475 Commits (c65bc2e1d14a2d4daed7c1921ac518f2c5ac3d17)

Author	SHA1	Message	Date
Robert Haas	c65bc2e1d1	Make it possible for loadable modules to add EXPLAIN options. ... 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>	9 months ago
Tom Lane	8b1b342544	Improve EXPLAIN's display of window functions. ... 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	10 months ago
Peter Geoghegan	0fbceae841	Show index search count in EXPLAIN ANALYZE, take 2. ... 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	10 months ago
Peter Geoghegan	d00107cd63	Revert "Show index search count in EXPLAIN ANALYZE." ... This reverts commit 5ead85fbc8. This commit shows test failures with debug_parallel_query=regress. The underlying issue needs to be debugged, so revert for now.	10 months ago
Peter Geoghegan	5ead85fbc8	Show index search count in EXPLAIN ANALYZE. ... Expose the count of index searches/index descents in EXPLAIN ANALYZE's output for index scan nodes. This information is particularly useful with scans that use ScalarArrayOp quals, where the number of index scans isn't predictable in advance (at least not with optimizations like the one added to nbtree by Postgres 17 commit 5bf748b8). It will also be useful when EXPLAIN ANALYZE shows details of an nbtree index scan that uses skip scan optimizations set to be introduced by an upcoming patch. The instrumentation works by teaching 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 must already increment the index's pg_stat_*_indexes.idx_scan counter (we're counting the same event, but at the scan level rather than the relation level). The new counter is stored in the scan descriptor (IndexScanDescData), which explain.c reaches by going through the scan node's PlanState. This approach doesn't match the approach used when tracking other index scan specific costs (e.g., "Rows Removed by Filter:"). It is similar to the approach used in other cases where we must track costs that are only readily accessible inside an access method, and not from the executor (e.g., "Heap Blocks:" output for a Bitmap Heap Scan). It is inherently necessary to maintain a counter that can be incremented multiple times during a single amgettuple call (or amgetbitmap call), and directly exposing PlanState.instrument to index access methods seems unappealing. Author: Peter Geoghegan <pg@bowt.ie> Reviewed-By: Tomas Vondra <tomas@vondra.me> Reviewed-By: Robert Haas <robertmhaas@gmail.com> Reviewed-By: Masahiro Ikeda <ikedamsh@oss.nttdata.com> Reviewed-By: Matthias van de Meent <boekewurm+postgres@gmail.com> Discussion: https://postgr.es/m/CAH2-Wz=PKR6rB7qbx+Vnd7eqeB5VTcrW=iJvAsTsKbdG+kW_UA@mail.gmail.com Discussion: https://postgr.es/m/CAH2-WzkRqvaqR2CTNqTZP0z6FuL4-3ED6eQB0yx38XBNj1v-4Q@mail.gmail.com	10 months ago
Robert Haas	51d3e279c3	Fix missing space in EXPLAIN ANALYZE output. ... Commit ddb17e387a introduced this regression. Ideally, the regression tests would have caught this mistake, but apparently they don't test with timing enabled, presumably because that would make the output vary. Author: Thom Brown <thom@linux.com> Reviewed-by: Fabrízio de Royes Mello <fabriziomello@gmail.com> Discussion: http://postgr.es/m/CAA-aLv6nq=UeiyvM7_Mxgo9TVBzs2oh46b9vfyLzuyVEz3j1-g@mail.gmail.com	10 months ago
Robert Haas	555960a0fb	Create explain_dr.c and move DestReceiver-related code there. ... explain.c has grown rather large, and the code that deals with the DestReceiver that supports the SERIALIZE option is pretty easily severable from the rest of explain.c; hence, move it to a separate file. Reviewed-by: Peter Geoghegan <pg@bowt.ie> Discussion: http://postgr.es/m/CA+TgmoYutMw1Jgo8BWUmB3TqnOhsEAJiYO=rOQufF4gPLWmkLQ@mail.gmail.com	10 months ago
Robert Haas	9173e8b604	Create explain_format.c and move relevant code there. ... explain.c has grown rather large, so move various functions that are principally concerned with output generation to a new source file, explain_format.c, instead of lumping them in with everything else that is part of explain.c Reviewed-by: Peter Geoghegan <pg@bowt.ie> Discussion: http://postgr.es/m/CA+TgmoYutMw1Jgo8BWUmB3TqnOhsEAJiYO=rOQufF4gPLWmkLQ@mail.gmail.com	10 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	10 months ago
Robert Haas	ddb17e387a	Allow EXPLAIN to indicate fractional rows. ... When nloops > 1, we now display two digits after the decimal point, rather than none. This is important because what we print is actually planstate->instrument->ntuples / nloops, and sometimes what you want to know is planstate->instrument->ntuples. You can estimate that by multiplying the displayed row count by the displayed nloops value, but the fact that the displayed value is rounded makes that inexact. It's still inexact even if we show these two extra decimal places, but less so. Perhaps we will agree on a way to further improve this output later, but for now this seems better than doing nothing. Author: Ibrar Ahmed <ibrar.ahmad@gmail.com> Author: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com> Reviewed-by: David G. Johnston <david.g.johnston@gmail.com> Reviewed-by: Amit Kapila <amit.kapila16@gmail.com> Reviewed-by: Vignesh C <vignesh21@gmail.com> Reviewed-by: Greg Stark <stark@mit.edu> Reviewed-by: Naeem Akhter <akhternaeem@gmail.com> Reviewed-by: Hamid Akhtar <hamid.akhtar@percona.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Andrei Lepikhov <a.lepikhov@postgrespro.ru> Reviewed-by: Guillaume Lelarge <guillaume@lelarge.info> Reviewed-by: Matheus Alcantara <matheusssilv97@gmail.com> Reviewed-by: Alena Rybakina <a.rybakina@postgrespro.ru> Discussion: http://postgr.es/m/603c8f070905281830g2e5419c4xad2946d149e21f9d%40mail.gmail.com	10 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	10 months ago
Michael Paquier	320545bfcf	Add information about WAL buffers being full to EXPLAIN (WAL) ... This is similar to ce5bcc4a9f, relying on the addition of wal_buffers_full to WalUsage. This time, the information is added to the output generated by EXPLAIN (WAL). Author: Bertrand Drouvot Reviewed-by: Ilia Evdokimov Discussion: https://postgr.es/m/Z6SOha5YFFgvpwQY@ip-10-97-1-34.eu-west-3.compute.internal	10 months ago
David Rowley	11012c5037	Fix an assortment of spelling mistakes and typos ... Author: Alexander Lakhin <exclusion@gmail.com> Discussion: https://postgr.es/m/5812a0b9-b0cf-4151-9a14-d9f00e4f2858@gmail.com	12 months ago
Bruce Momjian	50e6eb731d	Update copyright for 2025 ... Backpatch-through: 13	12 months ago
David Rowley	c2a4078eba	Enable BUFFERS with EXPLAIN ANALYZE by default ... The topic of turning EXPLAIN's BUFFERS option on with the ANALYZE option has come up a few times over the past few years. In many ways, doing this seems like a good idea as it may be more obvious to users why a given query is running more slowly than they might expect. Also, from my own (David's) personal experience, I've seen users posting to the mailing lists with two identical plans, one slow and one fast asking why their query is sometimes slow. In many cases, this is due to additional reads. Having BUFFERS on by default may help reduce some of these questions, and if not, make it more obvious to the user before they post, or save a round-trip to the mailing list when additional I/O effort is the cause of the slowness. The general consensus is that we want BUFFERS on by default with ANALYZE. However, there were more than zero concerns raised with doing so. The primary reason against is the additional verbosity, making it harder to read large plans. Another concern was that buffer information isn't always useful so may not make sense to have it on by default. It's currently December, so let's commit this to see if anyone comes forward with a strong objection against making this change. We have over half a year remaining in the v18 cycle where we could still easily consider reverting this if someone were to come forward with a convincing enough reason as to why doing this is a bad idea. There were two patches independently submitted to achieve this goal, one by me and the other by Guillaume. This commit is a mix of both of these patches with some additional work done by me to adjust various additional places in the documentation which include EXPLAIN ANALYZE output. Author: Guillaume Lelarge, David Rowley Reviewed-by: Robert Haas, Greg Sabino Mullane, Michael Christofides Discussion: https://postgr.es/m/CANNMO++W7MM8T0KyXN3ZheXXt-uLVM3aEtZd+WNfZ=obxffUiA@mail.gmail.com	1 year 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	1 year ago
Álvaro Herrera	da94e871e8	Unify repetitive error messages	1 year 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	1 year ago
David Rowley	161320b4b9	Adjust EXPLAIN's output for disabled nodes ... c01743aa4 added EXPLAIN output to display the plan node's disabled_node count whenever that count is above 0. Seemingly, there weren't many people who liked that output as each parent of a disabled node would also have a "Disabled Nodes" output due to the way disabled_nodes is accumulated towards the root plan node. It was often hard and sometimes impossible to figure out which nodes were disabled from looking at EXPLAIN. You might think it would be possible to manually add up the numbers from the "Disabled Nodes" output of a given node's children to figure out if that node has a higher disabled_nodes count than its children, but that wouldn't have worked for Append and Merge Append nodes if some disabled child nodes were run-time pruned during init plan. Those children are not displayed in EXPLAIN. Here we attempt to improve this output by only showing "Disabled: true" against only the nodes which are explicitly disabled themselves. That seems to be the output that's desired by the most people who voiced their opinion. This is done by summing up the disabled_nodes of the given node's children and checking if that number is less than the disabled_nodes of the current node. This commit also fixes a bug in make_sort() which was neglecting to set the Sort's disabled_nodes field. This should have copied what was done in cost_sort(), but it hadn't been updated. With the new output, the choice to not maintain that field properly was clearly wrong as the disabled-ness of the node was attributed to the Sort's parent instead. Reviewed-by: Laurenz Albe, Alena Rybakina Discussion: https://postgr.es/m/9e4ad616bebb103ec2084bf6f724cfc739e7fabb.camel@cybertec.at	1 year ago
Tatsuo Ishii	40708acd65	Add memory/disk usage for more executor nodes. ... This commit is similar to 95d6e9af07, expanding the idea to CTE scan, table function scan and recursive union scan nodes so that the maximum tuplestore memory or disk usage is shown with EXPLAIN ANALYZE command. Also adjust show_storage_info() so that it accepts storage type and storage size arguments instead of Tuplestorestate. This allows the node types to share the formatting code using show_storage_info(). Due to this show_material_info() and show_windowagg_info() are also modified. Reviewed-by: David Rowley Discussion: https://postgr.es/m/20240918.211246.1127161704188186085.ishii%40postgresql.org	1 year ago
Tatsuo Ishii	95d6e9af07	Add memory/disk usage for Window aggregate nodes in EXPLAIN. ... This commit is similar to 1eff8279d and expands the idea to Window aggregate nodes so that users can know how much memory or disk the tuplestore used. This commit uses newly introduced tuplestore_get_stats() to inquire this information and add some additional output in EXPLAIN ANALYZE to display the information for the Window aggregate node. Reviewed-by: David Rowley, Ashutosh Bapat, Maxim Orlov, Jian He Discussion: https://postgr.es/m/20240706.202254.89740021795421286.ishii%40postgresql.org	1 year ago
David Rowley	9fba1ed294	Adjust tuplestore stats API ... 1eff8279d added an API to tuplestore.c to allow callers to obtain storage telemetry data. That API wasn't quite good enough for callers that perform tuplestore_clear() as the telemetry functions only accounted for the current state of the tuplestore, not the maximums before tuplestore_clear() was called. There's a pending patch that would like to add tuplestore telemetry output to EXPLAIN ANALYZE for WindowAgg. That node type uses tuplestore_clear() before moving to the next window partition and we want to show the maximum space used, not the space used for the final partition. Reviewed-by: Tatsuo Ishii, Ashutosh Bapat Discussion: https://postgres/m/CAApHDvoY8cibGcicLV0fNh=9JVx9PANcWvhkdjBnDCc9Quqytg@mail.gmail.com	1 year ago
Richard Guo	247dea89f7	Introduce an RTE for the grouping step ... If there are subqueries in the grouping expressions, each of these subqueries in the targetlist and HAVING clause is expanded into distinct SubPlan nodes. As a result, only one of these SubPlan nodes would be converted to reference to the grouping key column output by the Agg node; others would have to get evaluated afresh. This is not efficient, and with grouping sets this can cause wrong results issues in cases where they should go to NULL because they are from the wrong grouping set. Furthermore, during re-evaluation, these SubPlan nodes might use nulled column values from grouping sets, which is not correct. This issue is not limited to subqueries. For other types of expressions that are part of grouping items, if they are transformed into another form during preprocessing, they may fail to match lower target items. This can also lead to wrong results with grouping sets. To fix this issue, we introduce a new kind of RTE representing the output of the grouping step, with columns that are the Vars or expressions being grouped on. In the parser, we replace the grouping expressions in the targetlist and HAVING clause with Vars referencing this new RTE, so that the output of the parser directly expresses the semantic requirement that the grouping expressions be gotten from the grouping output rather than computed some other way. In the planner, we first preprocess all the columns of this new RTE and then replace any Vars in the targetlist and HAVING clause that reference this new RTE with the underlying grouping expressions, so that we will have only one instance of a SubPlan node for each subquery contained in the grouping expressions. Bump catversion because this changes the querytree produced by the parser. Thanks to Tom Lane for the idea to invent a new kind of RTE. Per reports from Geoff Winkless, Tobias Wendorff, Richard Guo from various threads. Author: Richard Guo Reviewed-by: Ashutosh Bapat, Sutou Kouhei Discussion: https://postgr.es/m/CAMbWs4_dp7e7oTwaiZeBX8+P1rXw4ThkZxh1QG81rhu9Z47VsQ@mail.gmail.com	1 year ago
Robert Haas	c01743aa48	Show number of disabled nodes in EXPLAIN ANALYZE output. ... Now that disable_cost is not included in the cost estimate, there's no visible sign in EXPLAIN output of which plan nodes are disabled. Fix that by propagating the number of disabled nodes from Path to Plan, and then showing it in the EXPLAIN output. There is some question about whether this is a desirable change. While I personally believe that it is, it seems best to make it a separate commit, in case we decide to back out just this part, or rework it. Reviewed by Andres Freund, Heikki Linnakangas, and David Rowley. Discussion: http://postgr.es/m/CA+TgmoZ_+MS+o6NeGK2xyBv-xM+w1AfFVuHE4f_aq6ekHv7YSQ@mail.gmail.com	1 year ago
Nathan Bossart	a99cc6c6b4	Use PqMsg_* macros in more places. ... Commit f4b54e1ed9, which introduced macros for protocol characters, missed updating a few places. It also did not introduce macros for messages sent from parallel workers to their leader processes. This commit adds a new section in protocol.h for those. Author: Aleksander Alekseev Discussion: https://postgr.es/m/CAJ7c6TNTd09AZq8tGaHS3LDyH_CCnpv0oOz2wN1dGe8zekxrdQ%40mail.gmail.com Backpatch-through: 17	1 year ago
David Rowley	5a1e6df3b8	Show Parallel Bitmap Heap Scan worker stats in EXPLAIN ANALYZE ... Nodes like Memoize report the cache stats for each parallel worker, so it makes sense to show the exact and lossy pages in Parallel Bitmap Heap Scan in a similar way. Likewise, Sort shows the method and memory used for each worker. There was some discussion on whether the leader stats should include the totals for each parallel worker or not. I did some analysis on this to see what other parallel node types do and it seems only Parallel Hash does anything like this. All the rest, per what's supported by ExecParallelRetrieveInstrumentation() are consistent with each other. Author: David Geier <geidav.pg@gmail.com> Author: Heikki Linnakangas <hlinnaka@iki.fi> Author: Donghang Lin <donghanglin@gmail.com> Author: Alena Rybakina <lena.ribackina@yandex.ru> Author: David Rowley <dgrowleyml@gmail.com> Reviewed-by: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Michael Christofides <michael@pgmustard.com> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com> Reviewed-by: Tomas Vondra <tomas.vondra@enterprisedb.com> Reviewed-by: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Donghang Lin <donghanglin@gmail.com> Reviewed-by: Masahiro Ikeda <Masahiro.Ikeda@nttdata.com> Discussion: https://postgr.es/m/b3d80961-c2e5-38cc-6a32-61886cdf766d%40gmail.com	1 year ago
David Rowley	7340d9362a	Widen lossy and exact page counters for Bitmap Heap Scan ... Both of these counters were using the "long" data type. On MSVC that's a 32-bit type. On modern hardware, I was able to demonstrate that we can wrap those counters with a query that only takes 15 minutes to run. This issue may manifest itself either by not showing the values of the counters because they've wrapped and are less than zero, resulting in them being filtered by the > 0 checks in show_tidbitmap_info(), or bogus numbers being displayed which are modulus 2^32 of the actual number. Widen these counters to uint64. Discussion: https://postgr.es/m/CAApHDvpS_97TU+jWPc=T83WPp7vJa1dTw3mojEtAVEZOWh9bjQ@mail.gmail.com	1 year ago
David Rowley	53abb1e0eb	Fix newly introduced issue in EXPLAIN for Materialize nodes ... The code added in 1eff8279d was lacking a check to see if the tuplestore had been created. In nodeMaterial.c this is done by ExecMaterial() rather than by ExecInitMaterial(), so the tuplestore won't be created unless the node has been executed at least once, as demonstrated by Alexander in his report. Here we skip showing any of the new EXPLAIN ANALYZE information when the Materialize node has not been executed. Reported-by: Alexander Lakhin Discussion: https://postgr.es/m/fe7fc8fb-86e5-ecb0-3cb2-dd2c9a6c482f@gmail.com	1 year ago
David Rowley	1eff8279d4	Add memory/disk usage for Material nodes in EXPLAIN ... Up until now, there was no ability to easily determine if a Material node caused the underlying tuplestore to spill to disk or even see how much memory the tuplestore used if it didn't. Here we add some new functions to tuplestore.c to query this information and add some additional output in EXPLAIN ANALYZE to display this information for the Material node. There are a few other executor node types that use tuplestores, so we could also consider adding these details to the EXPLAIN ANALYZE for those nodes too. Let's consider those independently from this. Having the tuplestore.c infrastructure in to allow that is step 1. Author: David Rowley Reviewed-by: Matthias van de Meent, Dmitry Dolgov Discussion: https://postgr.es/m/CAApHDvp5Py9g4Rjq7_inL3-MCK1Co2CRt_YWFwTU2zfQix0p4A@mail.gmail.com	1 year ago
Richard Guo	aa86129e19	Support "Right Semi Join" plan shapes ... Hash joins can support semijoin with the LHS input on the right, using the existing logic for inner join, combined with the assurance that only the first match for each inner tuple is considered, which can be achieved by leveraging the HEAP_TUPLE_HAS_MATCH flag. This can be very useful in some cases since we may now have the option to hash the smaller table instead of the larger. Merge join could likely support "Right Semi Join" too. However, the benefit of swapping inputs tends to be small here, so we do not address that in this patch. Note that this patch also modifies a test query in join.sql to ensure it continues testing as intended. With this patch the original query would result in a right-semi-join rather than semi-join, compromising its original purpose of testing the fix for neqjoinsel's behavior for semi-joins. Author: Richard Guo Reviewed-by: wenhui qiu, Alena Rybakina, Japin Li Discussion: https://postgr.es/m/CAMbWs4_X1mN=ic+SxcyymUqFx9bB8pqSLTGJ-F=MHy4PW3eRXw@mail.gmail.com	1 year ago
David Rowley	0de37b5106	Fix some inconsistencies in EXPLAIN output ... 06286709e added a SERIALIZE option to EXPLAIN which included showing the amount of kilobytes serialized. The calculation to convert bytes into kilobytes wasn't consistent with how that's done in the rest of EXPLAIN. Traditionally we round up to the nearest kB, but the new code rounded to the nearest kB. To fix this, invent a macro that does the conversion and use that macro everywhere that requires this conversion. Additionally, 5de890e36 added EXPLAIN (MEMORY) but included the memory sizes in bytes. Convert these values to kilobytes to align with the other memory related outputs. In passing, swap out a "long" type in show_hash_info() and use a uint64 instead. We do support platforms where sizeof(Size) == 8 and sizeof(long) == 4, so using a long there is questionable. Reported-by: jian he Reviewed-by: jian he Discussion: https://www.postgresql.org/message-id/CACJufxE4Sp7xvgOwhqtFx5hS85AxMKobPWDo-xZHZVTpK3EBjA@mail.gmail.com	2 years ago
Peter Eisentraut	27074bce08	Fix incorrect format placeholders	2 years ago
Amit Langote	de3600452b	Add basic JSON_TABLE() functionality ... JSON_TABLE() allows JSON data to be converted into a relational view and thus used, for example, in a FROM clause, like other tabular data. Data to show in the view is selected from a source JSON object using a JSON path expression to get a sequence of JSON objects that's called a "row pattern", which becomes the source to compute the SQL/JSON values that populate the view's output columns. Column values themselves are computed using JSON path expressions applied to each of the JSON objects comprising the "row pattern", for which the SQL/JSON query functions added in 6185c9737c are used. To implement JSON_TABLE() as a table function, this augments the TableFunc and TableFuncScanState nodes that are currently used to support XMLTABLE() with some JSON_TABLE()-specific fields. Note that the JSON_TABLE() spec includes NESTED COLUMNS and PLAN clauses, which are required to provide more flexibility to extract data out of nested JSON objects, but they are not implemented here to keep this commit of manageable size. Author: Nikita Glukhov <n.gluhov@postgrespro.ru> Author: Teodor Sigaev <teodor@sigaev.ru> Author: Oleg Bartunov <obartunov@gmail.com> Author: Alexander Korotkov <aekorotkov@gmail.com> Author: Andrew Dunstan <andrew@dunslane.net> Author: Amit Langote <amitlangote09@gmail.com> Author: Jian He <jian.universality@gmail.com> Reviewers have included (in no particular order): Andres Freund, Alexander Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu, Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby, Álvaro Herrera, Jian He Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru Discussion: https://postgr.es/m/20220616233130.rparivafipt6doj3@alap3.anarazel.de Discussion: https://postgr.es/m/abd9b83b-aa66-f230-3d6d-734817f0995d%40postgresql.org Discussion: https://postgr.es/m/CA+HiwqE4XTdfb1nW=Ojoy_tQSRhYt-q_kb6i5d4xcKyrLC1Nbg@mail.gmail.com	2 years ago
Tom Lane	06286709ee	Invent SERIALIZE option for EXPLAIN. ... EXPLAIN (ANALYZE, SERIALIZE) allows collection of statistics about the volume of data emitted by a query, as well as the time taken to convert the data to the on-the-wire format. Previously there was no way to investigate this without actually sending the data to the client, in which case network transmission costs might swamp what you wanted to see. In particular this feature allows investigating the costs of de-TOASTing compressed or out-of-line data during formatting. Stepan Rutz and Matthias van de Meent, reviewed by Tomas Vondra and myself Discussion: https://postgr.es/m/ca0adb0e-fa4e-c37e-1cd7-91170b18cae1@gmx.de	2 years ago
Tom Lane	fd0398fcb0	Improve EXPLAIN's display of SubPlan nodes and output parameters. ... Historically we've printed SubPlan expression nodes as "(SubPlan N)", which is pretty uninformative. Trying to reproduce the original SQL for the subquery is still as impractical as before, and would be mighty verbose as well. However, we can still do better than that. Displaying the "testexpr" when present, and adding a keyword to indicate the SubLinkType, goes a long way toward showing what's really going on. In addition, this patch gets rid of EXPLAIN's use of "$n" to represent subplan and initplan output Params. Instead we now print "(SubPlan N).colX" or "(InitPlan N).colX" to represent the X'th output column of that subplan. This eliminates confusion with the use of "$n" to represent PARAM_EXTERN Params, and it's useful for the first part of this change because it eliminates needing some other indication of which subplan is referenced by a SubPlan that has a testexpr. In passing, this adds simple regression test coverage of the ROWCOMPARE_SUBLINK code paths, which were entirely unburdened by testing before. Tom Lane and Dean Rasheed, reviewed by Aleksander Alekseev. Thanks to Chantal Keller for raising the question of whether this area couldn't be improved. Discussion: https://postgr.es/m/2838538.1705692747@sss.pgh.pa.us	2 years ago
Michael Paquier	a04ddd077e	Improve support for ExplainOneQuery() hook ... There is a hook called ExplainOneQuery_hook that gives modules the possibility to plug into this code path, but, like utility.c for utility statement execution, there is no corresponding "standard" routine in the case of EXPLAIN executed for one Query. This commit adds a new standard_ExplainOneQuery() in explain.c, which is able to run explain on a non-utility Query without calling its hook. Per the feedback received from a couple of hackers, this change gives the possibility to cut a few hundred lines of code in some of the popular out-of-core modules as these maintained a copy of ExplainOneQuery(), adding custom extra information at the beginning or the end of the EXPLAIN output. Author: Mats Kindahl Reviewed-by: Aleksander Alekseev, Jelte Fennema-Nio, Andrei Lepikhov Discussion: https://postgr.es/m/CA+14427V_B4EAoC_o-iYYucRdMSOTfpuH9k-QbexffY1HYJBiA@mail.gmail.com	2 years ago
Peter Eisentraut	dbbca2cf29	Remove unused #include's from backend .c files ... as determined by include-what-you-use (IWYU) While IWYU also suggests to *add* a bunch of #include's (which is its main purpose), this patch does not do that. In some cases, a more specific #include replaces another less specific one. Some manual adjustments of the automatic result: - IWYU currently doesn't know about includes that provide global variable declarations (like -Wmissing-variable-declarations), so those includes are being kept manually. - All includes for port(ability) headers are being kept for now, to play it safe. - No changes of catalog/pg_foo.h to catalog/pg_foo_d.h, to keep the patch from exploding in size. Note that this patch touches just *.c files, so nothing declared in header files changes in hidden ways. As a small example, in src/backend/access/transam/rmgr.c, some IWYU pragma annotations are added to handle a special case there. Discussion: https://www.postgresql.org/message-id/flat/af837490-6b2f-46df-ba05-37ea6a6653fc%40eisentraut.org	2 years ago
Alvaro Herrera	5de890e361	Add EXPLAIN (MEMORY) to report planner memory consumption ... This adds a new "Memory:" line under the "Planning:" group (which currently only has "Buffers:") when the MEMORY option is specified. In order to make the reporting reasonably accurate, we create a separate memory context for planner activities, to be used only when this option is given. The total amount of memory allocated by that context is reported as "allocated"; we subtract memory in the context's freelists from that and report that result as "used". We use MemoryContextStatsInternal() to obtain the quantities. The code structure to show buffer usage during planning was not in amazing shape, so I (Álvaro) modified the patch a bit to clean that up in passing. Author: Ashutosh Bapat Reviewed-by: David Rowley, Andrey Lepikhov, Jian He, Andy Fan Discussion: https://www.postgresql.org/message-id/CAExHW5sZA=5LJ_ZPpRO-w09ck8z9p7eaYAqq3Ks9GDfhrxeWBw@mail.gmail.com	2 years ago
Michael Paquier	b199eb89c6	Fix some typos ... Author: Yongtao Huang Discussion: https://postgr.es/m/CAOe1Go1F99o5JsphtXdDC5bxm7AzetU8q3AxLh4AAVGKu1AzEQ@mail.gmail.com	2 years 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
Michael Paquier	295c36c0c1	Add local_blk_{read|write}_time I/O timing statistics for local blocks ... There was no I/O timing statistics for counting read and write timings on local blocks, contrary to the counterparts for temp and shared blocks. This information is available when track_io_timing is enabled. The output of EXPLAIN is updated to show this information. An update of pg_stat_statements is planned next. Author: Nazir Bilal Yavuz Reviewed-by: Robert Haas, Melanie Plageman Discussion: https://postgr.es/m/CAN55FZ19Ss279mZuqGbuUNxka0iPbLgYuOQXqAKewrjNrp27VA@mail.gmail.com	2 years ago
Michael Paquier	13d00729d4	Rename I/O timing statistics columns to shared_blk_{read|write}_time ... These two counters, defined in BufferUsage to track respectively the time spent while reading and writing blocks have historically only tracked data related to shared buffers, when track_io_timing is enabled. An upcoming patch to add specific counters for local buffers will take advantage of this rename as it has come up that no data is currently tracked for local buffers, and tracking local and shared buffers using the same fields would be inconsistent with the treatment done for temp buffers. Renaming the existing fields clarifies what the block type of each stats field is. pg_stat_statement is updated to reflect the rename. No extension version bump is required as 5a3423ad8e has done one, affecting v17~. Author: Nazir Bilal Yavuz Reviewed-by: Robert Haas, Melanie Plageman Discussion: https://postgr.es/m/CAN55FZ19Ss279mZuqGbuUNxka0iPbLgYuOQXqAKewrjNrp27VA@mail.gmail.com	2 years ago
Daniel Gustafsson	5a3423ad8e	Add JIT deform_counter ... generation_counter includes time spent on both JIT:ing expressions and tuple deforming which are configured independently via options jit_expressions and jit_tuple_deforming. As they are combined in the same counter it's not apparent what fraction of time the tuple deforming takes. This adds deform_counter dedicated to tuple deforming, which allows seeing more directly the influence jit_tuple_deforming is having on the query. The counter is exposed in EXPLAIN and pg_stat_statements bumpin pg_stat_statements to 1.11. Author: Dmitry Dolgov <9erthalion6@gmail.com> Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com> Reviewed-by: Daniel Gustafsson <daniel@yesql.se> Discussion: https://postgr.es/m/20220612091253.eegstkufdsu4kfls@erthalion.local	2 years ago
Michael Paquier	2ecbb0a493	Remove dependency to query text in JumbleQuery() ... Since 3db72eb, the query ID of utilities is generated using the Query structure, making the use of the query string in JumbleQuery() unnecessary. This commit removes the argument "querytext" from JumbleQuery(). Reported-by: Joe Conway Reviewed-by: Nathan Bossart Discussion: https://postgr.es/m/ZJlQAWE4COFqHuAV@paquier.xyz	3 years ago
Tom Lane	0245f8db36	Pre-beta mechanical code beautification. ... Run pgindent, pgperltidy, and reformat-dat-files. This set of diffs is a bit larger than typical. We've updated to pg_bsd_indent 2.1.2, which properly indents variable declarations that have multi-line initialization expressions (the continuation lines are now indented one tab stop). We've also updated to perltidy version 20230309 and changed some of its settings, which reduces its desire to add whitespace to lines to make assignments etc. line up. Going forward, that should make for fewer random-seeming changes to existing code. Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql	3 years ago
Tom Lane	16dc2703c5	Support "Right Anti Join" plan shapes. ... Merge and hash joins can support antijoin with the non-nullable input on the right, using very simple combinations of their existing logic for right join and anti join. This gives the planner more freedom about how to order the join. It's particularly useful for hash join, since we may now have the option to hash the smaller table instead of the larger. Richard Guo, reviewed by Ronan Dunklau and myself Discussion: https://postgr.es/m/CAMbWs48xh9hMzXzSy3VaPzGAz+fkxXXTUbCLohX1_L8THFRm2Q@mail.gmail.com	3 years ago
Peter Eisentraut	0d15afc875	Simplify useless 0L constants ... In ancient times, these belonged to arguments or fields that were actually of type long, but now they are not anymore, so this "L" decoration is just confusing. (Some other 0L and other "L" constants remain, where they are actually associated with a long type.)	3 years ago
Tom Lane	3c05284d83	Invent GENERIC_PLAN option for EXPLAIN. ... This provides a very simple way to see the generic plan for a parameterized query. Without this, it's necessary to define a prepared statement and temporarily change plan_cache_mode, which is a bit tedious. One thing that's a bit of a hack perhaps is that we disable execution-time partition pruning when the GENERIC_PLAN option is given. That's because the pruning code may attempt to fetch the value of one of the parameters, which would fail. Laurenz Albe, reviewed by Julien Rouhaud, Christoph Berg, Michel Pelletier, Jim Jones, and myself Discussion: https://postgr.es/m/0a29b954b10b57f0d135fe12aa0909bd41883eb0.camel@cybertec.at	3 years ago
David Rowley	5352ca22e0	Rename force_parallel_mode to debug_parallel_query ... force_parallel_mode is meant to be used to allow us to exercise the parallel query infrastructure to ensure that it's working as we expect. It seems some users think this GUC is for forcing the query planner into picking a parallel plan regardless of the costs. A quick look at the documentation would have made them realize that they were wrong, but the GUC is likely too conveniently named which, evidently, seems to often result in users expecting that it forces the planner into usefully parallelizing queries. Here we rename the GUC to something which casual users are less likely to mistakenly think is what they need to make their query run more quickly. For now, the old name can still be used. We'll revisit if the old name mapping can be removed once the buildfarm configs are all updated. Reviewed-by: John Naylor Discussion: https://postgr.es/m/CAApHDvrsOi92_uA7PEaHZMH-S4Xv+MGhQWA+GrP8b1kjpS1HjQ@mail.gmail.com	3 years ago
David Rowley	e9aaf06328	Remove dead NoMovementScanDirection code ... Here remove some dead code from heapgettup() and heapgettup_pagemode() which was trying to support NoMovementScanDirection scans. This code can never be reached as standard_ExecutorRun() never calls ExecutePlan with NoMovementScanDirection. Additionally, plans which were scanning an unordered index would use NoMovementScanDirection rather than ForwardScanDirection. There was no real need for this, so here we adjust this so we use ForwardScanDirection for unordered index scans. A comment in pathnodes.h claimed that NoMovementScanDirection was used for PathKey reasons, but if that was true, it no longer is, per code in build_index_paths(). This does change the non-text format of the EXPLAIN output so that unordered index scans now have a "Forward" scan direction rather than "NoMovement". The text format of EXPLAIN has not changed. Author: Melanie Plageman Reviewed-by: Tom Lane, David Rowley Discussion: https://postgr.es/m/CAAKRu_bvkhka0CZQun28KTqhuUh5ZqY=_T8QEqZqOL02rpi2bw@mail.gmail.com	3 years ago