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* Update copyright for 2025Bruce Momjian2025-01-01
| | | | Backpatch-through: 13
* Fix possible crash during WindowAgg evaluationDavid Rowley2024-12-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When short-circuiting WindowAgg node evaluation on the top-level WindowAgg node using quals on monotonic window functions, because the WindowAgg run condition can mean there's no need to evaluate subsequent window function results in the same partition once the run condition becomes false, it was possible that the executor would use stale results from the previous invocation of the window function in some cases. A fix for this was partially done by a5832722, but that commit only fixed the issue for non-top-level WindowAgg nodes. I mistakenly thought that the top-level WindowAgg didn't have this issue, but Jayesh's example case clearly shows that's incorrect. At the time, I also thought that this only affected 32-bit systems as all window functions which then supported run conditions returned BIGINT, however, that's wrong as ExecProject is still called and that could cause evaluation of any other window function belonging to the same WindowAgg node, one of which may return a byref type. The only queries affected by this are WindowAggs with a "Run Condition" which contains at least one window function with a byref result type, such as lead() or lag() on a byref column. The window clause must also contain a PARTITION BY clause (without a PARTITION BY, execution of the WindowAgg stops immediately when the run condition becomes false and there's no risk of using the stale results). Reported-by: Jayesh Dehankar Discussion: https://postgr.es/m/193261e2c4d.3dd3cd7c1842.871636075166132237@zohocorp.com Backpatch-through: 15, where WindowAgg run conditions were added
* Remove useless casts to (void *)Peter Eisentraut2024-11-28
| | | | | | | | Many of them just seem to have been copied around for no real reason. Their presence causes (small) risks of hiding actual type mismatches or silently discarding qualifiers Discussion: https://www.postgresql.org/message-id/flat/461ea37c-8b58-43b4-9736-52884e862820@eisentraut.org
* Optimize WindowAgg's use of tuplestoresDavid Rowley2024-09-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When WindowAgg finished one partition of a PARTITION BY, it previously would call tuplestore_end() to purge all the stored tuples before again calling tuplestore_begin_heap() and carefully setting up all of the tuplestore read pointers exactly as required for the given frameOptions. Since the frameOptions don't change between partitions, this part does not make much sense. For queries that had very few rows per partition, the overhead of this was very large. It seems much better to create the tuplestore and the read pointers once and simply call tuplestore_clear() at the end of each partition. tuplestore_clear() moves all of the read pointers back to the start position and deletes all the previously stored tuples. A simple test query with 1 million partitions and 1 tuple per partition has been shown to run around 40% faster than without this change. The additional effort seems to have mostly been spent in malloc/free. Making this work required adding a new bool field to WindowAggState which had the unfortunate effect of being the 9th bool field in a group resulting in the struct being enlarged. Here we shuffle the fields around a little so that the two bool fields for runcondition relating stuff fit into existing padding. Also, move the "runcondition" field to be near those. This frees up enough space with the other bool fields so that the newly added one fits into the padding bytes. This was done to address a very small but apparent performance regression with queries containing a large number of rows per partition. Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Reviewed-by: Tatsuo Ishii <ishii@postgresql.org> Discussion: https://postgr.es/m/CAHoyFK9n-QCXKTUWT_xxtXninSMEv%2BgbJN66-y6prM3f4WkEHw%40mail.gmail.com
* Speedup WindowAgg code by moving uncommon code out-of-lineDavid Rowley2024-09-05
| | | | | | | | | | The code to calculate the frame offsets is only performed once per scan. Moving this code out of line gives a small (around 4-5%) speedup when testing with some CPUs. Other tested CPUs are indifferent to the change. Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Reviewed-by: Tatsuo Ishii <ishii@postgresql.org> Discussion: https://postgr.es/m/CAApHDvqPgFtwme2Zyf75BpMLwYr2mnUstDyPiP%3DEpudYuQTPPQ%40mail.gmail.com
* Fix unnecessary use of moving-aggregate mode with non-moving frame.Tom Lane2024-03-27
| | | | | | | | | | | | | | | | | | | | When a plain aggregate is used as a window function, and the window frame start is specified as UNBOUNDED PRECEDING, the frame's head cannot move so we do not need to use moving-aggregate mode. The check for that was put into initialize_peragg(), failing to notice that ExecInitWindowAgg() calls that function before it's filled in winstate->frameOptions. Since makeNode() would have zeroed the field, this didn't provoke uninitialized-value complaints, nor would the erroneous decision have resulted in more than a little inefficiency. Still, it's wrong, so move the initialization of winstate->frameOptions earlier to make it work properly. While here, also fix a thinko in a comment. Both errors crept in in commit a9d9acbf2 which introduced the moving-aggregate mode. Spotted by Vallimaharajan G. Back-patch to all supported branches. Discussion: https://postgr.es/m/18e7f2a5167.fe36253866818.977923893562469143@zohocorp.com
* Update copyright for 2024Bruce Momjian2024-01-03
| | | | | | | | Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
* Retire MemoryContextResetAndDeleteChildren() macro.Nathan Bossart2023-11-15
| | | | | | | | | | | | | | | | | As of commit eaa5808e8e, MemoryContextResetAndDeleteChildren() is just a backwards compatibility macro for MemoryContextReset(). Now that some time has passed, this macro seems more likely to create confusion. This commit removes the macro and replaces all remaining uses with calls to MemoryContextReset(). Any third-party code that use this macro will need to be adjusted to call MemoryContextReset() instead. Since the two have behaved the same way since v9.5, such adjustments won't produce any behavior changes for all currently-supported versions of PostgreSQL. Reviewed-by: Amul Sul, Tom Lane, Alvaro Herrera, Dagfinn Ilmari Mannsåker Discussion: https://postgr.es/m/20231113185950.GA1668018%40nathanxps13
* Remove obsolete executor cleanup codeAmit Langote2023-09-28
| | | | | | | | | | | | | | | | | | | This commit removes unnecessary ExecExprFreeContext() calls in ExecEnd* routines because the actual cleanup is managed by FreeExecutorState(). With no callers remaining for ExecExprFreeContext(), this commit also removes the function. This commit also drops redundant ExecClearTuple() calls, because ExecResetTupleTable() in ExecEndPlan() already takes care of resetting and dropping all TupleTableSlots initialized with ExecInitScanTupleSlot() and ExecInitExtraTupleSlot(). After these modifications, the ExecEnd*() routines for ValuesScan, NamedTuplestoreScan, and WorkTableScan became redundant. So, this commit removes them. Reviewed-by: Robert Haas Discussion: https://postgr.es/m/CA+HiwqFGkMSge6TgC9KQzde0ohpAycLQuV7ooitEEpbKB0O_mg@mail.gmail.com
* Pre-beta mechanical code beautification.Tom Lane2023-05-19
| | | | | | | | | | | | | | | Run pgindent, pgperltidy, and reformat-dat-files. This set of diffs is a bit larger than typical. We've updated to pg_bsd_indent 2.1.2, which properly indents variable declarations that have multi-line initialization expressions (the continuation lines are now indented one tab stop). We've also updated to perltidy version 20230309 and changed some of its settings, which reduces its desire to add whitespace to lines to make assignments etc. line up. Going forward, that should make for fewer random-seeming changes to existing code. Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
* Rename ExecAggTransReparent, and improve its documentation.Tom Lane2023-04-24
| | | | | | | | | | | | | The name of this function suggests that it ought to reparent R/W expanded objects to be children of the persistent aggcontext, instead of copying them. In fact it does no such thing, and if you try to make it do so you will see multiple regression failures. Rename it to the less-misleading ExecAggCopyTransValue, and add commentary about why that attractive-sounding optimization won't work. Also adjust comments at call sites, some of which were describing logic that has since been moved into ExecAggCopyTransValue. Discussion: https://postgr.es/m/3004282.1681930251@sss.pgh.pa.us
* Ensure result of an aggregate's finalfunc is made read-only.Tom Lane2023-04-16
| | | | | | | | | | | | | | | The finalfunc might return a read-write expanded object. If we de-duplicate multiple call sites for the aggregate, any function(s) receiving the aggregate result earlier could alter or destroy the value that reaches the ones called later. This is a brown-paper-bag bug in commit 42b746d4c, because we actually considered the need for read-only-ness but failed to realize that it applied to the case with a finalfunc as well as the case without. Per report from Justin Pryzby. New error in HEAD, no need for back-patch. Discussion: https://postgr.es/m/ZDm5TuKsh3tzoEjz@telsasoft.com
* Disable WindowAgg inverse transitions when subplans are presentDavid Rowley2023-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | When an aggregate function is used as a WindowFunc and a tuple transitions out of the window frame, we ordinarily try to make use of the aggregate function's inverse transition function to "unaggregate" the exiting tuple. This optimization is disabled for various cases, including when the aggregate contains a volatile function. In such a case we'd be unable to ensure that the transition value was calculated to the same value during transitions and inverse transitions. Unfortunately, we did this check by calling contain_volatile_functions() which does not recursively search SubPlans for volatile functions. If the aggregate function's arguments or its FILTER clause contained a subplan with volatile functions then we'd fail to notice this. Here we fix this by just disabling the optimization when the WindowFunc contains any subplans. Volatile functions are not the only reason that a subplan may have nonrepeatable results. Bug: #17777 Reported-by: Anban Company Discussion: https://postgr.es/m/17777-860b739b6efde977%40postgresql.org Reviewed-by: Tom Lane Backpatch-through: 11
* Update copyright for 2023Bruce Momjian2023-01-02
| | | | Backpatch-through: 11
* Fix 32-bit build dangling pointer issue in WindowAggDavid Rowley2022-12-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 9d9c02ccd added window "run conditions", which allows the evaluation of monotonic window functions to be skipped when the run condition is no longer true. Prior to this commit, once the run condition was no longer true and we stopped evaluating the window functions, we simply just left the ecxt_aggvalues[] and ecxt_aggnulls[] arrays alone to store whatever value was stored there the last time the window function was evaluated. Leaving a stale value in there isn't really a problem on 64-bit builds as all of the window functions which we recognize as monotonic all return int8, which is passed by value on 64-bit builds. However, on 32-bit builds, this was a problem as the value stored in the ecxt_values[] element would be a by-ref value and it would be pointing to some memory which would get reset once the tuple context is destroyed. Since the WindowAgg node will output these values in the resulting tupleslot, this could be problematic for the top-level WindowAgg node which must look at these values to filter out the rows that don't meet its filter condition. Here we fix this by just zeroing the ecxt_aggvalues[] and setting the ecxt_aggnulls[] array to true when the run condition first becomes false. This results in the WindowAgg's output having NULLs for the WindowFunc's columns rather than the stale or pointer pointing to possibly freed memory. These tuples with the NULLs can only make it as far as the top-level WindowAgg node before they're filtered out. To ensure that these tuples *are* always filtered out, we now insist that OpExprs making up the run condition are strict OpExprs. Currently, all the window functions which the planner recognizes as monotonic return INT8 and the operator which is used for the run condition must be a member of a btree opclass. In reality, these restrictions exclude nothing that's built-in to Postgres and are unlikely to exclude anyone's custom operators due to the requirement that the operator is part of a btree opclass. It would be unusual if those were not strict. Reported-by: Sergey Shinderuk, using valgrind Reviewed-by: Richard Guo, Sergey Shinderuk Discussion: https://postgr.es/m/29184c50-429a-ebd7-f1fb-0589c6723a35@postgrespro.ru Backpatch-through: 15, where 9d9c02ccd was added
* Refactor aclcheck functionsPeter Eisentraut2022-11-13
| | | | | | | | | | | | | | | | | | Instead of dozens of mostly-duplicate pg_foo_aclcheck() functions, write one common function object_aclcheck() that can handle almost all of them. We already have all the information we need, such as which system catalog corresponds to which catalog table and which column is the ACL column. There are a few pg_foo_aclcheck() that don't work via the generic function and have special APIs, so those stay as is. I also changed most pg_foo_aclmask() functions to static functions, since they are not used outside of aclchk.c. Reviewed-by: Corey Huinker <corey.huinker@gmail.com> Reviewed-by: Antonin Houska <ah@cybertec.at> Discussion: https://www.postgresql.org/message-id/flat/95c30f96-4060-2f48-98b5-a4392d3b6066@enterprisedb.com
* Remove uses of MemoryContextContains in nodeAgg.c and nodeWindowAgg.c.Tom Lane2022-10-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MemoryContextContains is no longer reliable in the wake of c6e0fe1f2, so we need to get rid of these uses. It appears that there's no really good reason to force the result of an aggregate's finalfn or serialfn to be allocated in the per-tuple context. The only other plausible case is that the result points to or into the aggregate's transition value, and that's fine because it will last as long as we need it to. (This conclusion depends on the assumption that finalfns are not allowed to scribble on the transition value, but we've long required that.) So we can just drop the MemoryContextContains plus datumCopy business, although we do need to take care to not return a read-write pointer when the transition value is an expanded datum. Likewise, we don't really need to force the result of a window function to be in the output context. In this case, the plausible alternative is that it's pointing into the temporary tuple slot used by WinGetFuncArgInPartition or WinGetFuncArgInFrame (since those functions could return such a pointer, which might become the window function's result). That will hold still for long enough, unless there is another window function using the same WindowObject. I'm content to always perform a datumCopy when there's more than one such function. On net, these changes should provide small speed improvements as well as removing problematic code. Tom Lane and David Rowley Discussion: https://postgr.es/m/1913788.1664898906@sss.pgh.pa.us
* More -Wshadow=compatible-local warning fixesDavid Rowley2022-08-26
| | | | | | | | | | | | In a similar effort to f01592f91, here we're targetting fixing the warnings where we've deemed the shadowing variable to serve a close enough purpose to the shadowed variable just to reuse the shadowed version and not declare the shadowing variable at all. By my count, this takes the warning count from 106 down to 71. Author: Justin Pryzby Discussion: https://postgr.es/m/20220825020839.GT2342@telsasoft.com
* Teach planner and executor about monotonic window funcsDavid Rowley2022-04-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Window functions such as row_number() always return a value higher than the previously returned value for tuples in any given window partition. Traditionally queries such as; SELECT * FROM ( SELECT *, row_number() over (order by c) rn FROM t ) t WHERE rn <= 10; were executed fairly inefficiently. Neither the query planner nor the executor knew that once rn made it to 11 that nothing further would match the outer query's WHERE clause. It would blindly continue until all tuples were exhausted from the subquery. Here we implement means to make the above execute more efficiently. This is done by way of adding a pg_proc.prosupport function to various of the built-in window functions and adding supporting code to allow the support function to inform the planner if the window function is monotonically increasing, monotonically decreasing, both or neither. The planner is then able to make use of that information and possibly allow the executor to short-circuit execution by way of adding a "run condition" to the WindowAgg to allow it to determine if some of its execution work can be skipped. This "run condition" is not like a normal filter. These run conditions are only built using quals comparing values to monotonic window functions. For monotonic increasing functions, quals making use of the btree operators for <, <= and = can be used (assuming the window function column is on the left). You can see here that once such a condition becomes false that a monotonic increasing function could never make it subsequently true again. For monotonically decreasing functions the >, >= and = btree operators for the given type can be used for run conditions. The best-case situation for this is when there is a single WindowAgg node without a PARTITION BY clause. Here when the run condition becomes false the WindowAgg node can simply return NULL. No more tuples will ever match the run condition. It's a little more complex when there is a PARTITION BY clause. In this case, we cannot return NULL as we must still process other partitions. To speed this case up we pull tuples from the outer plan to check if they're from the same partition and simply discard them if they are. When we find a tuple belonging to another partition we start processing as normal again until the run condition becomes false or we run out of tuples to process. When there are multiple WindowAgg nodes to evaluate then this complicates the situation. For intermediate WindowAggs we must ensure we always return all tuples to the calling node. Any filtering done could lead to incorrect results in WindowAgg nodes above. For all intermediate nodes, we can still save some work when the run condition becomes false. We've no need to evaluate the WindowFuncs anymore. Other WindowAgg nodes cannot reference the value of these and these tuples will not appear in the final result anyway. The savings here are small in comparison to what can be saved in the top-level WingowAgg, but still worthwhile. Intermediate WindowAgg nodes never filter out tuples, but here we change WindowAgg so that the top-level WindowAgg filters out tuples that don't match the intermediate WindowAgg node's run condition. Such filters appear in the "Filter" clause in EXPLAIN for the top-level WindowAgg node. Here we add prosupport functions to allow the above to work for; row_number(), rank(), dense_rank(), count(*) and count(expr). It appears technically possible to do the same for min() and max(), however, it seems unlikely to be useful enough, so that's not done here. Bump catversion Author: David Rowley Reviewed-by: Andy Fan, Zhihong Yu Discussion: https://postgr.es/m/CAApHDvqvp3At8++yF8ij06sdcoo1S_b2YoaT9D4Nf+MObzsrLQ@mail.gmail.com
* Update copyright for 2022Bruce Momjian2022-01-07
| | | | Backpatch-through: 10
* Update copyright for 2021Bruce Momjian2021-01-02
| | | | Backpatch-through: 9.5
* Remove useless entries for aggregate functions from fmgrtab.c.Tom Lane2020-11-04
| | | | | | | | | | | | | | | | | | | | | | | 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
* Update copyrights for 2020Bruce Momjian2020-01-01
| | | | Backpatch-through: update all files in master, backpatch legal files through 9.4
* Make the order of the header file includes consistent in backend modules.Amit Kapila2019-11-12
| | | | | | | | | | | 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
* Don't include utils/array.h from acl.h.Andres Freund2019-08-16
| | | | | | | | | | | | | | | | | | 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
* Fix inconsistencies and typos in the tree, take 9Michael Paquier2019-08-05
| | | | | | | | 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
* Phase 2 pgindent run for v12.Tom Lane2019-05-22
| | | | | | | | | 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
* Collations with nondeterministic comparisonPeter Eisentraut2019-03-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Refactor planner's header files.Tom Lane2019-01-29
| | | | | | | | | | | | | | | | | | | | | | | | 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
* Change function call information to be variable length.Andres Freund2019-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Introduce notion of different types of slots (without implementing them).Andres Freund2018-11-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Freund2018-11-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Fix bugs with degenerate window ORDER BY clauses in GROUPS/RANGE mode.Tom Lane2018-07-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Make new error code name match SQL standard more closelyPeter Eisentraut2018-06-11
| | | | Discussion: https://www.postgresql.org/message-id/dff3d555-bea4-ac24-29b2-29521b9d08e8%402ndquadrant.com
* Fix brown-paper-bag bug in commit 0a459cec96d3856f476c2db298c6b52f592894e8.Tom Lane2018-02-23
| | | | | | | | | | 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
* Allow tupleslots to have a fixed tupledesc, use in executor nodes.Andres Freund2018-02-16
| | | | | | | | | | | | | | | | | | | | | 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
* Do execGrouping.c via expression eval machinery, take two.Andres Freund2018-02-16
| | | | | | | | | | | | | 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
* Revert "Do execGrouping.c via expression eval machinery."Andres Freund2018-02-15
| | | | | | | | | | | | | | | This reverts commit 773aec7aa98abd38d6d9435913bb8e14e392c274. 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.
* Do execGrouping.c via expression eval machinery.Andres Freund2018-02-15
| | | | | | | | | 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
* Support all SQL:2011 options for window frame clauses.Tom Lane2018-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Replace AclObjectKind with ObjectTypePeter Eisentraut2018-01-19
| | | | | | | | | 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>
* Update copyright for 2018Bruce Momjian2018-01-02
| | | | Backpatch-through: certain files through 9.3
* Explicitly track whether aggregate final functions modify transition state.Tom Lane2017-10-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up to now, there's been hard-wired assumptions that normal aggregates' final functions never modify their transition states, while ordered-set aggregates' final functions always do. This has always been a bit limiting, and in particular it's getting in the way of improving the built-in ordered-set aggregates to allow merging of transition states. Therefore, let's introduce catalog and CREATE AGGREGATE infrastructure that lets the finalfn's behavior be declared explicitly. There are now three possibilities for the finalfn behavior: it's purely read-only, it trashes the transition state irrecoverably, or it changes the state in such a way that no more transfn calls are possible but the state can still be passed to other, compatible finalfns. There are no examples of this third case today, but we'll shortly make the built-in OSAs act like that. This change allows user-defined aggregates to explicitly disclaim support for use as window functions, and/or to prevent transition state merging, if their implementations cannot handle that. While it was previously possible to handle the window case with a run-time error check, there was not any way to prevent transition state merging, which in retrospect is something commit 804163bc2 should have provided for. But better late than never. In passing, split out pg_aggregate.c's extern function declarations into a new header file pg_aggregate_fn.h, similarly to what we've done for some other catalog headers, so that pg_aggregate.h itself can be safe for frontend files to include. This lets pg_dump use the symbolic names for relevant constants. Discussion: https://postgr.es/m/4834.1507849699@sss.pgh.pa.us
* Move ExecProcNode from dispatch to function pointer based model.Andres Freund2017-07-30
| | | | | | | | | | | | | | | | | | | | | | 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 Freund2017-07-30
| | | | | | | | | | | | | | | | | 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 Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | 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
* Phase 2 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 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
* Initial pgindent run with pg_bsd_indent version 2.0.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Faster expression evaluation and targetlist projection.Andres Freund2017-03-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
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