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path: root/src/backend/executor/nodeAgg.c
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* Rethink node-level representation of partial-aggregation modes.Tom Lane2016-06-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | The original coding had three separate booleans representing partial aggregation behavior, which was confusing, unreadable, and error-prone, not least because the booleans weren't always listed in the same order. It was also inadequate for the allegedly-desirable future extension to support intermediate partial aggregation, because we'd need separate markers for serialization and deserialization in such a case. Merge these bools into an enum "AggSplit" to provide symbolic names for the supported operating modes (and document what those are). By assigning the values of the enum constants carefully, we can treat AggSplit values as options bitmasks so that tests of what to do aren't noticeably more expensive than before. While at it, get rid of Aggref.aggoutputtype. That's not needed since commit 59a3795c2 got rid of setrefs.c's special-purpose Aggref comparison code, and it likewise seemed more confusing than helpful. Assorted comment cleanup as well (there's still more that I want to do in that line). catversion bump for change in Aggref node contents. Should be the last one for partial-aggregation changes. Discussion: <29309.1466699160@sss.pgh.pa.us>
* Fix type-safety problem with parallel aggregate serial/deserialization.Tom Lane2016-06-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original specification for this called for the deserialization function to have signature "deserialize(serialtype) returns transtype", which is a security violation if transtype is INTERNAL (which it always would be in practice) and serialtype is not (which ditto). The patch blithely overrode the opr_sanity check for that, which was sloppy-enough work in itself, but the indisputable reason this cannot be allowed to stand is that CREATE FUNCTION will reject such a signature and thus it'd be impossible for extensions to create parallelizable aggregates. The minimum fix to make the signature type-safe is to add a second, dummy argument of type INTERNAL. But to lock it down a bit more and make misuse of INTERNAL-accepting functions less likely, let's get rid of the ability to specify a "serialtype" for an aggregate and just say that the only useful serialtype is BYTEA --- which, in practice, is the only interesting value anyway, due to the usefulness of the send/recv infrastructure for this purpose. That means we only have to allow "serialize(internal) returns bytea" and "deserialize(bytea, internal) returns internal" as the signatures for these support functions. In passing fix bogus signature of int4_avg_combine, which I found thanks to adding an opr_sanity check on combinefunc signatures. catversion bump due to removing pg_aggregate.aggserialtype and adjusting signatures of assorted built-in functions. David Rowley and Tom Lane Discussion: <27247.1466185504@sss.pgh.pa.us>
* Fix handling of argument and result datatypes for partial aggregation.Tom Lane2016-06-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When doing partial aggregation, the args list of the upper (combining) Aggref node is replaced by a Var representing the output of the partial aggregation steps, which has either the aggregate's transition data type or a serialized representation of that. However, nodeAgg.c blindly continued to use the args list as an indication of the user-level argument types. This broke resolution of polymorphic transition datatypes at executor startup (though it accidentally failed to fail for the ANYARRAY case, which is likely the only one anyone had tested). Moreover, the constructed FuncExpr passed to the finalfunc contained completely wrong information, which would have led to bogus answers or crashes for any case where the finalfunc examined that information (which is only likely to be with polymorphic aggregates using a non-polymorphic transition type). As an independent bug, apply_partialaggref_adjustment neglected to resolve a polymorphic transition datatype before assigning it as the output type of the lower-level Aggref node. This again accidentally failed to fail for ANYARRAY but would be unlikely to work in other cases. To fix the first problem, record the user-level argument types in a separate OID-list field of Aggref, and look to that rather than the args list when asking what the argument types were. (It turns out to be convenient to include any "direct" arguments in this list too, although those are not currently subject to being overwritten.) Rather than adding yet another resolve_aggregate_transtype() call to fix the second problem, add an aggtranstype field to Aggref, and store the resolved transition type OID there when the planner first computes it. (By doing this in the planner and not the parser, we can allow the aggregate's transition type to change from time to time, although no DDL support yet exists for that.) This saves nothing of consequence for simple non-polymorphic aggregates, but for polymorphic transition types we save a catalog lookup during executor startup as well as several planner lookups that are new in 9.6 due to parallel query planning. In passing, fix an error that was introduced into count_agg_clauses_walker some time ago: it was applying exprTypmod() to something that wasn't an expression node at all, but a TargetEntry. exprTypmod silently returned -1 so that there was not an obvious failure, but this broke the intended sensitivity of aggregate space consumption estimates to the typmod of varchar and similar data types. This part needs to be back-patched. Catversion bump due to change of stored Aggref nodes. Discussion: <8229.1466109074@sss.pgh.pa.us>
* pgindent run for 9.6Robert Haas2016-06-09
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* Tweak a few more things in preparation for upcoming pgindent run.Robert Haas2016-05-03
| | | | | | | | These adjustments adjust code and comments in minor ways to prevent pgindent from mangling them. Among other things, I tried to avoid situations where pgindent would emit "a +b" instead of "a + b", and I tried to avoid having it break up inline comments across multiple lines.
* Fix bug in aggregate (de)serialization commit.Robert Haas2016-03-29
| | | | | | | | | resulttypeLen and resulttypeByVal must be set correctly when serializing aggregates, not just when finalizing them. This was in David's final patch but I downloaded the wrong version by mistake and failed to spot the error. David Rowley
* Allow aggregate transition states to be serialized and deserialized.Robert Haas2016-03-29
| | | | | | | | | This is necessary infrastructure for supporting parallel aggregation for aggregates whose transition type is "internal". Such values can't be passed between cooperating processes, because they are just pointers. David Rowley, reviewed by Tomas Vondra and by me.
* Reuse abbreviated keys in ordered [set] aggregates.Robert Haas2016-02-17
| | | | | | | | | When processing ordered aggregates following a sort that could make use of the abbreviated key optimization, only call the equality operator to compare successive pairs of tuples when their abbreviated keys were not equal. Peter Geoghegan, reviewd by Andreas Karlsson and by me.
* Support multi-stage aggregation.Robert Haas2016-01-20
| | | | | | | | | | | | | | | | | | | Aggregate nodes now have two new modes: a "partial" mode where they output the unfinalized transition state, and a "finalize" mode where they accept unfinalized transition states rather than individual values as input. These new modes are not used anywhere yet, but they will be necessary for parallel aggregation. The infrastructure also figures to be useful for cases where we want to aggregate local data and remote data via the FDW interface, and want to bring back partial aggregates from the remote side that can then be combined with locally generated partial aggregates to produce the final value. It may also be useful even when neither FDWs nor parallelism are in play, as explained in the comments in nodeAgg.c. David Rowley and Simon Riggs, reviewed by KaiGai Kohei, Heikki Linnakangas, Haribabu Kommi, and me.
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Share transition state between different aggregates when possible.Heikki Linnakangas2015-08-04
| | | | | | | | | | | | 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.
* Manual cleanup of pgindent results.Tom Lane2015-05-24
| | | | | | Fix some places where pgindent did silly stuff, often because project style wasn't followed to begin with. (I've not touched the atomics headers, though.)
* pgindent run for 9.5Bruce Momjian2015-05-23
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* Support GROUPING SETS, CUBE and ROLLUP.Andres Freund2015-05-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This SQL standard functionality allows to aggregate data by different GROUP BY clauses at once. Each grouping set returns rows with columns grouped by in other sets set to NULL. This could previously be achieved by doing each grouping as a separate query, conjoined by UNION ALLs. Besides being considerably more concise, grouping sets will in many cases be faster, requiring only one scan over the underlying data. The current implementation of grouping sets only supports using sorting for input. Individual sets that share a sort order are computed in one pass. If there are sets that don't share a sort order, additional sort & aggregation steps are performed. These additional passes are sourced by the previous sort step; thus avoiding repeated scans of the source data. The code is structured in a way that adding support for purely using hash aggregation or a mix of hashing and sorting is possible. Sorting was chosen to be supported first, as it is the most generic method of implementation. Instead of, as in an earlier versions of the patch, representing the chain of sort and aggregation steps as full blown planner and executor nodes, all but the first sort are performed inside the aggregation node itself. This avoids the need to do some unusual gymnastics to handle having to return aggregated and non-aggregated tuples from underlying nodes, as well as having to shut down underlying nodes early to limit memory usage. The optimizer still builds Sort/Agg node to describe each phase, but they're not part of the plan tree, but instead additional data for the aggregation node. They're a convenient and preexisting way to describe aggregation and sorting. The first (and possibly only) sort step is still performed as a separate execution step. That retains similarity with existing group by plans, makes rescans fairly simple, avoids very deep plans (leading to slow explains) and easily allows to avoid the sorting step if the underlying data is sorted by other means. A somewhat ugly side of this patch is having to deal with a grammar ambiguity between the new CUBE keyword and the cube extension/functions named cube (and rollup). To avoid breaking existing deployments of the cube extension it has not been renamed, neither has cube been made a reserved keyword. Instead precedence hacking is used to make GROUP BY cube(..) refer to the CUBE grouping sets feature, and not the function cube(). To actually group by a function cube(), unlikely as that might be, the function name has to be quoted. Needs a catversion bump because stored rules may change. Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
* Extend abbreviated key infrastructure to datum tuplesorts.Robert Haas2015-05-13
| | | | Andrew Gierth, reviewed by Peter Geoghegan and by me.
* Use outerPlanState macro instead of referring to leffttree.Robert Haas2015-05-04
| | | | | | | 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.
* Use FLEXIBLE_ARRAY_MEMBER in some more places.Tom Lane2015-02-20
| | | | | | Fix a batch of structs that are only visible within individual .c files. Michael Paquier
* Use abbreviated keys for faster sorting of text datums.Robert Haas2015-01-19
| | | | | | | | | | | | | | | | | | | | | This commit extends the SortSupport infrastructure to allow operator classes the option to provide abbreviated representations of Datums; in the case of text, we abbreviate by taking the first few characters of the strxfrm() blob. If the abbreviated comparison is insufficent to resolve the comparison, we fall back on the normal comparator. This can be much faster than the old way of doing sorting if the first few bytes of the string are usually sufficient to resolve the comparison. There is the potential for a performance regression if all of the strings to be sorted are identical for the first 8+ characters and differ only in later positions; therefore, the SortSupport machinery now provides an infrastructure to abort the use of abbreviation if it appears that abbreviation is producing comparatively few distinct keys. HyperLogLog, a streaming cardinality estimator, is included in this commit and used to make that determination for text. Peter Geoghegan, reviewed by me.
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* Redesign API presented by nodeAgg.c for ordered-set and similar aggregates.Tom Lane2014-07-03
| | | | | | | | | | | | | The previous design exposed the input and output ExprContexts of the Agg plan node, but work on grouping sets has suggested that we'll regret doing that. Instead provide more narrowly-defined APIs that can be implemented in multiple ways, namely a way to get a short-term memory context and a way to register an aggregate shutdown callback. Back-patch to 9.4 where the bad APIs were introduced, since we don't want third-party code using these APIs and then having to change in 9.5. Andrew Gierth
* pgindent run for 9.4Bruce Momjian2014-05-06
| | | | | This includes removing tabs after periods in C comments, which was applied to back branches, so this change should not effect backpatching.
* Allow polymorphic aggregates to have non-polymorphic state data types.Tom Lane2014-04-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* Create infrastructure for moving-aggregate optimization.Tom Lane2014-04-12
| | | | | | | | | | | | | | | | | | | 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
* Save a few cycles in advance_transition_function().Tom Lane2014-01-08
| | | | | | | | | | | | | | Keep a pre-initialized FunctionCallInfoData in AggStatePerAggData, and re-use that at each row instead of doing InitFunctionCallInfoData each time. This saves only half a dozen assignments and maybe some stack manipulation, and yet that seems to be good for a percent or two of the overall query run time for simple aggregates such as count(*). The cost is that the FunctionCallInfoData (which is about a kilobyte, on 64-bit machines) stays allocated for the duration of the query instead of being short-lived stack data. But we're already paying an equivalent space cost for each regular FuncExpr or OpExpr node, so I don't feel bad about paying it for aggregate functions. The code seems a little cleaner this way too, since the number of things passed to advance_transition_function decreases.
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* Support ordered-set (WITHIN GROUP) aggregates.Tom Lane2013-12-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Allow aggregate functions to be VARIADIC.Tom Lane2013-09-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* Implement the FILTER clause for aggregate function calls.Noah Misch2013-07-16
| | | | | | | | | 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.
* sepgsql: Enforce db_procedure:{execute} permission.Robert Haas2013-04-12
| | | | | | | To do this, we add an additional object access hook type, OAT_FUNCTION_EXECUTE. KaiGai Kohei
* Update copyrights for 2013Bruce Momjian2013-01-01
| | | | | Fully update git head, and update back branches in ./COPYRIGHT and legal.sgml files.
* Split tuple struct defs from htup.h to htup_details.hAlvaro Herrera2012-08-30
| | | | | | | | | | | | This reduces unnecessary exposure of other headers through htup.h, which is very widely included by many files. I have chosen to move the function prototypes to the new file as well, because that means htup.h no longer needs to include tupdesc.h. In itself this doesn't have much effect in indirect inclusion of tupdesc.h throughout the tree, because it's also required by execnodes.h; but it's something to explore in the future, and it seemed best to do the htup.h change now while I'm busy with it.
* Update copyright notices for year 2012.Bruce Momjian2012-01-01
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* Rearrange the implementation of index-only scans.Tom Lane2011-10-11
| | | | | | | | | | | | | | | | | | | | | | This commit changes index-only scans so that data is read directly from the index tuple without first generating a faux heap tuple. The only immediate benefit is that indexes on system columns (such as OID) can be used in index-only scans, but this is necessary infrastructure if we are ever to support index-only scans on expression indexes. The executor is now ready for that, though the planner still needs substantial work to recognize the possibility. To do this, Vars in index-only plan nodes have to refer to index columns not heap columns. I introduced a new special varno, INDEX_VAR, to mark such Vars to avoid confusion. (In passing, this commit renames the two existing special varnos to OUTER_VAR and INNER_VAR.) This allows ruleutils.c to handle them with logic similar to what we use for subplan reference Vars. Since index-only scans are now fundamentally different from regular indexscans so far as their expression subtrees are concerned, I also chose to change them to have their own plan node type (and hence, their own executor source file).
* Make EXPLAIN ANALYZE report the numbers of rows rejected by filter steps.Tom Lane2011-09-22
| | | | | | | | | | | | | | | This provides information about the numbers of tuples that were visited but not returned by table scans, as well as the numbers of join tuples that were considered and discarded within a join plan node. There is still some discussion going on about the best way to report counts for outer-join situations, but I think most of what's in the patch would not change if we revise that, so I'm going to go ahead and commit it as-is. Documentation changes to follow (they weren't in the submitted patch either). Marko Tiikkaja, reviewed by Marc Cousin, somewhat revised by Tom
* Pass collations to functions in FunctionCallInfoData, not FmgrInfo.Tom Lane2011-04-12
| | | | | | | | | | | Since collation is effectively an argument, not a property of the function, FmgrInfo is really the wrong place for it; and this becomes critical in cases where a cached FmgrInfo is used for varying purposes that might need different collation settings. Fix by passing it in FunctionCallInfoData instead. In particular this allows a clean fix for bug #5970 (record_cmp not working). This requires touching a bit more code than the original method, but nobody ever thought that collations would not be an invasive patch...
* pgindent run before PG 9.1 beta 1.Bruce Momjian2011-04-10
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* Revise collation derivation method and expression-tree representation.Tom Lane2011-03-19
| | | | | | | | | | | | | | | | | | | All expression nodes now have an explicit output-collation field, unless they are known to only return a noncollatable data type (such as boolean or record). Also, nodes that can invoke collation-aware functions store a separate field that is the collation value to pass to the function. This avoids confusion that arises when a function has collatable inputs and noncollatable output type, or vice versa. Also, replace the parser's on-the-fly collation assignment method with a post-pass over the completed expression tree. This allows us to use a more complex (and hopefully more nearly spec-compliant) assignment rule without paying for it in extra storage in every expression node. Fix assorted bugs in the planner's handling of collations by making collation one of the defining properties of an EquivalenceClass and by converting CollateExprs into discardable RelabelType nodes during expression preprocessing.
* Per-column collation supportPeter Eisentraut2011-02-08
| | | | | | | | This adds collation support for columns and domains, a COLLATE clause to override it per expression, and B-tree index support. Peter Eisentraut reviewed by Pavel Stehule, Itagaki Takahiro, Robert Haas, Noah Misch
* Stamp copyrights for year 2011.Bruce Momjian2011-01-01
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* Remove cvs keywords from all files.Magnus Hagander2010-09-20
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* Make NestLoop plan nodes pass outer-relation variables into their innerTom Lane2010-07-12
| | | | | | | | | | | | relation using the general PARAM_EXEC executor parameter mechanism, rather than the ad-hoc kluge of passing the outer tuple down through ExecReScan. The previous method was hard to understand and could never be extended to handle parameters coming from multiple join levels. This patch doesn't change the set of possible plans nor have any significant performance effect, but it's necessary infrastructure for future generalization of the concept of an inner indexscan plan. ExecReScan's second parameter is now unused, so it's removed.
* pgindent run for 9.0Bruce Momjian2010-02-26
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* Wrap calls to SearchSysCache and related functions using macros.Robert Haas2010-02-14
| | | | | | | | | | | | The purpose of this change is to eliminate the need for every caller of SearchSysCache, SearchSysCacheCopy, SearchSysCacheExists, GetSysCacheOid, and SearchSysCacheList to know the maximum number of allowable keys for a syscache entry (currently 4). This will make it far easier to increase the maximum number of keys in a future release should we choose to do so, and it makes the code shorter, too. Design and review by Tom Lane.
* Extend the set of frame options supported for window functions.Tom Lane2010-02-12
| | | | | | | | | This patch allows the frame to start from CURRENT ROW (in either RANGE or ROWS mode), and it also adds support for ROWS n PRECEDING and ROWS n FOLLOWING start and end points. (RANGE value PRECEDING/FOLLOWING isn't there yet --- the grammar works, but that's all.) Hitoshi Harada, reviewed by Pavel Stehule
* Create an official API function for C functions to use to check if they areTom Lane2010-02-08
| | | | | | | | | | being called as aggregates, and to get the aggregate transition state memory context if needed. Use it instead of poking directly into AggState and WindowAggState in places that shouldn't know so much. We should have done this in 8.4, probably, but better late than never. Revised version of a patch by Hitoshi Harada.
* Update copyright for the year 2010.Bruce Momjian2010-01-02
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* Support ORDER BY within aggregate function calls, at long last providing aTom Lane2009-12-15
| | | | | | | | | | | | | non-kluge method for controlling the order in which values are fed to an aggregate function. At the same time eliminate the old implementation restriction that DISTINCT was only supported for single-argument aggregates. Possibly release-notable behavioral change: formerly, agg(DISTINCT x) dropped null values of x unconditionally. Now, it does so only if the agg transition function is strict; otherwise nulls are treated as DISTINCT normally would, ie, you get one copy. Andrew Gierth, reviewed by Hitoshi Harada
* Remove no-longer-needed ExecCountSlots infrastructure.Tom Lane2009-09-27
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* In a non-hashed Agg node, reset the "aggcontext" at group boundaries, insteadTom Lane2009-07-23
| | | | | | | | | | | of individually pfree'ing pass-by-reference transition values. This should be at least as fast as the prior coding, and it has the major advantage of clearing out any working data an aggregate function may have stored in or underneath the aggcontext. This avoids memory leakage when an aggregate such as array_agg() is used in GROUP BY mode. Per report from Chris Spotts. Back-patch to 8.4. In principle the problem could arise in prior versions, but since they didn't have array_agg the issue seems not critical.
* ExecAgg() failed to finish running out set-returning functions in the lastTom Lane2009-06-17
| | | | | | aggregated tuple of a run. Per report from Laurenz Albe. This is a new bug in 8.4, but only because prior versions rejected SRFs in an Agg plan node altogether.