76 Commits (4d3f03f42227bb351c2021a9ccea2fff9c023cfc)

Author	SHA1	Message	Date
Tom Lane	f21636e5d5	Remove useless entries for aggregate functions from fmgrtab.c. ... Gen_fmgrtab.pl treated aggregate functions the same as other built-in functions, which is wasteful because there is no real need to have entries for them in the fmgr_builtins[] table. Suppressing those entries saves about 3KB in the compiled table on my machine; which is not a lot but it's not nothing either, considering that that table is pretty "hot". The only outside code change needed is that ExecInitWindowAgg() can't be allowed to call fmgr_info_cxt() on a plain aggregate function. But that saves a few cycles anyway. Having done that, the aggregate_dummy() function is unreferenced and might as well be dropped. Using "aggregate_dummy" as the prosrc value for an aggregate is now just a documentation convention not something that matters. There was some discussion of using NULL instead to save a few bytes in pg_proc, but we'd have to remove prosrc's BKI_FORCE_NOT_NULL marking which doesn't seem a great idea. Anyway, it's possible there's client-side code that expects to see "aggregate_dummy" there, so I'm loath to change it without a strong reason. Discussion: https://postgr.es/m/533989.1604263665@sss.pgh.pa.us	5 years ago
Bruce Momjian	7559d8ebfa	Update copyrights for 2020 ... Backpatch-through: update all files in master, backpatch legal files through 9.4	6 years ago
Amit Kapila	14aec03502	Make the order of the header file includes consistent in backend modules. ... Similar to commits 7e735035f2 and dddf4cdc33, this commit makes the order of header file inclusion consistent for backend modules. In the passing, removed a couple of duplicate inclusions. Author: Vignesh C Reviewed-by: Kuntal Ghosh and Amit Kapila Discussion: https://postgr.es/m/CALDaNm2Sznv8RR6Ex-iJO6xAdsxgWhCoETkaYX=+9DW3q0QCfA@mail.gmail.com	6 years ago
Andres Freund	6a04d345fd	Don't include utils/array.h from acl.h. ... For most uses of acl.h the details of how "Acl" internally looks like are irrelevant. It might make sense to move a lot of the implementation details into a separate header at a later point. The main motivation of this change is to avoid including fmgr.h (via array.h, which needs it for exposed structs) in a lot of files that otherwise don't need it. A subsequent commit will remove the fmgr.h include from a lot of files. Directly include utils/array.h and utils/expandeddatum.h from the files that need them, but previously included them indirectly, via acl.h. Author: Andres Freund Discussion: https://postgr.es/m/20190803193733.g3l3x3o42uv4qj7l@alap3.anarazel.de	6 years ago
Michael Paquier	8548ddc61b	Fix inconsistencies and typos in the tree, take 9 ... This addresses more issues with code comments, variable names and unreferenced variables. Author: Alexander Lakhin Discussion: https://postgr.es/m/7ab243e0-116d-3e44-d120-76b3df7abefd@gmail.com	6 years ago
Tom Lane	8255c7a5ee	Phase 2 pgindent run for v12. ... Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com	7 years ago
Peter Eisentraut	5e1963fb76	Collations with nondeterministic comparison ... This adds a flag "deterministic" to collations. If that is false, such a collation disables various optimizations that assume that strings are equal only if they are byte-wise equal. That then allows use cases such as case-insensitive or accent-insensitive comparisons or handling of strings with different Unicode normal forms. This functionality is only supported with the ICU provider. At least glibc doesn't appear to have any locales that work in a nondeterministic way, so it's not worth supporting this for the libc provider. The term "deterministic comparison" in this context is from Unicode Technical Standard #10 (https://unicode.org/reports/tr10/#Deterministic_Comparison). This patch makes changes in three areas: - CREATE COLLATION DDL changes and system catalog changes to support this new flag. - Many executor nodes and auxiliary code are extended to track collations. Previously, this code would just throw away collation information, because the eventually-called user-defined functions didn't use it since they only cared about equality, which didn't need collation information. - String data type functions that do equality comparisons and hashing are changed to take the (non-)deterministic flag into account. For comparison, this just means skipping various shortcuts and tie breakers that use byte-wise comparison. For hashing, we first need to convert the input string to a canonical "sort key" using the ICU analogue of strxfrm(). Reviewed-by: Daniel Verite <daniel@manitou-mail.org> Reviewed-by: Peter Geoghegan <pg@bowt.ie> Discussion: https://www.postgresql.org/message-id/flat/1ccc668f-4cbc-0bef-af67-450b47cdfee7@2ndquadrant.com	7 years ago
Tom Lane	f09346a9c6	Refactor planner's header files. ... Create a new header optimizer/optimizer.h, which exposes just the planner functions that can be used "at arm's length", without need to access Paths or the other planner-internal data structures defined in nodes/relation.h. This is intended to provide the whole planner API seen by most of the rest of the system; although FDWs still need to use additional stuff, and more thought is also needed about just what selfuncs.c should rely on. The main point of doing this now is to limit the amount of new #include baggage that will be needed by "planner support functions", which I expect to introduce later, and which will be in relevant datatype modules rather than anywhere near the planner. This commit just moves relevant declarations into optimizer.h from other header files (a couple of which go away because everything got moved), and adjusts #include lists to match. There's further cleanup that could be done if we want to decide that some stuff being exposed by optimizer.h doesn't belong in the planner at all, but I'll leave that for another day. Discussion: https://postgr.es/m/11460.1548706639@sss.pgh.pa.us	7 years ago
Andres Freund	a9c35cf85c	Change function call information to be variable length. ... Before this change FunctionCallInfoData, the struct arguments etc for V1 function calls are stored in, always had space for FUNC_MAX_ARGS/100 arguments, storing datums and their nullness in two arrays. For nearly every function call 100 arguments is far more than needed, therefore wasting memory. Arg and argnull being two separate arrays also guarantees that to access a single argument, two cachelines have to be touched. Change the layout so there's a single variable-length array with pairs of value / isnull. That drastically reduces memory consumption for most function calls (on x86-64 a two argument function now uses 64bytes, previously 936 bytes), and makes it very likely that argument value and its nullness are on the same cacheline. Arguments are stored in a new NullableDatum struct, which, due to padding, needs more memory per argument than before. But as usually far fewer arguments are stored, and individual arguments are cheaper to access, that's still a clear win. It's likely that there's other places where conversion to NullableDatum arrays would make sense, e.g. TupleTableSlots, but that's for another commit. Because the function call information is now variable-length allocations have to take the number of arguments into account. For heap allocations that can be done with SizeForFunctionCallInfoData(), for on-stack allocations there's a new LOCAL_FCINFO(name, nargs) macro that helps to allocate an appropriately sized and aligned variable. Some places with stack allocation function call information don't know the number of arguments at compile time, and currently variably sized stack allocations aren't allowed in postgres. Therefore allow for FUNC_MAX_ARGS space in these cases. They're not that common, so for now that seems acceptable. Because of the need to allocate FunctionCallInfo of the appropriate size, older extensions may need to update their code. To avoid subtle breakages, the FunctionCallInfoData struct has been renamed to FunctionCallInfoBaseData. Most code only references FunctionCallInfo, so that shouldn't cause much collateral damage. This change is also a prerequisite for more efficient expression JIT compilation (by allocating the function call information on the stack, allowing LLVM to optimize it away); previously the size of the call information caused problems inside LLVM's optimizer. Author: Andres Freund Reviewed-By: Tom Lane Discussion: https://postgr.es/m/20180605172952.x34m5uz6ju6enaem@alap3.anarazel.de	7 years ago
Bruce Momjian	97c39498e5	Update copyright for 2019 ... Backpatch-through: certain files through 9.4	7 years ago
Andres Freund	1a0586de36	Introduce notion of different types of slots (without implementing them). ... 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	7 years ago
Andres Freund	1ef6bd2954	Don't require return slots for nodes without projection. ... 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	7 years ago
Tom Lane	ff4f889164	Fix bugs with degenerate window ORDER BY clauses in GROUPS/RANGE mode. ... nodeWindowAgg.c failed to cope with the possibility that no ordering columns are defined in the window frame for GROUPS mode or RANGE OFFSET mode, leading to assertion failures or odd errors, as reported by Masahiko Sawada and Lukas Eder. In RANGE OFFSET mode, an ordering column is really required, so add an Assert about that. In GROUPS mode, the code would work, except that the node initialization code wasn't in sync with the execution code about when to set up tuplestore read pointers and spare slots. Fix the latter for consistency's sake (even though I think the changes described below make the out-of-sync cases unreachable for now). Per SQL spec, a single ordering column is required for RANGE OFFSET mode, and at least one ordering column is required for GROUPS mode. The parser enforced the former but not the latter; add a check for that. We were able to reach the no-ordering-column cases even with fully spec compliant queries, though, because the planner would drop partitioning and ordering columns from the generated plan if they were redundant with earlier columns according to the redundant-pathkey logic, for instance "PARTITION BY x ORDER BY y" in the presence of a "WHERE x=y" qual. While in principle that's an optimization that could save some pointless comparisons at runtime, it seems unlikely to be meaningful in the real world. I think this behavior was not so much an intentional optimization as a side-effect of an ancient decision to construct the plan node's ordering-column info by reverse-engineering the PathKeys of the input path. If we give up redundant-column removal then it takes very little code to generate the plan node info directly from the WindowClause, ensuring that we have the expected number of ordering columns in all cases. (If anyone does complain about this, the planner could perhaps be taught to remove redundant columns only when it's safe to do so, ie *not* in RANGE OFFSET mode. But I doubt anyone ever will.) With these changes, the WindowAggPath.winpathkeys field is not used for anything anymore, so remove it. The test cases added here are not actually very interesting given the removal of the redundant-column-removal logic, but they would represent important corner cases if anyone ever tries to put that back. Tom Lane and Masahiko Sawada. Back-patch to v11 where RANGE OFFSET and GROUPS modes were added. Discussion: https://postgr.es/m/CAD21AoDrWqycq-w_+Bx1cjc+YUhZ11XTj9rfxNiNDojjBx8Fjw@mail.gmail.com Discussion: https://postgr.es/m/153086788677.17476.8002640580496698831@wrigleys.postgresql.org	8 years ago
Peter Eisentraut	387543f7bd	Make new error code name match SQL standard more closely ... Discussion: https://www.postgresql.org/message-id/dff3d555-bea4-ac24-29b2-29521b9d08e8%402ndquadrant.com	8 years ago
Tom Lane	9fe802c818	Fix brown-paper-bag bug in commit 0a459cec96. ... RANGE_OFFSET comparisons need to examine the first ORDER BY column, which isn't necessarily the first column in the incoming tuples. No idea how this slipped through initial testing. Per bug #15082 from Zhou Digoal. Discussion: https://postgr.es/m/151939899974.1461.9411971793110285476@wrigleys.postgresql.org	8 years ago
Andres Freund	ad7dbee368	Allow tupleslots to have a fixed tupledesc, use in executor nodes. ... 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	8 years ago
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
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
Peter Eisentraut	8b9e9644dc	Replace AclObjectKind with ObjectType ... AclObjectKind was basically just another enumeration for object types, and we already have a preferred one for that. It's only used in aclcheck_error. By using ObjectType instead, we can also give some more precise error messages, for example "index" instead of "relation". Reviewed-by: Michael Paquier <michael.paquier@gmail.com>	8 years ago
Bruce Momjian	9d4649ca49	Update copyright for 2018 ... Backpatch-through: certain files through 9.3	8 years ago
Tom Lane	4de2d4fba3	Explicitly track whether aggregate final functions modify transition state. ... 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	8 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
Andres Freund	d47cfef711	Move interrupt checking from ExecProcNode() to executor nodes. ... 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	9 years ago
Tom Lane	382ceffdf7	Phase 3 of pgindent updates. ... 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	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
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
Heikki Linnakangas	181bdb90ba	Fix typos in comments. ... Backpatch to all supported versions, where applicable, to make backpatching of future fixes go more smoothly. Josh Soref Discussion: https://www.postgresql.org/message-id/CACZqfqCf+5qRztLPgmmosr-B0Ye4srWzzw_mo4c_8_B_mtjmJQ@mail.gmail.com	9 years ago
Andres Freund	ea15e18677	Remove obsoleted code relating to targetlist SRF evaluation. ... 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	9 years ago
Bruce Momjian	1d25779284	Update copyright via script for 2017	9 years ago
Tom Lane	9a00f03e47	Improve speed of aggregates that use array_append as transition function. ... In the previous coding, if an aggregate's transition function returned an expanded array, nodeAgg.c and nodeWindowAgg.c would always copy it and thus force it into the flat representation. This led to ping-ponging between flat and expanded formats, which costs a lot. For an aggregate using array_append as transition function, I measured about a 15X slowdown compared to the pre-9.5 code, when working on simple int[] arrays. Of course, the old code was already O(N^2) in this usage due to copying flat arrays all the time, but it wasn't quite this inefficient. To fix, teach nodeAgg.c and nodeWindowAgg.c to allow expanded transition values without copying, so long as the transition function takes care to return the transition value already properly parented under the aggcontext. That puts a bit of extra responsibility on the transition function, but doing it this way allows us to not need any extra logic in the fast path of advance_transition_function (ie, with a pass-by-value transition value, or with a modified-in-place pass-by-reference value). We already know that that's a hot spot so I'm loath to add any cycles at all there. Also, while only array_append currently knows how to follow this convention, this solution allows other transition functions to opt-in without needing to have a whitelist in the core aggregation code. (The reason we would need a whitelist is that currently, if you pass a R/W expanded-object pointer to an arbitrary function, it's allowed to do anything with it including deleting it; that breaks the core agg code's assumption that it should free discarded values. Returning a value under aggcontext is the transition function's signal that it knows it is an aggregate transition function and will play nice. Possibly the API rules for expanded objects should be refined, but that would not be a back-patchable change.) With this fix, an aggregate using array_append is no longer O(N^2), so it's much faster than pre-9.5 code rather than much slower. It's still a bit slower than the bespoke infrastructure for array_agg, but the differential seems to be only about 10%-20% rather than orders of magnitude. Discussion: <6315.1477677885@sss.pgh.pa.us>	9 years ago
Tom Lane	ac4a9d92fc	Fix incorrect handling of polymorphic aggregates used as window functions. ... The transfunction was told that its first argument and result were of the window function output type, not the aggregate state type. This'd only matter if the transfunction consults get_fn_expr_argtype, which typically only polymorphic functions would do. Although we have several regression tests around polymorphic aggs, none of them detected this mistake --- in fact, they still didn't fail when I injected the same mistake into nodeAgg.c. So add some more tests covering both plain agg and window-function-agg cases. Per report from Sebastian Luque. Back-patch to 9.6 where the error was introduced (by sloppy refactoring in commit 804163bc2, looks like). Report: <87int2qkat.fsf@gmail.com>	9 years ago
Tom Lane	ea268cdc9a	Add macros to make AllocSetContextCreate() calls simpler and safer. ... I found that half a dozen (nearly 5%) of our AllocSetContextCreate calls had typos in the context-sizing parameters. While none of these led to especially significant problems, they did create minor inefficiencies, and it's now clear that expecting people to copy-and-paste those calls accurately is not a great idea. Let's reduce the risk of future errors by introducing single macros that encapsulate the common use-cases. Three such macros are enough to cover all but two special-purpose contexts; those two calls can be left as-is, I think. While this patch doesn't in itself improve matters for third-party extensions, it doesn't break anything for them either, and they can gradually adopt the simplified notation over time. In passing, change TopMemoryContext to use the default allocation parameters. Formerly it could only be extended 8K at a time. That was probably reasonable when this code was written; but nowadays we create many more contexts than we did then, so that it's not unusual to have a couple hundred K in TopMemoryContext, even without considering various dubious code that sticks other things there. There seems no good reason not to let it use growing blocks like most other contexts. Back-patch to 9.6, mostly because that's still close enough to HEAD that it's easy to do so, and keeping the branches in sync can be expected to avoid some future back-patching pain. The bugs fixed by these changes don't seem to be significant enough to justify fixing them further back. Discussion: <21072.1472321324@sss.pgh.pa.us>	9 years ago
Robert Haas	4bc424b968	pgindent run for 9.6	10 years ago
Bruce Momjian	ee94300446	Update copyright for 2016 ... Backpatch certain files through 9.1	10 years ago
Heikki Linnakangas	804163bc25	Share transition state between different aggregates when possible. ... If there are two different aggregates in the query with same inputs, and the aggregates have the same initial condition and transition function, only calculate the state value once, and only call the final functions separately. For example, AVG(x) and SUM(x) aggregates have the same transition function, which accumulates the sum and number of input tuples. For a query like "SELECT AVG(x), SUM(x) FROM x", we can therefore accumulate the state function only once, which gives a nice speedup. David Rowley, reviewed and edited by me.	11 years ago
Bruce Momjian	807b9e0dff	pgindent run for 9.5	11 years ago
Robert Haas	40f42d2a34	Use outerPlanState macro instead of referring to leffttree. ... This makes the executor code more consistent. It also removes an apparently superfluous NULL test in nodeGroup.c. Qingqing Zhou, reviewed by Tom Lane, and further revised by me.	11 years ago
Bruce Momjian	4baaf863ec	Update copyright for 2015 ... Backpatch certain files through 9.0	11 years ago
Peter Eisentraut	303f4d1012	Assorted message fixes and improvements	11 years ago
Bruce Momjian	0a78320057	pgindent run for 9.4 ... This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.	12 years ago
Tom Lane	f0fedfe82c	Allow polymorphic aggregates to have non-polymorphic state data types. ... Before 9.4, such an aggregate couldn't be declared, because its final function would have to have polymorphic result type but no polymorphic argument, which CREATE FUNCTION would quite properly reject. The ordered-set-aggregate patch found a workaround: allow the final function to be declared as accepting additional dummy arguments that have types matching the aggregate's regular input arguments. However, we failed to notice that this problem applies just as much to regular aggregates, despite the fact that we had a built-in regular aggregate array_agg() that was known to be undeclarable in SQL because its final function had an illegal signature. So what we should have done, and what this patch does, is to decouple the extra-dummy-arguments behavior from ordered-set aggregates and make it generally available for all aggregate declarations. We have to put this into 9.4 rather than waiting till later because it slightly alters the rules for declaring ordered-set aggregates. The patch turned out a bit bigger than I'd hoped because it proved necessary to record the extra-arguments option in a new pg_aggregate column. I'd thought we could just look at the final function's pronargs at runtime, but that didn't work well for variadic final functions. It's probably just as well though, because it simplifies life for pg_dump to record the option explicitly. While at it, fix array_agg() to have a valid final-function signature, and add an opr_sanity test to notice future deviations from polymorphic consistency. I also marked the percentile_cont() aggregates as not needing extra arguments, since they don't.	12 years ago
Tom Lane	e0c91a7ff0	Improve some O(N^2) behavior in window function evaluation. ... Repositioning the tuplestore seek pointer in window_gettupleslot() turns out to be a very significant expense when the window frame is sizable and the frame end can move. To fix, introduce a tuplestore function for skipping an arbitrary number of tuples in one call, parallel to the one we introduced for tuplesort objects in commit 8d65da1f. This reduces the cost of window_gettupleslot() to O(1) if the tuplestore has not spilled to disk. As in the previous commit, I didn't try to do any real optimization of tuplestore_skiptuples for the case where the tuplestore has spilled to disk. There is probably no practical way to get the cost to less than O(N) anyway, but perhaps someone can think of something later. Also fix PersistHoldablePortal() to make use of this API now that we have it. Based on a suggestion by Dean Rasheed, though this turns out not to look much like his patch.	12 years ago
Tom Lane	a9d9acbf21	Create infrastructure for moving-aggregate optimization. ... Until now, when executing an aggregate function as a window function within a window with moving frame start (that is, any frame start mode except UNBOUNDED PRECEDING), we had to recalculate the aggregate from scratch each time the frame head moved. This patch allows an aggregate definition to include an alternate "moving aggregate" implementation that includes an inverse transition function for removing rows from the aggregate's running state. As long as this can be done successfully, runtime is proportional to the total number of input rows, rather than to the number of input rows times the average frame length. This commit includes the core infrastructure, documentation, and regression tests using user-defined aggregates. Follow-on commits will update some of the built-in aggregates to use this feature. David Rowley and Florian Pflug, reviewed by Dean Rasheed; additional hacking by me	12 years ago
Bruce Momjian	7e04792a1c	Update copyright for 2014 ... Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.	12 years ago
Tom Lane	8d65da1f01	Support ordered-set (WITHIN GROUP) aggregates. ... This patch introduces generic support for ordered-set and hypothetical-set aggregate functions, as well as implementations of the instances defined in SQL:2008 (percentile_cont(), percentile_disc(), rank(), dense_rank(), percent_rank(), cume_dist()). We also added mode() though it is not in the spec, as well as versions of percentile_cont() and percentile_disc() that can compute multiple percentile values in one pass over the data. Unlike the original submission, this patch puts full control of the sorting process in the hands of the aggregate's support functions. To allow the support functions to find out how they're supposed to sort, a new API function AggGetAggref() is added to nodeAgg.c. This allows retrieval of the aggregate call's Aggref node, which may have other uses beyond the immediate need. There is also support for ordered-set aggregates to install cleanup callback functions, so that they can be sure that infrastructure such as tuplesort objects gets cleaned up. In passing, make some fixes in the recently-added support for variadic aggregates, and make some editorial adjustments in the recent FILTER additions for aggregates. Also, simplify use of IsBinaryCoercible() by allowing it to succeed whenever the target type is ANY or ANYELEMENT. It was inconsistent that it dealt with other polymorphic target types but not these. Atri Sharma and Andrew Gierth; reviewed by Pavel Stehule and Vik Fearing, and rather heavily editorialized upon by Tom Lane	12 years ago
Tom Lane	0d3f4406df	Allow aggregate functions to be VARIADIC. ... There's no inherent reason why an aggregate function can't be variadic (even VARIADIC ANY) if its transition function can handle the case. Indeed, this patch to add the feature touches none of the planner or executor, and little of the parser; the main missing stuff was DDL and pg_dump support. It is true that variadic aggregates can create the same sort of ambiguity about parameters versus ORDER BY keys that was complained of when we (briefly) had both one- and two-argument forms of string_agg(). However, the policy formed in response to that discussion only said that we'd not create any built-in aggregates with varying numbers of arguments, not that we shouldn't allow users to do it. So the logical extension of that is we can allow users to make variadic aggregates as long as we're wary about shipping any such in core. In passing, this patch allows aggregate function arguments to be named, to the extent of remembering the names in pg_proc and dumping them in pg_dump. You can't yet call an aggregate using named-parameter notation. That seems like a likely future extension, but it'll take some work, and it's not what this patch is really about. Likewise, there's still some work needed to make window functions handle VARIADIC fully, but I left that for another day. initdb forced because of new aggvariadic field in Aggref parse nodes.	12 years ago
Noah Misch	b560ec1b0d	Implement the FILTER clause for aggregate function calls. ... This is SQL-standard with a few extensions, namely support for subqueries and outer references in clause expressions. catversion bump due to change in Aggref and WindowFunc. David Fetter, reviewed by Dean Rasheed.	13 years ago