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* Refactor ChangeVarNodesExtended() using the custom callbackAlexander Korotkov2025-05-07
| | | | | | | | | | | | | | fc069a3a6319 implemented Self-Join Elimination (SJE) and put related logic to ChangeVarNodes_walker(). This commit provides refactoring to remove the SJE-related logic from ChangeVarNodes_walker() but adds a custom callback to ChangeVarNodesExtended(), which has a chance to process a node before ChangeVarNodes_walker(). Passing this callback to ChangeVarNodesExtended() allows SJE-related node handling to be kept within the analyzejoins.c. Reported-by: Richard Guo <guofenglinux@gmail.com> Discussion: https://postgr.es/m/CAMbWs49PE3CvnV8vrQ0Dr%3DHqgZZmX0tdNbzVNJxqc8yg-8kDQQ%40mail.gmail.com Author: Andrei Lepikhov <lepihov@gmail.com> Author: Alexander Korotkov <aekorotkov@gmail.com>
* Revert "Refactor ChangeVarNodesExtended() using the custom callback"Alexander Korotkov2025-05-03
| | | | | | | | This reverts commit 250a718aadad68793e82103282247556a46a3cfc. It shouldn't be pushed during the release freeze. Reported-by: Tom Lane Discussion: https://postgr.es/m/E1uBIbY-000owH-0O%40gemulon.postgresql.org
* Refactor ChangeVarNodesExtended() using the custom callbackAlexander Korotkov2025-05-03
| | | | | | | | | | | | | | fc069a3a6319 implemented Self-Join Elimination (SJE) and put related logic to ChangeVarNodes_walker(). This commit provides refactoring to remove the SJE-related logic from ChangeVarNodes_walker() but adds a custom callback to ChangeVarNodesExtended(), which has a chance to process a node before ChangeVarNodes_walker(). Passing this callback to ChangeVarNodesExtended() allows SJE-related node handling to be kept within the analyzejoins.c. Reported-by: Richard Guo <guofenglinux@gmail.com> Discussion: https://postgr.es/m/CAMbWs49PE3CvnV8vrQ0Dr%3DHqgZZmX0tdNbzVNJxqc8yg-8kDQQ%40mail.gmail.com Author: Andrei Lepikhov <lepihov@gmail.com> Author: Alexander Korotkov <aekorotkov@gmail.com>
* Fixes for ChangeVarNodes_walker()Alexander Korotkov2025-04-29
| | | | | | | | | | | | | | | | | This commit fixes two bug in ChangeVarNodes_walker() function. * When considering RestrictInfo, walk down to its clauses based on the presense of relid to be deleted not just in clause_relids but also in required_relids. * Incrementally adjust num_base_rels based on the change of clause_relids instead of recalculating it using clause_relids, which could contain outer-join relids. Reported-by: Richard Guo <guofenglinux@gmail.com> Discussion: https://postgr.es/m/CAMbWs49PE3CvnV8vrQ0Dr%3DHqgZZmX0tdNbzVNJxqc8yg-8kDQQ%40mail.gmail.com Author: Andrei Lepikhov <lepihov@gmail.com> Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
* Restore comments in ChangeVarNodesExtended()Alexander Korotkov2025-04-28
| | | | | | | | This commit restores comments in ChangeVarNodesExtended(), which were accidentally removed by fc069a3a6319. Reported-by: Richard Guo <guofenglinux@gmail.com> Discussion: https://postgr.es/m/CAMbWs49PE3CvnV8vrQ0Dr%3DHqgZZmX0tdNbzVNJxqc8yg-8kDQQ%40mail.gmail.com
* Fix incorrect handling of subquery pullupRichard Guo2025-03-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When pulling up a subquery, if the subquery's target list items are used in grouping set columns, we need to wrap them in PlaceHolderVars. This ensures that expressions retain their separate identity so that they will match grouping set columns when appropriate. In 90947674f, we decided to wrap subquery outputs that are non-var expressions in PlaceHolderVars. This prevents const-simplification from merging them into the surrounding expressions after subquery pullup, which could otherwise lead to failing to match those subexpressions to grouping set columns, with the effect that they'd not go to null when expected. However, that left some loose ends. If the subquery's target list contains two or more identical Var expressions, we can still fail to match the Var expression to the expected grouping set expression. This is not related to const-simplification, but rather to how we match expressions to lower target items in setrefs.c. For sort/group expressions, we use ressortgroupref matching, which works well. For other expressions, we primarily rely on comparing the expressions to determine if they are the same. Therefore, we need a way to prevent setrefs.c from matching the expression to some other identical ones. To fix, wrap all subquery outputs in PlaceHolderVars if the parent query uses grouping sets, ensuring that they preserve their separate identity throughout the whole planning process. Reported-by: Dean Rasheed <dean.a.rasheed@gmail.com> Author: Richard Guo <guofenglinux@gmail.com> Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com> Discussion: https://postgr.es/m/CAMbWs4-meSahaanKskpBn0KKxdHAXC1_EJCVWHxEodqirrGJnw@mail.gmail.com
* Eliminate code duplication in replace_rte_variables callbacksRichard Guo2025-02-25
| | | | | | | | | | | | | | | | | | The callback functions ReplaceVarsFromTargetList_callback and pullup_replace_vars_callback are both used to replace Vars in an expression tree that reference a particular RTE with items from a targetlist, and they both need to expand whole-tuple references and deal with OLD/NEW RETURNING list Vars. As a result, currently there is significant code duplication between these two functions. This patch introduces a new function, ReplaceVarFromTargetList, to perform the replacement and calls it from both callback functions, thereby eliminating code duplication. Author: Dean Rasheed <dean.a.rasheed@gmail.com> Author: Richard Guo <guofenglinux@gmail.com> Reviewed-by: Jian He <jian.universality@gmail.com> Discussion: https://postgr.es/m/CAEZATCWhr=FM4X5kCPvVs-g2XEk+ceLsNtBK_zZMkqFn9vUjsw@mail.gmail.com
* Expand virtual generated columns in the plannerRichard Guo2025-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 83ea6c540 added support for virtual generated columns that are computed on read. All Var nodes in the query that reference virtual generated columns must be replaced with the corresponding generation expressions. Currently, this replacement occurs in the rewriter. However, this approach has several issues. If a Var referencing a virtual generated column has any varnullingrels, those varnullingrels need to be propagated into the generation expression. Failing to do so can lead to "wrong varnullingrels" errors and improper outer-join removal. Additionally, if such a Var comes from the nullable side of an outer join, we may need to wrap the generation expression in a PlaceHolderVar to ensure that it is evaluated at the right place and hence is forced to null when the outer join should do so. In certain cases, such as when the query uses grouping sets, we also need a PlaceHolderVar for anything that is not a simple Var to isolate subexpressions. Failure to do so can result in incorrect results. To fix these issues, this patch expands the virtual generated columns in the planner rather than in the rewriter, and leverages the pullup_replace_vars architecture to avoid code duplication. The generation expressions will be correctly marked with nullingrel bits and wrapped in PlaceHolderVars when needed by the pullup_replace_vars callback function. This requires handling the OLD/NEW RETURNING list Vars in pullup_replace_vars_callback, as it may now deal with Vars referencing the result relation instead of a subquery. The "wrong varnullingrels" error was reported by Alexander Lakhin. The incorrect result issue and the improper outer-join removal issue were reported by Richard Guo. Author: Richard Guo <guofenglinux@gmail.com> Author: Dean Rasheed <dean.a.rasheed@gmail.com> Reviewed-by: Jian He <jian.universality@gmail.com> Discussion: https://postgr.es/m/75eb1a6f-d59f-42e6-8a78-124ee808cda7@gmail.com
* Implement Self-Join EliminationAlexander Korotkov2025-02-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Self-Join Elimination (SJE) feature removes an inner join of a plain table to itself in the query tree if it is proven that the join can be replaced with a scan without impacting the query result. Self-join and inner relation get replaced with the outer in query, equivalence classes, and planner info structures. Also, the inner restrictlist moves to the outer one with the removal of duplicated clauses. Thus, this optimization reduces the length of the range table list (this especially makes sense for partitioned relations), reduces the number of restriction clauses and, in turn, selectivity estimations, and potentially improves total planner prediction for the query. This feature is dedicated to avoiding redundancy, which can appear after pull-up transformations or the creation of an EquivalenceClass-derived clause like the below. SELECT * FROM t1 WHERE x IN (SELECT t3.x FROM t1 t3); SELECT * FROM t1 WHERE EXISTS (SELECT t3.x FROM t1 t3 WHERE t3.x = t1.x); SELECT * FROM t1,t2, t1 t3 WHERE t1.x = t2.x AND t2.x = t3.x; In the future, we could also reduce redundancy caused by subquery pull-up after unnecessary outer join removal in cases like the one below. SELECT * FROM t1 WHERE x IN (SELECT t3.x FROM t1 t3 LEFT JOIN t2 ON t2.x = t1.x); Also, it can drastically help to join partitioned tables, removing entries even before their expansion. The SJE proof is based on innerrel_is_unique() machinery. We can remove a self-join when for each outer row: 1. At most, one inner row matches the join clause; 2. Each matched inner row must be (physically) the same as the outer one; 3. Inner and outer rows have the same row mark. In this patch, we use the next approach to identify a self-join: 1. Collect all merge-joinable join quals which look like a.x = b.x; 2. Add to the list above the baseretrictinfo of the inner table; 3. Check innerrel_is_unique() for the qual list. If it returns false, skip this pair of joining tables; 4. Check uniqueness, proved by the baserestrictinfo clauses. To prove the possibility of self-join elimination, the inner and outer clauses must match exactly. The relation replacement procedure is not trivial and is partly combined with the one used to remove useless left joins. Tests covering this feature were added to join.sql. Some of the existing regression tests changed due to self-join removal logic. Discussion: https://postgr.es/m/flat/64486b0b-0404-e39e-322d-0801154901f3%40postgrespro.ru Author: Andrey Lepikhov <a.lepikhov@postgrespro.ru> Author: Alexander Kuzmenkov <a.kuzmenkov@postgrespro.ru> Co-authored-by: Alexander Korotkov <aekorotkov@gmail.com> Co-authored-by: Alena Rybakina <lena.ribackina@yandex.ru> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Simon Riggs <simon@2ndquadrant.com> Reviewed-by: Jonathan S. Katz <jkatz@postgresql.org> Reviewed-by: David Rowley <david.rowley@2ndquadrant.com> Reviewed-by: Thomas Munro <thomas.munro@enterprisedb.com> Reviewed-by: Konstantin Knizhnik <k.knizhnik@postgrespro.ru> Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Reviewed-by: Hywel Carver <hywel@skillerwhale.com> Reviewed-by: Laurenz Albe <laurenz.albe@cybertec.at> Reviewed-by: Ronan Dunklau <ronan.dunklau@aiven.io> Reviewed-by: vignesh C <vignesh21@gmail.com> Reviewed-by: Zhihong Yu <zyu@yugabyte.com> Reviewed-by: Greg Stark <stark@mit.edu> Reviewed-by: Jaime Casanova <jcasanov@systemguards.com.ec> Reviewed-by: Michał Kłeczek <michal@kleczek.org> Reviewed-by: Alena Rybakina <lena.ribackina@yandex.ru> Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
* Handle default NULL insertion a little better.Tom Lane2025-01-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a column is omitted in an INSERT, and there's no column default, the code in preptlist.c generates a NULL Const to be inserted. Furthermore, if the column is of a domain type, we wrap the Const in CoerceToDomain, so as to throw a run-time error if the domain has a NOT NULL constraint. That's fine as far as it goes, but there are two problems: 1. We're being sloppy about the type/typmod that the Const is labeled with. It really should have the domain's base type/typmod, since it's the input to CoerceToDomain not the output. This can result in coerce_to_domain inserting a useless length-coercion function (useless because it's being applied to a null). The coercion would typically get const-folded away later, but it'd be better not to create it in the first place. 2. We're not applying expression preprocessing (specifically, eval_const_expressions) to the resulting expression tree. The planner's primary expression-preprocessing pass already happened, so that means the length coercion step and CoerceToDomain node miss preprocessing altogether. This is at the least inefficient, since it means the length coercion and CoerceToDomain will actually be executed for each inserted row, though they could be const-folded away in most cases. Worse, it seems possible that missing preprocessing for the length coercion could result in an invalid plan (for example, due to failing to perform default-function-argument insertion). I'm not aware of any live bug of that sort with core datatypes, and it might be unreachable for extension types as well because of restrictions of CREATE CAST, but I'm not entirely convinced that it's unreachable. Hence, it seems worth back-patching the fix (although I only went back to v14, as the patch doesn't apply cleanly at all in v13). There are several places in the rewriter that are building null domain constants the same way as preptlist.c. While those are before the planner and hence don't have any reachable bug, they're still applying a length coercion that will be const-folded away later, uselessly wasting cycles. Hence, make a utility routine that all of these places can call to do it right. Making this code more careful about the typmod assigned to the generated NULL constant has visible but cosmetic effects on some of the plans shown in contrib/postgres_fdw's regression tests. Discussion: https://postgr.es/m/1865579.1738113656@sss.pgh.pa.us Backpatch-through: 14
* Add OLD/NEW support to RETURNING in DML queries.Dean Rasheed2025-01-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows the RETURNING list of INSERT/UPDATE/DELETE/MERGE queries to explicitly return old and new values by using the special aliases "old" and "new", which are automatically added to the query (if not already defined) while parsing its RETURNING list, allowing things like: RETURNING old.colname, new.colname, ... RETURNING old.*, new.* Additionally, a new syntax is supported, allowing the names "old" and "new" to be changed to user-supplied alias names, e.g.: RETURNING WITH (OLD AS o, NEW AS n) o.colname, n.colname, ... This is useful when the names "old" and "new" are already defined, such as inside trigger functions, allowing backwards compatibility to be maintained -- the interpretation of any existing queries that happen to already refer to relations called "old" or "new", or use those as aliases for other relations, is not changed. For an INSERT, old values will generally be NULL, and for a DELETE, new values will generally be NULL, but that may change for an INSERT with an ON CONFLICT ... DO UPDATE clause, or if a query rewrite rule changes the command type. Therefore, we put no restrictions on the use of old and new in any DML queries. Dean Rasheed, reviewed by Jian He and Jeff Davis. Discussion: https://postgr.es/m/CAEZATCWx0J0-v=Qjc6gXzR=KtsdvAE7Ow=D=mu50AgOe+pvisQ@mail.gmail.com
* Update copyright for 2025Bruce Momjian2025-01-01
| | | | Backpatch-through: 13
* Remove useless casts to (void *)Peter Eisentraut2024-11-28
| | | | | | | | Many of them just seem to have been copied around for no real reason. Their presence causes (small) risks of hiding actual type mismatches or silently discarding qualifiers Discussion: https://www.postgresql.org/message-id/flat/461ea37c-8b58-43b4-9736-52884e862820@eisentraut.org
* Fix unnecessary casts of copyObject() resultPeter Eisentraut2024-10-17
| | | | | | | | | The result is already of the correct type, so these casts don't do anything. Reviewed-by: Nathan Bossart <nathandbossart@gmail.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/637eeea8-5663-460b-a114-39572c0f6c6e%40eisentraut.org
* Avoid inserting PlaceHolderVars in cases where pre-v16 PG did not.Tom Lane2024-08-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 2489d76c4 removed some logic from pullup_replace_vars() that avoided wrapping a PlaceHolderVar around a pulled-up subquery output expression if the expression could be proven to go to NULL anyway (because it contained Vars or PHVs of the pulled-up relation and did not contain non-strict constructs). But removing that logic turns out to cause performance regressions in some cases, because the extra PHV blocks subexpression folding, and will do so even if outer-join reduction later turns it into a no-op with no phnullingrels bits. This can for example prevent an expression from being matched to an index. The reason for always adding a PHV was to ensure we had someplace to put the varnullingrels marker bits of the Var being replaced. However, it turns out we can optimize in exactly the same cases that the previous code did, because we can instead attach the needed varnullingrels bits to the contained Var(s)/PHV(s). This is not a complete solution --- it would be even better if we could remove PHVs after reducing them to no-ops. It doesn't look practical to back-patch such an improvement, but this change seems safe and at least gets rid of the performance-regression cases. Per complaint from Nikhil Raj. Back-patch to v16 where the problem appeared. Discussion: https://postgr.es/m/CAG1ps1xvnTZceKK24OUfMKLPvDP2vjT-d+F2AOCWbw_v3KeEgg@mail.gmail.com
* Support MERGE into updatable views.Dean Rasheed2024-02-29
| | | | | | | | | | | | | | | | | | | This allows the target relation of MERGE to be an auto-updatable or trigger-updatable view, and includes support for WITH CHECK OPTION, security barrier views, and security invoker views. A trigger-updatable view must have INSTEAD OF triggers for every type of action (INSERT, UPDATE, and DELETE) mentioned in the MERGE command. An auto-updatable view must not have any INSTEAD OF triggers. Mixing auto-update and trigger-update actions (i.e., having a partial set of INSTEAD OF triggers) is not supported. Rule-updatable views are also not supported, since there is no rewriter support for non-SELECT rules with MERGE operations. Dean Rasheed, reviewed by Jian He and Alvaro Herrera. Discussion: https://postgr.es/m/CAEZATCVcB1g0nmxuEc-A+gGB0HnfcGQNGYH7gS=7rq0u0zOBXA@mail.gmail.com
* Update copyright for 2024Bruce Momjian2024-01-03
| | | | | | | | Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12
* Re-allow INDEX_VAR as rt_index in ChangeVarNodes().Tom Lane2023-06-08
| | | | | | | | | | | | | Apparently some extensions are in the habit of calling ChangeVarNodes() with INDEX_VAR as the rt_index to replace. That worked before 2489d76c4, at least as long as there were not PlaceHolderVars in the expression; but now it fails because bms_is_member spits up. Add a test to avoid that. Per report from Anton Melnikov, though this is not his proposed patch. Discussion: https://postgr.es/m/5b370a46-f6d2-373d-9dbc-0d55250e82c1@inbox.ru
* Fix various typosDavid Rowley2023-04-18
| | | | | | | | | | | | This fixes many spelling mistakes in comments, but a few references to invalid parameter names, function names and option names too in comments and also some in string constants Also, fix an #undef that was undefining the incorrect definition Author: Alexander Lakhin Reviewed-by: Justin Pryzby Discussion: https://postgr.es/m/d5f68d19-c0fc-91a9-118d-7c6a5a3f5fad@gmail.com
* Remove local optimizations of empty Bitmapsets into null pointers.Tom Lane2023-03-02
| | | | | | | | These are all dead code now that it's done centrally. Patch by me; thanks to Nathan Bossart and Richard Guo for review. Discussion: https://postgr.es/m/1159933.1677621588@sss.pgh.pa.us
* Fix multi-row DEFAULT handling for INSERT ... SELECT rules.Dean Rasheed2023-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Given an updatable view with a DO ALSO INSERT ... SELECT rule, a multi-row INSERT ... VALUES query on the view fails if the VALUES list contains any DEFAULTs that are not replaced by view defaults. This manifests as an "unrecognized node type" error, or an Assert failure, in an assert-enabled build. The reason is that when RewriteQuery() attempts to replace the remaining DEFAULT items with NULLs in any product queries, using rewriteValuesRTEToNulls(), it assumes that the VALUES RTE is located at the same rangetable index in each product query. However, if the product query is an INSERT ... SELECT, then the VALUES RTE is actually in the SELECT part of that query (at the same index), rather than the top-level product query itself. Fix, by descending to the SELECT in such cases. Note that we can't simply use getInsertSelectQuery() for this, since that expects to be given a raw rule action with OLD and NEW placeholder entries, so we duplicate its logic instead. While at it, beef up the checks in getInsertSelectQuery() by checking that the jointree->fromlist node is indeed a RangeTblRef, and that the RTE it points to has rtekind == RTE_SUBQUERY. Per bug #17803, from Alexander Lakhin. Back-patch to all supported branches. Dean Rasheed, reviewed by Tom Lane. Discussion: https://postgr.es/m/17803-53c63ed4ecb4eac6%40postgresql.org
* Make Vars be outer-join-aware.Tom Lane2023-01-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Traditionally we used the same Var struct to represent the value of a table column everywhere in parse and plan trees. This choice predates our support for SQL outer joins, and it's really a pretty bad idea with outer joins, because the Var's value can depend on where it is in the tree: it might go to NULL above an outer join. So expression nodes that are equal() per equalfuncs.c might not represent the same value, which is a huge correctness hazard for the planner. To improve this, decorate Var nodes with a bitmapset showing which outer joins (identified by RTE indexes) may have nulled them at the point in the parse tree where the Var appears. This allows us to trust that equal() Vars represent the same value. A certain amount of klugery is still needed to cope with cases where we re-order two outer joins, but it's possible to make it work without sacrificing that core principle. PlaceHolderVars receive similar decoration for the same reason. In the planner, we include these outer join bitmapsets into the relids that an expression is considered to depend on, and in consequence also add outer-join relids to the relids of join RelOptInfos. This allows us to correctly perceive whether an expression can be calculated above or below a particular outer join. This change affects FDWs that want to plan foreign joins. They *must* follow suit when labeling foreign joins in order to match with the core planner, but for many purposes (if postgres_fdw is any guide) they'd prefer to consider only base relations within the join. To support both requirements, redefine ForeignScan.fs_relids as base+OJ relids, and add a new field fs_base_relids that's set up by the core planner. Large though it is, this commit just does the minimum necessary to install the new mechanisms and get check-world passing again. Follow-up patches will perform some cleanup. (The README additions and comments mention some stuff that will appear in the follow-up.) Patch by me; thanks to Richard Guo for review. Discussion: https://postgr.es/m/830269.1656693747@sss.pgh.pa.us
* Update copyright for 2023Bruce Momjian2023-01-02
| | | | Backpatch-through: 11
* Rework query relation permission checkingAlvaro Herrera2022-12-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, information about the permissions to be checked on relations mentioned in a query is stored in their range table entries. So the executor must scan the entire range table looking for relations that need to have permissions checked. This can make the permission checking part of the executor initialization needlessly expensive when many inheritance children are present in the range range. While the permissions need not be checked on the individual child relations, the executor still must visit every range table entry to filter them out. This commit moves the permission checking information out of the range table entries into a new plan node called RTEPermissionInfo. Every top-level (inheritance "root") RTE_RELATION entry in the range table gets one and a list of those is maintained alongside the range table. This new list is initialized by the parser when initializing the range table. The rewriter can add more entries to it as rules/views are expanded. Finally, the planner combines the lists of the individual subqueries into one flat list that is passed to the executor for checking. To make it quick to find the RTEPermissionInfo entry belonging to a given relation, RangeTblEntry gets a new Index field 'perminfoindex' that stores the corresponding RTEPermissionInfo's index in the query's list of the latter. ExecutorCheckPerms_hook has gained another List * argument; the signature is now: typedef bool (*ExecutorCheckPerms_hook_type) (List *rangeTable, List *rtePermInfos, bool ereport_on_violation); The first argument is no longer used by any in-core uses of the hook, but we leave it in place because there may be other implementations that do. Implementations should likely scan the rtePermInfos list to determine which operations to allow or deny. Author: Amit Langote <amitlangote09@gmail.com> Discussion: https://postgr.es/m/CA+HiwqGjJDmUhDSfv-U2qhKJjt9ST7Xh9JXC_irsAQ1TAUsJYg@mail.gmail.com
* Don't bother to attach column name lists to RowExprs of named types.Tom Lane2022-03-17
| | | | | | | | | If a RowExpr is marked as returning a named composite type, we aren't going to consult its colnames list; we'll use the attribute names shown for the type in pg_attribute. Hence, skip storing that list, to save a few nanoseconds when copying the expression tree around. Discussion: https://postgr.es/m/2950001.1638729947@sss.pgh.pa.us
* Update copyright for 2022Bruce Momjian2022-01-07
| | | | Backpatch-through: 10
* Update copyright for 2021Bruce Momjian2021-01-02
| | | | Backpatch-through: 9.5
* Reconsider the representation of join alias Vars.Tom Lane2020-01-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The core idea of this patch is to make the parser generate join alias Vars (that is, ones with varno pointing to a JOIN RTE) only when the alias Var is actually different from any raw join input, that is a type coercion and/or COALESCE is necessary to generate the join output value. Otherwise just generate varno/varattno pointing to the relevant join input column. In effect, this means that the planner's flatten_join_alias_vars() transformation is already done in the parser, for all cases except (a) columns that are merged by JOIN USING and are transformed in the process, and (b) whole-row join Vars. In principle that would allow us to skip doing flatten_join_alias_vars() in many more queries than we do now, but we don't have quite enough infrastructure to know that we can do so --- in particular there's no cheap way to know whether there are any whole-row join Vars. I'm not sure if it's worth the trouble to add a Query-level flag for that, and in any case it seems like fit material for a separate patch. But even without skipping the work entirely, this should make flatten_join_alias_vars() faster, particularly where there are nested joins that it previously had to flatten recursively. An essential part of this change is to replace Var nodes' varnoold/varoattno fields with varnosyn/varattnosyn, which have considerably more tightly-defined meanings than the old fields: when they differ from varno/varattno, they identify the Var's position in an aliased JOIN RTE, and the join alias is what ruleutils.c should print for the Var. This is necessary because the varno change destroyed ruleutils.c's ability to find the JOIN RTE from the Var's varno. Another way in which this change broke ruleutils.c is that it's no longer feasible to determine, from a JOIN RTE's joinaliasvars list, which join columns correspond to which columns of the join's immediate input relations. (If those are sub-joins, the joinaliasvars entries may point to columns of their base relations, not the sub-joins.) But that was a horrid mess requiring a lot of fragile assumptions already, so let's just bite the bullet and add some more JOIN RTE fields to make it more straightforward to figure that out. I added two integer-List fields containing the relevant column numbers from the left and right input rels, plus a count of how many merged columns there are. This patch depends on the ParseNamespaceColumn infrastructure that I added in commit 5815696bc. The biggest bit of code change is restructuring transformFromClauseItem's handling of JOINs so that the ParseNamespaceColumn data is propagated upward correctly. Other than that and the ruleutils fixes, everything pretty much just works, though some processing is now inessential. I grabbed two pieces of low-hanging fruit in that line: 1. In find_expr_references, we don't need to recurse into join alias Vars anymore. There aren't any except for references to merged USING columns, which are more properly handled when we scan the join's RTE. This change actually fixes an edge-case issue: we will now record a dependency on any type-coercion function present in a USING column's joinaliasvar, even if that join column has no references in the query text. The odds of the missing dependency causing a problem seem quite small: you'd have to posit somebody dropping an implicit cast between two data types, without removing the types themselves, and then having a stored rule containing a whole-row Var for a join whose USING merge depends on that cast. So I don't feel a great need to change this in the back branches. But in theory this way is more correct. 2. markRTEForSelectPriv and markTargetListOrigin don't need to recurse into join alias Vars either, because the cases they care about don't apply to alias Vars for USING columns that are semantically distinct from the underlying columns. This removes the only case in which markVarForSelectPriv could be called with NULL for the RTE, so adjust the comments to describe that hack as being strictly internal to markRTEForSelectPriv. catversion bump required due to changes in stored rules. Discussion: https://postgr.es/m/7115.1577986646@sss.pgh.pa.us
* Update copyrights for 2020Bruce Momjian2020-01-01
| | | | Backpatch-through: update all files in master, backpatch legal files through 9.4
* Refactor attribute mappings used in logical tuple conversionMichael Paquier2019-12-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | Tuple conversion support in tupconvert.c is able to convert rowtypes between two relations, inner and outer, which are logically equivalent but have a different ordering or even dropped columns (used mainly for inheritance tree and partitions). This makes use of attribute mappings, which are simple arrays made of AttrNumber elements with a length matching the number of attributes of the outer relation. The length of the attribute mapping has been treated as completely independent of the mapping itself until now, making it easy to pass down an incorrect mapping length. This commit refactors the code related to attribute mappings and moves it into an independent facility called attmap.c, extracted from tupconvert.c. This merges the attribute mapping with its length, avoiding to try to guess what is the length of a mapping to use as this is computed once, when the map is built. This will avoid mistakes like what has been fixed in dc816e58, which has used an incorrect mapping length by matching it with the number of attributes of an inner relation (a child partition) instead of an outer relation (a partitioned table). Author: Michael Paquier Reviewed-by: Amit Langote Discussion: https://postgr.es/m/20191121042556.GD153437@paquier.xyz
* Fix inconsistencies and typos in the treeMichael Paquier2019-07-16
| | | | | | | | | | | This is numbered take 7, and addresses a set of issues around: - Fixes for typos and incorrect reference names. - Removal of unneeded comments. - Removal of unreferenced functions and structures. - Fixes regarding variable name consistency. Author: Alexander Lakhin Discussion: https://postgr.es/m/10bfd4ac-3e7c-40ab-2b2e-355ed15495e8@gmail.com
* Fix typos in various placesMichael Paquier2019-06-03
| | | | | | Author: Andrea Gelmini Reviewed-by: Michael Paquier, Justin Pryzby Discussion: https://postgr.es/m/20190528181718.GA39034@glet
* Phase 2 pgindent run for v12.Tom Lane2019-05-22
| | | | | | | | | Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
* 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
* Split QTW_EXAMINE_RTES flag into QTW_EXAMINE_RTES_BEFORE/_AFTER.Tom Lane2019-01-25
| | | | | | | | | | | | | This change allows callers of query_tree_walker() to choose whether to visit an RTE before or after visiting the contents of the RTE (i.e., prefix or postfix tree order). All existing users of QTW_EXAMINE_RTES want the QTW_EXAMINE_RTES_BEFORE behavior, but an upcoming patch will want QTW_EXAMINE_RTES_AFTER, and it seems like a potentially useful change on its own. Andreas Karlsson (extracted from CTE inlining patch) Discussion: https://postgr.es/m/8810.1542402910@sss.pgh.pa.us
* Update copyright for 2019Bruce Momjian2019-01-02
| | | | Backpatch-through: certain files through 9.4
* Fix typo in comment.Heikki Linnakangas2018-04-09
| | | | Author: Kyotaro Horiguchi
* Update copyright for 2018Bruce Momjian2018-01-02
| | | | Backpatch-through: certain files through 9.3
* Change TRUE/FALSE to true/falsePeter Eisentraut2017-11-08
| | | | | | | | | | | | | | The lower case spellings are C and C++ standard and are used in most parts of the PostgreSQL sources. The upper case spellings are only used in some files/modules. So standardize on the standard spellings. The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so those are left as is when using those APIs. In code comments, we use the lower-case spelling for the C concepts and keep the upper-case spelling for the SQL concepts. Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
* Improve implementation of CRE-stack-flattening in map_variable_attnos().Tom Lane2017-10-13
| | | | | | | | | | | | I (tgl) objected to the obscure implementation introduced in commit 1c497fa72. This one seems a bit less action-at-a-distance-y, at the price of repeating a few lines of code. Improve the comments about what the function is doing, too. Amit Khandekar, whacked around a bit more by me Discussion: https://postgr.es/m/CAJ3gD9egYTyHUH0nTMxm8-1m3RvdqEbaTyGC-CUNtYf7tKNDaQ@mail.gmail.com
* Avoid coercing a whole-row variable that is already coerced.Robert Haas2017-10-12
| | | | | | | | | | Marginal efficiency and beautification hack. I'm not sure whether this case ever arises currently, but the pending patch for update tuple routing will cause it to arise. Amit Khandekar Discussion: http://postgr.es/m/CAJ3gD9cazfppe7-wwUbabPcQ4_0SubkiPFD1+0r5_DkVNWo5yg@mail.gmail.com
* Support arrays over domains.Tom Lane2017-09-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allowing arrays with a domain type as their element type was left un-done in the original domain patch, but not for any very good reason. This omission leads to such surprising results as array_agg() not working on a domain column, because the parser can't identify a suitable output type for the polymorphic aggregate. In order to fix this, first clean up the APIs of coerce_to_domain() and some internal functions in parse_coerce.c so that we consistently pass around a CoercionContext along with CoercionForm. Previously, we sometimes passed an "isExplicit" boolean flag instead, which is strictly less information; and coerce_to_domain() didn't even get that, but instead had to reverse-engineer isExplicit from CoercionForm. That's contrary to the documentation in primnodes.h that says that CoercionForm only affects display and not semantics. I don't think this change fixes any live bugs, but it makes things more consistent. The main reason for doing it though is that now build_coercion_expression() receives ccontext, which it needs in order to be able to recursively invoke coerce_to_target_type(). Next, reimplement ArrayCoerceExpr so that the node does not directly know any details of what has to be done to the individual array elements while performing the array coercion. Instead, the per-element processing is represented by a sub-expression whose input is a source array element and whose output is a target array element. This simplifies life in parse_coerce.c, because it can build that sub-expression by a recursive invocation of coerce_to_target_type(). The executor now handles the per-element processing as a compiled expression instead of hard-wired code. The main advantage of this is that we can use a single ArrayCoerceExpr to handle as many as three successive steps per element: base type conversion, typmod coercion, and domain constraint checking. The old code used two stacked ArrayCoerceExprs to handle type + typmod coercion, which was pretty inefficient, and adding yet another array deconstruction to do domain constraint checking seemed very unappetizing. In the case where we just need a single, very simple coercion function, doing this straightforwardly leads to a noticeable increase in the per-array-element runtime cost. Hence, add an additional shortcut evalfunc in execExprInterp.c that skips unnecessary overhead for that specific form of expression. The runtime speed of simple cases is within 1% or so of where it was before, while cases that previously required two levels of array processing are significantly faster. Finally, create an implicit array type for every domain type, as we do for base types, enums, etc. Everything except the array-coercion case seems to just work without further effort. Tom Lane, reviewed by Andrew Dunstan Discussion: https://postgr.es/m/9852.1499791473@sss.pgh.pa.us
* Reduce excessive dereferencing of function pointersPeter Eisentraut2017-09-07
| | | | | | | | | | | | It is equivalent in ANSI C to write (*funcptr) () and funcptr(). These two styles have been applied inconsistently. After discussion, we'll use the more verbose style for plain function pointer variables, to make it clear that it's a variable, and the shorter style when the function pointer is in a struct (s.func() or s->func()), because then it's clear that it's not a plain function name, and otherwise the excessive punctuation makes some of those invocations hard to read. Discussion: https://www.postgresql.org/message-id/f52c16db-14ed-757d-4b48-7ef360b1631d@2ndquadrant.com
* Teach map_partition_varattnos to handle whole-row expressions.Robert Haas2017-08-03
| | | | | | | | | | Otherwise, partitioned tables with RETURNING expressions or subject to a WITH CHECK OPTION do not work properly. Amit Langote, reviewed by Amit Khandekar and Etsuro Fujita. A few comment changes by me. Discussion: http://postgr.es/m/9a39df80-871e-6212-0684-f93c83be4097@lab.ntt.co.jp
* Phase 3 of pgindent updates.Tom Lane2017-06-21
| | | | | | | | | | | | | | | | | | | | | | | | | Don't move parenthesized lines to the left, even if that means they flow past the right margin. By default, BSD indent lines up statement continuation lines that are within parentheses so that they start just to the right of the preceding left parenthesis. However, traditionally, if that resulted in the continuation line extending to the right of the desired right margin, then indent would push it left just far enough to not overrun the margin, if it could do so without making the continuation line start to the left of the current statement indent. That makes for a weird mix of indentations unless one has been completely rigid about never violating the 80-column limit. This behavior has been pretty universally panned by Postgres developers. Hence, disable it with indent's new -lpl switch, so that parenthesized lines are always lined up with the preceding left paren. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
* Cast result of copyObject() to correct typePeter Eisentraut2017-03-28
| | | | | | | | | | | | | | copyObject() is declared to return void *, which allows easily assigning the result independent of the input, but it loses all type checking. If the compiler supports typeof or something similar, cast the result to the input type. This creates a greater amount of type safety. In some cases, where the result is assigned to a generic type such as Node * or Expr *, new casts are now necessary, but in general casts are now unnecessary in the normal case and indicate that something unusual is happening. Reviewed-by: Mark Dilger <hornschnorter@gmail.com>
* Update copyright via script for 2017Bruce Momjian2017-01-03
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* Update copyright for 2016Bruce Momjian2016-01-02
| | | | Backpatch certain files through 9.1
* Get rid of the planner's LateralJoinInfo data structure.Tom Lane2015-12-11
| | | | | | | | | | | | | | | | | | | | I originally modeled this data structure on SpecialJoinInfo, but after commit acfcd45cacb6df23 that looks like a pretty poor decision. All we really need is relid sets identifying laterally-referenced rels; and most of the time, what we want to know about includes indirect lateral references, a case the LateralJoinInfo data was unsuited to compute with any efficiency. The previous commit redefined RelOptInfo.lateral_relids as the transitive closure of lateral references, so that it easily supports checking indirect references. For the places where we really do want just direct references, add a new RelOptInfo field direct_lateral_relids, which is easily set up as a copy of lateral_relids before we perform the transitive closure calculation. Then we can just drop lateral_info_list and LateralJoinInfo and the supporting code. This makes the planner's handling of lateral references noticeably more efficient, and shorter too. Such a change can't be back-patched into stable branches for fear of breaking extensions that might be looking at the planner's data structures; but it seems not too late to push it into 9.5, so I've done so.