473 Commits (e6ccd1ce1644d1b40b7981f8bc172394de524f99)

Author	SHA1	Message	Date
Andres Freund	bf6c614a2f	Do execGrouping.c via expression eval machinery, take two. ... This has a performance benefit on own, although not hugely so. The primary benefit is that it will allow for to JIT tuple deforming and comparator invocations. Large parts of this were previously committed (773aec7aa), but the commit contained an omission around cross-type comparisons and was thus reverted. Author: Andres Freund Discussion: https://postgr.es/m/20171129080934.amqqkke2zjtekd4t@alap3.anarazel.de	8 years ago
Andres Freund	2a41507dab	Revert "Do execGrouping.c via expression eval machinery." ... This reverts commit 773aec7aa9. There's an unresolved issue in the reverted commit: It only creates one comparator function, but in for the nodeSubplan.c case we need more (c.f. FindTupleHashEntry vs LookupTupleHashEntry calls in nodeSubplan.c). This isn't too difficult to fix, but it's not entirely trivial either. The fact that the issue only causes breakage on 32bit systems shows that the current test coverage isn't that great. To avoid turning half the buildfarm red till those two issues are addressed, revert.	8 years ago
Andres Freund	773aec7aa9	Do execGrouping.c via expression eval machinery. ... This has a performance benefit on own, although not hugely so. The primary benefit is that it will allow for to JIT tuple deforming and comparator invocations. Author: Andres Freund Discussion: https://postgr.es/m/20171129080934.amqqkke2zjtekd4t@alap3.anarazel.de	8 years ago
Robert Haas	e44dd84325	Avoid listing the same ResultRelInfo in more than one EState list. ... Doing so causes EXPLAIN ANALYZE to show trigger statistics multiple times. Commit 2f17844104 seems to be to blame for this. Amit Langote, revieed by Amit Khandekar, Etsuro Fujita, and me.	8 years ago
Tom Lane	0a459cec96	Support all SQL:2011 options for window frame clauses. ... This patch adds the ability to use "RANGE offset PRECEDING/FOLLOWING" frame boundaries in window functions. We'd punted on that back in the original patch to add window functions, because it was not clear how to do it in a reasonably data-type-extensible fashion. That problem is resolved here by adding the ability for btree operator classes to provide an "in_range" support function that defines how to add or subtract the RANGE offset value. Factoring it this way also allows the operator class to avoid overflow problems near the ends of the datatype's range, if it wishes to expend effort on that. (In the committed patch, the integer opclasses handle that issue, but it did not seem worth the trouble to avoid overflow failures for datetime types.) The patch includes in_range support for the integer_ops opfamily (int2/int4/int8) as well as the standard datetime types. Support for other numeric types has been requested, but that seems like suitable material for a follow-on patch. In addition, the patch adds GROUPS mode which counts the offset in ORDER-BY peer groups rather than rows, and it adds the frame_exclusion options specified by SQL:2011. As far as I can see, we are now fully up to spec on window framing options. Existing behaviors remain unchanged, except that I changed the errcode for a couple of existing error reports to meet the SQL spec's expectation that negative "offset" values should be reported as SQLSTATE 22013. Internally and in relevant parts of the documentation, we now consistently use the terminology "offset PRECEDING/FOLLOWING" rather than "value PRECEDING/FOLLOWING", since the term "value" is confusingly vague. Oliver Ford, reviewed and whacked around some by me Discussion: https://postgr.es/m/CAGMVOdu9sivPAxbNN0X+q19Sfv9edEPv=HibOJhB14TJv_RCQg@mail.gmail.com	8 years ago
Robert Haas	9da0cc3528	Support parallel btree index builds. ... To make this work, tuplesort.c and logtape.c must also support parallelism, so this patch adds that infrastructure and then applies it to the particular case of parallel btree index builds. Testing to date shows that this can often be 2-3x faster than a serial index build. The model for deciding how many workers to use is fairly primitive at present, but it's better than not having the feature. We can refine it as we get more experience. Peter Geoghegan with some help from Rushabh Lathia. While Heikki Linnakangas is not an author of this patch, he wrote other patches without which this feature would not have been possible, and therefore the release notes should possibly credit him as an author of this feature. Reviewed by Claudio Freire, Heikki Linnakangas, Thomas Munro, Tels, Amit Kapila, me. Discussion: http://postgr.es/m/CAM3SWZQKM=Pzc=CAHzRixKjp2eO5Q0Jg1SoFQqeXFQ647JiwqQ@mail.gmail.com Discussion: http://postgr.es/m/CAH2-Wz=AxWqDoVvGU7dq856S4r6sJAj6DBn7VMtigkB33N5eyg@mail.gmail.com	8 years ago
Robert Haas	2f17844104	Allow UPDATE to move rows between partitions. ... When an UPDATE causes a row to no longer match the partition constraint, try to move it to a different partition where it does match the partition constraint. In essence, the UPDATE is split into a DELETE from the old partition and an INSERT into the new one. This can lead to surprising behavior in concurrency scenarios because EvalPlanQual rechecks won't work as they normally did; the known problems are documented. (There is a pending patch to improve the situation further, but it needs more review.) Amit Khandekar, reviewed and tested by Amit Langote, David Rowley, Rajkumar Raghuwanshi, Dilip Kumar, Amul Sul, Thomas Munro, Álvaro Herrera, Amit Kapila, and me. A few final revisions by me. Discussion: http://postgr.es/m/CAJ3gD9do9o2ccQ7j7+tSgiE1REY65XRiMb=yJO3u3QhyP8EEPQ@mail.gmail.com	8 years ago
Alvaro Herrera	8b08f7d482	Local partitioned indexes ... When CREATE INDEX is run on a partitioned table, create catalog entries for an index on the partitioned table (which is just a placeholder since the table proper has no data of its own), and recurse to create actual indexes on the existing partitions; create them in future partitions also. As a convenience gadget, if the new index definition matches some existing index in partitions, these are picked up and used instead of creating new ones. Whichever way these indexes come about, they become attached to the index on the parent table and are dropped alongside it, and cannot be dropped on isolation unless they are detached first. To support pg_dump'ing these indexes, add commands CREATE INDEX ON ONLY <table> (which creates the index on the parent partitioned table, without recursing) and ALTER INDEX ATTACH PARTITION (which is used after the indexes have been created individually on each partition, to attach them to the parent index). These reconstruct prior database state exactly. Reviewed-by: (in alphabetical order) Peter Eisentraut, Robert Haas, Amit Langote, Jesper Pedersen, Simon Riggs, David Rowley Discussion: https://postgr.es/m/20171113170646.gzweigyrgg6pwsg4@alvherre.pgsql	8 years ago
Andres Freund	69c3936a14	Expression evaluation based aggregate transition invocation. ... Previously aggregate transition and combination functions were invoked by special case code in nodeAgg.c, evaluating input and filters separately using the expression evaluation machinery. That turns out to not be great for performance for several reasons: - repeated expression evaluations have some cost - the transition functions invocations are poorly predicted, as commonly there are multiple aggregates in a query, resulting in the same call-stack invoking different functions. - filter and input computation had to be done separately - the special case code made it hard to implement JITing of the whole transition function invocation Address this by building one large expression that computes input, evaluates filters, and invokes transition functions. This leads to moderate speedups in queries bottlenecked by aggregate computations, and enables large speedups for similar cases once JITing is done. There's potential for further improvement: - It'd be nice if we could simplify the somewhat expensive aggstate->all_pergroups lookups. - right now there's still an advance_transition_function invocation in nodeAgg.c, leading to some code duplication. Author: Andres Freund Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de	8 years ago
Robert Haas	cc6337d2fe	Simplify and encapsulate tuple routing support code. ... Instead of having ExecSetupPartitionTupleRouting return multiple out parameters, have it return a pointer to a structure containing all of those different things. Also, provide and use a cleanup function, ExecCleanupTupleRouting, instead of cleaning up all of the resources allocated by ExecSetupPartitionTupleRouting individually. Amit Khandekar, reviewed by Amit Langote, David Rowley, and me Discussion: http://postgr.es/m/CAJ3gD9fWfxgKC+PfJZF3hkgAcNOy-LpfPxVYitDEXKHjeieWQQ@mail.gmail.com	8 years ago
Robert Haas	c759395617	Code review for Parallel Append. ... - Remove unnecessary #include mistakenly added in execnodes.h. - Fix mistake in comment in choose_next_subplan_for_leader. - Adjust row estimates in cost_append for a possibly-different parallel divisor. - Clamp row estimates in cost_append after operations that may not produce integers. Amit Kapila, with cosmetic adjustments by me. Discussion: http://postgr.es/m/CAA4eK1+qcbeai3coPpRW=GFCzFeLUsuY4T-AKHqMjxpEGZBPQg@mail.gmail.com	8 years ago
Bruce Momjian	9d4649ca49	Update copyright for 2018 ... Backpatch-through: certain files through 9.3	8 years ago
Andres Freund	f9ccf92e16	Simplify representation of aggregate transition values a bit. ... Previously aggregate transition values for hash and other forms of aggregation (i.e. sort and no group by) were represented differently. Hash based aggregation used a grouping set indexed array pointing to an array of transition values, whereas other forms of aggregation used one flattened array with the index being computed out of grouping set and transition offsets. That made upcoming changes hard, so represent both as grouping set indexed array of per-group data. As a nice side-effect this also makes aggregation slightly faster, because computing offsets with `transno + (setno * numTrans)` turns out not to be that cheap (too big for x86 lea for example). Author: Andres Freund Discussion: https://postgr.es/m/20171128003121.nmxbm2ounxzb6n2t@alap3.anarazel.de	8 years ago
Andres Freund	b40933101c	Perform slot validity checks in a separate pass over expression. ... This reduces code duplication a bit, but the primary benefit that it makes JITing expression evaluation easier. When doing so we can't, as previously done in the interpreted case, really change opcode without recompiling. Nor dow we just carry around unnecessary branches to avoid re-checking over and over. As a minor side-effect this makes ExecEvalStepOp() O(log(N)) rather than O(N). Author: Andres Freund Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de	8 years ago
Tom Lane	6719b238e8	Rearrange execution of PARAM_EXTERN Params for plpgsql's benefit. ... This patch does three interrelated things: * Create a new expression execution step type EEOP_PARAM_CALLBACK and add the infrastructure needed for add-on modules to generate that. As discussed, the best control mechanism for that seems to be to add another hook function to ParamListInfo, which will be called by ExecInitExpr if it's supplied and a PARAM_EXTERN Param is found. For stand-alone expressions, we add a new entry point to allow the ParamListInfo to be specified directly, since it can't be retrieved from the parent plan node's EState. * Redesign the API for the ParamListInfo paramFetch hook so that the ParamExternData array can be entirely virtual. This also lets us get rid of ParamListInfo.paramMask, instead leaving it to the paramFetch hook to decide which param IDs should be accessible or not. plpgsql_param_fetch was already doing the identical masking check, so having callers do it too seemed redundant. While I was at it, I added a "speculative" flag to paramFetch that the planner can specify as TRUE to avoid unwanted failures. This solves an ancient problem for plpgsql that it couldn't provide values of non-DTYPE_VAR variables to the planner for fear of triggering premature "record not assigned yet" or "field not found" errors during planning. * Rework plpgsql to get rid of the need for "unshared" parameter lists, by dint of turning the single ParamListInfo per estate into a nearly read-only data structure that doesn't instantiate any per-variable data. Instead, the paramFetch hook controls access to per-variable data and can make the right decisions on the fly, replacing the cases that we used to need multiple ParamListInfos for. This might perhaps have been a performance loss on its own, but by using a paramCompile hook we can bypass plpgsql_param_fetch entirely during normal query execution. (It's now only called when, eg, we copy the ParamListInfo into a cursor portal. copyParamList() or SerializeParamList() effectively instantiate the virtual parameter array as a simple physical array without a paramFetch hook, which is what we want in those cases.) This allows reverting most of commit 6c82d8d1f, though I kept the cosmetic code-consolidation aspects of that (eg the assign_simple_var function). Performance testing shows this to be at worst a break-even change, and it can provide wins ranging up to 20% in test cases involving accesses to fields of "record" variables. The fact that values of such variables can now be exposed to the planner might produce wins in some situations, too, but I've not pursued that angle. In passing, remove the "parent" pointer from the arguments to ExecInitExprRec and related functions, instead storing that pointer in a transient field in ExprState. The ParamListInfo pointer for a stand-alone expression is handled the same way; we'd otherwise have had to add yet another recursively-passed-down argument in expression compilation. Discussion: https://postgr.es/m/32589.1513706441@sss.pgh.pa.us	8 years ago
Andres Freund	1804284042	Add parallel-aware hash joins. ... Introduce parallel-aware hash joins that appear in EXPLAIN plans as Parallel Hash Join with Parallel Hash. While hash joins could already appear in parallel queries, they were previously always parallel-oblivious and had a partial subplan only on the outer side, meaning that the work of the inner subplan was duplicated in every worker. After this commit, the planner will consider using a partial subplan on the inner side too, using the Parallel Hash node to divide the work over the available CPU cores and combine its results in shared memory. If the join needs to be split into multiple batches in order to respect work_mem, then workers process different batches as much as possible and then work together on the remaining batches. The advantages of a parallel-aware hash join over a parallel-oblivious hash join used in a parallel query are that it: * avoids wasting memory on duplicated hash tables * avoids wasting disk space on duplicated batch files * divides the work of building the hash table over the CPUs One disadvantage is that there is some communication between the participating CPUs which might outweigh the benefits of parallelism in the case of small hash tables. This is avoided by the planner's existing reluctance to supply partial plans for small scans, but it may be necessary to estimate synchronization costs in future if that situation changes. Another is that outer batch 0 must be written to disk if multiple batches are required. A potential future advantage of parallel-aware hash joins is that right and full outer joins could be supported, since there is a single set of matched bits for each hashtable, but that is not yet implemented. A new GUC enable_parallel_hash is defined to control the feature, defaulting to on. Author: Thomas Munro Reviewed-By: Andres Freund, Robert Haas Tested-By: Rafia Sabih, Prabhat Sahu Discussion: https://postgr.es/m/CAEepm=2W=cOkiZxcg6qiFQP-dHUe09aqTrEMM7yJDrHMhDv_RA@mail.gmail.com https://postgr.es/m/CAEepm=37HKyJ4U6XOLi=JgfSHM3o6B-GaeO-6hkOmneTDkH+Uw@mail.gmail.com	8 years ago
Robert Haas	ab72716778	Support Parallel Append plan nodes. ... When we create an Append node, we can spread out the workers over the subplans instead of piling on to each subplan one at a time, which should typically be a bit more efficient, both because the startup cost of any plan executed entirely by one worker is paid only once and also because of reduced contention. We can also construct Append plans using a mix of partial and non-partial subplans, which may allow for parallelism in places that otherwise couldn't support it. Unfortunately, this patch doesn't handle the important case of parallelizing UNION ALL by running each branch in a separate worker; the executor infrastructure is added here, but more planner work is needed. Amit Khandekar, Robert Haas, Amul Sul, reviewed and tested by Ashutosh Bapat, Amit Langote, Rafia Sabih, Amit Kapila, and Rajkumar Raghuwanshi. Discussion: http://postgr.es/m/CAJ3gD9dy0K_E8r727heqXoBmWZ83HwLFwdcaSSmBQ1+S+vRuUQ@mail.gmail.com	8 years ago
Andres Freund	5bcf389ecf	Fix EXPLAIN ANALYZE of hash join when the leader doesn't participate. ... If a hash join appears in a parallel query, there may be no hash table available for explain.c to inspect even though a hash table may have been built in other processes. This could happen either because parallel_leader_participation was set to off or because the leader happened to hit the end of the outer relation immediately (even though the complete relation is not empty) and decided not to build the hash table. Commit bf11e7ee introduced a way for workers to exchange instrumentation via the DSM segment for Sort nodes even though they are not parallel-aware. This commit does the same for Hash nodes, so that explain.c has a way to find instrumentation data from an arbitrary participant that actually built the hash table. Author: Thomas Munro Reviewed-By: Andres Freund Discussion: https://postgr.es/m/CAEepm%3D3DUQC2-z252N55eOcZBer6DPdM%3DFzrxH9dZc5vYLsjaA%40mail.gmail.com	8 years ago
Peter Eisentraut	2eb4a831e5	Change TRUE/FALSE to true/false ... 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>	8 years ago
Tom Lane	7c70996ebf	Allow bitmap scans to operate as index-only scans when possible. ... 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	8 years ago
Robert Haas	f0392e677e	Revert "Move new structure member to the end." ... This reverts commit 94d622f27b. That commit was supposed to get pushed to REL_10_STABLE, but I messed up.	8 years ago
Robert Haas	94d622f27b	Move new structure member to the end. ... Reduces ABI breakage. Per Tom Lane. Discussion: http://postgr.es/m/4035.1509113974@sss.pgh.pa.us	8 years ago
Robert Haas	639c1a6bb9	Fix mistaken failure to allow parallelism in corner case. ... 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	8 years ago
Tom Lane	c3dfe0fec0	Repair breakage of aggregate FILTER option. ... 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	8 years ago
Robert Haas	60f7c0abef	Use ResultRelInfo ** rather than ResultRelInfo * for tuple routing. ... 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	8 years ago
Tom Lane	305cf1fd72	Fix AggGetAggref() so it won't lie to aggregate final functions. ... 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	8 years ago
Andres Freund	84ad4b036d	Reduce memory usage of targetlist SRFs. ... Previously nodeProjectSet only released memory once per input tuple, rather than once per returned tuple. If the computation of an individual returned tuple requires a lot of memory, that can lead to problems. Instead change things so that the expression context can be reset once per output tuple, which requires a new memory context to store SRF arguments in. This is a longstanding issue, but was hard to fix before 9.6, due to the way tSRFs where evaluated. But it's fairly easy to fix now. We could backpatch this into 10, but given there've been fewc omplaints that doesn't seem worth the risk so far. Reported-By: Lucas Fairchild Author: Andres Freund, per discussion with Tom Lane Discussion: https://postgr.es/m/4514.1507318623@sss.pgh.pa.us	8 years ago
Tom Lane	0f79440fb0	Fix SQL-spec incompatibilities in new transition table feature. ... The standard says that all changes of the same kind (insert, update, or delete) caused in one table by a single SQL statement should be reported in a single transition table; and by that, they mean to include foreign key enforcement actions cascading from the statement's direct effects. It's also reasonable to conclude that if the standard had wCTEs, they would say that effects of wCTEs applying to the same table as each other or the outer statement should be merged into one transition table. We weren't doing it like that. Hence, arrange to merge tuples from multiple update actions into a single transition table as much as we can. There is a problem, which is that if the firing of FK enforcement triggers and after-row triggers with transition tables is interspersed, we might need to report more tuples after some triggers have already seen the transition table. It seems like a bad idea for the transition table to be mutable between trigger calls. There's no good way around this without a major redesign of the FK logic, so for now, resolve it by opening a new transition table each time this happens. Also, ensure that AFTER STATEMENT triggers fire just once per statement, or once per transition table when we're forced to make more than one. Previous versions of Postgres have allowed each FK enforcement query to cause an additional firing of the AFTER STATEMENT triggers for the referencing table, but that's certainly not per spec. (We're still doing multiple firings of BEFORE STATEMENT triggers, though; is that something worth changing?) Also, forbid using transition tables with column-specific UPDATE triggers. The spec requires such transition tables to show only the tuples for which the UPDATE trigger would have fired, which means maintaining multiple transition tables or else somehow filtering the contents at readout. Maybe someday we'll bother to support that option, but it looks like a lot of trouble for a marginal feature. The transition tables are now managed by the AfterTriggers data structures, rather than being directly the responsibility of ModifyTable nodes. This removes a subtransaction-lifespan memory leak introduced by my previous band-aid patch 3c4359521. In passing, refactor the AfterTriggers data structures to reduce the management overhead for them, by using arrays of structs rather than several parallel arrays for per-query-level and per-subtransaction state. I failed to resist the temptation to do some copy-editing on the SGML docs about triggers, above and beyond merely documenting the effects of this patch. Back-patch to v10, because we don't want the semantics of transition tables to change post-release. Patch by me, with help and review from Thomas Munro. Discussion: https://postgr.es/m/20170909064853.25630.12825@wrigleys.postgresql.org	8 years ago
Tom Lane	2d44c58c79	Avoid memory leaks when a GatherMerge node is rescanned. ... Rescanning a GatherMerge led to leaking some memory in the executor's query-lifespan context, because most of the node's working data structures were simply abandoned and rebuilt from scratch. In practice, this might never amount to much, given the cost of relaunching worker processes --- but it's still pretty messy, so let's fix it. We can rearrange things so that the tuple arrays are simply cleared and reused, and we don't need to rebuild the TupleTableSlots either, just clear them. One small complication is that because we might get a different number of workers on each iteration, we can't keep the old convention that the leader's gm_slots[] entry is the last one; the leader might clobber a TupleTableSlot that we need for a worker in a future iteration. Hence, adjust the logic so that the leader has slot 0 always, while the active workers have slots 1..n. Back-patch to v10 to keep all the existing versions of nodeGatherMerge.c in sync --- because of the renumbering of the slots, there would otherwise be a very large risk that any future backpatches in this module would introduce bugs. Discussion: https://postgr.es/m/8670.1504192177@sss.pgh.pa.us	8 years ago
Tom Lane	04e9678614	Code review for nodeGatherMerge.c. ... Comment the fields of GatherMergeState, and organize them a bit more sensibly. Comment GMReaderTupleBuffer more usefully too. Improve assorted other comments that were obsolete or just not very good English. Get rid of the use of a GMReaderTupleBuffer for the leader process; that was confusing, since only the "done" field was used, and that in a way redundant with need_to_scan_locally. In gather_merge_init, avoid calling load_tuple_array for already-known-exhausted workers. I'm not sure if there's a live bug there, but the case is unlikely to be well tested due to timing considerations. Remove some useless code, such as duplicating the tts_isempty test done by TupIsNull. Remove useless initialization of ps.qual, replacing that with an assertion that we have no qual to check. (If we did, the code would fail to check it.) Avoid applying heap_copytuple to a null tuple. While that fails to crash, it's confusing and it makes the code less legible not more so IMO. Propagate a couple of these changes into nodeGather.c, as well. Back-patch to v10, partly because of the possibility that the gather_merge_init change is fixing a live bug, but mostly to keep the branches in sync to ease future bug fixes.	8 years ago
Robert Haas	bf11e7ee2e	Propagate sort instrumentation from workers back to leader. ... Up until now, when parallel query was used, no details about the sort method or space used by the workers were available; details were shown only for any sorting done by the leader. Fix that. Commit 1177ab1dab forced the test case added by commit 1f6d515a67 to run without parallelism; now that we have this infrastructure, allow that again, with a little tweaking to make it pass with and without force_parallel_mode. Robert Haas and Tom Lane Discussion: http://postgr.es/m/CA+Tgmoa2VBZW6S8AAXfhpHczb=Rf6RqQ2br+zJvEgwJ0uoD_tQ@mail.gmail.com	8 years ago
Robert Haas	3452dc5240	Push tuple limits through Gather and Gather Merge. ... If we only need, say, 10 tuples in total, then we certainly don't need more than 10 tuples from any single process. Pushing down the limit lets workers exit early when possible. For Gather Merge, there is an additional benefit: a Sort immediately below the Gather Merge can be done as a bounded sort if there is an applicable limit. Robert Haas and Tom Lane Discussion: http://postgr.es/m/CA+TgmoYa3QKKrLj5rX7UvGqhH73G1Li4B-EKxrmASaca2tFu9Q@mail.gmail.com	8 years ago
Robert Haas	c4b841ba6a	Fix interaction of triggers, partitioning, and EXPLAIN ANALYZE. ... Add a new EState member es_leaf_result_relations, so that the trigger code knows about ResultRelInfos created by tuple routing. Also make sure ExplainPrintTriggers knows about partition-related ResultRelInfos. Etsuro Fujita, reviewed by Amit Langote Discussion: http://postgr.es/m/57163e18-8e56-da83-337a-22f2c0008051@lab.ntt.co.jp	9 years ago
Tom Lane	21d304dfed	Final pgindent + perltidy run for v10.	9 years ago
Andres Freund	cc9f08b6b8	Move ExecProcNode from dispatch to function pointer based model. ... This allows us to add stack-depth checks the first time an executor node is called, and skip that overhead on following calls. Additionally it yields a nice speedup. While it'd probably have been a good idea to have that check all along, it has become more important after the new expression evaluation framework in b8d7f053c5 - there's no stack depth check in common paths anymore now. We previously relied on ExecEvalExpr() being executed somewhere. We should move towards that model for further routines, but as this is required for v10, it seems better to only do the necessary (which already is quite large). Author: Andres Freund, Tom Lane Reported-By: Julien Rouhaud Discussion: https://postgr.es/m/22833.1490390175@sss.pgh.pa.us https://postgr.es/m/b0af9eaa-130c-60d0-9e4e-7a135b1e0c76@dalibo.com	9 years ago
Andrew Gierth	501ed02cf6	Fix transition tables for partition/inheritance. ... We disallow row-level triggers with transition tables on child tables. Transition tables for triggers on the parent table contain only those columns present in the parent. (We can't mix tuple formats in a single transition table.) Patch by Thomas Munro Discussion: https://postgr.es/m/CA%2BTgmoZzTBBAsEUh4MazAN7ga%3D8SsMC-Knp-6cetts9yNZUCcg%40mail.gmail.com	9 years ago
Peter Eisentraut	113b0045e2	Reformat comments about ResultRelInfo ... Also add a comment on its new member PartitionRoot. Reported-by: Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>	9 years ago
Tom Lane	c7b8998ebb	Phase 2 of pgindent updates. ... Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4d wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us	9 years ago
Tom Lane	e3860ffa4d	Initial pgindent run with pg_bsd_indent version 2.0. ... The new indent version includes numerous fixes thanks to Piotr Stefaniak. The main changes visible in this commit are: * Nicer formatting of function-pointer declarations. * No longer unexpectedly removes spaces in expressions using casts, sizeof, or offsetof. * No longer wants to add a space in "struct structname *varname", as well as some similar cases for const- or volatile-qualified pointers. * Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely. * Fixes bug where comments following declarations were sometimes placed with no space separating them from the code. * Fixes some odd decisions for comments following case labels. * Fixes some cases where comments following code were indented to less than the expected column 33. On the less good side, it now tends to put more whitespace around typedef names that are not listed in typedefs.list. This might encourage us to put more effort into typedef name collection; it's not really a bug in indent itself. There are more changes coming after this round, having to do with comment indentation and alignment of lines appearing within parentheses. I wanted to limit the size of the diffs to something that could be reviewed without one's eyes completely glazing over, so it seemed better to split up the changes as much as practical. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us	9 years ago
Magnus Hagander	bb1f8f9e5b	Fix typos in comments ... Author: Daniel Gustafsson <daniel@yesql.se>	9 years ago
Bruce Momjian	a6fd7b7a5f	Post-PG 10 beta1 pgindent run ... perltidy run not included.	9 years ago
Robert Haas	e180c8aa8c	Fire per-statement triggers on partitioned tables. ... Even though no actual tuples are ever inserted into a partitioned table (the actual tuples are in the partitions, not the partitioned table itself), we still need to have a ResultRelInfo for the partitioned table, or per-statement triggers won't get fired. Amit Langote, per a report from Rajkumar Raghuwanshi. Reviewed by me. Discussion: http://postgr.es/m/CAKcux6%3DwYospCRY2J4XEFuVy0L41S%3Dfic7rmkbsU-GXhhSbmBg%40mail.gmail.com	9 years ago
Tom Lane	9c7f5229ad	Optimize joins when the inner relation can be proven unique. ... If there can certainly be no more than one matching inner row for a given outer row, then the executor can move on to the next outer row as soon as it's found one match; there's no need to continue scanning the inner relation for this outer row. This saves useless scanning in nestloop and hash joins. In merge joins, it offers the opportunity to skip mark/restore processing, because we know we have not advanced past the first possible match for the next outer row. Of course, the devil is in the details: the proof of uniqueness must depend only on joinquals (not otherquals), and if we want to skip mergejoin mark/restore then it must depend only on merge clauses. To avoid adding more planning overhead than absolutely necessary, the present patch errs in the conservative direction: there are cases where inner_unique or skip_mark_restore processing could be used, but it will not do so because it's not sure that the uniqueness proof depended only on "safe" clauses. This could be improved later. David Rowley, reviewed and rather heavily editorialized on by me Discussion: https://postgr.es/m/CAApHDvqF6Sw-TK98bW48TdtFJ+3a7D2mFyZ7++=D-RyPsL76gw@mail.gmail.com	9 years ago
Kevin Grittner	18ce3a4ab2	Add infrastructure to support EphemeralNamedRelation references. ... A QueryEnvironment concept is added, which allows new types of objects to be passed into queries from parsing on through execution. At this point, the only thing implemented is a collection of EphemeralNamedRelation objects -- relations which can be referenced by name in queries, but do not exist in the catalogs. The only type of ENR implemented is NamedTuplestore, but provision is made to add more types fairly easily. An ENR can carry its own TupleDesc or reference a relation in the catalogs by relid. Although these features can be used without SPI, convenience functions are added to SPI so that ENRs can easily be used by code run through SPI. The initial use of all this is going to be transition tables in AFTER triggers, but that will be added to each PL as a separate commit. An incidental effect of this patch is to produce a more informative error message if an attempt is made to modify the contents of a CTE from a referencing DML statement. No tests previously covered that possibility, so one is added. Kevin Grittner and Thomas Munro Reviewed by Heikki Linnakangas, David Fetter, and Thomas Munro with valuable comments and suggestions from many others	9 years ago
Andrew Gierth	b5635948ab	Support hashed aggregation with grouping sets. ... This extends the Aggregate node with two new features: HashAggregate can now run multiple hashtables concurrently, and a new strategy MixedAggregate populates hashtables while doing sorted grouping. The planner will now attempt to save as many sorts as possible when planning grouping sets queries, while not exceeding work_mem for the estimated combined sizes of all hashtables used. No SQL-level changes are required. There should be no user-visible impact other than the new EXPLAIN output and possible changes to result ordering when ORDER BY was not used (which affected a few regression tests). The enable_hashagg option is respected. Author: Andrew Gierth Reviewers: Mark Dilger, Andres Freund Discussion: https://postgr.es/m/87vatszyhj.fsf@news-spur.riddles.org.uk	9 years ago
Andres Freund	b8d7f053c5	Faster expression evaluation and targetlist projection. ... This replaces the old, recursive tree-walk based evaluation, with non-recursive, opcode dispatch based, expression evaluation. Projection is now implemented as part of expression evaluation. This both leads to significant performance improvements, and makes future just-in-time compilation of expressions easier. The speed gains primarily come from: - non-recursive implementation reduces stack usage / overhead - simple sub-expressions are implemented with a single jump, without function calls - sharing some state between different sub-expressions - reduced amount of indirect/hard to predict memory accesses by laying out operation metadata sequentially; including the avoidance of nearly all of the previously used linked lists - more code has been moved to expression initialization, avoiding constant re-checks at evaluation time Future just-in-time compilation (JIT) has become easier, as demonstrated by released patches intended to be merged in a later release, for primarily two reasons: Firstly, due to a stricter split between expression initialization and evaluation, less code has to be handled by the JIT. Secondly, due to the non-recursive nature of the generated "instructions", less performance-critical code-paths can easily be shared between interpreted and compiled evaluation. The new framework allows for significant future optimizations. E.g.: - basic infrastructure for to later reduce the per executor-startup overhead of expression evaluation, by caching state in prepared statements. That'd be helpful in OLTPish scenarios where initialization overhead is measurable. - optimizing the generated "code". A number of proposals for potential work has already been made. - optimizing the interpreter. Similarly a number of proposals have been made here too. The move of logic into the expression initialization step leads to some backward-incompatible changes: - Function permission checks are now done during expression initialization, whereas previously they were done during execution. In edge cases this can lead to errors being raised that previously wouldn't have been, e.g. a NULL array being coerced to a different array type previously didn't perform checks. - The set of domain constraints to be checked, is now evaluated once during expression initialization, previously it was re-built every time a domain check was evaluated. For normal queries this doesn't change much, but e.g. for plpgsql functions, which caches ExprStates, the old set could stick around longer. The behavior around might still change. Author: Andres Freund, with significant changes by Tom Lane, changes by Heikki Linnakangas Reviewed-By: Tom Lane, Heikki Linnakangas Discussion: https://postgr.es/m/20161206034955.bh33paeralxbtluv@alap3.anarazel.de	9 years ago
Robert Haas	355d3993c5	Add a Gather Merge executor node. ... Like Gather, we spawn multiple workers and run the same plan in each one; however, Gather Merge is used when each worker produces the same output ordering and we want to preserve that output ordering while merging together the streams of tuples from various workers. (In a way, Gather Merge is like a hybrid of Gather and MergeAppend.) This works out to a win if it saves us from having to perform an expensive Sort. In cases where only a small amount of data would need to be sorted, it may actually be faster to use a regular Gather node and then sort the results afterward, because Gather Merge sometimes needs to wait synchronously for tuples whereas a pure Gather generally doesn't. But if this avoids an expensive sort then it's a win. Rushabh Lathia, reviewed and tested by Amit Kapila, Thomas Munro, and Neha Sharma, and reviewed and revised by me. Discussion: http://postgr.es/m/CAGPqQf09oPX-cQRpBKS0Gq49Z+m6KBxgxd_p9gX8CKk_d75HoQ@mail.gmail.com	9 years ago
Robert Haas	f35742ccb7	Support parallel bitmap heap scans. ... The index is scanned by a single process, but then all cooperating processes can iterate jointly over the resulting set of heap blocks. In the future, we might also want to support using a parallel bitmap index scan to set up for a parallel bitmap heap scan, but that's a job for another day. Dilip Kumar, with some corrections and cosmetic changes by me. The larger patch set of which this is a part has been reviewed and tested by (at least) Andres Freund, Amit Khandekar, Tushar Ahuja, Rafia Sabih, Haribabu Kommi, Thomas Munro, and me. Discussion: http://postgr.es/m/CAFiTN-uc4=0WxRGfCzs-xfkMYcSEWUC-Fon6thkJGjkh9i=13A@mail.gmail.com	9 years ago
Alvaro Herrera	fcec6caafa	Support XMLTABLE query expression ... XMLTABLE is defined by the SQL/XML standard as a feature that allows turning XML-formatted data into relational form, so that it can be used as a <table primary> in the FROM clause of a query. This new construct provides significant simplicity and performance benefit for XML data processing; what in a client-side custom implementation was reported to take 20 minutes can be executed in 400ms using XMLTABLE. (The same functionality was said to take 10 seconds using nested PostgreSQL XPath function calls, and 5 seconds using XMLReader under PL/Python). The implemented syntax deviates slightly from what the standard requires. First, the standard indicates that the PASSING clause is optional and that multiple XML input documents may be given to it; we make it mandatory and accept a single document only. Second, we don't currently support a default namespace to be specified. This implementation relies on a new executor node based on a hardcoded method table. (Because the grammar is fixed, there is no extensibility in the current approach; further constructs can be implemented on top of this such as JSON_TABLE, but they require changes to core code.) Author: Pavel Stehule, Álvaro Herrera Extensively reviewed by: Craig Ringer Discussion: https://postgr.es/m/CAFj8pRAgfzMD-LoSmnMGybD0WsEznLHWap8DO79+-GTRAPR4qA@mail.gmail.com	9 years ago
Robert Haas	4c728f3829	Pass the source text for a parallel query to the workers. ... With this change, you can see the query that a parallel worker is executing in pg_stat_activity, and if the worker crashes you can see what query it was executing when it crashed. Rafia Sabih, reviewed by Kuntal Ghosh and Amit Kapila and slightly revised by me.	9 years ago