275 Commits (c2da1a5d6325a92d834c9cb036f65d362e4bfc3e)

Author	SHA1	Message	Date
Álvaro Herrera	c2da1a5d63	Make query jumbling also squash PARAM_EXTERN params ... Commit 62d712ecfd 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	4 days ago
Álvaro Herrera	debad29d22	Improve jumble squashing through CoerceViaIO and RelabelType ... There's no principled reason for query jumbling to only remove the first layer of RelabelType and CoerceViaIO. Change it to see through as many layers as there are.	4 days ago
Álvaro Herrera	0f65f3eec4	Fix squashing algorithm for query texts ... The algorithm to squash lists of constants added by commit 62d712ecfd 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	2 weeks ago
Michael Paquier	f85f6ab051	Revert support for improved tracking of nested queries ... This commit reverts the two following commits: - 499edb0974, track more precisely query locations for nested statements. - 06450c7b8c, a follow-up fix of 499edb0974 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 45e0ba30fc, 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	2 weeks ago
David Rowley	c3eda50b06	Change internal queryid type from uint64 to int64 ... 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	4 weeks ago
Michael Paquier	35a428f30b	pg_stat_statements: Fix parameter number gaps in normalized queries ... pg_stat_statements anticipates that certain constant locations may be recorded multiple times and attempts to avoid calculating a length for these locations in fill_in_constant_lengths(). However, during generate_normalized_query() where normalized query strings are generated, these locations are not excluded from consideration. This could increment the parameter number counter for every recorded occurrence at such a location, leading to an incorrect normalization in certain cases with gaps in the numbers reported. For example, take this query: SELECT WHERE '1' IN ('2'::int, '3'::int::text) Before this commit, it would be normalized like that, with gaps in the parameter numbers: SELECT WHERE $1 IN ($3::int, $4::int::text) However the correct, less confusing one should be like that: SELECT WHERE $1 IN ($2::int, $3::int::text) This commit fixes the computation of the parameter numbers to track the number of constants replaced with an $n by a separate counter instead of the iterator used to loop through the list of locations. The underlying query IDs are not changed, neither are the normalized strings for existing PGSS hash entries. New entries with fresh normalized queries would automatically get reshaped based on the new parameter numbering. Issue discovered while discussing a separate problem for HEAD, but this affects all the stable branches. Author: Sami Imseih <samimseih@gmail.com> Discussion: https://postgr.es/m/CAA5RZ0tzxvWXsacGyxrixdhy3tTTDfJQqxyFBRFh31nNHBQ5qA@mail.gmail.com Backpatch-through: 13	1 month ago
Amit Langote	1722d5eb05	Revert "Don't lock partitions pruned by initial pruning" ... 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	1 month ago
Michael Paquier	06450c7b8c	Fix regression with location calculation of nested statements ... The statement location calculated for some nested query cases was wrong when multiple queries are sent as a single string, these being separated by semicolons. As pointed by Sami Imseih, the location calculation was incorrect when the last query of nested statement with multiple queries does **NOT** finish with a semicolon for the last statement. In this case, the statement length tracked by RawStmt is 0, which is equivalent to say that the string should be used until its end. The code previously discarded this case entirely, causing the location to remain at 0, the same as pointing at the beginning of the string. This caused pg_stat_statements to store incorrect query strings. This issue has been introduced in 499edb0974. I have looked at the diffs generated by pgaudit back then, and noticed the difference generated for this nested query case, but I have missed the point that it was an actual regression with an existing case. A test case is added in pg_stat_statements to provide some coverage, restoring the pre-17 behavior for the calculation of the query locations. Special thanks to David Steele, who, through an analysis of the test diffs generated by pgaudit with the new v18 logic, has poked me about the fact that my original analysis of the matter was wrong. The test output of pg_overexplain is updated to reflect the new logic, as the new locations refer to the beginning of the argument passed to the function explain_filter(). When the module was introduced in 8d5ceb113e, which was after 499edb0974 (for the new calculation method), the locations of the test were not actually right: the plan generated for the query string given in input of the function pointed to the top-level query, not the nested one. Reported-by: David Steele <david@pgbackrest.org> Author: Michael Paquier <michael@paquier.xyz> Reviewed-by: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com> Reviewed-by: Jian He <jian.universality@gmail.com> Reviewed-by: Sami Imseih <samimseih@gmail.com> Reviewed-by: David Steele <david@pgbackrest.org> Discussion: https://postgr.es/m/844a3b38-bbf1-4fb2-9fd6-f58c35c09917@pgbackrest.org	1 month ago
Peter Eisentraut	09a47c68e2	Fix whitespace	2 months ago
Álvaro Herrera	9fbd53dea5	Remove the query_id_squash_values GUC ... Commit 62d712ecfd 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	3 months ago
David Rowley	f31aad9b07	Fix query jumbling to account for NULL nodes ... 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	3 months ago
Tom Lane	55527368bd	Use PG_MODULE_MAGIC_EXT in our installable shared libraries. ... It seems potentially useful to label our shared libraries with version information, now that a facility exists for retrieving that. This patch labels them with the PG_VERSION string. There was some discussion about using semantic versioning conventions, but that doesn't seem terribly helpful for modules with no SQL-level presence; and for those that do have SQL objects, we typically expect them to support multiple revisions of the SQL definitions, so it'd still not be very helpful. I did not label any of src/test/modules/. It seems unnecessary since we don't install those, and besides there ought to be someplace that still provides test coverage for the original PG_MODULE_MAGIC macro. Author: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/dd4d1b59-d0fe-49d5-b28f-1e463b68fa32@gmail.com	3 months ago
Michael Paquier	787514b30b	Use relation name instead of OID in query jumbling for RangeTblEntry ... custom_query_jumble (introduced in 5ac462e2b7 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 3430215fe3, 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	3 months ago
Michael Paquier	3430215fe3	pg_stat_statements: Add more tests with temp tables and namespaces ... These tests provide coverage for RangeTblEntry and how query jumbling works with search_path, as well as the case where relations are re-created, generating a different query ID as the relation OID is used in the computation. A patch is under discussion to switch to a different approach based on the relation name, and there was no test coverage for this area, including how queries are currently grouped with search_path. This is useful to track how the situation changes between HEAD and any patches proposed. Christoph has proposed the test with ON COMMIT DROP temporary tables, and I have written the second part. Author: Christoph Berg <myon@debian.org> Author: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/Z9iWXKGwkm8RAC93@msg.df7cb.de	3 months ago
Álvaro Herrera	62d712ecfd	Introduce squashing of constant lists in query jumbling ... 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	3 months ago
Robert Haas	95dbd827f2	EXPLAIN: Always use two fractional digits for row counts. ... Commit ddb17e387a attempted to avoid confusing users by displaying digits after the decimal point only when nloops > 1, since it's impossible to have a fraction row count after a single iteration. However, this made the regression tests unstable since parallal queries will have nloops>1 for all nodes below the Gather or Gather Merge in normal cases, but if the workers don't start in time and the leader finishes all the work, they will suddenly have nloops==1, making it unpredictable whether the digits after the decimal point would be displayed or not. Although 44cbba9a7f seemed to fix the immediate failures, it may still be the case that there are lower-probability failures elsewhere in the regression tests. Various fixes are possible here. For example, it has previously been proposed that we should try to display the digits after the decimal point only if rows/nloops is an integer, but currently rows is storead as a float so it's not theoretically an exact quantity -- precision could be lost in extreme cases. It has also been proposed that we should try to display the digits after the decimal point only if we're under some sort of construct that could potentially cause looping regardless of whether it actually does. While such ideas are not without merit, this patch adopts the much simpler solution of always display two decimal digits. If that approach stands up to scrutiny from the buildfarm and human users, it spares us the trouble of doing anything more complex; if not, we can reassess. This commit incidentally reverts 44cbba9a7f, which should no longer be needed. Author: Robert Haas <robertmhaas@gmail.com> Author: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com> Discussion: http://postgr.es/m/CA+TgmoazzVHn8sFOMFAEwoqBTDxKT45D7mvkyeHgqtoD2cn58Q@mail.gmail.com	4 months ago
Amit Langote	525392d572	Don't lock partitions pruned by initial pruning ... Before executing a cached generic plan, AcquireExecutorLocks() in plancache.c locks all relations in a plan's range table to ensure the plan is safe for execution. However, this locks runtime-prunable relations that will later be pruned during "initial" runtime pruning, introducing unnecessary overhead. This commit defers locking for such relations to executor startup and ensures that if the CachedPlan is invalidated due to concurrent DDL during this window, replanning is triggered. Deferring these locks avoids unnecessary locking overhead for pruned partitions, resulting in significant speedup, particularly when many partitions are pruned during initial runtime pruning. * Changes to locking when executing generic plans: AcquireExecutorLocks() now locks only unprunable relations, that is, those found in PlannedStmt.unprunableRelids (introduced in commit cbc127917e), to avoid locking runtime-prunable partitions unnecessarily. The remaining locks are taken by ExecDoInitialPruning(), which acquires them only for partitions that survive pruning. This deferral does not affect the locks required for permission checking in InitPlan(), which takes place before initial pruning. ExecCheckPermissions() now includes an Assert to verify that all relations undergoing permission checks, none of which can be in the set of runtime-prunable relations, are properly locked. * Plan invalidation handling: Deferring locks introduces a window where prunable relations may be altered by concurrent DDL, invalidating the plan. A new function, ExecutorStartCachedPlan(), wraps ExecutorStart() to detect and handle invalidation caused by deferred locking. If invalidation occurs, ExecutorStartCachedPlan() updates CachedPlan using the new UpdateCachedPlan() function and retries execution with the updated plan. To ensure all code paths that may be affected by this handle invalidation properly, all callers of ExecutorStart that may execute a PlannedStmt from a CachedPlan have been updated to use ExecutorStartCachedPlan() instead. UpdateCachedPlan() replaces stale plans in CachedPlan.stmt_list. A new CachedPlan.stmt_context, created as a child of CachedPlan.context, allows freeing old PlannedStmts while preserving the CachedPlan structure and its statement list. This ensures that loops over statements in upstream callers of ExecutorStartCachedPlan() remain intact. ExecutorStart() and ExecutorStart_hook implementations now return a boolean value indicating whether plan initialization succeeded with a valid PlanState tree in QueryDesc.planstate, or false otherwise, in which case QueryDesc.planstate is NULL. Hook implementations are required to call standard_ExecutorStart() at the beginning, and if it returns false, they should do the same without proceeding. * Testing: To verify these changes, the delay_execution module tests scenarios where cached plans become invalid due to changes in prunable relations after deferred locks. * Note to extension authors: ExecutorStart_hook implementations must verify plan validity after calling standard_ExecutorStart(), as explained earlier. For example: if (prev_ExecutorStart) plan_valid = prev_ExecutorStart(queryDesc, eflags); else plan_valid = standard_ExecutorStart(queryDesc, eflags); if (!plan_valid) return false; <extension-code> return true; Extensions accessing child relations, especially prunable partitions, via ExecGetRangeTableRelation() must now ensure their RT indexes are present in es_unpruned_relids (introduced in commit cbc127917e), or they will encounter an error. This is a strict requirement after this change, as only relations in that set are locked. The idea of deferring some locks to executor startup, allowing locks for prunable partitions to be skipped, was first proposed by Tom Lane. Reviewed-by: Robert Haas <robertmhaas@gmail.com> (earlier versions) Reviewed-by: David Rowley <dgrowleyml@gmail.com> (earlier versions) Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> (earlier versions) Reviewed-by: Tomas Vondra <tomas@vondra.me> Reviewed-by: Junwang Zhao <zhjwpku@gmail.com> Discussion: https://postgr.es/m/CA+HiwqFGkMSge6TgC9KQzde0ohpAycLQuV7ooitEEpbKB0O_mg@mail.gmail.com	4 months ago
Michael Paquier	ce5bcc4a9f	pg_stat_statements: Add wal_buffers_full ... wal_buffers_full tracks the number of times WAL buffers become full, giving hints to be able to tune the GUC wal_buffers. Up to now, this information was only available in pg_stat_wal. With this field available in WalUsage since eaf502747b, exposing it in pg_stat_statements is straight-forward, and it offers more granularity at query level. pg_stat_statements does not need a version bump as one has been done in commit cf54a2c002 for this development cycle. Author: Bertrand Drouvot Reviewed-by: Ilia Evdokimov Discussion: https://postgr.es/m/Z6SOha5YFFgvpwQY@ip-10-97-1-34.eu-west-3.compute.internal	4 months ago
Bruce Momjian	50e6eb731d	Update copyright for 2025 ... Backpatch-through: 13	6 months ago
Michael Paquier	7f97b4734f	Fix some comments related to library unloading ... Library unloading has never been supported with its code removed in ab02d702ef, and there were some comments still mentioning that it was a possible operation. ChangAo has noticed the incorrect references in dfmgr.c, while I have noticed the other ones while scanning the rest of the tree for similar mistakes. Author: ChangAo Chen, Michael Paquier Reviewed-by: Tom Lane Discussion: https://postgr.es/m/tencent_1D09840A1632D406A610C8C4E2491D74DB0A@qq.com	6 months ago
David Rowley	89988ac589	Fix further fallout from EXPLAIN ANALYZE BUFFERS change ... c2a4078eb adjusted EXPLAIN ANALYZE to default the BUFFERS to ON. This (hopefully) fixes the last remaining issue with regression test failures with -D RELCACHE_FORCE_RELEASE -D CATCACHE_FORCE_RELEASE builds, where the planner accesses more buffers due to the cold caches. Discussion: https://postgr.es/m/CAApHDvqLdzgz77JsE-yTki3w9UiKQ-uTMLRctazcu+99-ips3g@mail.gmail.com	7 months ago
Tom Lane	3eea7a0c97	Simplify executor's determination of whether to use parallelism. ... Our parallel-mode code only works when we are executing a query in full, so ExecutePlan must disable parallel mode when it is asked to do partial execution. The previous logic for this involved passing down a flag (variously named execute_once or run_once) from callers of ExecutorRun or PortalRun. This is overcomplicated, and unsurprisingly some of the callers didn't get it right, since it requires keeping state that not all of them have handy; not to mention that the requirements for it were undocumented. That led to assertion failures in some corner cases. The only state we really need for this is the existing QueryDesc.already_executed flag, so let's just put all the responsibility in ExecutePlan. (It could have been done in ExecutorRun too, leading to a slightly shorter patch -- but if there's ever more than one caller of ExecutePlan, it seems better to have this logic in the subroutine than the callers.) This makes those ExecutorRun/PortalRun parameters unnecessary. In master it seems okay to just remove them, returning the API for those functions to what it was before parallelism. Such an API break is clearly not okay in stable branches, but for them we can just leave the parameters in place after documenting that they do nothing. Per report from Yugo Nagata, who also reviewed and tested this patch. Back-patch to all supported branches. Discussion: https://postgr.es/m/20241206062549.710dc01cf91224809dd6c0e1@sraoss.co.jp	7 months ago
Michael Paquier	5d4298e75f	pg_stat_statements: Avoid some locking during PGSS entry scans ... A single PGSS entry's spinlock is used to be able to modify "counters" without holding pgss->lock exclusively, as mentioned at the top of pg_stat_statements.c and within pgssEntry. Within a single pgssEntry, stats_since and minmax_stats_since are never modified without holding pgss->lock exclusively, so there is no need to hold an entry's spinlock when reading stats_since and minmax_stats_since, as done when scanning all the PGSS entries for function calls of pg_stat_statements(). This also restores the consistency between the code and the comments about the entry's spinlock usage. This change is a performance improvement (it can be argued that this is a logic bug), so there is no need for a backpatch. This saves two instructions from being read while holding an entry's spinlock. Author: Karina Litskevich Reviewed-by: Michael Paquier, wenhui qiu Discussion: https://postgr.es/m/CACiT8ibhCmzbcOxM0v4pRLH3abk-95LPkt7_uC2JMP+miPjxsg@mail.gmail.com	8 months ago
Peter Eisentraut	9be4e5d293	Remove unused #include's from contrib, pl, test .c files ... as determined by IWYU Similar to commit dbbca2cf29, but for contrib, pl, and src/test/. Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Discussion: https://www.postgresql.org/message-id/flat/0df1d5b1-8ca8-4f84-93be-121081bde049%40eisentraut.org	8 months ago
Michael Paquier	6b652e6ce8	Set query ID for inner queries of CREATE TABLE AS and DECLARE ... Some utility statements contain queries that can be planned and executed: CREATE TABLE AS and DECLARE CURSOR. This commit adds query ID computation for the inner queries executed by these two utility commands, with and without EXPLAIN. This change leads to four new callers of JumbleQuery() and post_parse_analyze_hook() so as extensions can decide what to do with this new data. Previously, extensions relying on the query ID, like pg_stat_statements, were not able to track these nested queries as the query_id was 0. For pg_stat_statements, this commit leads to additions under !toplevel when pg_stat_statements.track is set to "all", as shown in its regression tests. The output of EXPLAIN for these two utilities gains a "Query Identifier" if compute_query_id is enabled. Author: Anthonin Bonnefoy Reviewed-by: Michael Paquier, Jian He Discussion: https://postgr.es/m/CAO6_XqqM6S9bQ2qd=75W+yKATwoazxSNhv5sjW06fjGAtHbTUA@mail.gmail.com	8 months ago
Michael Paquier	499edb0974	Track more precisely query locations for nested statements ... 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 45e0ba30fc 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	8 months ago
Tom Lane	14e5680eee	Improve parser's reporting of statement start locations. ... Up to now, the parser's reporting of a statement's stmt_location included any preceding whitespace or comments. This isn't really desirable but was done to avoid accounting honestly for nonterminals that reduce to empty. It causes problems for pg_stat_statements, which partially compensates by manually stripping whitespace, but is not bright enough to strip /*-style comments. There will be more problems with an upcoming patch to improve reporting of errors in extension scripts, so it's time to do something about this. The thing we have to do to make it work right is to adjust YYLLOC_DEFAULT to scan the inputs of each production to find the first one that has a valid location (i.e., did not reduce to empty). In theory this adds a little bit of per-reduction overhead, but in practice it's negligible. I checked by measuring the time to run raw_parser() on the contents of information_schema.sql, and there was basically no change. Having done that, we can rely on any nonterminal that didn't reduce to completely empty to have a correct starting location, and we don't need the kluges the stmtmulti production formerly used. This should have a side benefit of allowing parse error reports to include an error position in some cases where they formerly failed to do so, due to trying to report the position of an empty nonterminal. I did not go looking for an example though. The one previously known case where that could happen (OptSchemaEltList) no longer needs the kluge it had; but I rather doubt that that was the only case. Discussion: https://postgr.es/m/ZvV1ClhnbJLCz7Sm@msg.df7cb.de	8 months ago
Michael Paquier	45e0ba30fc	pg_stat_statements: Add tests for nested queries with level tracking ... There have never been any regression tests in PGSS for various query patterns for nested queries combined with level tracking, like: - Multi-statements. - CREATE TABLE AS - CREATE/REFRESH MATERIALIZED VIEW - DECLARE CURSOR - EXPLAIN, with a subset of the above supported. - COPY. All the tests added here track historical, sometimes confusing, existing behaviors. For example, EXPLAIN stores two PGSS entries with the same top-level query string but two different query IDs as one is calculated for the top-level EXPLAIN (this part is right) and a second one for the inner query in the EXPLAIN (this part is not right). A couple of patches are under discussion to improve the situation, and all the tests added here will prove useful to evaluate the changes discussed. Author: Anthonin Bonnefoy Reviewed-by: Michael Paquier, Jian He Discussion: https://postgr.es/m/CAO6_XqqM6S9bQ2qd=75W+yKATwoazxSNhv5sjW06fjGAtHbTUA@mail.gmail.com	8 months ago
Michael Paquier	cf54a2c002	pg_stat_statements: Add columns to track parallel worker activity ... The view pg_stat_statements gains two columns: - parallel_workers_to_launch, the number of parallel workers planned to be launched. - parallel_workers_launched, the number of parallel workers actually launched. The ratio of both columns offers hints that parallel workers are lacking on a per-statement basis, requiring some tuning, in coordination with "calls", the number of times a query is executed. As of now, these numbers are tracked within Gather and GatherMerge nodes. They could be extended to utilities that make use of parallel workers (parallel btree and brin, VACUUM). The module is bumped to 1.12. Author: Guillaume Lelarge Discussion: https://postgr.es/m/CAECtzeWtTGOK0UgKXdDGpfTVSa5bd_VbUt6K6xn8P7X+_dZqKw@mail.gmail.com	9 months ago
Peter Eisentraut	10b721821d	Use macro to define the number of enum values ... Refactoring in the interest of code consistency, a follow-up to 2e068db56e. The argument against inserting a special enum value at the end of the enum definition is that a switch statement might generate a compiler warning unless it has a default clause. Aleksander Alekseev, reviewed by Michael Paquier, Dean Rasheed, Peter Eisentraut Discussion: https://postgr.es/m/CAJ7c6TMsiaV5urU_Pq6zJ2tXPDwk69-NKVh4AMN5XrRiM7N%2BGA%40mail.gmail.com	9 months ago
Michael Paquier	dc68515968	Show values of SET statements as constants in pg_stat_statements ... This is a continuation of work like 11c34b342b, done to reduce the bloat of pg_stat_statements by applying more normalization to query entries. This commit is able to detect and normalize values in VariableSetStmt, resulting in: SET conf_param = $1 Compared to other parse nodes, VariableSetStmt is embedded in much more places in the parser, impacting many query patterns in pg_stat_statements. A custom jumble function is used, with an extra field in the node to decide if arguments should be included in the jumbling or not, a location field being not enough for this purpose. This approach allows for a finer tuning. Clauses relying on one or more keywords are not normalized, for example: * DEFAULT * FROM CURRENT * List of keywords. SET SESSION CHARACTERISTICS AS TRANSACTION, where it is critical to differentiate different sets of options, is a good example of why normalization should not happen. Some queries use VariableSetStmt for some subclauses with SET, that also have their values normalized: - ALTER DATABASE - ALTER ROLE - ALTER SYSTEM - CREATE/ALTER FUNCTION ba90eac7a9 has added test coverage for most of the existing SET patterns. The expected output of these tests shows the difference this commit creates. Normalization could be perhaps applied to more portions of the grammar but what is done here is conservative, and good enough as a starting point. Author: Greg Sabino Mullane, Michael Paquier Discussion: https://postgr.es/m/36e5bffe-e989-194f-85c8-06e7bc88e6f7@amazon.com Discussion: https://postgr.es/m/B44FA29D-EBD0-4DD9-ABC2-16F1CB087074@amazon.com Discussion: https://postgr.es/m/CAKAnmmJtJY2jzQN91=2QAD2eAJAA-Per61eyO48-TyxEg-q0Rg@mail.gmail.com	9 months ago
Michael Paquier	ba90eac7a9	pg_stat_statements: Expand tests for SET statements ... There are many grammar flavors that depend on the parse node VariableSetStmt. This closes the gap in pg_stat_statements by providing test coverage for what should be a large majority of them, improving more the work begun in de2aca2885. This will be used to ease the evaluation of a path towards more normalization of SET queries with query jumbling. Note that SET NAMES (grammar from the standard, synonym of SET client_encoding) is omitted on purpose, this could use UTF8 with a conditional script where UTF8 is supported, but that does not seem worth the maintenance cost for the sake of these tests. The author has submitted most of these in a TAP test (filled in any holes I could spot), still queries in a SQL file of pg_stat_statements is able to achieve the same goal while being easier to look at when testing normalization patterns. Author: Greg Sabino Mullane, Michael Paquier Discussion: https://postgr.es/m/CAKAnmmJtJY2jzQN91=2QAD2eAJAA-Per61eyO48-TyxEg-q0Rg@mail.gmail.com	9 months ago
Michael Paquier	933848d16d	Add missing query ID reporting in extended query protocol ... This commit adds query ID reports for two code paths when processing extended query protocol messages: - When receiving a bind message, setting it to the first Query retrieved from a cached cache. - When receiving an execute message, setting it to the first PlannedStmt stored in a portal. An advantage of this method is that this is able to cover all the types of portals handled in the extended query protocol, particularly these two when the report done in ExecutorStart() is not enough (neither is an addition in ExecutorRun(), actually, for the second point): - Multiple execute messages, with multiple ExecutorRun(). - Portal with execute/fetch messages, like a query with a RETURNING clause and a fetch size that stores the tuples in a first execute message going though ExecutorStart() and ExecuteRun(), followed by one or more execute messages doing only fetches from the tuplestore created in the first message. This corresponds to the case where execute_is_fetch is set, for example. Note that the query ID reporting done in ExecutorStart() is still necessary, as an EXECUTE requires it. Query ID reporting is optimistic and more calls to pgstat_report_query_id() don't matter as the first report takes priority except if the report is forced. The comment in ExecutorStart() is adjusted to reflect better the reality with the extended query protocol. The test added in pg_stat_statements is a courtesy of Robert Haas. This uses psql's \bind metacommand, hence this part is backpatched down to v16. Reported-by: Kaido Vaikla, Erik Wienhold Author: Sami Imseih Reviewed-by: Jian He, Andrei Lepikhov, Michael Paquier Discussion: https://postgr.es/m/CA+427g8DiW3aZ6pOpVgkPbqK97ouBdf18VLiHFesea2jUk3XoQ@mail.gmail.com Discussion: https://postgr.es/m/CA+TgmoZxtnf_jZ=VqBSyaU8hfUkkwoJCJ6ufy4LGpXaunKrjrg@mail.gmail.com Discussion: https://postgr.es/m/1391613709.939460.1684777418070@office.mailbox.org Backpatch-through: 14	9 months ago
Tom Lane	94537982ec	Remove obsolete comment in pg_stat_statements. ... Commit 76db9cb63 removed the use of multiple nesting counters, but missed one comment describing that arrangement. Back-patch to v17 where 76db9cb63 came in, just to avoid confusion. Julien Rouhaud Discussion: https://postgr.es/m/gfcwh3zjxc2vygltapgo7g6yacdor5s4ynr234b6v2ohhuvt7m@gr42joxalenw	10 months ago
Michael Paquier	7b1ddbae36	pg_stat_statements: Add tests with extended query protocol ... There are currently no tests in the tree checking that queries using the extended query protocol are able to map with their query ID. This can be achieved for some paths of the extended query protocol with the psql meta-commands \bind or \bind_named, so let's add some tests based on both. I have found that to be a useful addition while working on a different issue. Discussion: https://postgr.es/m/ZuEt6MOEBSlifBfn@paquier.xyz	10 months ago
Nathan Bossart	8928817769	Remove volatile qualifiers from pg_stat_statements.c. ... Prior to commit 0709b7ee72, which changed the spinlock primitives to function as compiler barriers, access to variables within a spinlock-protected section required using a volatile pointer, but that is no longer necessary. Reviewed-by: Bertrand Drouvot, Michael Paquier Discussion: https://postgr.es/m/Zqkv9iK7MkNS0KaN%40nathan	11 months ago
Fujii Masao	97f2bc5aa5	pg_stat_statements: Add regression test for privilege handling. ... This commit adds a regression test to verify that pg_stat_statements correctly handles privileges, improving its test coverage. Author: Keisuke Kuroda Reviewed-by: Michael Paquier, Fujii Masao Discussion: https://postgr.es/m/2224ccf2e12c41ccb81702ef3303d5ac@nttcom.co.jp	11 months ago
Michael Paquier	c145f321b6	Propagate query IDs of utility statements in functions ... For utility statements defined within a function, the query tree is copied to a PlannedStmt as utility commands do not require planning. However, the query ID was missing from the information passed down. This leads to plugins relying on the query ID like pg_stat_statements to not be able to track utility statements within function calls. Tests are added to check this behavior, depending on pg_stat_statements.track. This is an old bug. Now, query IDs for utilities are compiled using their parsed trees rather than the query string since v16 (3db72ebcbe), leading to less bloat with utilities, so backpatch down only to this version. Author: Anthonin Bonnefoy Discussion: https://postgr.es/m/CAO6_XqrGp-uwBqi3vBPLuRULKkddjC7R5QZCgsFren=8E+m2Sg@mail.gmail.com Backpatch-through: 16	11 months ago
Peter Eisentraut	17974ec259	Revise GUC names quoting in messages again ... After further review, we want to move in the direction of always quoting GUC names in error messages, rather than the previous (PG16) wildly mixed practice or the intermittent (mid-PG17) idea of doing this depending on how possibly confusing the GUC name is. This commit applies appropriate quotes to (almost?) all mentions of GUC names in error messages. It partially supersedes a243569bf6 and 8d9978a717, which had moved things a bit in the opposite direction but which then were abandoned in a partial state. Author: Peter Smith <smithpb2250@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/CAHut%2BPv-kSN8SkxSdoHano_wPubqcg5789ejhCDZAcLFceBR-w%40mail.gmail.com	1 year ago
Nathan Bossart	3b42bdb471	Use new overflow-safe integer comparison functions. ... Commit 6b80394781 introduced integer comparison functions designed to be as efficient as possible while avoiding overflow. This commit makes use of these functions in many of the in-tree qsort() comparators to help ensure transitivity. Many of these comparator functions should also see a small performance boost. Author: Mats Kindahl Reviewed-by: Andres Freund, Fabrízio de Royes Mello Discussion: https://postgr.es/m/CA%2B14426g2Wa9QuUpmakwPxXFWG_1FaY0AsApkvcTBy-YfS6uaw%40mail.gmail.com	1 year ago
Bruce Momjian	29275b1d17	Update copyright for 2024 ... Reported-by: Michael Paquier Discussion: https://postgr.es/m/ZZKTDPxBBMt3C0J9@paquier.xyz Backpatch-through: 12	2 years ago
Peter Eisentraut	8ce5aef2e6	Make Perl warnings fatal in newly added TAP tests ... New TAP tests added by commits 9a17be1e and 4710b67d missed to convert warnings to FATAL. This commit fixes that. Author: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>	2 years ago
Peter Eisentraut	1141e29b61	Revert "pg_stat_statements: Add coverage for entry_dealloc()" ... This reverts commit 742f6b3e6d. The new test failed on big-endian platforms. Discussion: https://www.postgresql.org/message-id/flat/40d1e4f2-835f-448f-a541-8ff5db75bf3d@eisentraut.org	2 years ago
Peter Eisentraut	4710b67d4d	pg_stat_statements: Add TAP test for testing restarts ... This tests that pg_stat_statement contents are successfully kept across restart. (This similar to src/test/recovery/t/029_stats_restart.pl for the stats collector.) Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Julien Rouhaud <rjuju123@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/40d1e4f2-835f-448f-a541-8ff5db75bf3d@eisentraut.org	2 years ago
Peter Eisentraut	742f6b3e6d	pg_stat_statements: Add coverage for entry_dealloc() ... This involves creating more than pg_stat_statements.max entries and checking that the limit is kept and the least used entries are kicked out. Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Julien Rouhaud <rjuju123@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/40d1e4f2-835f-448f-a541-8ff5db75bf3d@eisentraut.org	2 years ago
Peter Eisentraut	3e527aeeed	pg_stat_statements: Add test coverage for pg_stat_statements_reset_1_7 ... Run pg_stat_statements_reset() once while the appropriate extension version is installed. Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/40d1e4f2-835f-448f-a541-8ff5db75bf3d@eisentraut.org	2 years ago
Peter Eisentraut	3727b8d0e3	pg_stat_statements: Add test coverage for pg_stat_statements_1_8() ... This requires reading pg_stat_statements at least once while the 1.8 version of the extension is installed. Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://www.postgresql.org/message-id/flat/40d1e4f2-835f-448f-a541-8ff5db75bf3d@eisentraut.org	2 years ago
Alexander Korotkov	dc9f8a7983	Track statement entry timestamp in contrib/pg_stat_statements ... This patch adds 'stats_since' and 'minmax_stats_since' columns to the pg_stat_statements view and pg_stat_statements() function. The new min/max reset mode for the pg_stat_stetments_reset() function is controlled by the parameter minmax_only. 'stat_since' column is populated with the current timestamp when a new statement is added to the pg_stat_statements hashtable. It provides clean information about statistics collection time intervals for each statement. Besides it can be used by sampling solutions to detect situations when a statement was evicted and stored again between samples. Such a sampling solution could derive any pg_stat_statements statistic values for an interval between two samples with the exception of all min/max statistics. To address this issue this patch adds the ability to reset min/max statistics independently of the statement reset using the new minmax_only parameter of the pg_stat_statements_reset(userid oid, dbid oid, queryid bigint, minmax_only boolean) function. The timestamp of such reset is stored in the minmax_stats_since field for each statement. pg_stat_statements_reset() function now returns the timestamp of a reset as the result. Discussion: https://postgr.es/m/flat/72e80e7b160a6eb189df9ef6f068cce3765d37f8.camel%40moonset.ru Author: Andrei Zubkov Reviewed-by: Julien Rouhaud, Hayato Kuroda, Yuki Seino, Chengxi Sun Reviewed-by: Anton Melnikov, Darren Rush, Michael Paquier, Sergei Kornilov Reviewed-by: Alena Rybakina, Andrei Lepikhov	2 years ago
Alexander Korotkov	6ab1dbd26b	Add NOT NULL checking of pg_stat_statements_reset() in tests ... This is preliminary patch. It adds NOT NULL checking for the result of pg_stat_statements_reset() function. It is needed for upcoming patch "Track statement entry timestamp" that will change the result type of this function to the timestamp of a reset performed. Discussion: https://postgr.es/m/flat/72e80e7b160a6eb189df9ef6f068cce3765d37f8.camel%40moonset.ru Author: Andrei Zubkov Reviewed-by: Julien Rouhaud, Hayato Kuroda, Yuki Seino, Chengxi Sun Reviewed-by: Anton Melnikov, Darren Rush, Michael Paquier, Sergei Kornilov Reviewed-by: Alena Rybakina, Andrei Lepikhov	2 years ago
Michael Paquier	108161bcb9	pg_stat_statements: Remove duplicated tests for SET statements ... This looks like a copy-paste mistake introduced in de2aca2885, that has added checks for more patterns of SET statements while ignoring the original test block that existed. Backpatch down to where this has been introduced, as this shaves some cycles. Author: Sergei Kornilov Discussion: https://postgr.es/m/5689421699428803@mail-sendbernar-production-main-46.myt.yp-c.yandex.net Backpatch-through: 16	2 years ago