aboutsummaryrefslogtreecommitdiff
path: root/src/backend/parser/analyze.c
Commit message (Collapse)AuthorAge
* Track more precisely query locations for nested statementsMichael Paquier2024-10-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, a Query generated through the transform phase would have unset stmt_location, tracking the starting point of a query string. Extensions relying on the statement location to extract its relevant parts in the source text string would fallback to use the whole statement instead, leading to confusing results like in pg_stat_statements for queries relying on nested queries, like: - EXPLAIN, with top-level and nested query using the same query string, and a query ID coming from the nested query when the non-top-level entry. - Multi-statements, with only partial portions of queries being normalized. - COPY TO with a query, SELECT or DMLs. This patch improves things by keeping track of the statement locations and propagate it to Query during transform, allowing PGSS to only show the relevant part of the query for nested query. This leads to less bloat in entries for non-top-level entries, as queries can now be grouped within the same (toplevel, queryid) duos in pg_stat_statements. The result gives a stricter one-one mapping between query IDs and its query strings. The regression tests introduced in 45e0ba30fc40 produce differences reflecting the new logic. Author: Anthonin Bonnefoy Reviewed-by: Michael Paquier, Jian He Discussion: https://postgr.es/m/CAO6_XqqM6S9bQ2qd=75W+yKATwoazxSNhv5sjW06fjGAtHbTUA@mail.gmail.com
* Improve node type forward referencePeter Eisentraut2024-10-17
| | | | | | | | | | Instead of using Node *, we can use an incomplete struct. That way, everything has the correct type and fewer casts are required. This technique is already used elsewhere in node type definitions. 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
* Track sort direction in SortGroupClausePeter Eisentraut2024-10-14
| | | | | | | | | | | | | | Functions make_pathkey_from_sortop() and transformWindowDefinitions(), which receive a SortGroupClause, were determining the sort order (ascending vs. descending) by comparing that structure's operator strategy to BTLessStrategyNumber, but could just as easily have gotten it from the SortGroupClause object, if it had such a field, so add one. This reduces the number of places that hardcode the assumption that the strategy refers specifically to a btree strategy, rather than some other index AM's operators. Author: Mark Dilger <mark.dilger@enterprisedb.com> Discussion: https://www.postgresql.org/message-id/flat/E72EAA49-354D-4C2E-8EB9-255197F55330@enterprisedb.com
* Convert node test compile-time settings into run-time parametersPeter Eisentraut2024-08-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This converts COPY_PARSE_PLAN_TREES WRITE_READ_PARSE_PLAN_TREES RAW_EXPRESSION_COVERAGE_TEST into run-time parameters debug_copy_parse_plan_trees debug_write_read_parse_plan_trees debug_raw_expression_coverage_test They can be activated for tests using PG_TEST_INITDB_EXTRA_OPTS. The compile-time symbols are kept for build farm compatibility, but they now just determine the default value of the run-time settings. Furthermore, support for these settings is not compiled in at all unless assertions are enabled, or the new symbol DEBUG_NODE_TESTS_ENABLED is defined at compile time, or any of the legacy compile-time setting symbols are defined. So there is no run-time overhead in production builds. (This is similar to the handling of DISCARD_CACHES_ENABLED.) Discussion: https://www.postgresql.org/message-id/flat/30747bd8-f51e-4e0c-a310-a6e2c37ec8aa%40eisentraut.org
* Re-allow planner to use Merge Append to efficiently implement UNION.Robert Haas2024-05-21
| | | | | | | | | | | This reverts commit 7204f35919b7e021e8d1bc9f2d76fd6bfcdd2070, thus restoring 66c0185a3 (Allow planner to use Merge Append to efficiently implement UNION) as well as the follow-on commits d5d2205c8, 3b1a7eb28, 7487044d6. Per further discussion on pgsql-release, we wish to ship beta1 with this feature, and patch the bug that was found just before wrap, rather than shipping beta1 with the feature reverted.
* Revert commit 66c0185a3 and follow-on patches.Tom Lane2024-05-20
| | | | | | | | | | | | | | | | | | | This reverts 66c0185a3 (Allow planner to use Merge Append to efficiently implement UNION) as well as the follow-on commits d5d2205c8, 3b1a7eb28, 7487044d6. In addition to those, 07746a8ef had to be removed then re-applied in a different place, because 66c0185a3 moved the relevant code. The reason for this last-minute thrashing is that depesz found a case in which the patched code creates a completely wrong plan that silently gives incorrect query results. It's unclear what the cause is or how many cases are affected, but with beta1 wrap staring us in the face, there's no time for closer investigation. After we figure that out, we can decide whether to un-revert this for beta2 or hold it for v18. Discussion: https://postgr.es/m/Zktzf926vslR35Fv@depesz.com (also some private discussion among pgsql-release)
* Allow planner to use Merge Append to efficiently implement UNIONDavid Rowley2024-03-25
| | | | | | | | | | | | | | | | | | | | | Until now, UNION queries have often been suboptimal as the planner has only ever considered using an Append node and making the results unique by either using a Hash Aggregate, or by Sorting the entire Append result and running it through the Unique operator. Both of these methods always require reading all rows from the union subqueries. Here we adjust the union planner so that it can request that each subquery produce results in target list order so that these can be Merge Appended together and made unique with a Unique node. This can improve performance significantly as the union child can make use of the likes of btree indexes and/or Merge Joins to provide the top-level UNION with presorted input. This is especially good if the top-level UNION contains a LIMIT node that limits the output rows to a small subset of the unioned rows as cheap startup plans can be used. Author: David Rowley Reviewed-by: Richard Guo, Andy Fan Discussion: https://postgr.es/m/CAApHDvpb_63XQodmxKUF8vb9M7CxyUyT4sWvEgqeQU-GB7QFoQ@mail.gmail.com
* Add RETURNING support to MERGE.Dean Rasheed2024-03-17
| | | | | | | | | | | | | | | | | | | | | | | | | | This allows a RETURNING clause to be appended to a MERGE query, to return values based on each row inserted, updated, or deleted. As with plain INSERT, UPDATE, and DELETE commands, the returned values are based on the new contents of the target table for INSERT and UPDATE actions, and on its old contents for DELETE actions. Values from the source relation may also be returned. As with INSERT/UPDATE/DELETE, the output of MERGE ... RETURNING may be used as the source relation for other operations such as WITH queries and COPY commands. Additionally, a special function merge_action() is provided, which returns 'INSERT', 'UPDATE', or 'DELETE', depending on the action executed for each row. The merge_action() function can be used anywhere in the RETURNING list, including in arbitrary expressions and subqueries, but it is an error to use it anywhere outside of a MERGE query's RETURNING list. Dean Rasheed, reviewed by Isaac Morland, Vik Fearing, Alvaro Herrera, Gurjeet Singh, Jian He, Jeff Davis, Merlin Moncure, Peter Eisentraut, and Wolfgang Walther. Discussion: http://postgr.es/m/CAEZATCWePEGQR5LBn-vD6SfeLZafzEm2Qy_L_Oky2=qw2w3Pzg@mail.gmail.com
* Make INSERT-from-multiple-VALUES-rows handle domain target columns.Tom Lane2024-03-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a3c7a993d fixed some cases involving target columns that are arrays or composites by applying transformAssignedExpr to the VALUES entries, and then stripping off any assignment ArrayRefs or FieldStores that the transformation added. But I forgot about domains over arrays or composites :-(. Such cases would either fail with surprising complaints about mismatched datatypes, or insert unexpected coercions that could lead to odd results. To fix, extend the stripping logic to get rid of CoerceToDomain if it's atop an ArrayRef or FieldStore. While poking at this, I realized that there's a poorly documented and not-at-all-tested behavior nearby: we coerce each VALUES column to the domain type separately, and rely on the rewriter to merge those operations so that the domain constraints are checked only once. If that merging did not happen, it's entirely possible that we'd get unexpected domain constraint failures due to checking a partially-updated container value. There's no bug there, but while we're here let's improve the commentary about it and add some test cases that explicitly exercise that behavior. Per bug #18393 from Pablo Kharo. Back-patch to all supported branches. Discussion: https://postgr.es/m/18393-65fedb1a0de9260d@postgresql.org
* Remove unused #include's from backend .c filesPeter Eisentraut2024-03-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | as determined by include-what-you-use (IWYU) While IWYU also suggests to *add* a bunch of #include's (which is its main purpose), this patch does not do that. In some cases, a more specific #include replaces another less specific one. Some manual adjustments of the automatic result: - IWYU currently doesn't know about includes that provide global variable declarations (like -Wmissing-variable-declarations), so those includes are being kept manually. - All includes for port(ability) headers are being kept for now, to play it safe. - No changes of catalog/pg_foo.h to catalog/pg_foo_d.h, to keep the patch from exploding in size. Note that this patch touches just *.c files, so nothing declared in header files changes in hidden ways. As a small example, in src/backend/access/transam/rmgr.c, some IWYU pragma annotations are added to handle a special case there. Discussion: https://www.postgresql.org/message-id/flat/af837490-6b2f-46df-ba05-37ea6a6653fc%40eisentraut.org
* Add hint about not qualifying UPDATE...SET target with relation name.Tom Lane2024-01-20
| | | | | | | | | | | | | | | Target columns in UPDATE ... SET must not be qualified with the target table; we disallow this because it'd create ambiguity about which name is the column name in case of field-qualified names. However, newbies have been seen to expect that they could qualify a target name just like other names. The error message when they do is confusing: "column "foo" of relation "foo" does not exist". To improve matters, issue a HINT if the invalid name is qualified and matches the relation's alias. James Coleman (editorialized a bit by me) Discussion: https://postgr.es/m/CAAaqYe8S2Qa060UV-YF5GoSd5PkEhLV94x-fEi3=TOtpaXCV+w@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
* Avoid unnecessary plancache revalidation of utility statements.Tom Lane2023-08-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Revalidation of a plancache entry (after a cache invalidation event) requires acquiring a snapshot. Normally that is harmless, but not if the cached statement is one that needs to run without acquiring a snapshot. We were already aware of that for TransactionStmts, but for some reason hadn't extrapolated to the other statements that PlannedStmtRequiresSnapshot() knows mustn't set a snapshot. This can lead to unexpected failures of commands such as SET TRANSACTION ISOLATION LEVEL. We can fix it in the same way, by excluding those command types from revalidation. However, we can do even better than that: there is no need to revalidate for any statement type for which parse analysis, rewrite, and plan steps do nothing interesting, which is nearly all utility commands. To mechanize this, invent a parser function stmt_requires_parse_analysis() that tells whether parse analysis does anything beyond wrapping a CMD_UTILITY Query around the raw parse tree. If that's what it does, then rewrite and plan will just skip the Query, so that it is not possible for the same raw parse tree to produce a different plan tree after cache invalidation. stmt_requires_parse_analysis() is basically equivalent to the existing function analyze_requires_snapshot(), except that for obscure reasons that function omits ReturnStmt and CallStmt. It is unclear whether those were oversights or intentional. I have not been able to demonstrate a bug from not acquiring a snapshot while analyzing these commands, but at best it seems mighty fragile. It seems safer to acquire a snapshot for parse analysis of these commands too, which allows making stmt_requires_parse_analysis and analyze_requires_snapshot equivalent. In passing this fixes a second bug, which is that ResetPlanCache would exclude ReturnStmts and CallStmts from revalidation. That's surely *not* safe, since they contain parsable expressions. Per bug #18059 from Pavel Kulakov. Back-patch to all supported branches. Discussion: https://postgr.es/m/18059-79c692f036b25346@postgresql.org
* Remove dependency to query text in JumbleQuery()Michael Paquier2023-06-28
| | | | | | | | | | | Since 3db72eb, the query ID of utilities is generated using the Query structure, making the use of the query string in JumbleQuery() unnecessary. This commit removes the argument "querytext" from JumbleQuery(). Reported-by: Joe Conway Reviewed-by: Nathan Bossart Discussion: https://postgr.es/m/ZJlQAWE4COFqHuAV@paquier.xyz
* Invent GENERIC_PLAN option for EXPLAIN.Tom Lane2023-03-24
| | | | | | | | | | | | | | | | | This provides a very simple way to see the generic plan for a parameterized query. Without this, it's necessary to define a prepared statement and temporarily change plan_cache_mode, which is a bit tedious. One thing that's a bit of a hack perhaps is that we disable execution-time partition pruning when the GENERIC_PLAN option is given. That's because the pruning code may attempt to fetch the value of one of the parameters, which would fail. Laurenz Albe, reviewed by Julien Rouhaud, Christoph Berg, Michel Pelletier, Jim Jones, and myself Discussion: https://postgr.es/m/0a29b954b10b57f0d135fe12aa0909bd41883eb0.camel@cybertec.at
* 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
* Move queryjumble.c code to src/backend/nodes/Michael Paquier2023-01-21
| | | | | | | | | | | | | This will ease a follow-up move that will generate automatically this code. The C file is renamed, for consistency with the node-related files whose code are generated by gen_node_support.pl: - queryjumble.c -> queryjumblefuncs.c - utils/queryjumble.h -> nodes/queryjumble.h Per a suggestion from Peter Eisentraut. Reviewed-by: Peter Eisentraut Discussion: https://postgr.es/m/Y5BHOUhX3zTH/ig6@paquier.xyz
* Update copyright for 2023Bruce Momjian2023-01-02
| | | | Backpatch-through: 11
* Suppress uninitialized-variable warning from a61b1f748.Tom Lane2022-12-27
| | | | | | | | | | | | Some compilers complain about sub_rteperminfos not being initialized, evidently because they don't detect that it is only used and set if isGeneralSelect is true. Make it follow the long-established pattern for its sibling variable sub_rtable. Per reports from Pavel Stehule and the buildfarm. Discussion: https://postgr.es/m/CAFj8pRDOvGOi-n616kM0Cc7qSbg_nGoS=-haB+D785sUXADqSg@mail.gmail.com
* 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
* Make subquery aliases optional in the FROM clause.Dean Rasheed2022-07-20
| | | | | | | | | | | | | | This allows aliases for sub-SELECTs and VALUES clauses in the FROM clause to be omitted. This is an extension of the SQL standard, supported by some other database systems, and so eases the transition from such systems, as well as removing the minor inconvenience caused by requiring these aliases. Patch by me, reviewed by Tom Lane. Discussion: https://postgr.es/m/CAEZATCUCGCf82=hxd9N5n6xGHPyYpQnxW8HneeH+uP7yNALkWA@mail.gmail.com
* Fix alias matching in transformLockingClause().Dean Rasheed2022-07-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | When locking a specific named relation for a FOR [KEY] UPDATE/SHARE clause, transformLockingClause() finds the relation to lock by scanning the rangetable for an RTE with a matching eref->aliasname. However, it failed to account for the visibility rules of a join RTE. If a join RTE doesn't have a user-supplied alias, it will have a generated eref->aliasname of "unnamed_join" that is not visible as a relation name in the parse namespace. Such an RTE needs to be skipped, otherwise it might be found in preference to a regular base relation with a user-supplied alias of "unnamed_join", preventing it from being locked. In addition, if a join RTE doesn't have a user-supplied alias, but does have a join_using_alias, then the RTE needs to be matched using that alias rather than the generated eref->aliasname, otherwise a misleading "relation not found" error will be reported rather than a "join cannot be locked" error. Backpatch all the way, except for the second part which only goes back to 14, where JOIN USING aliases were added. Dean Rasheed, reviewed by Tom Lane. Discussion: https://postgr.es/m/CAEZATCUY_KOBnqxbTSPf=7fz9HWPnZ5Xgb9SwYzZ8rFXe7nb=w@mail.gmail.com
* Pre-beta mechanical code beautification.Tom Lane2022-05-12
| | | | | Run pgindent, pgperltidy, and reformat-dat-files. I manually fixed a couple of comments that pgindent uglified.
* Fix core dump in transformValuesClause when there are no columns.Tom Lane2022-05-09
| | | | | | | | | | | | The parser code that transformed VALUES from row-oriented to column-oriented lists failed if there were zero columns. You can't write that straightforwardly (though probably you should be able to), but the case can be reached by expanding a "tab.*" reference to a zero-column table. Per bug #17477 from Wang Ke. Back-patch to all supported branches. Discussion: https://postgr.es/m/17477-0af3c6ac6b0a6ae0@postgresql.org
* Add support for MERGE SQL commandAlvaro Herrera2022-03-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MERGE performs actions that modify rows in the target table using a source table or query. MERGE provides a single SQL statement that can conditionally INSERT/UPDATE/DELETE rows -- a task that would otherwise require multiple PL statements. For example, MERGE INTO target AS t USING source AS s ON t.tid = s.sid WHEN MATCHED AND t.balance > s.delta THEN UPDATE SET balance = t.balance - s.delta WHEN MATCHED THEN DELETE WHEN NOT MATCHED AND s.delta > 0 THEN INSERT VALUES (s.sid, s.delta) WHEN NOT MATCHED THEN DO NOTHING; MERGE works with regular tables, partitioned tables and inheritance hierarchies, including column and row security enforcement, as well as support for row and statement triggers and transition tables therein. MERGE is optimized for OLTP and is parameterizable, though also useful for large scale ETL/ELT. MERGE is not intended to be used in preference to existing single SQL commands for INSERT, UPDATE or DELETE since there is some overhead. MERGE can be used from PL/pgSQL. MERGE does not support targetting updatable views or foreign tables, and RETURNING clauses are not allowed either. These limitations are likely fixable with sufficient effort. Rewrite rules are also not supported, but it's not clear that we'd want to support them. Author: Pavan Deolasee <pavan.deolasee@gmail.com> Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Author: Amit Langote <amitlangote09@gmail.com> Author: Simon Riggs <simon.riggs@enterprisedb.com> Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com> Reviewed-by: Andres Freund <andres@anarazel.de> (earlier versions) Reviewed-by: Peter Geoghegan <pg@bowt.ie> (earlier versions) Reviewed-by: Robert Haas <robertmhaas@gmail.com> (earlier versions) Reviewed-by: Japin Li <japinli@hotmail.com> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com> Reviewed-by: Zhihong Yu <zyu@yugabyte.com> Discussion: https://postgr.es/m/CANP8+jKitBSrB7oTgT9CY2i1ObfOt36z0XMraQc+Xrz8QB0nXA@mail.gmail.com Discussion: https://postgr.es/m/CAH2-WzkJdBuxj9PO=2QaO9-3h3xGbQPZ34kJH=HukRekwM-GZg@mail.gmail.com Discussion: https://postgr.es/m/20201231134736.GA25392@alvherre.pgsql
* Add parse_analyze_withcb()Peter Eisentraut2022-03-09
| | | | | | | | | This extracts code from pg_analyze_and_rewrite_withcb() into a separate function that mirrors the existing parse_analyze_fixedparams() and parse_analyze_varparams(). Reviewed-by: Nathan Bossart <bossartn@amazon.com> Discussion: https://www.postgresql.org/message-id/flat/c67ce276-52b4-0239-dc0e-39875bf81840@enterprisedb.com
* Add pg_analyze_and_rewrite_varparams()Peter Eisentraut2022-03-07
| | | | | | | | | | | | | | | | | | | | | This new function extracts common code from PrepareQuery() and exec_parse_message(). It is then exactly analogous to the existing pg_analyze_and_rewrite_fixedparams() and pg_analyze_and_rewrite_withcb(). To unify these two code paths, this makes PrepareQuery() now subject to log_parser_stats. Also, both paths now invoke TRACE_POSTGRESQL_QUERY_REWRITE_START(). PrepareQuery() no longer checks whether a utility statement was specified. The grammar doesn't allow that anyway, and exec_parse_message() supports it, so restricting it doesn't seem necessary. This also adds QueryEnvironment support to the *varparams functions, for consistency with its cousins, even though it is not used right now. Reviewed-by: Nathan Bossart <bossartn@amazon.com> Discussion: https://www.postgresql.org/message-id/flat/c67ce276-52b4-0239-dc0e-39875bf81840@enterprisedb.com
* Parse/analyze function renamingPeter Eisentraut2022-03-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are three parallel ways to call parse/analyze: with fixed parameters, with variable parameters, and by supplying your own parser callback. Some of the involved functions were confusingly named and made this API structure more confusing. This patch renames some functions to make this clearer: parse_analyze() -> parse_analyze_fixedparams() pg_analyze_and_rewrite() -> pg_analyze_and_rewrite_fixedparams() (Otherwise one might think this variant doesn't accept parameters, but in fact all three ways accept parameters.) pg_analyze_and_rewrite_params() -> pg_analyze_and_rewrite_withcb() (Before, and also when considering pg_analyze_and_rewrite(), one might think this is the only way to pass parameters. Moreover, the parser callback doesn't necessarily need to parse only parameters, it's just one of the things it could do.) parse_fixed_parameters() -> setup_parse_fixed_parameters() parse_variable_parameters() -> setup_parse_variable_parameters() (These functions don't actually do any parsing, they just set up callbacks to use during parsing later.) This patch also adds some const decorations to the fixed-parameters API, so the distinction from the variable-parameters API is more clear. Reviewed-by: Nathan Bossart <bossartn@amazon.com> Discussion: https://www.postgresql.org/message-id/flat/c67ce276-52b4-0239-dc0e-39875bf81840@enterprisedb.com
* Update copyright for 2022Bruce Momjian2022-01-07
| | | | Backpatch-through: 10
* Disable anonymous record hash support except in special casesPeter Eisentraut2021-09-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 01e658fa74 added hash support for row types. This also added support for hashing anonymous record types, using the same approach that the type cache uses for comparison support for record types: It just reports that it works, but it might fail at run time if a component type doesn't actually support the operation. We get away with that for comparison because most types support that. But some types don't support hashing, so the current state can result in failures at run time where the planner chooses hashing over sorting, whereas that previously worked if only sorting was an option. We do, however, want the record hashing support for path tracking in recursive unions, and the SEARCH and CYCLE clauses built on that. In that case, hashing is the only plan option. So enable that, this commit implements the following approach: The type cache does not report that hashing is available for the record type. This undoes that part of 01e658fa74. Instead, callers that require hashing no matter what can override that result themselves. This patch only touches the callers to make the aforementioned recursive query cases work, namely the parse analysis of unions, as well as the hash_array() function. Reported-by: Sait Talha Nisanci <sait.nisanci@microsoft.com> Bug: #17158 Discussion: https://www.postgresql.org/message-id/flat/17158-8a2ba823982537a4%40postgresql.org
* Avoid trying to lock OLD/NEW in a rule with FOR UPDATE.Tom Lane2021-08-19
| | | | | | | | | | | | | | transformLockingClause neglected to exclude the pseudo-RTEs for OLD/NEW when processing a rule's query. This led to odd errors or even crashes later on. This bug is very ancient, but it's not terribly surprising that nobody noticed, since the use-case for SELECT FOR UPDATE in a non-view rule is somewhere between thin and non-existent. Still, crashing is not OK. Per bug #17151 from Zhiyong Wu. Thanks to Masahiko Sawada for analysis of the problem. Discussion: https://postgr.es/m/17151-c03a3e6e4ec9aadb@postgresql.org
* Reconsider the handling of procedure OUT parameters.Tom Lane2021-06-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 2453ea142 redefined pg_proc.proargtypes to include the types of OUT parameters, for procedures only. While that had some advantages for implementing the SQL-spec behavior of DROP PROCEDURE, it was pretty disastrous from a number of other perspectives. Notably, since the primary key of pg_proc is name + proargtypes, this made it possible to have multiple procedures with identical names + input arguments and differing output argument types. That would make it impossible to call any one of the procedures by writing just NULL (or "?", or any other data-type-free notation) for the output argument(s). The change also seems likely to cause grave confusion for client applications that examine pg_proc and expect the traditional definition of proargtypes. Hence, revert the definition of proargtypes to what it was, and undo a number of complications that had been added to support that. To support the SQL-spec behavior of DROP PROCEDURE, when there are no argmode markers in the command's parameter list, we perform the lookup both ways (that is, matching against both proargtypes and proallargtypes), succeeding if we get just one unique match. In principle this could result in ambiguous-function failures that would not happen when using only one of the two rules. However, overloading of procedure names is thought to be a pretty rare usage, so this shouldn't cause many problems in practice. Postgres-specific code such as pg_dump can defend against any possibility of such failures by being careful to specify argmodes for all procedure arguments. This also fixes a few other bugs in the area of CALL statements with named parameters, and improves the documentation a little. catversion bump forced because the representation of procedures with OUT arguments changes. Discussion: https://postgr.es/m/3742981.1621533210@sss.pgh.pa.us
* Reject SELECT ... GROUP BY GROUPING SETS (()) FOR UPDATE.Tom Lane2021-06-01
| | | | | | | | | | | | | | | | | This case should be disallowed, just as FOR UPDATE with a plain GROUP BY is disallowed; FOR UPDATE only makes sense when each row of the query result can be identified with a single table row. However, we missed teaching CheckSelectLocking() to check groupingSets as well as groupClause, so that it would allow degenerate grouping sets. That resulted in a bad plan and a null-pointer dereference in the executor. Looking around for other instances of the same bug, the only one I found was in examine_simple_variable(). That'd just lead to silly estimates, but it should be fixed too. Per private report from Yaoguang Chen. Back-patch to all supported branches.
* Allow compute_query_id to be set to 'auto' and make it defaultAlvaro Herrera2021-05-15
| | | | | | | | | | | | | | | | | Allowing only on/off meant that all either all existing configuration guides would become obsolete if we disabled it by default, or that we would have to accept a performance loss in the default config if we enabled it by default. By allowing 'auto' as a middle ground, the performance cost is only paid by those who enable pg_stat_statements and similar modules. I only edited the release notes to comment-out a paragraph that is now factually wrong; further edits are probably needed to describe the related change in more detail. Author: Julien Rouhaud <rjuju123@gmail.com> Reviewed-by: Justin Pryzby <pryzby@telsasoft.com> Discussion: https://postgr.es/m/20210513002623.eugftm4nk2lvvks3@nol
* Initial pgindent and pgperltidy run for v14.Tom Lane2021-05-12
| | | | | | | | Also "make reformat-dat-files". The only change worthy of note is that pgindent messed up the formatting of launcher.c's struct LogicalRepWorkerId, which led me to notice that that struct wasn't used at all anymore, so I just took it out.
* adjust query id feature to use pg_stat_activity.query_idBruce Momjian2021-04-20
| | | | | | | | | | | Previously, it was pg_stat_activity.queryid to match the pg_stat_statements queryid column. This is an adjustment to patch 4f0b0966c8. This also adjusts some of the internal function calls to match. Catversion bumped. Reported-by: Álvaro Herrera, Julien Rouhaud Discussion: https://postgr.es/m/20210408032704.GA7498@alvherre.pgsql
* Allow table-qualified variable names in ON CONFLICT ... WHERE.Tom Lane2021-04-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously you could only use unqualified variable names here. While that's not a functional deficiency, since only the target table can be referenced, it's a surprising inconsistency with the rules for partial-index predicates, on which this syntax is supposedly modeled. The fix for that is no harder than passing addToRelNameSpace = true to addNSItemToQuery. However, it's really pretty bogus for transformOnConflictArbiter and transformOnConflictClause to be messing with the namespace item for the target table at all. It's not theirs to manage, it results in duplicative creations of namespace items, and transformOnConflictClause wasn't even doing it quite correctly (that coding resulted in two nsitems for the target table, since it hadn't cleaned out the existing one). Hence, make transformInsertStmt responsible for setting up the target nsitem once for both these clauses and RETURNING. Also, arrange for ON CONFLICT ... UPDATE's "excluded" pseudo-relation to be added to the rangetable before we run transformOnConflictArbiter. This produces a more helpful HINT if someone writes "excluded.col" in the arbiter expression. Per bug #16958 from Lukas Eder. Although I agree this is a bug, the consequences are hardly severe, so no back-patch. Discussion: https://postgr.es/m/16958-963f638020de271c@postgresql.org
* SQL-standard function bodyPeter Eisentraut2021-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds support for writing CREATE FUNCTION and CREATE PROCEDURE statements for language SQL with a function body that conforms to the SQL standard and is portable to other implementations. Instead of the PostgreSQL-specific AS $$ string literal $$ syntax, this allows writing out the SQL statements making up the body unquoted, either as a single statement: CREATE FUNCTION add(a integer, b integer) RETURNS integer LANGUAGE SQL RETURN a + b; or as a block CREATE PROCEDURE insert_data(a integer, b integer) LANGUAGE SQL BEGIN ATOMIC INSERT INTO tbl VALUES (a); INSERT INTO tbl VALUES (b); END; The function body is parsed at function definition time and stored as expression nodes in a new pg_proc column prosqlbody. So at run time, no further parsing is required. However, this form does not support polymorphic arguments, because there is no more parse analysis done at call time. Dependencies between the function and the objects it uses are fully tracked. A new RETURN statement is introduced. This can only be used inside function bodies. Internally, it is treated much like a SELECT statement. psql needs some new intelligence to keep track of function body boundaries so that it doesn't send off statements when it sees semicolons that are inside a function body. Tested-by: Jaime Casanova <jcasanov@systemguards.com.ec> Reviewed-by: Julien Rouhaud <rjuju123@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/1c11f1eb-f00c-43b7-799d-2d44132c02d7@2ndquadrant.com
* Make use of in-core query id added by commit 5fd9dfa5f5Bruce Momjian2021-04-07
| | | | | | | | | | | | | | | | | | | | | | | Use the in-core query id computation for pg_stat_activity, log_line_prefix, and EXPLAIN VERBOSE. Similar to other fields in pg_stat_activity, only the queryid from the top level statements are exposed, and if the backends status isn't active then the queryid from the last executed statements is displayed. Add a %Q placeholder to include the queryid in log_line_prefix, which will also only expose top level statements. For EXPLAIN VERBOSE, if a query identifier has been computed, either by enabling compute_query_id or using a third-party module, display it. Bump catalog version. Discussion: https://postgr.es/m/20210407125726.tkvjdbw76hxnpwfi@nol Author: Julien Rouhaud Reviewed-by: Alvaro Herrera, Nitin Jadhav, Zhihong Yu
* Move pg_stat_statements query jumbling to core.Bruce Momjian2021-04-07
| | | | | | | | | | | | | | | | | | | Add compute_query_id GUC to control whether a query identifier should be computed by the core (off by default). It's thefore now possible to disable core queryid computation and use pg_stat_statements with a different algorithm to compute the query identifier by using a third-party module. To ensure that a single source of query identifier can be used and is well defined, modules that calculate a query identifier should throw an error if compute_query_id specified to compute a query id and if a query idenfitier was already calculated. Discussion: https://postgr.es/m/20210407125726.tkvjdbw76hxnpwfi@nol Author: Julien Rouhaud Reviewed-by: Alvaro Herrera, Nitin Jadhav, Zhihong Yu
* Fix use of cursor sensitivity terminologyPeter Eisentraut2021-04-07
| | | | | | | | | | | | | | | | | | | | | Documentation and comments in code and tests have been using the terms sensitive/insensitive cursor incorrectly relative to the SQL standard. (Cursor sensitivity is only relevant for changes made in the same transaction as the cursor, not for concurrent changes in other sessions.) Moreover, some of the behavior of PostgreSQL is incorrect according to the SQL standard, confusing the issue further. (WHERE CURRENT OF changes are not visible in insensitive cursors, but they should be.) This change corrects the terminology and removes the claim that sensitive cursors are supported. It also adds a test case that checks the insensitive behavior in a "correct" way, using a change command not using WHERE CURRENT OF. Finally, it adds the ASENSITIVE cursor option to select the default asensitive behavior, per SQL standard. There are no changes to cursor behavior in this patch. Discussion: https://www.postgresql.org/message-id/flat/96ee8b30-9889-9e1b-b053-90e10c050e85%40enterprisedb.com
* Allow an alias to be attached to a JOIN ... USINGPeter Eisentraut2021-03-31
| | | | | | | | | | | | | | | This allows something like SELECT ... FROM t1 JOIN t2 USING (a, b, c) AS x where x has the columns a, b, c and unlike a regular alias it does not hide the range variables of the tables being joined t1 and t2. Per SQL:2016 feature F404 "Range variable for common column names". Reviewed-by: Vik Fearing <vik.fearing@2ndquadrant.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/flat/454638cf-d563-ab76-a585-2564428062af@2ndquadrant.com
* Implement GROUP BY DISTINCTTomas Vondra2021-03-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With grouping sets, it's possible that some of the grouping sets are duplicate. This is especially common with CUBE and ROLLUP clauses. For example GROUP BY CUBE (a,b), CUBE (b,c) is equivalent to GROUP BY GROUPING SETS ( (a, b, c), (a, b, c), (a, b, c), (a, b), (a, b), (a, b), (a), (a), (a), (c, a), (c, a), (c, a), (c), (b, c), (b), () ) Some of the grouping sets are calculated multiple times, which is mostly unnecessary. This commit implements a new GROUP BY DISTINCT feature, as defined in the SQL standard, which eliminates the duplicate sets. Author: Vik Fearing Reviewed-by: Erik Rijkers, Georgios Kokolatos, Tomas Vondra Discussion: https://postgr.es/m/bf3805a8-d7d1-ae61-fece-761b7ff41ecc@postgresfriends.org
* SEARCH and CYCLE clausesPeter Eisentraut2021-02-01
| | | | | | | | | | | | This adds the SQL standard feature that adds the SEARCH and CYCLE clauses to recursive queries to be able to do produce breadth- or depth-first search orders and detect cycles. These clauses can be rewritten into queries using existing syntax, and that is what this patch does in the rewriter. Reviewed-by: Vik Fearing <vik@postgresfriends.org> Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/db80ceee-6f97-9b4a-8ee8-3ba0c58e5be2@2ndquadrant.com
* Re-allow DISTINCT in pl/pgsql expressions.Tom Lane2021-01-22
| | | | | | | | | | | | | | | I'd omitted this from the grammar in commit c9d529848, figuring that it wasn't worth supporting. However we already have one complaint, so it seems that judgment was wrong. It doesn't require a huge amount of code, so add it back. (I'm still drawing the line at UNION/INTERSECT/EXCEPT though: those'd require an unreasonable amount of grammar refactoring, and the single-result-row restriction makes them near useless anyway.) Also rethink the documentation: this behavior is a property of all pl/pgsql expressions, not just assignments. Discussion: https://postgr.es/m/20210122134106.e94c5cd7@mail.verfriemelt.org
* Re-implement pl/pgsql's expression and assignment parsing.Tom Lane2021-01-04
| | | | | | | | | | | | | | | | | | | | | | | | | | Invent new RawParseModes that allow the core grammar to handle pl/pgsql expressions and assignments directly, and thereby get rid of a lot of hackery in pl/pgsql's parser. This moves a good deal of knowledge about pl/pgsql into the core code: notably, we have to invent a CoercionContext that matches pl/pgsql's (rather dubious) historical behavior for assignment coercions. That's getting away from the original idea of pl/pgsql as an arm's-length extension of the core, but really we crossed that bridge a long time ago. The main advantage of doing this is that we can now use the core parser to generate FieldStore and/or SubscriptingRef nodes to handle assignments to pl/pgsql variables that are records or arrays. That fixes a number of cases that had never been implemented in pl/pgsql assignment, such as nested records and array slicing, and it allows pl/pgsql assignment to support the datatype-specific subscripting behaviors introduced in commit c7aba7c14. There are cosmetic benefits too: when a syntax error occurs in a pl/pgsql expression, the error report no longer includes the confusing "SELECT" keyword that used to get prefixed to the expression text. Also, there seem to be some small speed gains. Discussion: https://postgr.es/m/4165684.1607707277@sss.pgh.pa.us
* Update copyright for 2021Bruce Momjian2021-01-02
| | | | Backpatch-through: 9.5
* Fix cases of discarding result from list API functionsPeter Eisentraut2020-11-11
| | | | | | | | | | | | Two cases violated list APIs by throwing away the return value. While the code was technically correct, it relied on internal knowledge of the list implementation, and the code wasn't really gaining anything that way. It is planned to make this a compiler warning in the future, so just fix these cases by assigning the return value properly. Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/e3753562-99cd-b65f-5aca-687dfd1ec2fc@2ndquadrant.com
* Calculate extraUpdatedCols in query rewriter, not parser.Tom Lane2020-10-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's unsafe to do this at parse time because addition of generated columns to a table would not invalidate stored rules containing UPDATEs on the table ... but there might now be dependent generated columns that were not there when the rule was made. This also fixes an oversight that rewriteTargetView failed to update extraUpdatedCols when transforming an UPDATE on an updatable view. (Since the new calculation is downstream of that, rewriteTargetView doesn't actually need to do anything; but before, there was a demonstrable bug there.) In v13 and HEAD, this leads to easily-visible bugs because (since commit c6679e4fc) we won't recalculate generated columns that aren't listed in extraUpdatedCols. In v12 this bitmap is mostly just used for trigger-firing decisions, so you'd only notice a problem if a trigger cared whether a generated column had been updated. I'd complained about this back in May, but then forgot about it until bug #16671 from Michael Paul Killian revived the issue. Back-patch to v12 where this field was introduced. If existing stored rules contain any extraUpdatedCols values, they'll be ignored because the rewriter will overwrite them, so the bug will be fixed even for existing rules. (But note that if someone were to update to 13.1 or 12.5, store some rules with UPDATEs on tables having generated columns, and then downgrade to a prior minor version, they might observe issues similar to what this patch fixes. That seems unlikely enough to not be worth going to a lot of effort to fix.) Discussion: https://postgr.es/m/10206.1588964727@sss.pgh.pa.us Discussion: https://postgr.es/m/16671-2fa55851859fb166@postgresql.org
* Add select_common_typmod()Peter Eisentraut2020-10-27
| | | | | | | | | | | | | | | This accompanies select_common_type() and select_common_collation(). Typmods were previously combined using hand-coded logic in several places. The logic in select_common_typmod() isn't very exciting, but it makes the code more compact and readable in a few locations, and in the future we can perhaps do more complicated things if desired. As a small enhancement, the type unification of the direct and aggregate arguments of hypothetical-set aggregates now unifies the typmod as well using this new function, instead of just dropping it. Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi> Discussion: https://www.postgresql.org/message-id/flat/97df3af9-8b5e-fb7f-a029-3eb7e80d7af9@2ndquadrant.com