summaryrefslogtreecommitdiff
path: root/src/include/nodes
AgeCommit message (Collapse)Author
2 daysUpdate various forward declarations to use typedefPeter Eisentraut
There are a number of forward declarations that use struct but not the customary typedef, because that could have led to repeat typedefs, which was not allowed. This is now allowed in C11, so we can update these to provide the typedefs as well, so that the later uses of the types look more consistent. Reviewed-by: Chao Li <li.evan.chao@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/10d32190-f31b-40a5-b177-11db55597355@eisentraut.org
2 daysRemove workarounds against repeat typedefsPeter Eisentraut
This is allowed in C11, so we don't need the workarounds anymore. Reviewed-by: Chao Li <li.evan.chao@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/10d32190-f31b-40a5-b177-11db55597355@eisentraut.org
7 daysEliminate duplicative hashtempcxt in nodeSubplan.c.Tom Lane
Instead of building a separate memory context that's used just for running hash functions, make the hash functions run in the per-tuple context of the node's innerecontext. This saves a little space at runtime, and it avoids needing to reset two contexts instead of one inside buildSubPlanHash's main loop. This largely reverts commit 133924e13. That's safe to do now because bf6c614a2 decoupled the evaluation context used by TupleHashTableMatch from that used for hash function evaluation, so that there's no longer a risk of resetting the innerecontext too soon. Per discussion of bug #19040, although this is not directly a fix for that. Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Haiyang Li <mohen.lhy@alibaba-inc.com> Reviewed-by: Fei Changhong <feichanghong@qq.com> Discussion: https://postgr.es/m/19040-c9b6073ef814f48c@postgresql.org
2025-08-19Pathify RHS unique-ification for semijoin planningRichard Guo
There are two implementation techniques for semijoins: one uses the JOIN_SEMI jointype, where the executor emits at most one matching row per left-hand side (LHS) row; the other unique-ifies the right-hand side (RHS) and then performs a plain inner join. The latter technique currently has some drawbacks related to the unique-ification step. * Only the cheapest-total path of the RHS is considered during unique-ification. This may cause us to miss some optimization opportunities; for example, a path with a better sort order might be overlooked simply because it is not the cheapest in total cost. Such a path could help avoid a sort at a higher level, potentially resulting in a cheaper overall plan. * We currently rely on heuristics to choose between hash-based and sort-based unique-ification. A better approach would be to generate paths for both methods and allow add_path() to decide which one is preferable, consistent with how path selection is handled elsewhere in the planner. * In the sort-based implementation, we currently pay no attention to the pathkeys of the input subpath or the resulting output. This can result in redundant sort nodes being added to the final plan. This patch improves semijoin planning by creating a new RelOptInfo for the RHS rel to represent its unique-ified version. It then generates multiple paths that represent elimination of distinct rows from the RHS, considering both a hash-based implementation using the cheapest total path of the original RHS rel, and sort-based implementations that either exploit presorted input paths or explicitly sort the cheapest total path. All resulting paths compete in add_path(), and those deemed worthy of consideration are added to the new RelOptInfo. Finally, the unique-ified rel is joined with the other side of the semijoin using a plain inner join. As a side effect, most of the code related to the JOIN_UNIQUE_OUTER and JOIN_UNIQUE_INNER jointypes -- used to indicate that the LHS or RHS path should be made unique -- has been removed. Besides, the T_Unique path now has the same meaning for both semijoins and upper DISTINCT clauses: it represents adjacent-duplicate removal on presorted input. This patch unifies their handling by sharing the same data structures and functions. This patch also removes the UNIQUE_PATH_NOOP related code along the way, as it is dead code -- if the RHS rel is provably unique, the semijoin should have already been simplified to a plain inner join by analyzejoins.c. Author: Richard Guo <guofenglinux@gmail.com> Reviewed-by: Alexandra Wang <alexandra.wang.oss@gmail.com> Reviewed-by: wenhui qiu <qiuwenhuifx@gmail.com> Discussion: https://postgr.es/m/CAMbWs4-EBnaRvEs7frTLbsXiweSTUXifsteF-d3rvv01FKO86w@mail.gmail.com
2025-08-17Update obsolete comments in ResultRelInfo struct.Etsuro Fujita
Commit c5b7ba4e6 changed things so that the ri_RootResultRelInfo field of this struct is set for both partitions and inheritance children and used for tuple routing and transition capture (before that commit, it was only set for partitions to route tuples into), but failed to update these comments. Author: Etsuro Fujita <etsuro.fujita@gmail.com> Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com> Discussion: https://postgr.es/m/CAPmGK14NF5CcdCmTZpxrvpvBiT0y4EqKikW1r_wAu1CEHeOmUA%40mail.gmail.com Backpatch-through: 14
2025-08-13Make type Datum be 8 bytes wide everywhere.Tom Lane
This patch makes sizeof(Datum) be 8 on all platforms including 32-bit ones. The objective is to allow USE_FLOAT8_BYVAL to be true everywhere, and in consequence to remove a lot of code that is specific to pass-by-reference handling of float8, int8, etc. The code for abbreviated sort keys can be simplified similarly. In this way we can reduce the maintenance effort involved in supporting 32-bit platforms, without going so far as to actually desupport them. Since Datum is strictly an in-memory concept, this has no impact on on-disk storage, though an initdb or pg_upgrade will be needed to fix affected catalog entries. We have required platforms to support [u]int64 for ages, so this breaks no supported platform. We can expect that this change will make 32-bit builds a bit slower and more memory-hungry, although being able to use pass-by-value handling of 8-byte types may buy back some of that. But we stopped optimizing for 32-bit cases a long time ago, and this seems like just another step on that path. This initial patch simply forces the correct type definition and USE_FLOAT8_BYVAL setting, and cleans up a couple of minor compiler complaints that ensued. This is sufficient for testing purposes. In the wake of a bunch of Datum-conversion cleanups by Peter Eisentraut, this now compiles cleanly with gcc on a 32-bit platform. (I'd only tested the previous version with clang, which it turns out is less picky than gcc about width-changing coercions.) There is a good deal of now-dead code that I'll remove in separate follow-up patches. A catversion bump is required because this affects initial catalog contents (on 32-bit machines) in two ways: pg_type.typbyval changes for some built-in types, and Const nodes in stored views/rules will now have 8 bytes not 4 for pass-by-value types. Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Peter Eisentraut <peter@eisentraut.org> Discussion: https://postgr.es/m/1749799.1752797397@sss.pgh.pa.us
2025-07-31Rename CachedPlanType to PlannedStmtOrigin for PlannedStmtMichael Paquier
Commit 719dcf3c42 introduced a field called CachedPlanType in PlannedStmt to allow extensions to determine whether a cached plan is generic or custom. After discussion, the concepts that we want to track are a bit wider than initially anticipated, as it is closer to knowing from which "source" or "origin" a PlannedStmt has been generated or retrieved. Custom and generic cached plans are a subset of that. Based on the state of HEAD, we have been able to define two more origins: - "standard", for the case where PlannedStmt is generated in standard_planner(), the most common case. - "internal", for the fake PlannedStmt generated internally by some query patterns. This could be tuned in the future depending on what is needed. This looks like a good starting point, at least. The default value is called "UNKNOWN", provided as fallback value. This value is not used in the core code, the idea is to let extensions building their own PlannedStmts know about this new field. Author: Michael Paquier <michael@paquier.xyz> Co-authored-by: Sami Imseih <samimseih@gmail.com> Discussion: https://postgr.es/m/aILaHupXbIGgF2wJ@paquier.xyz
2025-07-29Display Memoize planner estimates in EXPLAINDavid Rowley
There've been a few complaints that it can be overly difficult to figure out why the planner picked a Memoize plan. To help address that, here we adjust the EXPLAIN output to display the following additional details: 1) The estimated number of cache entries that can be stored at once 2) The estimated number of unique lookup keys that we expect to see 3) The number of lookups we expect 4) The estimated hit ratio Technically #4 can be calculated using #1, #2 and #3, but it's not a particularly obvious calculation, so we opt to display it explicitly. The original patch by Lukas Fittl only displayed the hit ratio, but there was a fear that might lead to more questions about how that was calculated. The idea with displaying all 4 is to be transparent which may allow queries to be tuned more easily. For example, if #2 isn't correct then maybe extended statistics or a manual n_distinct estimate can be used to help fix poor plan choices. Author: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com> Author: Lukas Fittl <lukas@fittl.com> Reviewed-by: David Rowley <dgrowleyml@gmail.com> Reviewed-by: Andrei Lepikhov <lepihov@gmail.com> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Discussion: https://postgr.es/m/CAP53Pky29GWAVVk3oBgKBDqhND0BRBN6yTPeguV_qSivFL5N_g%40mail.gmail.com
2025-07-24Introduce field tracking cached plan type in PlannedStmtMichael Paquier
PlannedStmt gains a new field, called CachedPlanType, able to track if a given plan tree originates from the cache and if we are dealing with a generic or custom cached plan. This field can be used for monitoring or statistical purposes, in the executor hooks, for example, based on the planned statement attached to a QueryDesc. A patch is under discussion for pg_stat_statements to provide an equivalent of the counters in pg_prepared_statements for custom and generic plans, to provide a more global view of such data, as this data is now restricted to the current session. The concept introduced in this commit is useful on its own, and has been extracted from a larger patch by the same author. Author: Sami Imseih <samimseih@gmail.com> Reviewed-by: Andrei Lepikhov <lepihov@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/CAA5RZ0uFw8Y9GCFvafhC=OA8NnMqVZyzXPfv_EePOt+iv1T-qQ@mail.gmail.com
2025-07-22Reduce "Var IS [NOT] NULL" quals during constant foldingRichard Guo
In commit b262ad440, we introduced an optimization that reduces an IS [NOT] NULL qual on a NOT NULL column to constant true or constant false, provided we can prove that the input expression of the NullTest is not nullable by any outer joins or grouping sets. This deduction happens quite late in the planner, during the distribution of quals to rels in query_planner. However, this approach has some drawbacks: we can't perform any further folding with the constant, and it turns out to be prone to bugs. Ideally, this deduction should happen during constant folding. However, the per-relation information about which columns are defined as NOT NULL is not available at that point. This information is currently collected from catalogs when building RelOptInfos for base or "other" relations. This patch moves the collection of NOT NULL attribute information for relations before pull_up_sublinks, storing it in a hash table keyed by relation OID. It then uses this information to perform the NullTest deduction for Vars during constant folding. This also makes it possible to leverage this information to pull up NOT IN subqueries. Note that this patch does not get rid of restriction_is_always_true and restriction_is_always_false. Removing them would prevent us from reducing some IS [NOT] NULL quals that we were previously able to reduce, because (a) the self-join elimination may introduce new IS NOT NULL quals after constant folding, and (b) if some outer joins are converted to inner joins, previously irreducible NullTest quals may become reducible. Author: Richard Guo <guofenglinux@gmail.com> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/CAMbWs4-bFJ1At4btk5wqbezdu8PLtQ3zv-aiaY3ry9Ymm=jgFQ@mail.gmail.com
2025-07-11Add option list to CHECKPOINT command.Nathan Bossart
This commit adds the boilerplate code for supporting a list of options in CHECKPOINT commands. No actual options are supported yet, but follow-up commits will add support for MODE and FLUSH_UNLOGGED. While at it, this commit refactors the code for executing CHECKPOINT commands to its own function since it's about to become significantly larger. Author: Christoph Berg <myon@debian.org> Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com> Discussion: https://postgr.es/m/aDnaKTEf-0dLiEfz%40msg.df7cb.de
2025-07-03Refactor subtype field of AlterDomainStmtMichael Paquier
AlterDomainStmt.subtype used characters for its subtypes of commands, SET|DROP DEFAULT|NOT NULL and ADD|DROP|VALIDATE CONSTRAINT, which were hardcoded in a couple of places of the code. The code is improved by using an enum instead, with the same character values as the original code. Note that the field was documented in parsenodes.h and that it forgot to mention 'V' (VALIDATE CONSTRAINT). Author: Quan Zongliang <quanzongliang@yeah.net> Reviewed-by: Peter Eisentraut <peter@eisentraut.org> Reviewed-by: wenhui qiu <qiuwenhuifx@gmail.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Discussion: https://postgr.es/m/41ff310b-16bd-44b9-a3ef-97e20f14b709@yeah.net
2025-07-02meson: Increase minimum version to 0.57.2Peter Eisentraut
The previous minimum was to maintain support for Python 3.5, but we now require Python 3.6 anyway (commit 45363fca637), so that reason is obsolete. A small raise to Meson 0.57 allows getting rid of a fair amount of version conditionals and silences some future-deprecated warnings. With the version bump, the following deprecation warnings appeared and are fixed: WARNING: Project targets '>=0.57' but uses feature deprecated since '0.55.0': ExternalProgram.path. use ExternalProgram.full_path() instead WARNING: Project targets '>=0.57' but uses feature deprecated since '0.56.0': meson.build_root. use meson.project_build_root() or meson.global_build_root() instead. It turns out that meson 0.57.0 and 0.57.1 are buggy for our use, so the minimum is actually set to 0.57.2. This is specific to this version series; in the future we won't necessarily need to be this precise. Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/flat/42e13eb0-862a-441e-8d84-4f0fd5f6def0%40eisentraut.org
2025-07-02Reformat some node commentsPeter Eisentraut
Use per-field comments for IndexInfo, instead of one big header comment listing all the fields. This makes the relevant comments easier to find, and it will also make it less likely that comments are not updated when fields are added or removed, as has happened in the past. Author: Japin Li <japinli@hotmail.com> Discussion: https://www.postgresql.org/message-id/flat/ME0P300MB04453E6C7EA635F0ECF41BFCB6832%40ME0P300MB0445.AUSP300.PROD.OUTLOOK.COM
2025-07-02Show sizes of FETCH queries as constants in pg_stat_statementsMichael Paquier
Prior to this patch, every FETCH call would generate a unique queryId with a different size specified. Depending on the workloads, this could lead to a significant bloat in pg_stat_statements, as repeatedly calling a specific cursor would result in a new queryId each time. For example, FETCH 1 c1; and FETCH 2 c1; would produce different queryIds. This patch improves the situation by normalizing the fetch size, so as semantically similar statements generate the same queryId. As a result, statements like the below, which differ syntactically but have the same effect, will now share a single queryId: FETCH FROM c1 FETCH NEXT c1 FETCH 1 c1 In order to do a normalization based on the keyword used in FETCH, FetchStmt is tweaked with a new FetchDirectionKeywords. This matters for "howMany", which could be set to a negative value depending on the direction, and we want to normalize the queries with enough information about the direction keywords provided, including RELATIVE, ABSOLUTE or all the ALL variants. Author: Sami Imseih <samimseih@gmail.com> Discussion: https://postgr.es/m/CAA5RZ0tA6LbHCg2qSS+KuM850BZC_+ZgHV7Ug6BXw22TNyF+MA@mail.gmail.com
2025-07-01Update comment for IndexInfo.ii_NullsNotDistinctPeter Eisentraut
Commit 7a7b3e11e61 added the ii_NullsNotDistinct field, but the comment was not updated. Author: Japin Li <japinli@hotmail.com> Reviewed-by: Richard Guo <guofenglinux@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/ME0P300MB04453E6C7EA635F0ECF41BFCB6832%40ME0P300MB0445.AUSP300.PROD.OUTLOOK.COM
2025-07-01Update comment for IndexInfo.ii_WithoutOverlapsPeter Eisentraut
Commit fc0438b4e80 added the ii_WithoutOverlaps field, but the comment was not updated. Author: Japin Li <japinli@hotmail.com> Reviewed-by: Richard Guo <guofenglinux@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/ME0P300MB04453E6C7EA635F0ECF41BFCB6832%40ME0P300MB0445.AUSP300.PROD.OUTLOOK.COM
2025-07-01Fix outdated comment for IndexInfoPeter Eisentraut
Commit 78416235713 removed the ii_OpclassOptions field, but the comment was not updated. Author: Japin Li <japinli@hotmail.com> Reviewed-by: Richard Guo <guofenglinux@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/ME0P300MB04453E6C7EA635F0ECF41BFCB6832%40ME0P300MB0445.AUSP300.PROD.OUTLOOK.COM
2025-06-24Make query jumbling also squash PARAM_EXTERN paramsÁlvaro Herrera
Commit 62d712ecfd94 made query jumbling squash lists of Consts as a single element, but there's no reason not to treat PARAM_EXTERN parameters the same. For these purposes, these values are indeed constants for any particular execution of a query. In particular, this should make list squashing more useful for applications using extended query protocol, which would use parameters extensively. A complication arises: if a query has both external parameters and squashable lists, then the parameter number used as placeholder for the squashed list might be inconsistent with regards to the parameter numbers used by the query literal. To reduce the surprise factor, all parameters are renumbered starting from 1 in that case. Author: Sami Imseih <samimseih@gmail.com> Author: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/CAA5RZ0tRXoPG2y6bMgBCWNDt0Tn=unRerbzYM=oW0syi1=C1OA@mail.gmail.com
2025-06-12Fix squashing algorithm for query textsÁlvaro Herrera
The algorithm to squash lists of constants added by commit 62d712ecfd94 was a bit too simplistic; we wanted to avoid adding unnecessary complexity, but cases like direct function calls of typecasting functions (and others) were missed, and bogus SQL syntax was being shown in pg_stat_statements normalized query text field. To fix normalization for those cases, we need the parser to transmit information about were each list of constant values starts and ends, so add that to a couple of nodes. Also add a few more test cases to make sure we're doing the right thing. The patch initially submitted by Sami added a new private struct in gram.y to carry the start/end information for A_Expr, but I (Álvaro) decided that a better fix was to remove the parser indirection via the in_expr production, and instead create separate components in the a_expr rule. I'm surprised that this works and doesn't require more changes, but I assume (without checking) that the grammar used to be more complex and got simplified at some point. Bump catversion. Author: Sami Imseih <samimseih@gmail.com> Author: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/CAA5RZ0tRXoPG2y6bMgBCWNDt0Tn=unRerbzYM=oW0syi1=C1OA@mail.gmail.com
2025-06-12Revert support for improved tracking of nested queriesMichael Paquier
This commit reverts the two following commits: - 499edb09741b, track more precisely query locations for nested statements. - 06450c7b8c70, a follow-up fix of 499edb09741b with query locations. The test introduced in this commit is not reverted. This is proving useful to track a problem that only pgaudit was able to detect. These prove to have issues with the tracking of SELECT statements, when these use multiple parenthesis which is something supported by the grammar. Incorrect location and lengths are causing pg_stat_statements to become confused, failing its job in query normalization with potential out-of-bound writes because the location and the length may not match with what can be handled. A lot of the query patterns discussed when this issue was reported have no test coverage in the main regression test suite, or the recovery test 027_stream_regress.pl would have caught the problems as pg_stat_statements is loaded by the node running the regression tests. A first step would be to improve the test coverage to stress more the query normalization logic. A different portion of this work was done in 45e0ba30fc40, with the addition of tests for nested queries. These can be left in the tree. They are useful to track the way inner queries are currently tracked by PGSS with non-top-level entries, and will be useful when reconsidering in the future the work reverted here. Reported-by: Alexander Kozhemyakin <a.kozhemyakin@postgrespro.ru> Discussion: https://postgr.es/m/18947-cdd2668beffe02bf@postgresql.org
2025-05-31Change internal plan ID type from uint64 to int64Michael Paquier
uint64 was chosen to be consistent with the type used by the query ID, but the conclusion of a recent discussion for the query ID is that int64 is a better fit as the signed form is shown to the user, for PGSS or EXPLAIN outputs. This commit changes the plan ID to use int64, following c3eda50b0648 that has done the same for the query ID. The plan ID is new to v18, introduced in 2a0cd38da5cc. Author: Michael Paquier <michael@paquier.xyz> Reviewed-by: Sami Imseih <samimseih@gmail.com> Discussion: https://postgr.es/m/aCvzJNwetyEI3Sgo@paquier.xyz
2025-05-30Change internal queryid type from uint64 to int64David Rowley
uint64 was perhaps chosen in cff440d36 as the type was uint32 prior to that widening work. Having this as uint64 doesn't make much sense and just adds the overhead of having to remember that we always output this in its signed form. Let's remove that overhead. The signed form output is seemingly required since we have no way to represent the full range of uint64 in an SQL type. We use BIGINT in places like pg_stat_statements, which maps directly to int64. The release notes "Source Code" section may want to mention this adjustment as some extensions may wish to adjust their code. Author: David Rowley <dgrowleyml@gmail.com> Suggested-by: Peter Eisentraut <peter@eisentraut.org> Reviewed-by: Sami Imseih <samimseih@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/50cb0c8b-994b-48f9-a1c4-13039eb3536b@eisentraut.org
2025-05-22Revert "Don't lock partitions pruned by initial pruning"Amit Langote
As pointed out by Tom Lane, the patch introduced fragile and invasive design around plan invalidation handling when locking of prunable partitions was deferred from plancache.c to the executor. In particular, it violated assumptions about CachedPlan immutability and altered executor APIs in ways that are difficult to justify given the added complexity and overhead. This also removes the firstResultRels field added to PlannedStmt in commit 28317de72, which was intended to support deferred locking of certain ModifyTable result relations. Reported-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/605328.1747710381@sss.pgh.pa.us
2025-05-08Track the number of presorted outer pathkeys in MergePathRichard Guo
When creating an explicit Sort node for the outer path of a mergejoin, we need to determine the number of presorted keys of the outer path to decide whether explicit incremental sort can be applied. Currently, this is done by repeatedly calling pathkeys_count_contained_in. This patch caches the number of presorted outer pathkeys in MergePath, allowing us to save several calls to pathkeys_count_contained_in. It can be considered a complement to the changes in commit 828e94c9d. Reported-by: David Rowley <dgrowleyml@gmail.com> Author: Richard Guo <guofenglinux@gmail.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Discussion: https://postgr.es/m/CAApHDvqvBireB_w6x8BN5txdvBEHxVgZBt=rUnpf5ww5P_E_ww@mail.gmail.com
2025-04-19Fix typos and grammar in the codeMichael Paquier
The large majority of these have been introduced by recent commits done in the v18 development cycle. Author: Alexander Lakhin <exclusion@gmail.com> Discussion: https://postgr.es/m/9a7763ab-5252-429d-a943-b28941e0e28b@gmail.com
2025-04-08Speedup child EquivalenceMember lookup in plannerDavid Rowley
When planning queries to partitioned tables, we clone all EquivalenceMembers belonging to the partitioned table into em_is_child EquivalenceMembers for each non-pruned partition. For partitioned tables with large numbers of partitions, this meant the ec_members list could become large and code searching that list would become slow. Effectively, the more partitions which were present, the more searches needed to be performed for operations such as find_ec_member_matching_expr() during create_plan() and the more partitions present, the longer these searches would take, i.e., a quadratic slowdown. To fix this, here we adjust how we store EquivalenceMembers for em_is_child members. Instead of storing these directly in ec_members, these are now stored in a new array of Lists in the EquivalenceClass, which is indexed by the relid. When we want to find EquivalenceMembers belonging to a certain child relation, we can narrow the search to the array element for that relation. To make EquivalenceMember lookup easier and to reduce the amount of code change, this commit provides a pair of functions to allow iteration over the EquivalenceMembers of an EC which also handles finding the child members, if required. Callers that never need to look at child members can remain using the foreach loop over ec_members, which will now often be faster due to only parent-level members being stored there. The actual performance increases here are highly dependent on the number of partitions and the query being planned. Performance increases can be visible with as few as 8 partitions, but the speedup is marginal for such low numbers of partitions. The speedups become much more visible with a few dozen to hundreds of partitions. With some tested queries using 56 partitions, the planner was around 3x faster than before. For use cases with thousands of partitions, these are likely to become significantly faster. Some testing has shown planner speedups of 60x or more with 8192 partitions. Author: Yuya Watari <watari.yuya@gmail.com> Co-authored-by: David Rowley <dgrowleyml@gmail.com> Reviewed-by: David Rowley <dgrowleyml@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Andrey Lepikhov <a.lepikhov@postgrespro.ru> Reviewed-by: Alena Rybakina <lena.ribackina@yandex.ru> Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Amit Langote <amitlangote09@gmail.com> Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Tested-by: Thom Brown <thom@linux.com> Tested-by: newtglobal postgresql_contributors <postgresql_contributors@newtglobalcorp.com> Discussion: https://postgr.es/m/CAJ2pMkZNCgoUKSE%2B_5LthD%2BKbXKvq6h2hQN8Esxpxd%2Bcxmgomg%40mail.gmail.com
2025-04-04Convert PathKey to use CompareTypePeter Eisentraut
Change the PathKey struct to use CompareType to record the sort direction instead of hardcoding btree strategy numbers. The CompareType is then converted to the index-type-specific strategy when the plan is created. This reduces the number of places btree strategy numbers are hardcoded, and it's a self-contained subset of a larger effort to allow non-btree indexes to behave like btrees. Author: Mark Dilger <mark.dilger@enterprisedb.com> Co-authored-by: Peter Eisentraut <peter@eisentraut.org> Discussion: https://www.postgresql.org/message-id/flat/E72EAA49-354D-4C2E-8EB9-255197F55330@enterprisedb.com
2025-04-04Make derived clause lookup in EquivalenceClass more efficientAmit Langote
Derived clauses are stored in ec_derives, a List of RestrictInfos. These clauses are later looked up by matching the left and right EquivalenceMembers along with the clause's parent EC. This linear search becomes expensive in queries with many joins or partitions, where ec_derives may contain thousands of entries. In particular, create_join_clause() can spend significant time scanning this list. To improve performance, introduce a hash table (ec_derives_hash) that is built when the list reaches 32 entries -- the same threshold used for join_rel_hash. The original list is retained alongside the hash table to support EC merging and serialization (_outEquivalenceClass()). Each clause is stored in the hash table using a canonicalized key: the EquivalenceMember with the lower memory address is placed in the key before the one with the higher memory address. This avoids storing or searching for both permutations of the same clause. For clauses involving a constant EM, the key places NULL in the first slot and the non-constant EM in the second. The hash table is initialized using list_length(ec_derives_list) as the size hint. simplehash internally adjusts this to the next power of two after dividing by the fillfactor, so this typically results in at least 64 buckets near the threshold -- avoiding immediate resizing while adapting to the actual number of entries. The lookup logic for derived clauses is now centralized in ec_search_derived_clause_for_ems(), which consults the hash table when available and falls back to the list otherwise. The new ec_clear_derived_clauses() always frees ec_derives_list, even though some of the original code paths that cleared the old ec_derives field did not. This ensures consistent cleanup and avoids leaking memory when large lists are discarded. An assertion originally placed in find_derived_clause_for_ec_member() is moved into ec_search_derived_clause_for_ems() so that it is enforced consistently, regardless of whether the hash table or list is used for lookup. This design incorporates suggestions by David Rowley, who proposed both the key canonicalization and the initial sizing approach to balance memory usage and CPU efficiency. Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Reviewed-by: Amit Langote <amitlangote09@gmail.com> Reviewed-by: David Rowley <dgrowleyml@gmail.com> Tested-by: Dmitry Dolgov <9erthalion6@gmail.com> Tested-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Tested-by: Amit Langote <amitlangote09@gmail.com> Tested-by: David Rowley <dgrowleyml@gmail.com> Discussion: https://postgr.es/m/CAExHW5vZiQtWU6moszLP5iZ8gLX_ZAUbgEX0DxGLx9PGWCtqUg@mail.gmail.com
2025-04-02Fix code commentPeter Eisentraut
The changes made in commit d2b4b4c2259 contained incorrect comments: They said that certain forward declarations were necessary to "avoid including pathnodes.h here", but the file is itself pathnodes.h! So change the comment to just say it's a forward declaration in one case, and in the other case we don't need the declaration at all because it already appeared earlier in the file.
2025-04-02Add support for NOT ENFORCED in foreign key constraintsPeter Eisentraut
This expands the NOT ENFORCED constraint flag, previously only supported for CHECK constraints (commit ca87c415e2f), to foreign key constraints. Normally, when a foreign key constraint is created on a table, action and check triggers are added to maintain data integrity. With this patch, if a constraint is marked as NOT ENFORCED, integrity checks are no longer required, making these triggers unnecessary. Consequently, when creating a NOT ENFORCED foreign key constraint, triggers will not be created, and the constraint will be marked as NOT VALID. Similarly, if an existing foreign key constraint is changed to NOT ENFORCED, the associated triggers will be dropped, and the constraint will also be marked as NOT VALID. Conversely, if a NOT ENFORCED foreign key constraint is changed to ENFORCED, the necessary triggers will be created, and the will be changed to VALID by performing necessary validation. Since not-enforced foreign key constraints have no triggers, the shortcut used for example in psql and pg_dump to skip looking for foreign keys if the relation is known not to have triggers no longer applies. (It already didn't work for partitioned tables.) Author: Amul Sul <sulamul@gmail.com> Reviewed-by: Joel Jacobson <joel@compiler.org> Reviewed-by: Andrew Dunstan <andrew@dunslane.net> Reviewed-by: Peter Eisentraut <peter@eisentraut.org> Reviewed-by: jian he <jian.universality@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Reviewed-by: Isaac Morland <isaac.morland@gmail.com> Reviewed-by: Alexandra Wang <alexandra.wang.oss@gmail.com> Tested-by: Triveni N <triveni.n@enterprisedb.com> Discussion: https://www.postgresql.org/message-id/flat/CAAJ_b962c5AcYW9KUt_R_ER5qs3fUGbe4az-SP-vuwPS-w-AGA@mail.gmail.com
2025-03-28Add support for not-null constraints on virtual generated columnsPeter Eisentraut
This was left out of the original patch for virtual generated columns (commit 83ea6c54025). This just involves a bit of extra work in the executor to expand the generation expressions and run a "IS NOT NULL" test against them. There is also a bit of work to make sure that not-null constraints are checked during a table rewrite. Author: jian he <jian.universality@gmail.com> Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com> Reviewed-by: Navneet Kumar <thanit3111@gmail.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://postgr.es/m/CACJufxHArQysbDkWFmvK+D1TPHQWWTxWN15cMuUaTYX3xhQXgg@mail.gmail.com
2025-03-28Rename a node field for clarityPeter Eisentraut
Rename ResultRelInfo.ri_ConstraintExprs to ri_CheckConstraintExprs. This reflects its specific purpose better and avoids confusion with adjacent fields with similar but distinct purposes. Discussion: https://postgr.es/m/CACJufxHArQysbDkWFmvK+D1TPHQWWTxWN15cMuUaTYX3xhQXgg@mail.gmail.com
2025-03-27Remove the query_id_squash_values GUCÁlvaro Herrera
Commit 62d712ecfd94 introduced the capability to calculate the same queryId for queries with different lengths of constants in a list for an IN clause. This behavior was originally enabled with a GUC query_id_squash_values. After a discussion about the value of such a GUC, it was decided to back out of the use of a GUC and make the squashing behavior the only available option. Author: Sami Imseih <samimseih@gmail.com> Discussion: https://postgr.es/m/Z-LZyygkkNyA8-kR@msg.df7cb.de Discussion: https://postgr.es/m/CA+q6zcVTK-3C-8NWV1oY2NZrvtnMCDqnyYYyk1T7WMUG65MeOQ@mail.gmail.com
2025-03-27Fix query jumbling to account for NULL nodesDavid Rowley
Previously NULL nodes were ignored. This could cause issues where the computed query ID could match for queries where fields that are next to each other in their Node struct where one field was NULL and the other non-NULL. For example, the Query struct had distinctClause and sortClause next to each other. If someone wrote; SELECT DISTINCT c1 FROM t; and then; SELECT c1 FROM t ORDER BY c1; these would produce the same query ID since, in the first query, we ignored the NULL sortClause and appended the jumble bytes for the distictClause. In the latter query, since we did nothing for the NULL distinctClause then jumble the non-NULL sortClause, and since the node representation stored is the same in both cases, the query IDs were identical. Here we fix this by always accounting for NULL nodes by recording that we saw a NULL in the jumble buffer. This fixes the issue as the order that the NULL is recorded isn't the same in the above two queries. Author: Bykov Ivan <i.bykov@modernsys.ru> Author: Michael Paquier <michael@paquier.xyz> Author: David Rowley <dgrowleyml@gmail.com> Discussion: https://postgr.es/m/aafce7966e234372b2ba876c0193f1e9%40localhost.localdomain
2025-03-26Use relation name instead of OID in query jumbling for RangeTblEntryMichael Paquier
custom_query_jumble (introduced in 5ac462e2b7ac as a node field attribute) is now assigned to the expanded reference name "eref" of RangeTblEntry, adding in the query jumble computation the non-qualified aliased relation name, without the list of column names. The relation OID is removed from the query jumbling. The effects of this change can be seen in the tests added by 3430215fe35f, where pg_stat_statements (PGSS) entries are now grouped using the relation name, ignoring the relation search_path may point at. For example, these two relations are different, but are now grouped in a single PGSS entry as they are assigned the same query ID: CREATE TABLE foo1.tab (a int); CREATE TABLE foo2.tab (b int); SET search_path = 'foo1'; SELECT count(*) FROM tab; SET search_path = 'foo2'; SELECT count(*) FROM tab; SELECT count(*) FROM foo1.tab; SELECT count(*) FROM foo2.tab; SELECT query, calls FROM pg_stat_statements WHERE query ~ 'FROM tab'; query | calls --------------------------+------- SELECT count(*) FROM tab | 4 (1 row) It is still possible to use an alias in the FROM clause to split these. This behavior is useful for relations re-created with the same name, where queries based on such relations would be grouped in the same PGSS entry. For permanent schemas, it should not really matter in practice. The main benefit is for workloads that use a lot of temporary relations, which are usually re-created with the same name continuously. These can be a heavy source of bloat in PGSS depending on the workload. Such entries can now be grouped together, improving the user experience. The original idea from Christoph Berg used catalog lookups to find temporary relations, something that the query jumble has never done, and it could cause some performance regressions. The idea to use RangeTblEntry.eref and the relation name, applying the same rules for all relations, temporary and not temporary, has been proposed by Tom Lane. The documentation additions have been suggested by Sami Imseih. Author: Michael Paquier <michael@paquier.xyz> Co-authored-by: Sami Imseih <samimseih@gmail.com> Reviewed-by: Christoph Berg <myon@debian.org> Reviewed-by: Lukas Fittl <lukas@fittl.com> Reviewed-by: Sami Imseih <samimseih@gmail.com> Discussion: https://postgr.es/m/Z9iWXKGwkm8RAC93@msg.df7cb.de
2025-03-25Add support for custom_query_jumble as a node field attributeMichael Paquier
This option gives the possibility for query jumble to define a custom routine for the field of a Node, extending support for custom_query_jumble as a node field attribute. When dealing with complex node structures, this can be simpler than having to enforce a custom function across a full node. Custom functions need to be defined in queryjumblefuncs.c, named as _jumble${node}_${field}(), and use in input the JumbleState, the node and its field. The field is not really required if we have the Node, but it makes custom implementations somewhat easier to think about. The code generated by gen_node_support.pl uses a macro called JUMBLE_CUSTOM(), hiding the internals of the logic inside queryjumblefuncs.c. This will be used by an upcoming patch manipulating adding a custom routine into a field of RangeTblEntry, but this facility can become useful in more cases. Reviewed-by: Christoph Berg <myon@debian.org> Discussion: https://postgr.es/m/Z9y43-dRvb4EtxQ0@paquier.xyz
2025-03-24Remove 'additional' pointer from TupleHashEntryData.Jeff Davis
Reduces memory required for hash aggregation by avoiding an allocation and a pointer in the TupleHashEntryData structure. That structure is used for all buckets, whether occupied or not, so the savings is substantial. Discussion: https://postgr.es/m/AApHDvpN4v3t_sdz4dvrv1Fx_ZPw=twSnxuTEytRYP7LFz5K9A@mail.gmail.com Reviewed-by: David Rowley <dgrowleyml@gmail.com>
2025-03-24Create accessor functions for TupleHashEntry.Jeff Davis
Refactor for upcoming optimizations. Reviewed-by: David Rowley <dgrowleyml@gmail.com> Discussion: https://postgr.es/m/1cc3b400a0e8eead18ff967436fa9e42c0c14cfb.camel@j-davis.com
2025-03-24HashAgg: use Bump allocator for hash TupleHashTable entries.Jeff Davis
The entries aren't freed until the entire hash table is destroyed, so use the Bump allocator to improve allocation speed, avoid wasting space on the chunk header, and avoid wasting space due to the power-of-two allocations. Discussion: https://postgr.es/m/CAApHDvqv1aNB4cM36FzRwivXrEvBO_LsG_eQ3nqDXTjECaatOQ@mail.gmail.com Reviewed-by: David Rowley
2025-03-24Allow plugins to set a 64-bit plan identifier in PlannedStmtMichael Paquier
This field can be optionally set in a PlannedStmt through the planner hook, giving extensions the possibility to assign an identifier related to a computed plan. The backend is changed to report it in the backend entry of a process running (including the extended query protocol), with semantics and APIs to set or get it similar to what is used for the existing query ID (introduced in the backend via 4f0b0966c8). The plan ID is reset at the same timing as the query ID. Currently, this information is not added to the system view pg_stat_activity; extensions can access it through PgBackendStatus. Some patches have been proposed to provide some features in the planning area, where a plan identifier is used as a key to know the plan involved (for statistics, plan storage and manipulations, etc.), and the point of this commit is to provide an anchor in the backend that extensions can rely on for future work. The reset of the plan identifier is controlled by core and follows the same pattern as the query identifier added in 4f0b0966c8. The contents of this commit are extracted from a larger set proposed originally by Lukas Fittl, that Sami Imseih has proposed as an independent change, with a few tweaks sprinkled by me. Author: Lukas Fittl <lukas@fittl.com> Author: Sami Imseih <samimseih@gmail.com> Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/CAP53Pkyow59ajFMHGpmb1BK9WHDypaWtUsS_5DoYUEfsa_Hktg@mail.gmail.com Discussion: https://postgr.es/m/CAA5RZ0vyWd4r35uUBUmhngv8XqeiJUkJDDKkLf5LCoWxv-t_pw@mail.gmail.com
2025-03-19Ensure first ModifyTable rel initialized if all are prunedAmit Langote
Commit cbc127917e introduced tracking of unpruned relids to avoid processing pruned relations, and changed ExecInitModifyTable() to initialize only unpruned result relations. As a result, MERGE statements that prune all target partitions can now lead to crashes or incorrect behavior during execution. The crash occurs because some executor code paths rely on ModifyTableState.resultRelInfo[0] being present and initialized, even when no result relations remain after pruning. For example, ExecMerge() and ExecMergeNotMatched() use the first resultRelInfo to determine the appropriate action. Similarly, ExecInitPartitionInfo() assumes that at least one result relation exists. To preserve these assumptions, ExecInitModifyTable() now includes the first result relation in the initialized result relation list if all result relations for that ModifyTable were pruned. To enable that, ExecDoInitialPruning() ensures the first relation is locked if it was pruned and locking is necessary. To support this exception to the pruning logic, PlannedStmt now includes a list of RT indexes identifying the first result relation of each ModifyTable node in the plan. This allows ExecDoInitialPruning() to check whether each such relation was pruned and, if so, lock it if necessary. Bug: #18830 Reported-by: Robins Tharakan <tharakan@gmail.com> Diagnozed-by: Tender Wang <tndrwang@gmail.com> Diagnozed-by: Dean Rasheed <dean.a.rasheed@gmail.com> Co-authored-by: Dean Rasheed <dean.a.rasheed@gmail.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com> Discussion: https://postgr.es/m/18830-1f31ea1dc930d444%40postgresql.org
2025-03-18Introduce squashing of constant lists in query jumblingÁlvaro Herrera
pg_stat_statements produces multiple entries for queries like SELECT something FROM table WHERE col IN (1, 2, 3, ...) depending on the number of parameters, because every element of ArrayExpr is individually jumbled. Most of the time that's undesirable, especially if the list becomes too large. Fix this by introducing a new GUC query_id_squash_values which modifies the node jumbling code to only consider the first and last element of a list of constants, rather than each list element individually. This affects both the query_id generated by query jumbling, as well as pg_stat_statements query normalization so that it suppresses printing of the individual elements of such a list. The default value is off, meaning the previous behavior is maintained. Author: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Sergey Dudoladov (mysterious, off-list) Reviewed-by: David Geier <geidav.pg@gmail.com> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Sami Imseih <samimseih@gmail.com> Reviewed-by: Sutou Kouhei <kou@clear-code.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Marcos Pegoraro <marcos@f10.com.br> Reviewed-by: Julien Rouhaud <rjuju123@gmail.com> Reviewed-by: Zhihong Yu <zyu@yugabyte.com> Tested-by: Yasuo Honda <yasuo.honda@gmail.com> Tested-by: Sergei Kornilov <sk@zsrv.org> Tested-by: Maciek Sakrejda <m.sakrejda@gmail.com> Tested-by: Chengxi Sun <sunchengxi@highgo.com> Tested-by: Jakub Wartak <jakub.wartak@enterprisedb.com> Discussion: https://postgr.es/m/CA+q6zcWtUbT_Sxj0V6HY6EZ89uv5wuG5aefpe_9n0Jr3VwntFg@mail.gmail.com
2025-03-18Make it possible for loadable modules to add EXPLAIN options.Robert Haas
Modules can use RegisterExtensionExplainOption to register new EXPLAIN options, and GetExplainExtensionId, GetExplainExtensionState, and SetExplainExtensionState to store related state inside the ExplainState object. Since this substantially increases the amount of code that needs to handle ExplainState-related tasks, move a few bits of existing code to a new file explain_state.c and add the rest of this infrastructure there. See the comments at the top of explain_state.c for further explanation of how this mechanism works. This does not yet provide a way for such such options to do anything useful. The intention is that we'll add hooks for that purpose in a separate commit. Discussion: http://postgr.es/m/CA+TgmoYSzg58hPuBmei46o8D3SKX+SZoO4K_aGQGwiRzvRApLg@mail.gmail.com Reviewed-by: Srinath Reddy <srinath2133@gmail.com> Reviewed-by: Andrei Lepikhov <lepihov@gmail.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Sami Imseih <samimseih@gmail.com>
2025-03-15BitmapHeapScan uses the read stream APIMelanie Plageman
Make Bitmap Heap Scan use the read stream API instead of invoking ReadBuffer() for each block indicated by the bitmap. The read stream API handles prefetching, so remove all of the explicit prefetching from bitmap heap scan code. Now, heap table AM implements a read stream callback which uses the bitmap iterator to return the next required block to the read stream code. Tomas Vondra conducted extensive regression testing of this feature. Andres Freund, Thomas Munro, and I analyzed regressions and Thomas Munro patched the read stream API. Author: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Tomas Vondra <tomas@vondra.me> Tested-by: Tomas Vondra <tomas@vondra.me> Tested-by: Andres Freund <andres@anarazel.de> Tested-by: Thomas Munro <thomas.munro@gmail.com> Tested-by: Nazir Bilal Yavuz <byavuz81@gmail.com> Discussion: https://postgr.es/m/flat/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA%40mail.gmail.com
2025-03-15Separate TBM[Shared|Private]Iterator and TBMIterateResultMelanie Plageman
Remove the TBMIterateResult member from the TBMPrivateIterator and TBMSharedIterator and make tbm_[shared|private_]iterate() take a TBMIterateResult as a parameter. This allows tidbitmap API users to manage multiple TBMIterateResults per scan. This is required for bitmap heap scan to use the read stream API, with which there may be multiple I/Os in flight at once, each one with a TBMIterateResult. Reviewed-by: Tomas Vondra <tomas@vondra.me> Discussion: https://postgr.es/m/d4bb26c9-fe07-439e-ac53-c0e244387e01%40vondra.me
2025-03-14Swap order of extern/static and pg_nodiscardPeter Eisentraut
When pg_nodiscard was first added, the C standard draft had it as a function specifier, and so the code comment about placement was written with that in mind. The final C23 standard has it as an attribute and the placement rules are a bit different for that. Specifically, it needs to be before extern or static. (Or at least both current clang and gcc require that.) So just swap these. (To be clear: The current implementation with gcc attributes doesn't care. This change is just for maximum forward compatibility for non-gcc compilers.) This also keeps the order consistent with the previously introduced pg_noreturn. Also update the code comment to reflect the mentioned developments since its introduction. Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org> Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://www.postgresql.org/message-id/flat/pxr5b3z7jmkpenssra5zroxi7qzzp6eswuggokw64axmdixpnk@zbwxuq7gbbcw
2025-03-11Improve EXPLAIN's display of window functions.Tom Lane
Up to now we just punted on showing the window definitions used in a plan, with window function calls represented as "OVER (?)". To improve that, show the window definition implemented by each WindowAgg plan node, and reference their window names in OVER. For nameless window clauses generated by "OVER (...)", assign unique names w1, w2, etc. In passing, re-order the properties shown for a WindowAgg node so that the Run Condition (if any) appears after the Window property and before the Filter (if any). This seems more sensible since the Run Condition is associated with the Window and acts before the Filter. Thanks to David G. Johnston and Álvaro Herrera for design suggestions. Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: David Rowley <dgrowleyml@gmail.com> Discussion: https://postgr.es/m/144530.1741469955@sss.pgh.pa.us
2025-03-11Show index search count in EXPLAIN ANALYZE, take 2.Peter Geoghegan
Expose the count of index searches/index descents in EXPLAIN ANALYZE's output for index scan/index-only scan/bitmap index scan nodes. This information is particularly useful with scans that use ScalarArrayOp quals, where the number of index searches can be unpredictable due to implementation details that interact with physical index characteristics (at least with nbtree SAOP scans, since Postgres 17 commit 5bf748b8). The information shown also provides useful context when EXPLAIN ANALYZE runs a plan with an index scan node that successfully applied the skip scan optimization (set to be added to nbtree by an upcoming patch). The instrumentation works by teaching all index AMs to increment a new nsearches counter whenever a new index search begins. The counter is incremented at exactly the same point that index AMs already increment the pg_stat_*_indexes.idx_scan counter (we're counting the same event, but at the scan level rather than the relation level). Parallel queries have workers copy their local counter struct into shared memory when an index scan node ends -- even when it isn't a parallel aware scan node. An earlier version of this patch that only worked with parallel aware scans became commit 5ead85fb (though that was quickly reverted by commit d00107cd following "debug_parallel_query=regress" buildfarm failures). Our approach doesn't match the approach used when tracking other index scan related costs (e.g., "Rows Removed by Filter:"). It is comparable to the approach used in similar cases involving costs that are only readily accessible inside an access method, not from the executor proper (e.g., "Heap Blocks:" output for a Bitmap Heap Scan, which was recently enhanced to show per-worker costs by commit 5a1e6df3, using essentially the same scheme as the one used here). It is necessary for index AMs to have direct responsibility for maintaining the new counter, since the counter might need to be incremented multiple times per amgettuple call (or per amgetbitmap call). But it is also necessary for the executor proper to manage the shared memory now used to transfer each worker's counter struct to the leader. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Robert Haas <robertmhaas@gmail.com> Reviewed-By: Tomas Vondra <tomas@vondra.me> Reviewed-By: Masahiro Ikeda <ikedamsh@oss.nttdata.com> Reviewed-By: Matthias van de Meent <boekewurm+postgres@gmail.com> Discussion: https://postgr.es/m/CAH2-WzkRqvaqR2CTNqTZP0z6FuL4-3ED6eQB0yx38XBNj1v-4Q@mail.gmail.com Discussion: https://postgr.es/m/CAH2-Wz=PKR6rB7qbx+Vnd7eqeB5VTcrW=iJvAsTsKbdG+kW_UA@mail.gmail.com
2025-03-05Add ALTER TABLE ... ALTER CONSTRAINT ... SET [NO] INHERITÁlvaro Herrera
This allows to redefine an existing non-inheritable constraint to be inheritable, which allows to straighten up situations with NO INHERIT constraints so that thay can become normal constraints without having to re-verify existing data. For existing inheritance children this may require creating additional constraints, if they don't exist already. It also allows to do the opposite, if only for symmetry. Author: Suraj Kharage <suraj.kharage@enterprisedb.com> Reviewed-by: jian he <jian.universality@gmail.com> Discussion: https://postgr.es/m/CAF1DzPVfOW6Kk=7SSh7LbneQDJWh=PbJrEC_Wkzc24tHOyQWGg@mail.gmail.com