasonably optimistic. Andreas Seltenreich found that it could fail with NaNs in the input geometries, and it seems likely to me that it might fail in corner cases due to roundoff error, even for ordinary input values. As a band-aid, make the function return SQL NULL instead of crashing. Report: <87d1md1xji.fsf@credativ.de>
* Avoid invalidating all foreign-join cached plans when user mappings change.Tom Lane2016-07-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We must not push down a foreign join when the foreign tables involved should be accessed under different user mappings. Previously we tried to enforce that rule literally during planning, but that meant that the resulting plans were dependent on the current contents of the pg_user_mapping catalog, and we had to blow away all cached plans containing any remote join when anything at all changed in pg_user_mapping. This could have been improved somewhat, but the fact that a syscache inval callback has very limited info about what changed made it hard to do better within that design. Instead, let's change the planner to not consider user mappings per se, but to allow a foreign join if both RTEs have the same checkAsUser value. If they do, then they necessarily will use the same user mapping at runtime, and we don't need to know specifically which one that is. Post-plan-time changes in pg_user_mapping no longer require any plan invalidation. This rule does give up some optimization ability, to wit where two foreign table references come from views with different owners or one's from a view and one's directly in the query, but nonetheless the same user mapping would have applied. We'll sacrifice the first case, but to not regress more than we have to in the second case, allow a foreign join involving both zero and nonzero checkAsUser values if the nonzero one is the same as the prevailing effective userID. In that case, mark the plan as only runnable by that userID. The plancache code already had a notion of plans being userID-specific, in order to support RLS. It was a little confused though, in particular lacking clarity of thought as to whether it was the rewritten query or just the finished plan that's dependent on the userID. Rearrange that code so that it's clearer what depends on which, and so that the same logic applies to both RLS-injected role dependency and foreign-join-injected role dependency. Note that this patch doesn't remove the other issue mentioned in the original complaint, which is that while we'll reliably stop using a foreign join if it's disallowed in a new context, we might fail to start using a foreign join if it's now allowed, but we previously created a generic cached plan that didn't use one. It was agreed that the chance of winning that way was not high enough to justify the much larger number of plan invalidations that would have to occur if we tried to cause it to happen. In passing, clean up randomly-varying spelling of EXPLAIN commands in postgres_fdw.sql, and fix a COSTS ON example that had been allowed to leak into the committed tests. This reverts most of commits fbe5a3fb7 and 5d4171d1c, which were the previous attempt at ensuring we wouldn't push down foreign joins that span permissions contexts. Etsuro Fujita and Tom Lane Discussion: <d49c1e5b-f059-20f4-c132-e9752ee0113e@lab.ntt.co.jp>
* Fix parsing NOT sequence in tsqueryTeodor Sigaev2016-07-15
| | | | | | | Digging around bug #14245 I found that commit 6734a1cacd44f5b731933cbc93182b135b167d0c missed that NOT operation is right associative in opposite to all other. This miss is resposible for tsquery parser fail on sequence of NOT operations
* Fix nested NOT operation cleanup in tsquery.Teodor Sigaev2016-07-15
| | | | | | | | | During normalization of tsquery tree it tries to simplify nested NOT operations but there it's obvioulsy missed that subsequent node could be a leaf node (value node) Bug #14245: Segfault on weird to_tsquery Reported by David Kellum.
* Adjust spellings of forms of "cancel"Peter Eisentraut2016-07-14
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* Fix GiST index build for NaN values in geometric types.Tom Lane2016-07-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GiST index build could go into an infinite loop when presented with boxes (or points, circles or polygons) containing NaN component values. This happened essentially because the code assumed that x == x is true for any "double" value x; but it's not true for NaNs. The looping behavior was not the only problem though: we also attempted to sort the items using simple double comparisons. Since NaNs violate the trichotomy law, qsort could (in principle at least) get arbitrarily confused and mess up the sorting of ordinary values as well as NaNs. And we based splitting choices on box size calculations that could produce NaNs, again resulting in undesirable behavior. To fix, replace all comparisons of doubles in this logic with float8_cmp_internal, which is NaN-aware and is careful to sort NaNs consistently, higher than any non-NaN. Also rearrange the box size calculation to not produce NaNs; instead it should produce an infinity for a box with NaN on one side and not-NaN on the other. I don't by any means claim that this solves all problems with NaNs in geometric values, but it should at least make GiST index insertion work reliably with such data. It's likely that the index search side of things still needs some work, and probably regular geometric operations too. But with this patch we're laying down a convention for how such cases ought to behave. Per bug #14238 from Guang-Dih Lei. Back-patch to 9.2; the code used before commit 7f3bd86843e5aad8 is quite different and doesn't lock up on my simple test case, nor on the submitter's dataset. Report: <20160708151747.1426.60150@wrigleys.postgresql.org> Discussion: <28685.1468246504@sss.pgh.pa.us>
* Properly adjust pointers when tuples are moved during CLUSTER.Robert Haas2016-07-07
| | | | | | | | Otherwise, when we abandon incremental memory accounting and use batch allocation for the final merge pass, we might crash. This has been broken since 0011c0091e886b874e485a46ff2c94222ffbf550. Peter Geoghegan, tested by Noah Misch
* Fix a prototype which is inconsistent with the function definition.Robert Haas2016-07-07
| | | | Peter Geoghegan
* Clarify resource utilization of parallel query.Robert Haas2016-07-07
| | | | | | | | | | | | temp_file_limit is a per-process limit, not a per-session limit across all cooperating parallel processes; change wording accordingly, per a suggestion from Tom Lane. Also, document under max_parallel_workers_per_gather the fact that each process involved in a parallel query may use as many resources as a separate session. Caveat emptor. Per a complaint from Peter Geoghegan.
* Fix typosPeter Eisentraut2016-07-06
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* Fix typo in comment.Fujii Masao2016-07-06
| | | | Author: Masahiko Sawada
* Be more paranoid in ruleutils.c's get_variable().Tom Lane2016-07-01
| | | | | | | | | | | | | | | | | | | We were merely Assert'ing that the Var matched the RTE it's supposedly from. But if the user passes incorrect information to pg_get_expr(), the RTE might in fact not match; this led either to Assert failures or core dumps, as reported by Chris Hanks in bug #14220. To fix, just convert the Asserts to test-and-elog. Adjust an existing test-and-elog elsewhere in the same function to be consistent in wording. (If we really felt these were user-facing errors, we might promote them to ereport's; but I can't convince myself that they're worth translating.) Back-patch to 9.3; the problematic code doesn't exist before that, and a quick check says that 9.2 doesn't crash on such cases. Michael Paquier and Thomas Munro Report: <20160629224349.1407.32667@wrigleys.postgresql.org>
* Fix crash bug in RestoreSnapshot.Robert Haas2016-07-01
| | | | | | | | | If serialized_snapshot->subxcnt > 0 and serialized_snapshot->xcnt == 0, the old coding would do the wrong thing and crash. This can happen on standby servers. Report by Andreas Seltenreich. Patch by Thomas Munro, reviewed by Amit Kapila and tested by Andreas Seltenreich.
* Change predecence of phrase operator.Teodor Sigaev2016-06-27
| | | | | | | | | | <-> operator now have higher predecence than & (AND) operator. This change was motivated by unexpected difference of similar queries: 'a & b <-> c'::tsquery and 'b <-> c & a'. Before first query means (a & b) <-> c and second one - '(b <-> c) & a', now phrase operator evaluates first. Per suggestion from Tom Lane 32260.1465402409@sss.pgh.pa.us
* Do not fallback to AND for FTS phrase operator.Teodor Sigaev2016-06-27
| | | | | | | | | If there is no positional information of lexemes then phrase operator will not fallback to AND operator. This change makes needing to modify TS_execute() interface, because somewhere (in indexes, for example) positional information is unaccesible and in this cases we need to force fallback to AND. Per discussion c19fcfec308e6ccd952cdde9e648b505@mail.gmail.com
* Make exact distance match for FTS phrase operatorTeodor Sigaev2016-06-27
| | | | | | | Phrase operator now requires exact distance betweens lexems instead of less-or-equal. Per discussion c19fcfec308e6ccd952cdde9e648b505@mail.gmail.com
* Rethink node-level representation of partial-aggregation modes.Tom Lane2016-06-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | The original coding had three separate booleans representing partial aggregation behavior, which was confusing, unreadable, and error-prone, not least because the booleans weren't always listed in the same order. It was also inadequate for the allegedly-desirable future extension to support intermediate partial aggregation, because we'd need separate markers for serialization and deserialization in such a case. Merge these bools into an enum "AggSplit" to provide symbolic names for the supported operating modes (and document what those are). By assigning the values of the enum constants carefully, we can treat AggSplit values as options bitmasks so that tests of what to do aren't noticeably more expensive than before. While at it, get rid of Aggref.aggoutputtype. That's not needed since commit 59a3795c2 got rid of setrefs.c's special-purpose Aggref comparison code, and it likewise seemed more confusing than helpful. Assorted comment cleanup as well (there's still more that I want to do in that line). catversion bump for change in Aggref node contents. Should be the last one for partial-aggregation changes. Discussion: <29309.1466699160@sss.pgh.pa.us>
* Fix handling of multixacts predating pg_upgradeAlvaro Herrera2016-06-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After pg_upgrade, it is possible that some tuples' Xmax have multixacts corresponding to the old installation; such multixacts cannot have running members anymore. In many code sites we already know not to read them and clobber them silently, but at least when VACUUM tries to freeze a multixact or determine whether one needs freezing, there's an attempt to resolve it to its member transactions by calling GetMultiXactIdMembers, and if the multixact value is "in the future" with regards to the current valid multixact range, an error like this is raised: ERROR: MultiXactId 123 has not been created yet -- apparent wraparound and vacuuming fails. Per discussion with Andrew Gierth, it is completely bogus to try to resolve multixacts coming from before a pg_upgrade, regardless of where they stand with regards to the current valid multixact range. It's possible to get from under this problem by doing SELECT FOR UPDATE of the problem tuples, but if tables are large, this is slow and tedious, so a more thorough solution is desirable. To fix, we realize that multixacts in xmax created in 9.2 and previous have a specific bit pattern that is never used in 9.3 and later (we already knew this, per comments and infomask tests sprinkled in various places, but we weren't leveraging this knowledge appropriately). Whenever the infomask of the tuple matches that bit pattern, we just ignore the multixact completely as if Xmax wasn't set; or, in the case of tuple freezing, we act as if an unwanted value is set and clobber it without decoding. This guarantees that no errors will be raised, and that the values will be progressively removed until all tables are clean. Most callers of GetMultiXactIdMembers are patched to recognize directly that the value is a removable "empty" multixact and avoid calling GetMultiXactIdMembers altogether. To avoid changing the signature of GetMultiXactIdMembers() in back branches, we keep the "allow_old" boolean flag but rename it to "from_pgupgrade"; if the flag is true, we always return an empty set instead of looking up the multixact. (I suppose we could remove the argument in the master branch, but I chose not to do so in this commit). This was broken all along, but the error-facing message appeared first because of commit 8e9a16ab8f7f and was partially fixed in a25c2b7c4db3. This fix, backpatched all the way back to 9.3, goes approximately in the same direction as a25c2b7c4db3 but should cover all cases. Bug analysis by Andrew Gierth and Álvaro Herrera. A number of public reports match this bug: https://www.postgresql.org/message-id/20140330040029.GY4582@tamriel.snowman.net https://www.postgresql.org/message-id/538F3D70.6080902@publicrelay.com https://www.postgresql.org/message-id/556439CF.7070109@pscs.co.uk https://www.postgresql.org/message-id/SG2PR06MB0760098A111C88E31BD4D96FB3540@SG2PR06MB0760.apcprd06.prod.outlook.com https://www.postgresql.org/message-id/20160615203829.5798.4594@wrigleys.postgresql.org
* Fix small memory leak in partial-aggregate deserialization functions.Tom Lane2016-06-23
| | | | | | | | | | | | | | | | A deserialize function's result is short-lived data during partial aggregation, since we're just going to pass it to the combine function and then it's of no use anymore. However, the built-in deserialize functions allocated their results in the aggregate state context, resulting in a query-lifespan memory leak. It's probably not possible for this to amount to anything much at present, since the number of leaked results would only be the number of worker processes. But it might become a problem in future. To fix, don't use the same convenience subroutine for setting up results that the aggregate transition functions use. David Rowley Report: <10050.1466637736@sss.pgh.pa.us>
* Fix type-safety problem with parallel aggregate serial/deserialization.Tom Lane2016-06-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original specification for this called for the deserialization function to have signature "deserialize(serialtype) returns transtype", which is a security violation if transtype is INTERNAL (which it always would be in practice) and serialtype is not (which ditto). The patch blithely overrode the opr_sanity check for that, which was sloppy-enough work in itself, but the indisputable reason this cannot be allowed to stand is that CREATE FUNCTION will reject such a signature and thus it'd be impossible for extensions to create parallelizable aggregates. The minimum fix to make the signature type-safe is to add a second, dummy argument of type INTERNAL. But to lock it down a bit more and make misuse of INTERNAL-accepting functions less likely, let's get rid of the ability to specify a "serialtype" for an aggregate and just say that the only useful serialtype is BYTEA --- which, in practice, is the only interesting value anyway, due to the usefulness of the send/recv infrastructure for this purpose. That means we only have to allow "serialize(internal) returns bytea" and "deserialize(bytea, internal) returns internal" as the signatures for these support functions. In passing fix bogus signature of int4_avg_combine, which I found thanks to adding an opr_sanity check on combinefunc signatures. catversion bump due to removing pg_aggregate.aggserialtype and adjusting signatures of assorted built-in functions. David Rowley and Tom Lane Discussion: <27247.1466185504@sss.pgh.pa.us>
* Restore foreign-key-aware estimation of join relation sizes.Tom Lane2016-06-18
| | | | | | | | | | | | | | | | | | | | This patch provides a new implementation of the logic added by commit 137805f89 and later removed by 77ba61080. It differs from the original primarily in expending much less effort per joinrel in large queries, which it accomplishes by doing most of the matching work once per query not once per joinrel. Hopefully, it's also less buggy and better commented. The never-documented enable_fkey_estimates GUC remains gone. There remains work to be done to make the selectivity estimates account for nulls in FK referencing columns; but that was true of the original patch as well. We may be able to address this point later in beta. In the meantime, any error should be in the direction of overestimating rather than underestimating joinrel sizes, which seems like the direction we want to err in. Tomas Vondra and Tom Lane Discussion: <31041.1465069446@sss.pgh.pa.us>