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* Update copyright for 2021Bruce Momjian2021-01-021-1/+1
| | | | Backpatch-through: 9.5
* Fix some grammar and typos in comments and docsMichael Paquier2020-11-021-1/+1
| | | | | | | | The documentation fixes are backpatched down to where they apply. Author: Justin Pryzby Discussion: https://postgr.es/m/20201031020801.GD3080@telsasoft.com Backpatch-through: 9.6
* Dial back -Wimplicit-fallthrough to level 3Alvaro Herrera2020-05-131-2/+2
| | | | | | | | | The additional pain from level 4 is excessive for the gain. Also revert all the source annotation changes to their original wordings, to avoid back-patching pain. Discussion: https://postgr.es/m/31166.1589378554@sss.pgh.pa.us
* Add -Wimplicit-fallthrough to CFLAGS and CXXFLAGSAlvaro Herrera2020-05-121-2/+2
| | | | | | | | | | | | | | | Use it at level 4, a bit more restrictive than the default level, and tweak our commanding comments to FALLTHROUGH. (However, leave zic.c alone, since it's external code; to avoid the warnings that would appear there, change CFLAGS for that file in the Makefile.) Author: Julien Rouhaud <rjuju123@gmail.com> Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/20200412081825.qyo5vwwco3fv4gdo@nol Discussion: https://postgr.es/m/flat/E1fDenm-0000C8-IJ@gemulon.postgresql.org
* Suppress -Wimplicit-fallthrough warning in new LIMIT WITH TIES code.Tom Lane2020-04-111-14/+19
| | | | | | | | | | | The placement of the fall-through comment in this code appears not to work to suppress the warning in recent gcc. Move it to the bottom of the case group, and add an assertion that we didn't get there through some other code path. Also improve wording of nearby comments. Julien Rouhaud, comment hacking by me Discussion: https://postgr.es/m/CAOBaU_aLdPGU5wCpaowNLF-Q8328iR7mj1yJAhMOVsdLwY+sdg@mail.gmail.com
* Support FETCH FIRST WITH TIESAlvaro Herrera2020-04-071-16/+144
| | | | | | | | | | | | | | | | | | WITH TIES is an option to the FETCH FIRST N ROWS clause (the SQL standard's spelling of LIMIT), where you additionally get rows that compare equal to the last of those N rows by the columns in the mandatory ORDER BY clause. There was a proposal by Andrew Gierth to implement this functionality in a more powerful way that would yield more features, but the other patch had not been finished at this time, so we decided to use this one for now in the spirit of incremental development. Author: Surafel Temesgen <surafel3000@gmail.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Tomas Vondra <tomas.vondra@2ndquadrant.com> Discussion: https://postgr.es/m/CALAY4q9ky7rD_A4vf=FVQvCGngm3LOes-ky0J6euMrg=_Se+ag@mail.gmail.com Discussion: https://postgr.es/m/87o8wvz253.fsf@news-spur.riddles.org.uk
* Update copyrights for 2020Bruce Momjian2020-01-011-1/+1
| | | | Backpatch-through: update all files in master, backpatch legal files through 9.4
* Don't shut down Gather[Merge] early under Limit.Amit Kapila2019-11-261-8/+6
| | | | | | | | | | | | | | | | | | | Revert part of commit 19df1702f5. Early shutdown was added by that commit so that we could collect statistics from workers, but unfortunately, it interacted badly with rescans. The problem is that we ended up destroying the parallel context which is required for rescans. This leads to rescans of a Limit node over a Gather node to produce unpredictable results as it tries to access destroyed parallel context. By reverting the early shutdown code, we might lose statistics in some cases of Limit over Gather [Merge], but that will require further study to fix. Reported-by: Jerry Sievers Diagnosed-by: Thomas Munro Author: Amit Kapila, testcase by Vignesh C Backpatch-through: 9.6 Discussion: https://postgr.es/m/87ims2amh6.fsf@jsievers.enova.com
* Update copyright for 2019Bruce Momjian2019-01-021-1/+1
| | | | Backpatch-through: certain files through 9.4
* Introduce notion of different types of slots (without implementing them).Andres Freund2018-11-151-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Upcoming work intends to allow pluggable ways to introduce new ways of storing table data. Accessing those table access methods from the executor requires TupleTableSlots to be carry tuples in the native format of such storage methods; otherwise there'll be a significant conversion overhead. Different access methods will require different data to store tuples efficiently (just like virtual, minimal, heap already require fields in TupleTableSlot). To allow that without requiring additional pointer indirections, we want to have different structs (embedding TupleTableSlot) for different types of slots. Thus different types of slots are needed, which requires adapting creators of slots. The slot that most efficiently can represent a type of tuple in an executor node will often depend on the type of slot a child node uses. Therefore we need to track the type of slot is returned by nodes, so parent slots can create slots based on that. Relatedly, JIT compilation of tuple deforming needs to know which type of slot a certain expression refers to, so it can create an appropriate deforming function for the type of tuple in the slot. But not all nodes will only return one type of slot, e.g. an append node will potentially return different types of slots for each of its subplans. Therefore add function that allows to query the type of a node's result slot, and whether it'll always be the same type (whether it's fixed). This can be queried using ExecGetResultSlotOps(). The scan, result, inner, outer type of slots are automatically inferred from ExecInitScanTupleSlot(), ExecInitResultSlot(), left/right subtrees respectively. If that's not correct for a node, that can be overwritten using new fields in PlanState. This commit does not introduce the actually abstracted implementation of different kind of TupleTableSlots, that will be left for a followup commit. The different types of slots introduced will, for now, still use the same backing implementation. While this already partially invalidates the big comment in tuptable.h, it seems to make more sense to update it later, when the different TupleTableSlot implementations actually exist. Author: Ashutosh Bapat and Andres Freund, with changes by Amit Khandekar Discussion: https://postgr.es/m/20181105210039.hh4vvi4vwoq5ba2q@alap3.anarazel.de
* Don't require return slots for nodes without projection.Andres Freund2018-11-091-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In a lot of nodes the return slot is not required. That can either be because the node doesn't do any projection (say an Append node), or because the node does perform projections but the projection is optimized away because the projection would yield an identical row. Slots aren't that small, especially for wide rows, so it's worthwhile to avoid creating them. It's not possible to just skip creating the slot - it's currently used to determine the tuple descriptor returned by ExecGetResultType(). So separate the determination of the result type from the slot creation. The work previously done internally ExecInitResultTupleSlotTL() can now also be done separately with ExecInitResultTypeTL() and ExecInitResultSlot(). That way nodes that aren't guaranteed to need a result slot, can use ExecInitResultTypeTL() to determine the result type of the node, and ExecAssignScanProjectionInfo() (via ExecConditionalAssignProjectionInfo()) determines that a result slot is needed, it is created with ExecInitResultSlot(). Besides the advantage of avoiding to create slots that then are unused, this is necessary preparation for later patches around tuple table slot abstraction. In particular separating the return descriptor and slot is a prerequisite to allow JITing of tuple deforming with knowledge of the underlying tuple format, and to avoid unnecessarily creating JITed tuple deforming for virtual slots. This commit removes a redundant argument from ExecInitResultTupleSlotTL(). While this commit touches a lot of the relevant lines anyway, it'd normally still not worthwhile to cause breakage, except that aforementioned later commits will touch *all* ExecInitResultTupleSlotTL() callers anyway (but fits worse thematically). Author: Andres Freund Discussion: https://postgr.es/m/20181105210039.hh4vvi4vwoq5ba2q@alap3.anarazel.de
* Prohibit shutting down resources if there is a possibility of back up.Amit Kapila2018-08-131-2/+8
| | | | | | | | | | | | | | | Currently, we release the asynchronous resources as soon as it is evident that no more rows will be needed e.g. when a Limit is filled. This can be problematic especially for custom and foreign scans where we can scan backward. Fix that by disallowing the shutting down of resources in such cases. Reported-by: Robert Haas Analysed-by: Robert Haas and Amit Kapila Author: Amit Kapila Reviewed-by: Robert Haas Backpatch-through: 9.6 where this code was introduced Discussion: https://postgr.es/m/86137f17-1dfb-42f9-7421-82fd786b04a1@anayrat.info
* Fix buffer usage stats for parallel nodes.Amit Kapila2018-08-031-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | The buffer usage stats is accounted only for the execution phase of the node. For Gather and Gather Merge nodes, such stats are accumulated at the time of shutdown of workers which is done after execution of node due to which we missed to account them for such nodes. Fix it by treating nodes as running while we shut down them. We can also miss accounting for a Limit node when Gather or Gather Merge is beneath it, because it can finish the execution before shutting down such nodes. So we allow a Limit node to shut down the resources before it completes the execution. In the passing fix the gather node code to allow workers to shut down as soon as we find that all the tuples from the workers have been retrieved. The original code use to do that, but is accidently removed by commit 01edb5c7fc. Reported-by: Adrien Nayrat Author: Amit Kapila and Robert Haas Reviewed-by: Robert Haas and Andres Freund Backpatch-through: 9.6 where this code was introduced Discussion: https://postgr.es/m/86137f17-1dfb-42f9-7421-82fd786b04a1@anayrat.info
* Allow tupleslots to have a fixed tupledesc, use in executor nodes.Andres Freund2018-02-161-9/+9
| | | | | | | | | | | | | | | | | | | | | The reason for doing so is that it will allow expression evaluation to optimize based on the underlying tupledesc. In particular it will allow to JIT tuple deforming together with the expression itself. For that expression initialization needs to be moved after the relevant slots are initialized - mostly unproblematic, except in the case of nodeWorktablescan.c. After doing so there's no need for ExecAssignResultType() and ExecAssignResultTypeFromTL() anymore, as all former callers have been converted to create a slot with a fixed descriptor. When creating a slot with a fixed descriptor, tts_values/isnull can be allocated together with the main slot, reducing allocation overhead and increasing cache density a bit. Author: Andres Freund Discussion: https://postgr.es/m/20171206093717.vqdxe5icqttpxs3p@alap3.anarazel.de
* Update copyright for 2018Bruce Momjian2018-01-021-1/+1
| | | | Backpatch-through: certain files through 9.3
* Push tuple limits through Gather and Gather Merge.Robert Haas2017-08-291-82/+16
| | | | | | | | | | | | 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
* Code review for pushing LIMIT through subqueries.Tom Lane2017-08-251-28/+30
| | | | | | | | | | | | Minor improvements for commit 1f6d515a6. We do not need the (rather expensive) test for SRFs in the targetlist, because since v10 any such SRFs would appear in separate ProjectSet nodes. Also, make the code look more like the existing cases by turning it into a simple recursion --- the argument that there might be some performance benefit to contorting the code seems unfounded to me, especially since any good compiler should turn the tail-recursion into iteration anyway. Discussion: http://postgr.es/m/CADE5jYLuugnEEUsyW6Q_4mZFYTxHxaVCQmGAsF0yiY8ZDggi-w@mail.gmail.com
* Push limit through subqueries to underlying sort, where possible.Robert Haas2017-08-211-0/+26
| | | | | | | Douglas Doole, reviewed by Ashutosh Bapat and by me. Minor formatting change by me. Discussion: http://postgr.es/m/CADE5jYLuugnEEUsyW6Q_4mZFYTxHxaVCQmGAsF0yiY8ZDggi-w@mail.gmail.com
* Move ExecProcNode from dispatch to function pointer based model.Andres Freund2017-07-301-2/+4
| | | | | | | | | | | | | | | | | | | | | | 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 b8d7f053c5c2bf2a7e - 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
* Move interrupt checking from ExecProcNode() to executor nodes.Andres Freund2017-07-301-0/+3
| | | | | | | | | | | | | | | | | In a followup commit ExecProcNode(), and especially the large switch it contains, will largely be replaced by a function pointer directly to the correct node. The node functions will then get invoked by a thin inline function wrapper. To avoid having to include miscadmin.h in headers - CHECK_FOR_INTERRUPTS() - move the interrupt checks into the individual executor routines. While looking through all executor nodes, I noticed a number of arguably missing interrupt checks, add these too. Author: Andres Freund, Tom Lane Reviewed-By: Tom Lane Discussion: https://postgr.es/m/22833.1490390175@sss.pgh.pa.us
* Phase 3 of pgindent updates.Tom Lane2017-06-211-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. 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
* Remove obsoleted code relating to targetlist SRF evaluation.Andres Freund2017-01-191-14/+5
| | | | | | | | | | | | | Since 69f4b9c plain expression evaluation (and thus normal projection) can't return sets of tuples anymore. Thus remove code dealing with that possibility. This will require adjustments in external code using ExecEvalExpr()/ExecProject() - that should neither be hard nor very common. Author: Andres Freund and Tom Lane Discussion: https://postgr.es/m/20160822214023.aaxz5l4igypowyri@alap3.anarazel.de
* Update copyright via script for 2017Bruce Momjian2017-01-031-1/+1
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* Update copyright for 2016Bruce Momjian2016-01-021-1/+1
| | | | Backpatch certain files through 9.1
* Update copyright for 2015Bruce Momjian2015-01-061-1/+1
| | | | Backpatch certain files through 9.0
* pgindent run for 9.4Bruce Momjian2014-05-061-1/+1
| | | | | This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
* Update copyright for 2014Bruce Momjian2014-01-071-1/+1
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Update copyrights for 2013Bruce Momjian2013-01-011-1/+1
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Update copyright notices for year 2012.Bruce Momjian2012-01-011-1/+1
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* Avoid integer overflow when LIMIT + OFFSET >= 2^63.Heikki Linnakangas2011-08-021-1/+1
| | | | This fixes bug #6139 reported by Hitoshi Harada.
* pgindent run before PG 9.1 beta 1.Bruce Momjian2011-04-101-7/+7
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* Stamp copyrights for year 2011.Bruce Momjian2011-01-011-1/+1
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* Dept of second thoughts: don't try to push LIMIT below a SRF.Tom Lane2010-11-181-1/+14
| | | | | | | | If we have Limit->Result->Sort, the Result might be projecting a tlist that contains a set-returning function. If so, it's possible for the SRF to sometimes return zero rows, which means we could need to fetch more than N rows from the Sort in order to satisfy LIMIT N. So top-N sorting cannot be used in this scenario.
* Further fallout from the MergeAppend patch.Tom Lane2010-11-181-17/+40
| | | | | | | | | | | | | | Fix things so that top-N sorting can be used in child Sort nodes of a MergeAppend node, when there is a LIMIT and no intervening joins or grouping. Actually doing this on the executor side isn't too bad, but it's a bit messier to get the planner to cost it properly. Per gripe from Robert Haas. In passing, fix an oversight in the original top-N-sorting patch: query_planner should not assume that a LIMIT can be used to make an explicit sort cheaper when there will be grouping or aggregation in between. Possibly this should be back-patched, but I'm not sure the mistake is serious enough to be a real problem in practice.
* Remove cvs keywords from all files.Magnus Hagander2010-09-201-1/+1
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* Make NestLoop plan nodes pass outer-relation variables into their innerTom Lane2010-07-121-4/+4
| | | | | | | | | | | | relation using the general PARAM_EXEC executor parameter mechanism, rather than the ad-hoc kluge of passing the outer tuple down through ExecReScan. The previous method was hard to understand and could never be extended to handle parameters coming from multiple join levels. This patch doesn't change the set of possible plans nor have any significant performance effect, but it's necessary infrastructure for future generalization of the concept of an inner indexscan plan. ExecReScan's second parameter is now unused, so it's removed.
* Update copyright for the year 2010.Bruce Momjian2010-01-021-2/+2
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* Remove no-longer-needed ExecCountSlots infrastructure.Tom Lane2009-09-271-11/+1
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* 8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef listBruce Momjian2009-06-111-3/+3
| | | | provided by Andrew.
* Revert DTrace patch from Robert LorBruce Momjian2009-04-021-4/+1
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* Add support for additional DTrace probes.Bruce Momjian2009-04-021-1/+4
| | | | Robert Lor
* Add new SQL:2008 error codes for invalid LIMIT and OFFSET values. RemovePeter Eisentraut2009-03-041-3/+3
| | | | | unused nonstandard error code that was perhaps intended for this but never used.
* Update copyright for 2009.Bruce Momjian2009-01-011-2/+2
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* Throw an error for negative LIMIT or OFFSET values, instead of silentlyTom Lane2008-03-101-3/+7
| | | | treating them as zero. Simon Riggs
* Update copyrights in source tree to 2008.Bruce Momjian2008-01-011-2/+2
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* pgindent run for 8.3.Bruce Momjian2007-11-151-11/+12
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* Fix parameter recalculation for Limit nodes: during a ReScan call we mustTom Lane2007-05-171-11/+23
| | | | | | | | | | | | | recompute the limit/offset immediately, so that the updated values are available when the child's ReScan function is invoked. Add a regression test for this, too. Bug is new in HEAD (due to the bounded-sorting patch) so no need for back-patch. I did not do anything about merging this signaling with chgParam processing, but if we were to do that we'd still need to compute the updated values at this point rather than during the first ProcNode call. Per observation and test case from Greg Stark, though I didn't use his patch.
* Teach tuplesort.c about "top N" sorting, in which only the first N tuplesTom Lane2007-05-041-1/+32
| | | | | | | | | | need be returned. We keep a heap of the current best N tuples and sift-up new tuples into it as we scan the input. For M input tuples this means only about M*log(N) comparisons instead of M*log(M), not to mention a lot less workspace when N is small --- avoiding spill-to-disk for large M is actually the most attractive thing about it. Patch includes planner and executor support for invoking this facility in ORDER BY ... LIMIT queries. Greg Stark, with some editorialization by moi.
* Update CVS HEAD for 2007 copyright. Back branches are typically notBruce Momjian2007-01-051-2/+2
| | | | back-stamped for this.
* Fix LIMIT/OFFSET for null limit values. This worked before 8.2 but was brokenTom Lane2006-12-031-16/+26
| | | | | | by the change to make limit values int8 instead of int4. (Specifically, you can do DatumGetInt32 safely on a null value, but not DatumGetInt64.) Per bug #2803 from Greg Johnson.
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