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* Properly check index mark/restore in ExecSupportsMarkRestore.Andrew Gierth2020-11-24
| | | | | | | | | | | | | | | | Previously this code assumed that all IndexScan nodes supported mark/restore, which is not true since it depends on optional index AM support functions. This could lead to errors about missing support functions in rare edge cases of mergejoins with no sort keys, where an unordered non-btree index scan was placed on the inner path without a protecting Materialize node. (Normally, the fact that merge join requires ordered input would avoid this error.) Backpatch all the way since this bug is ancient. Per report from Eugen Konkov on irc. Discussion: https://postgr.es/m/87o8jn50be.fsf@news-spur.riddles.org.uk
* Add missing call to ExecReScanGatherMerge.Robert Haas2017-08-15
| | | | | | Amit Kapila Discussion: http://postgr.es/m/CAA4eK1KeQWZOoDmDmGMwuqzPW9JhRS+ditQVFdAfGjNmMZzqMQ@mail.gmail.com
* Post-PG 10 beta1 pgindent runBruce Momjian2017-05-17
| | | | perltidy run not included.
* Add infrastructure to support EphemeralNamedRelation references.Kevin Grittner2017-03-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A QueryEnvironment concept is added, which allows new types of objects to be passed into queries from parsing on through execution. At this point, the only thing implemented is a collection of EphemeralNamedRelation objects -- relations which can be referenced by name in queries, but do not exist in the catalogs. The only type of ENR implemented is NamedTuplestore, but provision is made to add more types fairly easily. An ENR can carry its own TupleDesc or reference a relation in the catalogs by relid. Although these features can be used without SPI, convenience functions are added to SPI so that ENRs can easily be used by code run through SPI. The initial use of all this is going to be transition tables in AFTER triggers, but that will be added to each PL as a separate commit. An incidental effect of this patch is to produce a more informative error message if an attempt is made to modify the contents of a CTE from a referencing DML statement. No tests previously covered that possibility, so one is added. Kevin Grittner and Thomas Munro Reviewed by Heikki Linnakangas, David Fetter, and Thomas Munro with valuable comments and suggestions from many others
* Support XMLTABLE query expressionAlvaro Herrera2017-03-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | XMLTABLE is defined by the SQL/XML standard as a feature that allows turning XML-formatted data into relational form, so that it can be used as a <table primary> in the FROM clause of a query. This new construct provides significant simplicity and performance benefit for XML data processing; what in a client-side custom implementation was reported to take 20 minutes can be executed in 400ms using XMLTABLE. (The same functionality was said to take 10 seconds using nested PostgreSQL XPath function calls, and 5 seconds using XMLReader under PL/Python). The implemented syntax deviates slightly from what the standard requires. First, the standard indicates that the PASSING clause is optional and that multiple XML input documents may be given to it; we make it mandatory and accept a single document only. Second, we don't currently support a default namespace to be specified. This implementation relies on a new executor node based on a hardcoded method table. (Because the grammar is fixed, there is no extensibility in the current approach; further constructs can be implemented on top of this such as JSON_TABLE, but they require changes to core code.) Author: Pavel Stehule, Álvaro Herrera Extensively reviewed by: Craig Ringer Discussion: https://postgr.es/m/CAFj8pRAgfzMD-LoSmnMGybD0WsEznLHWap8DO79+-GTRAPR4qA@mail.gmail.com
* Use the new castNode() macro in a number of places.Andres Freund2017-01-26
| | | | | | | | | This is far from a pervasive conversion, but it's a good starting point. Author: Peter Eisentraut, with some minor changes by me Reviewed-By: Tom Lane Discussion: https://postgr.es/m/c5d387d9-3440-f5e0-f9d4-71d53b9fbe52@2ndquadrant.com
* Remove obsoleted code relating to targetlist SRF evaluation.Andres Freund2017-01-19
| | | | | | | | | | | | | 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
* Move targetlist SRF handling from expression evaluation to new executor node.Andres Freund2017-01-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Evaluation of set returning functions (SRFs_ in the targetlist (like SELECT generate_series(1,5)) so far was done in the expression evaluation (i.e. ExecEvalExpr()) and projection (i.e. ExecProject/ExecTargetList) code. This meant that most executor nodes performing projection, and most expression evaluation functions, had to deal with the possibility that an evaluated expression could return a set of return values. That's bad because it leads to repeated code in a lot of places. It also, and that's my (Andres's) motivation, made it a lot harder to implement a more efficient way of doing expression evaluation. To fix this, introduce a new executor node (ProjectSet) that can evaluate targetlists containing one or more SRFs. To avoid the complexity of the old way of handling nested expressions returning sets (e.g. having to pass up ExprDoneCond, and dealing with arguments to functions returning sets etc.), those SRFs can only be at the top level of the node's targetlist. The planner makes sure (via split_pathtarget_at_srfs()) that SRF evaluation is only necessary in ProjectSet nodes and that SRFs are only present at the top level of the node's targetlist. If there are nested SRFs the planner creates multiple stacked ProjectSet nodes. The ProjectSet nodes always get input from an underlying node. We also discussed and prototyped evaluating targetlist SRFs using ROWS FROM(), but that turned out to be more complicated than we'd hoped. While moving SRF evaluation to ProjectSet would allow to retain the old "least common multiple" behavior when multiple SRFs are present in one targetlist (i.e. continue returning rows until all SRFs are at the end of their input at the same time), we decided to instead only return rows till all SRFs are exhausted, returning NULL for already exhausted ones. We deemed the previous behavior to be too confusing, unexpected and actually not particularly useful. As a side effect, the previously prohibited case of multiple set returning arguments to a function, is now allowed. Not because it's particularly desirable, but because it ends up working and there seems to be no argument for adding code to prohibit it. Currently the behavior for COALESCE and CASE containing SRFs has changed, returning multiple rows from the expression, even when the SRF containing "arm" of the expression is not evaluated. That's because the SRFs are evaluated in a separate ProjectSet node. As that's quite confusing, we're likely to instead prohibit SRFs in those places. But that's still being discussed, and the code would reside in places not touched here, so that's a task for later. There's a lot of, now superfluous, code dealing with set return expressions around. But as the changes to get rid of those are verbose largely boring, it seems better for readability to keep the cleanup as a separate commit. Author: Tom Lane and Andres Freund Discussion: https://postgr.es/m/20160822214023.aaxz5l4igypowyri@alap3.anarazel.de
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Add SQL-accessible functions for inspecting index AM properties.Tom Lane2016-08-13
| | | | | | | | | | | | | | | | | | | | | Per discussion, we should provide such functions to replace the lost ability to discover AM properties by inspecting pg_am (cf commit 65c5fcd35). The added functionality is also meant to displace any code that was looking directly at pg_index.indoption, since we'd rather not believe that the bit meanings in that field are part of any client API contract. As future-proofing, define the SQL API to not assume that properties that are currently AM-wide or index-wide will remain so unless they logically must be; instead, expose them only when inquiring about a specific index or even specific index column. Also provide the ability for an index AM to override the behavior. In passing, document pg_am.amtype, overlooked in commit 473b93287. Andrew Gierth, with kibitzing by me and others Discussion: <87mvl5on7n.fsf@news-spur.riddles.org.uk>
* pgindent run for 9.6Robert Haas2016-06-09
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* Make the upper part of the planner work by generating and comparing Paths.Tom Lane2016-03-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I've been saying we needed to do this for more than five years, and here it finally is. This patch removes the ever-growing tangle of spaghetti logic that grouping_planner() used to use to try to identify the best plan for post-scan/join query steps. Now, there is (nearly) independent consideration of each execution step, and entirely separate construction of Paths to represent each of the possible ways to do that step. We choose the best Path or set of Paths using the same add_path() logic that's been used inside query_planner() for years. In addition, this patch removes the old restriction that subquery_planner() could return only a single Plan. It now returns a RelOptInfo containing a set of Paths, just as query_planner() does, and the parent query level can use each of those Paths as the basis of a SubqueryScanPath at its level. This allows finding some optimizations that we missed before, wherein a subquery was capable of returning presorted data and thereby avoiding a sort in the parent level, making the overall cost cheaper even though delivering sorted output was not the cheapest plan for the subquery in isolation. (A couple of regression test outputs change in consequence of that. However, there is very little change in visible planner behavior overall, because the point of this patch is not to get immediate planning benefits but to create the infrastructure for future improvements.) There is a great deal left to do here. This patch unblocks a lot of planner work that was basically impractical in the old code structure, such as allowing FDWs to implement remote aggregation, or rewriting plan_set_operations() to allow consideration of multiple implementation orders for set operations. (The latter will likely require a full rewrite of plan_set_operations(); what I've done here is only to fix it to return Paths not Plans.) I have also left unfinished some localized refactoring in createplan.c and planner.c, because it was not necessary to get this patch to a working state. Thanks to Robert Haas, David Rowley, and Amit Kapila for review.
* Restructure index access method API to hide most of it at the C level.Tom Lane2016-01-17
| | | | | | | | | | | | | | | | | | | | | | | | This patch reduces pg_am to just two columns, a name and a handler function. All the data formerly obtained from pg_am is now provided in a C struct returned by the handler function. This is similar to the designs we've adopted for FDWs and tablesample methods. There are multiple advantages. For one, the index AM's support functions are now simple C functions, making them faster to call and much less error-prone, since the C compiler can now check function signatures. For another, this will make it far more practical to define index access methods in installable extensions. A disadvantage is that SQL-level code can no longer see attributes of index AMs; in particular, some of the crosschecks in the opr_sanity regression test are no longer possible from SQL. We've addressed that by adding a facility for the index AM to perform such checks instead. (Much more could be done in that line, but for now we're content if the amvalidate functions more or less replace what opr_sanity used to do.) We might also want to expose some sort of reporting functionality, but this patch doesn't do that. Alexander Korotkov, reviewed by Petr Jelínek, and rather heavily editorialized on by me.
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Make sequential scans parallel-aware.Robert Haas2015-11-11
| | | | | | | | | | | | | | In addition, this path fills in a number of missing bits and pieces in the parallel infrastructure. Paths and plans now have a parallel_aware flag indicating whether whatever parallel-aware logic they have should be engaged. It is believed that we will need this flag for a number of path/plan types, not just sequential scans, which is why the flag is generic rather than part of the SeqScan structures specifically. Also, execParallel.c now gives parallel nodes a chance to initialize their PlanState nodes from the DSM during parallel worker startup. Amit Kapila, with a fair amount of adjustment by me. Review of previous patch versions by Haribabu Kommi and others.
* Add a Gather executor node.Robert Haas2015-09-30
| | | | | | | | | | | | | | | | | | | | | | | | A Gather executor node runs any number of copies of a plan in an equal number of workers and merges all of the results into a single tuple stream. It can also run the plan itself, if the workers are unavailable or haven't started up yet. It is intended to work with the Partial Seq Scan node which will be added in future commits. It could also be used to implement parallel query of a different sort by itself, without help from Partial Seq Scan, if the single_copy mode is used. In that mode, a worker executes the plan, and the parallel leader does not, merely collecting the worker's results. So, a Gather node could be inserted into a plan to split the execution of that plan across two processes. Nested Gather nodes aren't currently supported, but we might want to add support for that in the future. There's nothing in the planner to actually generate Gather nodes yet, so it's not quite time to break out the champagne. But we're getting close. Amit Kapila. Some designs suggestions were provided by me, and I also reviewed the patch. Single-copy mode, documentation, and other minor changes also by me.
* Redesign tablesample method API, and do extensive code review.Tom Lane2015-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original implementation of TABLESAMPLE modeled the tablesample method API on index access methods, which wasn't a good choice because, without specialized DDL commands, there's no way to build an extension that can implement a TSM. (Raw inserts into system catalogs are not an acceptable thing to do, because we can't undo them during DROP EXTENSION, nor will pg_upgrade behave sanely.) Instead adopt an API more like procedural language handlers or foreign data wrappers, wherein the only SQL-level support object needed is a single handler function identified by having a special return type. This lets us get rid of the supporting catalog altogether, so that no custom DDL support is needed for the feature. Adjust the API so that it can support non-constant tablesample arguments (the original coding assumed we could evaluate the argument expressions at ExecInitSampleScan time, which is undesirable even if it weren't outright unsafe), and discourage sampling methods from looking at invisible tuples. Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable within and across queries, as required by the SQL standard, and deal more honestly with methods that can't support that requirement. Make a full code-review pass over the tablesample additions, and fix assorted bugs, omissions, infelicities, and cosmetic issues (such as failure to put the added code stanzas in a consistent ordering). Improve EXPLAIN's output of tablesample plans, too. Back-patch to 9.5 so that we don't have to support the original API in production.
* pgindent run for 9.5Bruce Momjian2015-05-23
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* TABLESAMPLE, SQL Standard and extensibleSimon Riggs2015-05-15
| | | | | | | | | | | | | | Add a TABLESAMPLE clause to SELECT statements that allows user to specify random BERNOULLI sampling or block level SYSTEM sampling. Implementation allows for extensible sampling functions to be written, using a standard API. Basic version follows SQLStandard exactly. Usable concrete use cases for the sampling API follow in later commits. Petr Jelinek Reviewed by Michael Paquier and Simon Riggs
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* Remove dead code supporting mark/restore in SeqScan, TidScan, ValuesScan.Tom Lane2014-11-20
| | | | | | | | | | | | There seems no prospect that any of this will ever be useful, and indeed it's questionable whether some of it would work if it ever got called; it's certainly not been exercised in a very long time, if ever. So let's get rid of it, and make the comments about mark/restore in execAmi.c less wishy-washy. The mark/restore support for Result nodes is also currently dead code, but that's due to planner limitations not because it's impossible that it could be useful. So I left it in.
* Initial code review for CustomScan patch.Tom Lane2014-11-20
| | | | | | | | | | | | | | | | | | | | | | | | Get rid of the pernicious entanglement between planner and executor headers introduced by commit 0b03e5951bf0a1a8868db13f02049cf686a82165. Also, rearrange the CustomFoo struct/typedef definitions so that all the typedef names are seen as used by the compiler. Without this pgindent will mess things up a bit, which is not so important perhaps, but it also removes a bizarre discrepancy between the declaration arrangement used for CustomExecMethods and that used for CustomScanMethods and CustomPathMethods. Clean up the commentary around ExecSupportsMarkRestore to reflect the rather large change in its API. Const-ify register_custom_path_provider's argument. This necessitates casting away const in the function, but that seems better than forcing callers of the function to do so (or else not const-ify their method pointer structs, which was sort of the whole point). De-export fix_expr_common. I don't like the exporting of fix_scan_expr or replace_nestloop_params either, but this one surely has got little excuse.
* Introduce custom path and scan providers.Robert Haas2014-11-07
| | | | | | | | | | | This allows extension modules to define their own methods for scanning a relation, and get the core code to use them. It's unclear as yet how much use this capability will find, but we won't find out if we never commit it. KaiGai Kohei, reviewed at various times and in various levels of detail by Shigeru Hanada, Tom Lane, Andres Freund, Álvaro Herrera, and myself.
* 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.
* Update copyright for 2014Bruce Momjian2014-01-07
| | | | | Update all files in head, and files COPYRIGHT and legal.sgml in all back branches.
* 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
* Move Trigger and TriggerDesc structs out of rel.h into a new reltrigger.hAlvaro Herrera2011-07-04
| | | | | This lets us stop including rel.h into execnodes.h, which is a widely used header.
* Implement an API to let foreign-data wrappers actually be functional.Tom Lane2011-02-20
| | | | | | | This commit provides the core code and documentation needed. A contrib module test case will follow shortly. Shigeru Hanada, Jan Urbanski, Heikki Linnakangas
* Stamp copyrights for year 2011.Bruce Momjian2011-01-01
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* Support MergeAppend plans, to allow sorted output from append relations.Tom Lane2010-10-14
| | | | | | | | | This patch eliminates the former need to sort the output of an Append scan when an ordered scan of an inheritance tree is wanted. This should be particularly useful for fast-start cases such as queries with LIMIT. Original patch by Greg Stark, with further hacking by Hans-Jurgen Schonig, Robert Haas, and Tom Lane.
* 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.
* 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.
* Update copyright for the year 2010.Bruce Momjian2010-01-02
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* Move the handling of SELECT FOR UPDATE locking and rechecking out ofTom Lane2009-10-12
| | | | | | | | | | | | | | | | | | | execMain.c and into a new plan node type LockRows. Like the recent change to put table updating into a ModifyTable plan node, this increases planning flexibility by allowing the operations to occur below the top level of the plan tree. It's necessary in any case to restore the previous behavior of having FOR UPDATE locking occur before ModifyTable does. This partially refactors EvalPlanQual to allow multiple rows-under-test to be inserted into the EPQ machinery before starting an EPQ test query. That isn't sufficient to fix EPQ's general bogosity in the face of plans that return multiple rows per test row, though. Since this patch is mostly about getting some plan node infrastructure in place and not about fixing ten-year-old bugs, I will leave EPQ improvements for another day. Another behavioral change that we could now think about is doing FOR UPDATE before LIMIT, but that too seems like it should be treated as a followon patch.
* Split the processing of INSERT/UPDATE/DELETE operations out of execMain.c.Tom Lane2009-10-10
| | | | | | | | | | They are now handled by a new plan node type called ModifyTable, which is placed at the top of the plan tree. In itself this change doesn't do much, except perhaps make the handling of RETURNING lists and inherited UPDATEs a tad less klugy. But it is necessary preparation for the intended extension of allowing RETURNING queries inside WITH. Marko Tiikkaja
* Rewrite the planner's handling of materialized plan types so that there isTom Lane2009-09-12
| | | | | | | | | | | | | | | | an explicit model of rescan costs being different from first-time costs. The costing of Material nodes in particular now has some visible relationship to the actual runtime behavior, where before it was essentially fantasy. This also fixes up a couple of places where different materialized plan types were treated differently for no very good reason (probably just oversights). A couple of the regression tests are affected, because the planner now chooses to put the other relation on the inside of a nestloop-with-materialize. So far as I can see both changes are sane, and the planner is now more consistently following the expectation that it should prefer to materialize the smaller of two relations. Per a recent discussion with Robert Haas.
* Update copyright for 2009.Bruce Momjian2009-01-01
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* Support window functions a la SQL:2008.Tom Lane2008-12-28
| | | | Hitoshi Harada, with some kibitzing from Heikki and Tom.
* Change WorkTableScan to not support backward scan. The apparent supportTom Lane2008-10-28
| | | | | | | | | | didn't actually work, because nodeRecursiveunion.c creates the underlying tuplestore with backward scan disabled; which is a decision that we shouldn't reverse because of performance cost. We could imagine adding signaling from WorkTableScan to RecursiveUnion about whether backward scan is needed ... but in practice it'd be a waste of effort, because there simply isn't any current or plausible future scenario where WorkTableScan would be called on to scan backward. So just dike out the code that claims to support it.
* Add a new column to pg_am to specify whether an index AM supports backwardTom Lane2008-10-17
| | | | | | | | | | | | | | | | scanning; GiST and GIN do not, and it seems like too much trouble to make them do so. By teaching ExecSupportsBackwardScan() about this restriction, we ensure that the planner will protect a scroll cursor from the problem by adding a Materialize node. In passing, fix another longstanding bug in the same area: backwards scan of a plan with set-returning functions in the targetlist did not work either, since the TupFromTlist expansion code pays no attention to direction (and has no way to run a SRF backwards anyway). Again the fix is to make ExecSupportsBackwardScan check this restriction. Also adjust the index AM API specification to note that mark/restore support is unnecessary if the AM can't produce ordered output.
* Implement SQL-standard WITH clauses, including WITH RECURSIVE.Tom Lane2008-10-04
| | | | | | | | | | | | | There are some unimplemented aspects: recursive queries must use UNION ALL (should allow UNION too), and we don't have SEARCH or CYCLE clauses. These might or might not get done for 8.4, but even without them it's a pretty useful feature. There are also a couple of small loose ends and definitional quibbles, which I'll send a memo about to pgsql-hackers shortly. But let's land the patch now so we can get on with other development. Yoshiyuki Asaba, with lots of help from Tatsuo Ishii and Tom Lane
* Improve tuplestore.c to support multiple concurrent read positions.Tom Lane2008-10-01
| | | | | | | | | | | This facility replaces the former mark/restore support but is otherwise upward-compatible with previous uses. It's expected to be needed for single evaluation of CTEs and also for window functions, so I'm committing it separately instead of waiting for either one of those patches to be finished. Per discussion with Greg Stark and Hitoshi Harada. Note: I removed nodeFunctionscan's mark/restore support, instead of bothering to update it for this change, because it was dead code anyway.
* Do not allow Unique nodes to be scanned backwards. The code claimed that itTom Lane2008-08-05
| | | | | | | would work, but in fact it didn't return the same rows when moving backwards as when moving forwards. This would have no visible effect in a DISTINCT query (at least assuming the column datatypes use a strong definition of equality), but it gave entirely wrong answers for DISTINCT ON queries.
* As noted by Andrew Gierth, there's really no need any more to force a junkTom Lane2008-07-26
| | | | | | | | | | | | | | | | filter to be used when INSERT or SELECT INTO has a plan that returns raw disk tuples. The virtual-tuple-slot optimizations that were put in place awhile ago mean that ExecInsert has to do ExecMaterializeSlot, and that already copies the tuple if it's raw (and does so more efficiently than a junk filter, too). So get rid of that logic. This in turn means that we can throw away ExecMayReturnRawTuples, which wasn't used for any other purpose, and was always a kluge anyway. In passing, move a couple of SELECT-INTO-specific fields out of EState and into the private state of the SELECT INTO DestReceiver, as was foreseen in an old comment there. Also make intorel_receive use ExecMaterializeSlot not ExecCopySlotTuple, for consistency with ExecInsert and to possibly save a tuple copy step in some cases.
* Fix mis-calculation of extParam/allParam sets for plan nodes, as seen inTom Lane2008-07-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | bug #4290. The fundamental bug is that masking extParam by outer_params, as finalize_plan had been doing, caused us to lose the information that an initPlan depended on the output of a sibling initPlan. On reflection the best thing to do seemed to be not to try to adjust outer_params for this case but get rid of it entirely. The only thing it was really doing for us was to filter out param IDs associated with SubPlan nodes, and that can be done (with greater accuracy) while processing individual SubPlan nodes in finalize_primnode. This approach was vindicated by the discovery that the masking method was hiding a second bug: SS_finalize_plan failed to remove extParam bits for initPlan output params that were referenced in the main plan tree (it only got rid of those referenced by other initPlans). It's not clear that this caused any real problems, given the limited use of extParam by the executor, but it's certainly not what was intended. I originally thought that there was also a problem with needing to include indirect dependencies on external params in initPlans' param sets, but it turns out that the executor handles this correctly so long as the depended-on initPlan is earlier in the initPlans list than the one using its output. That seems a bit of a fragile assumption, but it is true at the moment, so I just documented it in some code comments rather than making what would be rather invasive changes to remove the assumption. Back-patch to 8.1. Previous versions don't have the case of initPlans referring to other initPlans' outputs, so while the existing logic is still questionable for them, there are not any known bugs to be fixed. So I'll refrain from changing them for now.
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