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* Back out the session_start and session_end hooks feature.Andrew Dunstan2017-11-16
| | | | | | | | | | It's become apparent during testing that there are problems with at least the testing regime. I don't think we should have it without a working test regime, and the difficulties might indicate implementation problems anyway, so I'm backing out the whole thing until that's sorted out. This reverts commits 7459484 9989f92 cd8ce3a
* Further refactoring of c.h and nearby files.Tom Lane2017-11-16
| | | | | | | | | | | | | | | | | | | | | This continues the work of commit 91aec93e6 by getting rid of a lot of Windows-specific funny business in "section 0". Instead of including pg_config_os.h in different places depending on platform, let's standardize on putting it before the system headers, and in consequence reduce win32.h to just what has to appear before the system headers or the body of c.h (the latter category seems to include only PGDLLIMPORT and PGDLLEXPORT). The rest of what was in win32.h is moved to a new sub-include of port.h, win32_port.h. Some of what was in port.h seems to better belong there too. It's possible that I missed some declaration ordering dependency that needs to be preserved, but hopefully the buildfarm will find that out in short order. Unlike the previous commit, no back-patch, since this is just cleanup not a prerequisite for a bug fix. Discussion: https://postgr.es/m/29650.1510761080@sss.pgh.pa.us
* Remove TRUE and FALSEPeter Eisentraut2017-11-15
| | | | | | | | | | Code should be using true and false. Existing code can be changed to those in a backward compatible way. The definitions in the ecpg header files are left around to avoid upsetting those users unnecessarily. Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
* Centralize executor-related partitioning code.Robert Haas2017-11-15
| | | | | | | | | | | | | Some code is moved from partition.c, which has grown very quickly lately; splitting the executor parts out might help to keep it from getting totally out of control. Other code is moved from execMain.c. All is moved to a new file execPartition.c. get_partition_for_tuple now has a new interface that more clearly separates executor concerns from generic concerns. Amit Langote. A slight comment tweak by me. Discussion: http://postgr.es/m/1f0985f8-3b61-8bc4-4350-baa6d804cb6d@lab.ntt.co.jp
* Add hooks for session start and session endAndrew Dunstan2017-11-15
| | | | | | | | | | These hooks can be used in loadable modules. A simple test module is included. Discussion: https://postgr.es/m/20170720204733.40f2b7eb.nagata@sraoss.co.jp Fabrízio de Royes Mello and Yugo Nagata Reviewed by Michael Paquier and Aleksandr Parfenov
* Add parallel_leader_participation GUC.Robert Haas2017-11-15
| | | | | | | | | | | Sometimes, for testing, it's useful to have the leader do nothing but read tuples from workers; and it's possible that could work out better even in production. Thomas Munro, reviewed by Amit Kapila and by me. A few final tweaks by me. Discussion: http://postgr.es/m/CAEepm=2U++Lp3bNTv2Bv_kkr5NE2pOyHhxU=G0YTa4ZhSYhHiw@mail.gmail.com
* Prevent int128 from requiring more than MAXALIGN alignment.Tom Lane2017-11-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Our initial work with int128 neglected alignment considerations, an oversight that came back to bite us in bug #14897 from Vincent Lachenal. It is unsurprising that int128 might have a 16-byte alignment requirement; what's slightly more surprising is that even notoriously lax Intel chips sometimes enforce that. Raising MAXALIGN seems out of the question: the costs in wasted disk and memory space would be significant, and there would also be an on-disk compatibility break. Nor does it seem very practical to try to allow some data structures to have more-than-MAXALIGN alignment requirement, as we'd have to push knowledge of that throughout various code that copies data structures around. The only way out of the box is to make type int128 conform to the system's alignment assumptions. Fortunately, gcc supports that via its __attribute__(aligned()) pragma; and since we don't currently support int128 on non-gcc-workalike compilers, we shouldn't be losing any platform support this way. Although we could have just done pg_attribute_aligned(MAXIMUM_ALIGNOF) and called it a day, I did a little bit of extra work to make the code more portable than that: it will also support int128 on compilers without __attribute__(aligned()), if the native alignment of their 128-bit-int type is no more than that of int64. Add a regression test case that exercises the one known instance of the problem, in parallel aggregation over a bigint column. This will need to be back-patched, along with the preparatory commit 91aec93e6. But let's see what the buildfarm makes of it first. Discussion: https://postgr.es/m/20171110185747.31519.28038@wrigleys.postgresql.org
* Rearrange c.h to create a "compiler characteristics" section.Tom Lane2017-11-14
| | | | | | | | | | | | | | | | | | Generalize section 1 to handle stuff that is principally about the compiler (not libraries), such as attributes, and collect stuff there that had been dropped into various other parts of c.h. Also, push all the gettext macros into section 8, so that section 0 is really just inclusions rather than inclusions and random other stuff. The primary goal here is to get pg_attribute_aligned() defined before section 3, so that we can use it with int128. But this seems like good cleanup anyway. This patch just moves macro definitions around, and shouldn't result in any changes in generated code. But I'll push it out separately to see if the buildfarm agrees. Discussion: https://postgr.es/m/20171110185747.31519.28038@wrigleys.postgresql.org
* Simplify index_[constraint_]create APIAlvaro Herrera2017-11-14
| | | | | | | | | | | | | | Instead of passing large swaths of boolean arguments, define some flags that can be used in a bitmask. This makes it easier not only to figure out what each call site is doing, but also to add some new flags. The flags are split in two -- one set for index_create directly and another for constraints. index_create() itself receives both, and then passes down the latter to index_constraint_create(), which can also be called standalone. Discussion: https://postgr.es/m/20171023151251.j75uoe27gajdjmlm@alvherre.pgsql Reviewed-by: Simon Riggs
* Track in the plan the types associated with PARAM_EXEC parameters.Robert Haas2017-11-13
| | | | | | | | | | | | Up until now, we only tracked the number of parameters, which was sufficient to allocate an array of Datums of the appropriate size, but not sufficient to, for example, know how to serialize a Datum stored in one of those slots. An upcoming patch wants to do that, so add this tracking to make it possible. Patch by me, reviewed by Tom Lane and Amit Kapila. Discussion: http://postgr.es/m/CA+TgmoYqpxDKn8koHdW8BEKk8FMUL0=e8m2Qe=M+r0UBjr3tuQ@mail.gmail.com
* Account for the effect of lossy pages when costing bitmap scans.Robert Haas2017-11-10
| | | | | | | Dilip Kumar, reviewed by Alexander Kumenkov, Amul Sul, and me. Some final adjustments by me. Discussion: http://postgr.es/m/CAFiTN-sYtqUOXQ4SpuhTv0Z9gD0si3YxZGv_PQAAMX8qbOotcg@mail.gmail.com
* Add some const decorations to prototypesPeter Eisentraut2017-11-10
| | | | Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
* Add hash partitioning.Robert Haas2017-11-09
| | | | | | | | | | | | | | | | | | | Hash partitioning is useful when you want to partition a growing data set evenly. This can be useful to keep table sizes reasonable, which makes maintenance operations such as VACUUM faster, or to enable partition-wise join. At present, we still depend on constraint exclusion for partitioning pruning, and the shape of the partition constraints for hash partitioning is such that that doesn't work. Work is underway to fix that, which should both improve performance and make partitioning pruning work with hash partitioning. Amul Sul, reviewed and tested by Dilip Kumar, Ashutosh Bapat, Yugo Nagata, Rajkumar Raghuwanshi, Jesper Pedersen, and by me. A few final tweaks also by me. Discussion: http://postgr.es/m/CAAJ_b96fhpJAP=ALbETmeLk1Uni_GFZD938zgenhF49qgDTjaQ@mail.gmail.com
* Refactor permissions checks for large objects.Tom Lane2017-11-09
| | | | | | | | | | | | | Up to now, ACL checks for large objects happened at the level of the SQL-callable functions, which led to CVE-2017-7548 because of a missing check. Push them down to be enforced in inv_api.c as much as possible, in hopes of preventing future bugs. This does have the effect of moving read and write permission errors to happen at lo_open time not loread or lowrite time, but that seems acceptable. Michael Paquier and Tom Lane Discussion: https://postgr.es/m/CAB7nPqRHmNOYbETnc_2EjsuzSM00Z+BWKv9sy6tnvSd5gWT_JA@mail.gmail.com
* Restrict lo_import()/lo_export() via SQL permissions not hard-wired checks.Tom Lane2017-11-09
| | | | | | | | | | | | | | | | | While it's generally unwise to give permissions on these functions to anyone but a superuser, we've been moving away from hard-wired permission checks inside functions in favor of using the SQL permission system to control access. Bring lo_import() and lo_export() into compliance with that approach. In particular, this removes the manual configuration option ALLOW_DANGEROUS_LO_FUNCTIONS. That dates back to 1999 (commit 4cd4a54c8); it's unlikely anyone has used it in many years. Moreover, if you really want such behavior, now you can get it with GRANT ... TO PUBLIC instead. Michael Paquier Discussion: https://postgr.es/m/CAB7nPqRHmNOYbETnc_2EjsuzSM00Z+BWKv9sy6tnvSd5gWT_JA@mail.gmail.com
* Change TRUE/FALSE to true/falsePeter Eisentraut2017-11-08
| | | | | | | | | | | | | | The lower case spellings are C and C++ standard and are used in most parts of the PostgreSQL sources. The upper case spellings are only used in some files/modules. So standardize on the standard spellings. The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so those are left as is when using those APIs. In code comments, we use the lower-case spelling for the C concepts and keep the upper-case spelling for the SQL concepts. Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
* Fix unportable spelling of int64 constant.Tom Lane2017-11-07
| | | | Per buildfarm member pademelon.
* Remove secondary checkpointSimon Riggs2017-11-07
| | | | | | | | | | Previously server reserved WAL for last two checkpoints, which used too much disk space for small servers. Bumps PG_CONTROL_VERSION Author: Simon Riggs <simon@2ndQuadrant.com> Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
* Exclude pg_internal.init from BASE_BACKUPSimon Riggs2017-11-07
| | | | | | | Add docs to explain this for other backup mechanisms Author: David Steele <david@pgmasters.net> Reviewed-by: Petr Jelinek <petr.jelinek@2ndQuadrant.com> et al
* Always require SELECT permission for ON CONFLICT DO UPDATE.Dean Rasheed2017-11-06
| | | | | | | | | | | | | | The update path of an INSERT ... ON CONFLICT DO UPDATE requires SELECT permission on the columns of the arbiter index, but it failed to check for that in the case of an arbiter specified by constraint name. In addition, for a table with row level security enabled, it failed to check updated rows against the table's SELECT policies when the update path was taken (regardless of how the arbiter index was specified). Backpatch to 9.5 where ON CONFLICT DO UPDATE and RLS were introduced. Security: CVE-2017-15099
* Teach planner to account for HAVING quals in aggregation plan nodes.Tom Lane2017-11-02
| | | | | | | | | | | | | | | | | | For some reason, we have never accounted for either the evaluation cost or the selectivity of filter conditions attached to Agg and Group nodes (which, in practice, are always conditions from a HAVING clause). Applying our regular selectivity logic to post-grouping conditions is a bit bogus, but it's surely better than taking the selectivity as 1.0. Perhaps someday the extended-statistics mechanism can be taught to provide statistics that would help us in getting non-default estimates here. Per a gripe from Benjamin Coutu. This is surely a bug fix, but I'm hesitant to back-patch because of the prospect of destabilizing existing plan choices. Given that it took us this long to notice the bug, it's probably not hurting too many people in the field. Discussion: https://postgr.es/m/20968.1509486337@sss.pgh.pa.us
* Revert bogus fixes of HOT-freezing bugAlvaro Herrera2017-11-02
| | | | | | | | | | It turns out we misdiagnosed what the real problem was. Revert the previous changes, because they may have worse consequences going forward. A better fix is forthcoming. The simplistic test case is kept, though disabled. Discussion: https://postgr.es/m/20171102112019.33wb7g5wp4zpjelu@alap3.anarazel.de
* Allow bitmap scans to operate as index-only scans when possible.Tom Lane2017-11-01
| | | | | | | | | | | | | | | | | | | | | | | | | If we don't have to return any columns from heap tuples, and there's no need to recheck qual conditions, and the heap page is all-visible, then we can skip fetching the heap page altogether. Skip prefetching pages too, when possible, on the assumption that the recheck flag will remain the same from one page to the next. While that assumption is hardly bulletproof, it seems like a good bet most of the time, and better than prefetching pages we don't need. This commit installs the executor infrastructure, but doesn't change any planner cost estimates, thus possibly causing bitmap scans to not be chosen in cases where this change renders them the best choice. I (tgl) am not entirely convinced that we need to account for this behavior in the planner, because I think typically the bitmap scan would get chosen anyway if it's the best bet. In any case the submitted patch took way too many shortcuts, resulting in too many clearly-bad choices, to be committable. Alexander Kuzmenkov, reviewed by Alexey Chernyshov, and whacked around rather heavily by me. Discussion: https://postgr.es/m/239a8955-c0fc-f506-026d-c837e86c827b@postgrespro.ru
* Fix ALTER TABLE code to update domain constraints when needed.Tom Lane2017-11-01
| | | | | | | | | | | | | | | | | It's possible for dropping a column, or altering its type, to require changes in domain CHECK constraint expressions; but the code was previously only expecting to find dependent table CHECK constraints. Make the necessary adjustments. This is a fairly old oversight, but it's a lot easier to encounter the problem in the context of domains over composite types than it was before. Given the lack of field complaints, I'm not going to bother with a back-patch, though I'd be willing to reconsider that decision if someone does complain. Patch by me, reviewed by Michael Paquier Discussion: https://postgr.es/m/30656.1509128130@sss.pgh.pa.us
* Fix problems with the "role" GUC and parallel query.Robert Haas2017-10-29
| | | | | | | | | | Without this fix, dropping a role can sometimes result in parallel query failures in sessions that have used "SET ROLE" to assume the dropped role, even if that setting isn't active any more. Report by Pavan Deolasee. Patch by Amit Kapila, reviewed by me. Discussion: http://postgr.es/m/CABOikdOomRcZsLsLK+Z+qENM1zxyaWnAvFh3MJZzZnnKiF+REg@mail.gmail.com
* Add hash_combine64.Robert Haas2017-10-29
| | | | | | | Extracted from a larger patch by Amul Sul, with some comment additions by me. Discussion: http://postgr.es/m/20171024113004.hn5qajypin4dy5sw@alap3.anarazel.de
* Revert "Move new structure member to the end."Robert Haas2017-10-27
| | | | | | This reverts commit 94d622f27be6d48e61a68496da4f2efb06fe8746. That commit was supposed to get pushed to REL_10_STABLE, but I messed up.
* Move new structure member to the end.Robert Haas2017-10-27
| | | | | | Reduces ABI breakage. Per Tom Lane. Discussion: http://postgr.es/m/4035.1509113974@sss.pgh.pa.us
* Fix mistaken failure to allow parallelism in corner case.Robert Haas2017-10-27
| | | | | | | | | | | | | | | If we try to run a parallel plan in serial mode because, for example, it's going to be scanned via a cursor, but for some reason we're already in parallel mode (for example because an outer query is running in parallel), we'd incorrectly try to launch workers. Fix by adding a flag to the EState, so that we can be certain that ExecutePlan() and ExecGather()/ExecGatherMerge() will have the same idea about whether we are executing serially or in parallel. Report and fix by Amit Kapila with help from Kuntal Ghosh. A few tweaks by me. Discussion: http://postgr.es/m/CAA4eK1+_BuZrmVCeua5Eqnm4Co9DAXdM5HPAOE2J19ePbR912Q@mail.gmail.com
* Support domains over composite types.Tom Lane2017-10-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | This is the last major omission in our domains feature: you can now make a domain over anything that's not a pseudotype. The major complication from an implementation standpoint is that places that might be creating tuples of a domain type now need to be prepared to apply domain_check(). It seems better that unprepared code fail with an error like "<type> is not composite" than that it silently fail to apply domain constraints. Therefore, relevant infrastructure like get_func_result_type() and lookup_rowtype_tupdesc() has been adjusted to treat domain-over-composite as a distinct case that unprepared code won't recognize, rather than just transparently treating it the same as plain composite. This isn't a 100% solution to the possibility of overlooked domain checks, but it catches most places. In passing, improve typcache.c's support for domains (it can now cache the identity of a domain's base type), and rewrite the argument handling logic in jsonfuncs.c's populate_record[set]_worker to reduce duplicative per-call lookups. I believe this is code-complete so far as the core and contrib code go. The PLs need varying amounts of work, which will be tackled in followup patches. Discussion: https://postgr.es/m/4206.1499798337@sss.pgh.pa.us
* Add a utility function to extract variadic function argumentsAndrew Dunstan2017-10-25
| | | | | | | | | | | This is epecially useful in the case or "VARIADIC ANY" functions. The caller can get the artguments and types regardless of whether or not and explicit VARIADIC array argument has been used. The function also provides an option to convert arguments on type "unknown" to to "text". Michael Paquier and me, reviewed by Tom Lane. Backpatch to 9.4 in order to support the following json bug fix.
* Allow the built-in ordered-set aggregates to share transition state.Tom Lane2017-10-16
| | | | | | | | | | | | | | | The built-in OSAs all share the same transition function, so they can share transition state as long as the final functions cooperate to not do the sort step more than once. To avoid running the tuplesort object in randomAccess mode unnecessarily, add a bit of infrastructure to nodeAgg.c to let the aggregate functions find out whether the transition state is actually being shared or not. This doesn't work for the hypothetical aggregates, since those inject a hypothetical row that isn't traceable to the shared input state. So they remain marked aggfinalmodify = 'w'. Discussion: https://postgr.es/m/CAB4ELO5RZhOamuT9Xsf72ozbenDLLXZKSk07FiSVsuJNZB861A@mail.gmail.com
* Repair breakage of aggregate FILTER option.Tom Lane2017-10-16
| | | | | | | | | | | | | | | | | An aggregate's input expression(s) are not supposed to be evaluated at all for a row where its FILTER test fails ... but commit 8ed3f11bb overlooked that requirement. Reshuffle so that aggregates having a filter clause evaluate their arguments separately from those without. This still gets the benefit of doing only one ExecProject in the common case of multiple Aggrefs, none of which have filters. While at it, arrange for filter clauses to be included in the common ExecProject evaluation, thus perhaps buying a little bit even when there are filters. Back-patch to v10 where the bug was introduced. Discussion: https://postgr.es/m/30065.1508161354@sss.pgh.pa.us
* gcc's support for __attribute__((noinline)) hasn't been around forever.Tom Lane2017-10-14
| | | | | Buildfarm member gaur says it wasn't there in 2.95.3. Guess that 3.0 and later have it.
* Explicitly track whether aggregate final functions modify transition state.Tom Lane2017-10-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now, there's been hard-wired assumptions that normal aggregates' final functions never modify their transition states, while ordered-set aggregates' final functions always do. This has always been a bit limiting, and in particular it's getting in the way of improving the built-in ordered-set aggregates to allow merging of transition states. Therefore, let's introduce catalog and CREATE AGGREGATE infrastructure that lets the finalfn's behavior be declared explicitly. There are now three possibilities for the finalfn behavior: it's purely read-only, it trashes the transition state irrecoverably, or it changes the state in such a way that no more transfn calls are possible but the state can still be passed to other, compatible finalfns. There are no examples of this third case today, but we'll shortly make the built-in OSAs act like that. This change allows user-defined aggregates to explicitly disclaim support for use as window functions, and/or to prevent transition state merging, if their implementations cannot handle that. While it was previously possible to handle the window case with a run-time error check, there was not any way to prevent transition state merging, which in retrospect is something commit 804163bc2 should have provided for. But better late than never. In passing, split out pg_aggregate.c's extern function declarations into a new header file pg_aggregate_fn.h, similarly to what we've done for some other catalog headers, so that pg_aggregate.h itself can be safe for frontend files to include. This lets pg_dump use the symbolic names for relevant constants. Discussion: https://postgr.es/m/4834.1507849699@sss.pgh.pa.us
* Improve sys/catcache performance.Andres Freund2017-10-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following are the individual improvements: 1) Avoidance of FunctionCallInfo based function calls, replaced by more efficient functions with a native C argument interface. 2) Don't extract columns from a cache entry's tuple whenever matching entries - instead store them as a Datum array. This also allows to get rid of having to build dummy tuples for negative & list entries, and of a hack for dealing with cstring vs. text weirdness. 3) Reorder members of catcache.h struct, so imortant entries are more likely to be on one cacheline. 4) Allowing the compiler to specialize critical SearchCatCache for a specific number of attributes allows to unroll loops and avoid other nkeys dependant initialization. 5) Only initializing the ScanKey when necessary, i.e. catcache misses, greatly reduces cache unnecessary cpu cache misses. 6) Split of the cache-miss case from the hash lookup, reducing stack allocations etc in the common case. 7) CatCTup and their corresponding heaptuple are allocated in one piece. This results in making cache lookups themselves roughly three times as fast - full-system benchmarks obviously improve less than that. I've also evaluated further techniques: - replace open coded hash with simplehash - the list walk right now shows up in profiles. Unfortunately it's not easy to do so safely as an entry's memory location can change at various times, which doesn't work well with the refcounting and cache invalidation. - Cacheline-aligning CatCTup entries - helps some with performance, but the win isn't big and the code for it is ugly, because the tuples have to be freed as well. - add more proper functions, rather than macros for SearchSysCacheCopyN etc., but right now they don't show up in profiles. The reason the macro wrapper for syscache.c/h have to be changed, rather than just catcache, is that doing otherwise would require exposing the SysCache array to the outside. That might be a good idea anyway, but it's for another day. Author: Andres Freund Reviewed-By: Robert Haas Discussion: https://postgr.es/m/20170914061207.zxotvyopetm7lrrp@alap3.anarazel.de
* Add pg_noinline macro to c.h.Andres Freund2017-10-13
| | | | | | | | | Forcing a function not to be inlined can be useful if it's the slow-path of a performance critical function, or should be visible in profiles to allow for proper cost attribution. Author: Andres Freund Discussion: https://postgr.es/m/20170914061207.zxotvyopetm7lrrp@alap3.anarazel.de
* Rely on sizeof(typename) rather than sizeof(variable) in pqformat.h.Tom Lane2017-10-13
| | | | | | | | | | | | | | In each of the pq_writeintN functions, the three uses of sizeof() should surely all be consistent. I started out to make them all sizeof(ni), but on reflection let's make them sizeof(typename) instead. That's more like our usual style elsewhere, and it's just barely possible that the failures buildfarm member hornet has shown since 4c119fbcd went in are caused by the compiler getting confused about sizeof() a parameter that it's optimizing away. In passing, improve a couple of comments. Discussion: https://postgr.es/m/E1e2RML-0002do-Lc@gemulon.postgresql.org
* Use C99 restrict via pg_restrict, rather than restrict directly.Andres Freund2017-10-12
| | | | | | | | | | | | | | | Unfortunately using 'restrict' plainly causes problems with MSVC, which supports restrict only as '__restrict'. Defining 'restrict' to '__restrict' unfortunately causes a conflict with MSVC's usage of __declspec(restrict) in headers. Therefore define pg_restrict to the appropriate keyword instead, and replace existing usages. This replaces the temporary workaround introduced in 36b4b91ba078. Author: Andres Freund Discussion: https://postgr.es/m/2656.1507830907@sss.pgh.pa.us
* Use ResultRelInfo ** rather than ResultRelInfo * for tuple routing.Robert Haas2017-10-12
| | | | | | | | | | | | The previous convention doesn't lend itself to creating ResultRelInfos lazily, as we already do in ExecGetTriggerResultRel. This patch doesn't make anything lazier than before, but the pending patch for UPDATE tuple routing proposes to do so (and there might be other opportunities as well). Amit Khandekar with some adjustments by me. Discussion: http://postgr.es/m/CA+TgmoYPVP9Lyf6vUFA5DwxS4c--x6LOj2y36BsJaYtp62eXPQ@mail.gmail.com
* Fix AggGetAggref() so it won't lie to aggregate final functions.Tom Lane2017-10-12
| | | | | | | | | | | | | | | | | | | | | | If we merge the transition calculations for two different aggregates, it's reasonable to assume that the transition function should not care which of those Aggref structs it gets from AggGetAggref(). It is not reasonable to make the same assumption about an aggregate final function, however. Commit 804163bc2 broke this, as it will pass whichever Aggref was first associated with the transition state in both cases. This doesn't create an observable bug so far as the core system is concerned, because the only existing uses of AggGetAggref() are in ordered-set aggregates that happen to not pay attention to anything but the input properties of the Aggref; and besides that, we disabled sharing of transition calculations for OSAs yesterday. Nonetheless, if some third-party code were using AggGetAggref() in a normal aggregate, they would be entitled to call this a bug. Hence, back-patch the fix to 9.6 where the problem was introduced. In passing, improve some of the comments about transition state sharing. Discussion: https://postgr.es/m/CAB4ELO5RZhOamuT9Xsf72ozbenDLLXZKSk07FiSVsuJNZB861A@mail.gmail.com
* Temporary attempt at a workaround for further MSVC restrict build failures.Andres Freund2017-10-11
| | | | | | | | It appears some versions of msvc use __declspec(restrict) in stdlib.h and subsidiary headers. Including those after defining 'restrict' to '__restrict' doesn't work. Try to get the buildfarm green to see whether there's further problems, by including stdlib.h just before said define.
* Work around overly strict restrict checks by MSVC.Andres Freund2017-10-11
| | | | | | | | | | | Apparently MSVC requires a * before a restrict in a variable declaration, even if the adorned type already is a pointer, just via typedef. As reported by buildfarm animal woodlouse. Author: Andres Freund Discussion: https://postgr.es/m/20171012001320.4putagiruuehtvb6@alap3.anarazel.de
* Improve performance of SendRowDescriptionMessage.Andres Freund2017-10-11
| | | | | | | | | | | | | | | There's three categories of changes leading to better performance: - Splitting the per-attribute part of SendRowDescriptionMessage into a v2 and a v3 version allows avoiding branches for every attribute. - Preallocating the size of the buffer to be big enough for all attributes and then using pq_write* avoids unnecessary buffer size checks & resizing. - Reusing a persistently allocated StringInfo for all SendRowDescriptionMessage() invocations avoids repeated allocations & reallocations. Author: Andres Freund Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
* pg_stat_statements: Widen query IDs from 32 bits to 64 bits.Robert Haas2017-10-11
| | | | | | | | | | | | | | | | | | This takes advantage of the infrastructure introduced by commit 81c5e46c490e2426db243eada186995da5bb0ba7 to greatly reduce the likelihood that two different queries will end up with the same query ID. It's still possible, of course, but whereas before it the chances of a collision reached 25% around 50,000 queries, it will now take more than 3 billion queries. Backward incompatibility: Because the type exposed at the SQL level is int8, users may now see negative query IDs in the pg_stat_statements view (and also, query IDs more than 4 billion, which was the old limit). Patch by me, reviewed by Michael Paquier and Peter Geoghegan. Discussion: http://postgr.es/m/CA+TgmobG_Kp4cBKFmsznUAaM1GWW6hhRNiZC0KjRMOOeYnz5Yw@mail.gmail.com
* Add more efficient functions to pqformat API.Andres Freund2017-10-11
| | | | | | | | | | | | | | | | | | | | | | | | | | There's three prongs to achieve greater efficiency here: 1) Allow reusing a stringbuffer across pq_beginmessage/endmessage, with the new pq_beginmessage_reuse/endmessage_reuse. This can be beneficial both because it avoids allocating the initial buffer, and because it's more likely to already have an correctly sized buffer. 2) Replacing pq_sendint() with pq_sendint$width() inline functions. Previously unnecessary and unpredictable branches in pq_sendint() were needed. Additionally the replacement functions are implemented more efficiently. pq_sendint is now deprecated, a separate commit will convert all in-tree callers. 3) Add pq_writeint$width(), pq_writestring(). These rely on sufficient space in the StringInfo's buffer, avoiding individual space checks & potential individual resizing. To allow this to be used for strings, expose mbutil.c's MAX_CONVERSION_GROWTH. Followup commits will make use of these facilities. Author: Andres Freund Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
* Allow to avoid NUL-byte management for stringinfos and use in format.c.Andres Freund2017-10-11
| | | | | | | | | | | | In a lot of the places having appendBinaryStringInfo() maintain a trailing NUL byte wasn't actually meaningful, e.g. when appending an integer which can contain 0 in one of its bytes. Removing this yields some small speedup, but more importantly will be more consistent when providing faster variants of pq_sendint etc. Author: Andres Freund Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
* Add configure infrastructure to detect support for C99's restrict.Andres Freund2017-10-11
| | | | | | | | | | | | | Will be used in later commits improving performance for a few key routines where information about aliasing allows for significantly better code generation. This allows to use the C99 'restrict' keyword without breaking C89, or for that matter C++, compilers. If not supported it's defined to be empty. Author: Andres Freund Discussion: https://postgr.es/m/20170914063418.sckdzgjfrsbekae4@alap3.anarazel.de
* Fix low-probability loss of NOTIFY messages due to XID wraparound.Tom Lane2017-10-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now async.c has used TransactionIdIsInProgress() to detect whether a notify message's source transaction is still running. However, that function has a quick-exit path that reports that XIDs before RecentXmin are no longer running. If a listening backend is doing nothing but listening, and not running any queries, there is nothing that will advance its value of RecentXmin. Once 2 billion transactions elapse, the RecentXmin check causes active transactions to be reported as not running. If they aren't committed yet according to CLOG, async.c decides they aborted and discards their messages. The timing for that is a bit tight but it can happen when multiple backends are sending notifies concurrently. The net symptom therefore is that a sufficiently-long-surviving listen-only backend starts to miss some fraction of NOTIFY traffic, but only under heavy load. The only function that updates RecentXmin is GetSnapshotData(). A brute-force fix would therefore be to take a snapshot before processing incoming notify messages. But that would add cycles, as well as contention for the ProcArrayLock. We can be smarter: having taken the snapshot, let's use that to check for running XIDs, and not call TransactionIdIsInProgress() at all. In this way we reduce the number of ProcArrayLock acquisitions from one per message to one per notify interrupt; that's the same under light load but should be a benefit under heavy load. Light testing says that this change is a wash performance-wise for normal loads. I looked around for other callers of TransactionIdIsInProgress() that might be at similar risk, and didn't find any; all of them are inside transactions that presumably have already taken a snapshot. Problem report and diagnosis by Marko Tiikkaja, patch by me. Back-patch to all supported branches, since it's been like this since 9.0. Discussion: https://postgr.es/m/20170926182935.14128.65278@wrigleys.postgresql.org
* Rewrite strnlen replacement implementation from 8a241792f96.Andres Freund2017-10-10
| | | | | | | | | | | | | The previous placement of the fallback implementation in libpgcommon was problematic, because libpqport functions need strnlen functionality. Move replacement into libpgport. Provide strnlen() under its posix name, instead of pg_strnlen(). Fix stupid configure bug, executing the test only when compiled with threading support. Author: Andres Freund Discussion: https://postgr.es/m/E1e1gR2-0005fB-SI@gemulon.postgresql.org