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* Update copyrights for 2020Bruce Momjian2020-01-01
| | | | Backpatch-through: update all files in master, backpatch legal files through 9.4
* Allow functions-in-FROM to be pulled up if they reduce to constants.Tom Lane2019-08-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows simplification of the plan tree in some common usage patterns: we can get rid of a join to the function RTE. In principle we could pull up any immutable expression, but restricting it to Consts avoids the risk that multiple evaluations of the expression might cost more than we can save. (Possibly this could be improved in future --- but we've more or less promised people that putting a function in FROM guarantees single evaluation, so we'd have to tread carefully.) To do this, we need to rearrange when eval_const_expressions() happens for expressions in function RTEs. I moved it to inline_set_returning_functions(), which already has to iterate over every function RTE, and in consequence renamed that function to preprocess_function_rtes(). A useful consequence is that inline_set_returning_function() no longer has to do this for itself, simplifying that code. In passing, break out pull_up_simple_subquery's code that knows where everything that needs pullup_replace_vars() processing is, so that the new pull_up_constant_function() routine can share it. We'd gotten away with one-and-a-half copies of that code so far, since pull_up_simple_values() could assume that a lot of cases didn't apply to it --- but I don't think pull_up_constant_function() can make any simplifying assumptions. Might as well make pull_up_simple_values() use it too. (Possibly this refactoring should go further: maybe we could share some of the code to fill in the pullup_replace_vars_context struct? For now, I left it that the callers fill that completely.) Note: the one existing test case that this patch changes has to be changed because inlining its function RTEs would destroy the point of the test, namely to check join order. Alexander Kuzmenkov and Aleksandr Parfenov, reviewed by Antonin Houska and Anastasia Lubennikova, and whacked around some more by me Discussion: https://postgr.es/m/402356c32eeb93d4fed01f66d6c7fe2d@postgrespro.ru
* Rename nodes/relation.h to nodes/pathnodes.h.Tom Lane2019-01-29
| | | | | | | | | | | | | The old name of this file was never a very good indication of what it was for. Now that there's also access/relation.h, we have a potential confusion hazard as well, so let's rename it to something more apropos. Per discussion, "pathnodes.h" is reasonable, since a good fraction of the file is Path node definitions. While at it, tweak a couple of other headers that were gratuitously importing relation.h into modules that don't need it. Discussion: https://postgr.es/m/7719.1548688728@sss.pgh.pa.us
* 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
* Make some small planner API cleanups.Tom Lane2019-01-29
| | | | | | | | | | | | | | | | | | | | | | Move a few very simple node-creation and node-type-testing functions from the planner's clauses.c to nodes/makefuncs and nodes/nodeFuncs. There's nothing planner-specific about them, as evidenced by the number of other places that were using them. While at it, rename and_clause() etc to is_andclause() etc, to clarify that they are node-type-testing functions not node-creation functions. And use "static inline" implementations for the shortest ones. Also, modify flatten_join_alias_vars() and some subsidiary functions to take a Query not a PlannerInfo to define the join structure that Vars should be translated according to. They were only using the "parse" field of the PlannerInfo anyway, so this just requires removing one level of indirection. The advantage is that now parse_agg.c can use flatten_join_alias_vars() without the horrid kluge of creating an incomplete PlannerInfo, which will allow that file to be decoupled from relation.h in a subsequent patch. Discussion: https://postgr.es/m/11460.1548706639@sss.pgh.pa.us
* In the planner, replace an empty FROM clause with a dummy RTE.Tom Lane2019-01-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The fact that "SELECT expression" has no base relations has long been a thorn in the side of the planner. It makes it hard to flatten a sub-query that looks like that, or is a trivial VALUES() item, because the planner generally uses relid sets to identify sub-relations, and such a sub-query would have an empty relid set if we flattened it. prepjointree.c contains some baroque logic that works around this in certain special cases --- but there is a much better answer. We can replace an empty FROM clause with a dummy RTE that acts like a table of one row and no columns, and then there are no such corner cases to worry about. Instead we need some logic to get rid of useless dummy RTEs, but that's simpler and covers more cases than what was there before. For really trivial cases, where the query is just "SELECT expression" and nothing else, there's a hazard that adding the extra RTE makes for a noticeable slowdown; even though it's not much processing, there's not that much for the planner to do overall. However testing says that the penalty is very small, close to the noise level. In more complex queries, this is able to find optimizations that we could not find before. The new RTE type is called RTE_RESULT, since the "scan" plan type it gives rise to is a Result node (the same plan we produced for a "SELECT expression" query before). To avoid confusion, rename the old ResultPath path type to GroupResultPath, reflecting that it's only used in degenerate grouping cases where we know the query produces just one grouped row. (It wouldn't work to unify the two cases, because there are different rules about where the associated quals live during query_planner.) Note: although this touches readfuncs.c, I don't think a catversion bump is required, because the added case can't occur in stored rules, only plans. Patch by me, reviewed by David Rowley and Mark Dilger Discussion: https://postgr.es/m/15944.1521127664@sss.pgh.pa.us
* Move inheritance expansion code into its own fileAlvaro Herrera2019-01-10
| | | | | | | | | | | | | | | | | This commit moves expand_inherited_tables and underlings from optimizer/prep/prepunionc.c to optimizer/utils/inherit.c. Also, all of the AppendRelInfo-based expression manipulation routines are moved to optimizer/utils/appendinfo.c. No functional code changes. One exception is the introduction of make_append_rel_info, but that's still just moving around code. Also, stop including <limits.h> in prepunion.c, which no longer needs it since 3fc6e2d7f5b6. I (Álvaro) noticed this because Amit was copying that to inherit.c, which likewise doesn't need it. Author: Amit Langote Discussion: https://postgr.es/m/3be67028-a00a-502c-199a-da00eec8fb6e@lab.ntt.co.jp
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Fix improper uses of canonicalize_qual().Tom Lane2018-03-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One of the things canonicalize_qual() does is to remove constant-NULL subexpressions of top-level AND/OR clauses. It does that on the assumption that what it's given is a top-level WHERE clause, so that NULL can be treated like FALSE. Although this is documented down inside a subroutine of canonicalize_qual(), it wasn't mentioned in the documentation of that function itself, and some callers hadn't gotten that memo. Notably, commit d007a9505 caused get_relation_constraints() to apply canonicalize_qual() to CHECK constraints. That allowed constraint exclusion to misoptimize situations in which a CHECK constraint had a provably-NULL subclause, as seen in the regression test case added here, in which a child table that should be scanned is not. (Although this thinko is ancient, the test case doesn't fail before 9.2, for reasons I've not bothered to track down in detail. There may be related cases that do fail before that.) More recently, commit f0e44751d added an independent bug by applying canonicalize_qual() to index expressions, which is even sillier since those might not even be boolean. If they are, though, I think this could lead to making incorrect index entries for affected index expressions in v10. I haven't attempted to prove that though. To fix, add an "is_check" parameter to canonicalize_qual() to specify whether it should assume WHERE or CHECK semantics, and make it perform NULL-elimination accordingly. Adjust the callers to apply the right semantics, or remove the call entirely in cases where it's not known that the expression has one or the other semantics. I also removed the call in some cases involving partition expressions, where it should be a no-op because such expressions should be canonical already ... and was a no-op, independently of whether it could in principle have done something, because it was being handed the qual in implicit-AND format which isn't what it expects. In HEAD, add an Assert to catch that type of mistake in future. This represents an API break for external callers of canonicalize_qual(). While that's intentional in HEAD to make such callers think about which case applies to them, it seems like something we probably wouldn't be thanked for in released branches. Hence, in released branches, the extra parameter is added to a new function canonicalize_qual_ext(), and canonicalize_qual() is a wrapper that retains its old behavior. Patch by me with suggestions from Dean Rasheed. Back-patch to all supported branches. Discussion: https://postgr.es/m/24475.1520635069@sss.pgh.pa.us
* Update copyright for 2018Bruce Momjian2018-01-02
| | | | Backpatch-through: certain files through 9.3
* Fix creation of resjunk tlist entries for inherited mixed UPDATE/DELETE.Tom Lane2017-11-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rewriteTargetListUD's processing is dependent on the relkind of the query's target table. That was fine at the time it was made to act that way, even for queries on inheritance trees, because all tables in an inheritance tree would necessarily be plain tables. However, the 9.5 feature addition allowing some members of an inheritance tree to be foreign tables broke the assumption that rewriteTargetListUD's output tlist could be applied to all child tables with nothing more than column-number mapping. This led to visible failures if foreign child tables had row-level triggers, and would also break in cases where child tables belonged to FDWs that used methods other than CTID for row identification. To fix, delay running rewriteTargetListUD until after the planner has expanded inheritance, so that it is applied separately to the (already mapped) tlist for each child table. We can conveniently call it from preprocess_targetlist. Refactor associated code slightly to avoid the need to heap_open the target relation multiple times during preprocess_targetlist. (The APIs remain a bit ugly, particularly around the point of which steps scribble on parse->targetList and which don't. But avoiding such scribbling would require a change in FDW callback APIs, which is more pain than it's worth.) Also fix ExecModifyTable to ensure that "tupleid" is reset to NULL when we transition from rows providing a CTID to rows that don't. (That's really an independent bug, but it manifests in much the same cases.) Add a regression test checking one manifestation of this problem, which was that row-level triggers on a foreign child table did not work right. Back-patch to 9.5 where the problem was introduced. Etsuro Fujita, reviewed by Ildus Kurbangaliev and Ashutosh Bapat Discussion: https://postgr.es/m/20170514150525.0346ba72@postgrespro.ru
* Basic partition-wise join functionality.Robert Haas2017-10-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of joining two partitioned tables in their entirety we can, if it is an equi-join on the partition keys, join the matching partitions individually. This involves teaching the planner about "other join" rels, which are related to regular join rels in the same way that other member rels are related to baserels. This can use significantly more CPU time and memory than regular join planning, because there may now be a set of "other" rels not only for every base relation but also for every join relation. In most practical cases, this probably shouldn't be a problem, because (1) it's probably unusual to join many tables each with many partitions using the partition keys for all joins and (2) if you do that scenario then you probably have a big enough machine to handle the increased memory cost of planning and (3) the resulting plan is highly likely to be better, so what you spend in planning you'll make up on the execution side. All the same, for now, turn this feature off by default. Currently, we can only perform joins between two tables whose partitioning schemes are absolutely identical. It would be nice to cope with other scenarios, such as extra partitions on one side or the other with no match on the other side, but that will have to wait for a future patch. Ashutosh Bapat, reviewed and tested by Rajkumar Raghuwanshi, Amit Langote, Rafia Sabih, Thomas Munro, Dilip Kumar, Antonin Houska, Amit Khandekar, and by me. A few final adjustments by me. Discussion: http://postgr.es/m/CAFjFpRfQ8GrQvzp3jA2wnLqrHmaXna-urjm_UY9BqXj=EaDTSA@mail.gmail.com Discussion: http://postgr.es/m/CAFjFpRcitjfrULr5jfuKWRPsGUX0LQ0k8-yG0Qw2+1LBGNpMdw@mail.gmail.com
* Teach adjust_appendrel_attrs(_multilevel) to do multiple translations.Robert Haas2017-08-15
| | | | | | | | | | | | | | | | Currently, child relations are always base relations, so when we translate parent relids to child relids, we only need to translate a singler relid. However, the proposed partition-wise join feature will create child joins, which will mean we need to translate a set of parent relids to the corresponding child relids. This is preliminary refactoring to make that possible. Ashutosh Bapat. Review and testing of the larger patch set of which this is a part by Amit Langote, Rajkumar Raghuwanshi, Rafia Sabih, Thomas Munro, Dilip Kumar, and me. Some adjustments, mostly cosmetic, by me. Discussion: http://postgr.es/m/CA+TgmobQK80vtXjAsPZWWXd7c8u13G86gmuLupN+uUJjA+i4nA@mail.gmail.com
* 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
* Improve RLS planning by marking individual quals with security levels.Tom Lane2017-01-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In an RLS query, we must ensure that security filter quals are evaluated before ordinary query quals, in case the latter contain "leaky" functions that could expose the contents of sensitive rows. The original implementation of RLS planning ensured this by pushing the scan of a secured table into a sub-query that it marked as a security-barrier view. Unfortunately this results in very inefficient plans in many cases, because the sub-query cannot be flattened and gets planned independently of the rest of the query. To fix, drop the use of sub-queries to enforce RLS qual order, and instead mark each qual (RestrictInfo) with a security_level field establishing its priority for evaluation. Quals must be evaluated in security_level order, except that "leakproof" quals can be allowed to go ahead of quals of lower security_level, if it's helpful to do so. This has to be enforced within the ordering of any one list of quals to be evaluated at a table scan node, and we also have to ensure that quals are not chosen for early evaluation (i.e., use as an index qual or TID scan qual) if they're not allowed to go ahead of other quals at the scan node. This is sufficient to fix the problem for RLS quals, since we only support RLS policies on simple tables and thus RLS quals will always exist at the table scan level only. Eventually these qual ordering rules should be enforced for join quals as well, which would permit improving planning for explicit security-barrier views; but that's a task for another patch. Note that FDWs would need to be aware of these rules --- and not, for example, send an insecure qual for remote execution --- but since we do not yet allow RLS policies on foreign tables, the case doesn't arise. This will need to be addressed before we can allow such policies. Patch by me, reviewed by Stephen Frost and Dean Rasheed. Discussion: https://postgr.es/m/8185.1477432701@sss.pgh.pa.us
* Update copyright via script for 2017Bruce Momjian2017-01-03
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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.
* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* pgindent run for 9.5Bruce Momjian2015-05-23
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* Add support for INSERT ... ON CONFLICT DO NOTHING/UPDATE.Andres Freund2015-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The newly added ON CONFLICT clause allows to specify an alternative to raising a unique or exclusion constraint violation error when inserting. ON CONFLICT refers to constraints that can either be specified using a inference clause (by specifying the columns of a unique constraint) or by naming a unique or exclusion constraint. DO NOTHING avoids the constraint violation, without touching the pre-existing row. DO UPDATE SET ... [WHERE ...] updates the pre-existing tuple, and has access to both the tuple proposed for insertion and the existing tuple; the optional WHERE clause can be used to prevent an update from being executed. The UPDATE SET and WHERE clauses have access to the tuple proposed for insertion using the "magic" EXCLUDED alias, and to the pre-existing tuple using the table name or its alias. This feature is often referred to as upsert. This is implemented using a new infrastructure called "speculative insertion". It is an optimistic variant of regular insertion that first does a pre-check for existing tuples and then attempts an insert. If a violating tuple was inserted concurrently, the speculatively inserted tuple is deleted and a new attempt is made. If the pre-check finds a matching tuple the alternative DO NOTHING or DO UPDATE action is taken. If the insertion succeeds without detecting a conflict, the tuple is deemed inserted. To handle the possible ambiguity between the excluded alias and a table named excluded, and for convenience with long relation names, INSERT INTO now can alias its target table. Bumps catversion as stored rules change. Author: Peter Geoghegan, with significant contributions from Heikki Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes. Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs, Dean Rasheed, Stephen Frost and many others.
* Support flattening of empty-FROM subqueries and one-row VALUES tables.Tom Lane2015-03-11
| | | | | | | | | We can't handle this in the general case due to limitations of the planner's data representations; but we can allow it in many useful cases, by being careful to flatten only when we are pulling a single-row subquery up into a FROM (or, equivalently, inner JOIN) node that will still have at least one remaining relation child. Per discussion of an example from Kyotaro Horiguchi.
* Update copyright for 2015Bruce Momjian2015-01-06
| | | | Backpatch certain files through 9.0
* Fix some more problems with nested append relations.Tom Lane2014-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As of commit a87c72915 (which later got backpatched as far as 9.1), we're explicitly supporting the notion that append relations can be nested; this can occur when UNION ALL constructs are nested, or when a UNION ALL contains a table with inheritance children. Bug #11457 from Nelson Page, as well as an earlier report from Elvis Pranskevichus, showed that there were still nasty bugs associated with such cases: in particular the EquivalenceClass mechanism could try to generate "join" clauses connecting an appendrel child to some grandparent appendrel, which would result in assertion failures or bogus plans. Upon investigation I concluded that all current callers of find_childrel_appendrelinfo() need to be fixed to explicitly consider multiple levels of parent appendrels. The most complex fix was in processing of "broken" EquivalenceClasses, which are ECs for which we have been unable to generate all the derived equality clauses we would like to because of missing cross-type equality operators in the underlying btree operator family. That code path is more or less entirely untested by the regression tests to date, because no standard opfamilies have such holes in them. So I wrote a new regression test script to try to exercise it a bit, which turned out to be quite a worthwhile activity as it exposed existing bugs in all supported branches. The present patch is essentially the same as far back as 9.2, which is where parameterized paths were introduced. In 9.0 and 9.1, we only need to back-patch a small fragment of commit 5b7b5518d, which fixes failure to propagate out the original WHERE clauses when a broken EC contains constant members. (The regression test case results show that these older branches are noticeably stupider than 9.2+ in terms of the quality of the plans generated; but we don't really care about plan quality in such cases, only that the plan not be outright wrong. A more invasive fix in the older branches would not be a good idea anyway from a plan-stability standpoint.)
* Make security barrier views automatically updatableStephen Frost2014-04-12
| | | | | | | | | | | | | | | | | Views which are marked as security_barrier must have their quals applied before any user-defined quals are called, to prevent user-defined functions from being able to see rows which the security barrier view is intended to prevent them from seeing. Remove the restriction on security barrier views being automatically updatable by adding a new securityQuals list to the RTE structure which keeps track of the quals from security barrier views at each level, independently of the user-supplied quals. When RTEs are later discovered which have securityQuals populated, they are turned into subquery RTEs which are marked as security_barrier to prevent any user-supplied quals being pushed down (modulo LEAKPROOF quals). Dean Rasheed, reviewed by Craig Ringer, Simon Riggs, KaiGai Kohei
* 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.
* More fixes for planner's handling of LATERAL.Tom Lane2012-08-12
| | | | | | | | | | | | | | | | | | | | | | | | Re-allow subquery pullup for LATERAL subqueries, except when the subquery is below an outer join and contains lateral references to relations outside that outer join. If we pull up in such a case, we risk introducing lateral cross-references into outer joins' ON quals, which is something the code is entirely unprepared to cope with right now; and I'm not sure it'll ever be worth coping with. Support lateral refs in VALUES (this seems to be the only additional path type that needs such support as a consequence of re-allowing subquery pullup). Put in a slightly hacky fix for joinpath.c's refusal to consider parameterized join paths even when there cannot be any unparameterized ones. This was causing "could not devise a query plan for the given query" failures in queries involving more than two FROM items. Put in an even more hacky fix for distribute_qual_to_rels() being unhappy with join quals that contain references to rels outside their syntactic scope; which is to say, disable that test altogether. Need to think about how to preserve some sort of debugging cross-check here, while not expending more cycles than befits a debugging cross-check.
* Run pgindent on 9.2 source tree in preparation for first 9.3Bruce Momjian2012-06-10
| | | | commit-fest.
* Preserve column names in the execution-time tupledesc for a RowExpr.Tom Lane2012-02-14
| | | | | | | | | | | | | | | The hstore and json datatypes both have record-conversion functions that pay attention to column names in the composite values they're handed. We used to not worry about inserting correct field names into tuple descriptors generated at runtime, but given these examples it seems useful to do so. Observe the nicer-looking results in the regression tests whose results changed. catversion bump because there is a subtle change in requirements for stored rule parsetrees: RowExprs from ROW() constructs now have to include field names. Andrew Dunstan and Tom Lane
* Update copyright notices for year 2012.Bruce Momjian2012-01-01
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* Stamp copyrights for year 2011.Bruce Momjian2011-01-01
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* Use appendrel planning logic for top-level UNION ALL structures.Tom Lane2010-11-08
| | | | | | | | | | | | | Formerly, we could convert a UNION ALL structure inside a subquery-in-FROM into an appendrel, as a side effect of pulling up the subquery into its parent; but top-level UNION ALL always caused use of plan_set_operations(). That didn't matter too much because you got an Append-based plan either way. However, now that the appendrel code can do things with MergeAppend, it's worthwhile to hack up the top-level case so it also uses appendrels. This is a bit of a stopgap; but going much further than this will require a major rewrite of the planner's set-operations support, which I'm not prepared to undertake now. For the moment let's grab the low-hanging fruit.
* Improve the planner's simplification of NOT constructs.Tom Lane2010-10-10
| | | | | | | | | | | | | | | | | This patch merges the responsibility for NOT-flattening into eval_const_expressions' processing. It wasn't done that way originally because prepqual.c is far older than eval_const_expressions. But putting this work into eval_const_expressions saves one pass over the qual trees, and in fact saves even more than that because we can exploit the knowledge that the subexpressions have already been recursively simplified. Doing it this way also lets us do it uniformly over all expressions, whereas prepqual.c formerly just did it at top level to save cycles. That should improve the planner's ability to recognize logically-equivalent constructs. While at it, also add the ability to fold a NOT into BooleanTest and NullTest constructs (the latter only for the scalar-datatype case). Per discussion of bug #5702.
* Remove cvs keywords from all files.Magnus Hagander2010-09-20
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* Update copyright for the year 2010.Bruce Momjian2010-01-02
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* Re-implement EvalPlanQual processing to improve its performance and eliminateTom Lane2009-10-26
| | | | | | | | | | | | | | | | | | | | | | | | | a lot of strange behaviors that occurred in join cases. We now identify the "current" row for every joined relation in UPDATE, DELETE, and SELECT FOR UPDATE/SHARE queries. If an EvalPlanQual recheck is necessary, we jam the appropriate row into each scan node in the rechecking plan, forcing it to emit only that one row. The former behavior could rescan the whole of each joined relation for each recheck, which was terrible for performance, and what's much worse could result in duplicated output tuples. Also, the original implementation of EvalPlanQual could not re-use the recheck execution tree --- it had to go through a full executor init and shutdown for every row to be tested. To avoid this overhead, I've associated a special runtime Param with each LockRows or ModifyTable plan node, and arranged to make every scan node below such a node depend on that Param. Thus, by signaling a change in that Param, the EPQ machinery can just rescan the already-built test plan. This patch also adds a prohibition on set-returning functions in the targetlist of SELECT FOR UPDATE/SHARE. This is needed to avoid the duplicate-output-tuple problem. It seems fairly reasonable since the other restrictions on SELECT FOR UPDATE are meant to ensure that there is a unique correspondence between source tuples and result tuples, which an output SRF destroys as much as anything else does.
* Do some minor code refactoring in preparation for changing the APIs ofTom Lane2009-05-12
| | | | | | | | | | | | | | | | | find_inheritance_children() and find_all_inheritors(). I got annoyed that these are buried inside the planner but mostly used elsewhere. So, create a new file catalog/pg_inherits.c and put them there, along with a couple of other functions that search pg_inherits. The code that modifies pg_inherits is (still) in tablecmds.c --- it's kind of entangled with unrelated code that modifies pg_depend and other stuff, so pulling it out seemed like a bigger change than I wanted to make right now. But this file provides a natural home for it if anyone ever gets around to that. This commit just moves code around; it doesn't change anything, except I succumbed to the temptation to make a couple of trivial optimizations in typeInheritsFrom().
* Improve pull_up_subqueries logic so that it doesn't insert unnecessaryTom Lane2009-04-28
| | | | | | | PlaceHolderVar nodes in join quals appearing in or below the lowest outer join that could null the subquery being pulled up. This improves the planner's ability to recognize constant join quals, and probably helps with detection of common sort keys (equivalence classes) as well.
* Update copyright for 2009.Bruce Momjian2009-01-01
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* Get rid of adjust_appendrel_attr_needed(), which has been broken ever sinceTom Lane2008-11-11
| | | | | | | | | | | we extended the appendrel mechanism to support UNION ALL optimization. The reason nobody noticed was that we are not actually using attr_needed data for appendrel children; hence it seems more reasonable to rip it out than fix it. Back-patch to 8.2 because an Assert failure is possible in corner cases. Per examination of an example from Jim Nasby. In HEAD, also get rid of AppendRelInfo.col_mappings, which is quite inadequate to represent UNION ALL situations; depend entirely on translated_vars instead.
* Improve sublink pullup code to handle ANY/EXISTS sublinks that are at topTom Lane2008-08-17
| | | | | | | | | | | | | level of a JOIN/ON clause, not only at top level of WHERE. (However, we can't do this in an outer join's ON clause, unless the ANY/EXISTS refers only to the nullable side of the outer join, so that it can effectively be pushed down into the nullable side.) Per request from Kevin Grittner. In passing, fix a bug in the initial implementation of EXISTS pullup: it would Assert if the EXIST's WHERE clause used a join alias variable. Since we haven't yet flattened join aliases when this transformation happens, it's necessary to include join relids in the computed set of RHS relids.
* Implement SEMI and ANTI joins in the planner and executor. (Semijoins replaceTom Lane2008-08-14
| | | | | | | | | | | | | | the old JOIN_IN code, but antijoins are new functionality.) Teach the planner to convert appropriate EXISTS and NOT EXISTS subqueries into semi and anti joins respectively. Also, LEFT JOINs with suitable upper-level IS NULL filters are recognized as being anti joins. Unify the InClauseInfo and OuterJoinInfo infrastructure into "SpecialJoinInfo". With that change, it becomes possible to associate a SpecialJoinInfo with every join attempt, which permits some cleanup of join selectivity estimation. That needs to be taken much further than this patch does, but the next step is to change the API for oprjoin selectivity functions, which seems like material for a separate patch. So for the moment the output size estimates for semi and especially anti joins are quite bogus.
* Arrange to "inline" SQL functions that appear in a query's FROM clause,Tom Lane2008-03-18
| | | | | | | are declared to return set, and consist of just a single SELECT. We can replace the FROM-item with a sub-SELECT and then optimize much as if we were dealing with a view. Patch from Richard Rowell, cleaned up by me.
* Update copyrights in source tree to 2008.Bruce Momjian2008-01-01
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* Update CVS HEAD for 2007 copyright. Back branches are typically notBruce Momjian2007-01-05
| | | | back-stamped for this.
* pgindent run for 8.2.Bruce Momjian2006-10-04
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* Update copyright for 2006. Update scripts.Bruce Momjian2006-03-05
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* Teach planner to convert simple UNION ALL subqueries into append relations,Tom Lane2006-02-03
| | | | | | | | | thereby sharing code with the inheritance case. This puts the UNION-ALL-view approach to partitioned tables on par with inheritance, so far as constraint exclusion is concerned: it works either way. (Still need to update the docs to say so.) The definition of "simple UNION ALL" is a little simpler than I would like --- basically the union arms can only be SELECT * FROM foo --- but it's good enough for partitioned-table cases.
* Restructure planner's handling of inheritance. Rather than processingTom Lane2006-01-31
| | | | | | | | | | | | | inheritance trees on-the-fly, which pretty well constrained us to considering only one way of planning inheritance, expand inheritance sets during the planner prep phase, and build a side data structure that can be consulted later to find which RTEs are members of which inheritance sets. As proof of concept, use the data structure to plan joins against inheritance sets more efficiently: we can now use indexes on the set members in inner-indexscan joins. (The generated plans could be improved further, but it'll take some executor changes.) This data structure will also support handling UNION ALL subqueries in the same way as inheritance sets, but that aspect of it isn't finished yet.
* Teach planner how to rearrange join order for some classes of OUTER JOIN.Tom Lane2005-12-20
| | | | | | Per my recent proposal. I ended up basing the implementation on the existing mechanism for enforcing valid join orders of IN joins --- the rules for valid outer-join orders are somewhat similar.