From 40acd5bf9ecbb386ba984a74552ac7393e6cc75a Mon Sep 17 00:00:00 2001 From: Atsushi Torikoshi Date: Tue, 16 Sep 2025 22:07:13 +0900 Subject: [PATCH v47] Add function to log the plan of the currently running query Currently, we have to wait for the query execution to finish to know its plan either using EXPLAIN ANALYZE or auto_explain. This is not so convenient, for example when investigating long-running queries on production environments. To improve this situation, this patch adds pg_log_query_plan() function that requests to log the plan of the currently executing query. On receipt of the request, ExecProcNodes of the current plan node and its subsidiary nodes are wrapped with ExecProcNodeFirst, which implelements logging query plan. When executor executes the one of the wrapped nodes, the query plan is logged. Our initial idea was to send a signal to the target backend process, which invokes EXPLAIN logic at the next CHECK_FOR_INTERRUPTS() call. However, we realized during prototyping that EXPLAIN is complex and may not be safely executed at arbitrary interrupt points. By default, only superusers are allowed to request to log the plans because allowing any users to issue this request at an unbounded rate would cause lots of log messages and which can lead to denial of service. --- contrib/auto_explain/auto_explain.c | 24 +-- doc/src/sgml/func/func-admin.sgml | 28 +++ src/backend/access/transam/xact.c | 30 ++++ src/backend/catalog/system_functions.sql | 2 + src/backend/commands/Makefile | 1 + src/backend/commands/dynamic_explain.c | 173 +++++++++++++++++++ src/backend/commands/explain.c | 38 +++- src/backend/commands/meson.build | 1 + src/backend/executor/execMain.c | 17 ++ src/backend/executor/execProcnode.c | 123 +++++++++++-- src/backend/storage/ipc/procsignal.c | 4 + src/backend/tcop/postgres.c | 4 + src/backend/utils/init/globals.c | 2 + src/include/access/xact.h | 3 + src/include/catalog/pg_proc.dat | 6 + src/include/commands/dynamic_explain.h | 27 +++ src/include/commands/explain.h | 9 +- src/include/commands/explain_state.h | 1 + src/include/executor/executor.h | 1 + src/include/miscadmin.h | 1 + src/include/storage/procsignal.h | 2 + src/test/regress/expected/misc_functions.out | 43 +++++ src/test/regress/sql/misc_functions.sql | 32 ++++ 23 files changed, 538 insertions(+), 34 deletions(-) create mode 100644 src/backend/commands/dynamic_explain.c create mode 100644 src/include/commands/dynamic_explain.h diff --git a/contrib/auto_explain/auto_explain.c b/contrib/auto_explain/auto_explain.c index 1f4badb4928..6c4217c9d1f 100644 --- a/contrib/auto_explain/auto_explain.c +++ b/contrib/auto_explain/auto_explain.c @@ -15,6 +15,7 @@ #include #include "access/parallel.h" +#include "commands/dynamic_explain.h" #include "commands/explain.h" #include "commands/explain_format.h" #include "commands/explain_state.h" @@ -404,26 +405,9 @@ explain_ExecutorEnd(QueryDesc *queryDesc) es->format = auto_explain_log_format; es->settings = auto_explain_log_settings; - ExplainBeginOutput(es); - ExplainQueryText(es, queryDesc); - ExplainQueryParameters(es, queryDesc->params, auto_explain_log_parameter_max_length); - ExplainPrintPlan(es, queryDesc); - if (es->analyze && auto_explain_log_triggers) - ExplainPrintTriggers(es, queryDesc); - if (es->costs) - ExplainPrintJITSummary(es, queryDesc); - ExplainEndOutput(es); - - /* Remove last line break */ - if (es->str->len > 0 && es->str->data[es->str->len - 1] == '\n') - es->str->data[--es->str->len] = '\0'; - - /* Fix JSON to output an object */ - if (auto_explain_log_format == EXPLAIN_FORMAT_JSON) - { - es->str->data[0] = '{'; - es->str->data[es->str->len - 1] = '}'; - } + ExplainStringAssemble(es, queryDesc, auto_explain_log_format, + auto_explain_log_triggers, + auto_explain_log_parameter_max_length); /* * Note: we rely on the existing logging of context or diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml index 57ff333159f..1dc19bbe3b4 100644 --- a/doc/src/sgml/func/func-admin.sgml +++ b/doc/src/sgml/func/func-admin.sgml @@ -184,6 +184,34 @@ + + + + pg_log_query_plan + + pg_log_query_plan ( pid integer ) + boolean + + + Requests to log the plan of the query currently running on the + backend with specified process ID. + It will be logged at LOG message level and + will appear in the server log based on the log + configuration set (See + for more information), but will not be sent to the client + regardless of . + + + Note that depending on the execution state of the query, + it may not be possible to log the plan. + + + This function is restricted to superusers by default, but other + users can be granted EXECUTE to run the function. + + + + diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index b46e7e9c2a6..8c2e7d5061f 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -36,6 +36,7 @@ #include "catalog/pg_enum.h" #include "catalog/storage.h" #include "commands/async.h" +#include "commands/dynamic_explain.h" #include "commands/tablecmds.h" #include "commands/trigger.h" #include "common/pg_prng.h" @@ -215,6 +216,7 @@ typedef struct TransactionStateData bool parallelChildXact; /* is any parent transaction parallel? */ bool chain; /* start a new block after this one */ bool topXidLogged; /* for a subxact: is top-level XID logged? */ + QueryDesc *queryDesc; /* my current QueryDesc */ struct TransactionStateData *parent; /* back link to parent */ } TransactionStateData; @@ -248,6 +250,7 @@ static TransactionStateData TopTransactionStateData = { .state = TRANS_DEFAULT, .blockState = TBLOCK_DEFAULT, .topXidLogged = false, + .queryDesc = NULL, }; /* @@ -933,6 +936,27 @@ GetCurrentTransactionNestLevel(void) return s->nestingLevel; } +/* + * SetCurrentQueryDesc + */ +void +SetCurrentQueryDesc(QueryDesc *queryDesc) +{ + TransactionState s = CurrentTransactionState; + + s->queryDesc = queryDesc; +} + +/* + * GetCurrentQueryDesc + */ +QueryDesc * +GetCurrentQueryDesc(void) +{ + TransactionState s = CurrentTransactionState; + + return s->queryDesc; +} /* * TransactionIdIsCurrentTransactionId @@ -2916,6 +2940,9 @@ AbortTransaction(void) /* Reset snapshot export state. */ SnapBuildResetExportedSnapshotState(); + /* Reset state for logging current query plan. */ + ResetLogQueryPlanState(); + /* * If this xact has started any unfinished parallel operation, clean up * its workers and exit parallel mode. Don't warn about leaked resources. @@ -5308,6 +5335,9 @@ AbortSubTransaction(void) /* Reset logical streaming state. */ ResetLogicalStreamingState(); + /* Reset state for logging current query plan. */ + ResetLogQueryPlanState(); + /* * No need for SnapBuildResetExportedSnapshotState() here, snapshot * exports are not supported in subtransactions. diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql index 566f308e443..ec2e1c1fd9a 100644 --- a/src/backend/catalog/system_functions.sql +++ b/src/backend/catalog/system_functions.sql @@ -775,6 +775,8 @@ REVOKE EXECUTE ON FUNCTION pg_ls_logicalmapdir() FROM PUBLIC; REVOKE EXECUTE ON FUNCTION pg_ls_replslotdir(text) FROM PUBLIC; +REVOKE EXECUTE ON FUNCTION pg_log_query_plan(integer) FROM PUBLIC; + -- -- We also set up some things as accessible to standard roles. -- diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile index cb2fbdc7c60..5e83907eb17 100644 --- a/src/backend/commands/Makefile +++ b/src/backend/commands/Makefile @@ -32,6 +32,7 @@ OBJS = \ define.o \ discard.o \ dropcmds.o \ + dynamic_explain.o \ event_trigger.o \ explain.o \ explain_dr.o \ diff --git a/src/backend/commands/dynamic_explain.c b/src/backend/commands/dynamic_explain.c new file mode 100644 index 00000000000..a60cc9bea2e --- /dev/null +++ b/src/backend/commands/dynamic_explain.c @@ -0,0 +1,173 @@ +/*------------------------------------------------------------------------- + * + * dynamic_explain.c + * Explain query plans during execution + * + * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group + * Portions Copyright (c) 1994-5, Regents of the University of California + * + * IDENTIFICATION + * src/backend/commands/dynamic_explain.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "access/xact.h" +#include "commands/dynamic_explain.h" +#include "commands/explain.h" +#include "commands/explain_format.h" +#include "commands/explain_state.h" +#include "miscadmin.h" +#include "storage/proc.h" +#include "storage/procarray.h" +#include "utils/backend_status.h" + + +/* + * Handle receipt of an interrupt indicating logging the plan of the currently + * running query. + * + * All the actual work is deferred to ProcessLogQueryPlanInterrupt(), + * because we cannot safely emit a log message inside the signal handler. + */ +void +HandleLogQueryPlanInterrupt(void) +{ + InterruptPending = true; + LogQueryPlanPending = true; + /* latch will be set by procsignal_sigusr1_handler */ +} + +/* + * Clear pg_log_query_plan() related state during (sub)transaction abort. + */ +void +ResetLogQueryPlanState(void) +{ + /* + * After abort, some elements of current QueryDesc are freed. To avoid + * accessing them, reset it. + */ + SetCurrentQueryDesc(NULL); + LogQueryPlanPending = false; +} + +/* + * Actual plan logging function. + */ +void +LogQueryPlan(void) +{ + ExplainState *es; + MemoryContext cxt; + MemoryContext old_cxt; + QueryDesc *queryDesc; + + cxt = AllocSetContextCreate(CurrentMemoryContext, + "log_query_plan temporary context", + ALLOCSET_DEFAULT_SIZES); + + old_cxt = MemoryContextSwitchTo(cxt); + + es = NewExplainState(); + + es->format = EXPLAIN_FORMAT_TEXT; + es->settings = true; + es->verbose = true; + es->signaled = true; + + /* + * Current QueryDesc is valid only during standard_ExecutorRun. However, + * ExecProcNode can be called afterward(i.e., ExecPostprocessPlan). To + * handle the case, check whether we have QueryDesc now. + */ + queryDesc = GetCurrentQueryDesc(); + + if (queryDesc == NULL) + { + LogQueryPlanPending = false; + return; + } + + ExplainStringAssemble(es, queryDesc, es->format, 0, -1); + + ereport(LOG_SERVER_ONLY, + errmsg("query and its plan running on the backend are:\n%s", + es->str->data)); + + MemoryContextSwitchTo(old_cxt); + MemoryContextDelete(cxt); + + LogQueryPlanPending = false; +} + +/* + * Process the request for logging query plan at CHECK_FOR_INTERRUPTS(). + * + * Since executing EXPLAIN-related code at an arbitrary CHECK_FOR_INTERRUPTS() + * point is potentially unsafe, this function just wraps the nodes of + * ExecProcNode with ExecProcNodeFirst, which logs query plan if requested. + * This way ensures that EXPLAIN-related code is executed only during + * ExecProcNodeFirst, where it is considered safe. + */ +void +ProcessLogQueryPlanInterrupt(void) +{ + QueryDesc *querydesc = GetCurrentQueryDesc(); + + if (querydesc == NULL) + { + LogQueryPlanPending = false; + return; + } + + /* Wrap ExecProcNodes with ExecProcNodeFirst */ + ExecSetExecProcNodeRecurse(querydesc->planstate); +} + +/* + * Signal a backend process to log the query plan of the running query. + * + * By default, only superusers are allowed to signal to log the plan because + * allowing any users to issue this request at an unbounded rate would + * cause lots of log messages and which can lead to denial of service. + * Additional roles can be permitted with GRANT. + */ +Datum +pg_log_query_plan(PG_FUNCTION_ARGS) +{ + int pid = PG_GETARG_INT32(0); + PGPROC *proc; + PgBackendStatus *be_status; + + proc = BackendPidGetProc(pid); + + if (proc == NULL) + { + /* + * This is just a warning so a loop-through-resultset will not abort + * if one backend terminated on its own during the run. + */ + ereport(WARNING, + (errmsg("PID %d is not a PostgreSQL backend process", pid))); + PG_RETURN_BOOL(false); + } + + be_status = pgstat_get_beentry_by_proc_number(proc->vxid.procNumber); + if (be_status->st_backendType != B_BACKEND) + { + ereport(WARNING, + (errmsg("PID %d is not a PostgreSQL client backend process", pid))); + PG_RETURN_BOOL(false); + } + + if (SendProcSignal(pid, PROCSIG_LOG_QUERY_PLAN, proc->vxid.procNumber) < 0) + { + ereport(WARNING, + (errmsg("could not send signal to process %d: %m", pid))); + PG_RETURN_BOOL(false); + } + + PG_RETURN_BOOL(true); +} diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c index 8345bc0264b..556779bafac 100644 --- a/src/backend/commands/explain.c +++ b/src/backend/commands/explain.c @@ -1084,6 +1084,37 @@ ExplainQueryParameters(ExplainState *es, ParamListInfo params, int maxlen) ExplainPropertyText("Query Parameters", str, es); } +/* + * ExplainStringAssemble - + * Assemble es->str for logging according to specified options and format + */ + +void +ExplainStringAssemble(ExplainState *es, QueryDesc *queryDesc, int logFormat, + bool logTriggers, int logParameterMaxLength) +{ + ExplainBeginOutput(es); + ExplainQueryText(es, queryDesc); + ExplainQueryParameters(es, queryDesc->params, logParameterMaxLength); + ExplainPrintPlan(es, queryDesc); + if (es->analyze && logTriggers) + ExplainPrintTriggers(es, queryDesc); + if (es->costs) + ExplainPrintJITSummary(es, queryDesc); + ExplainEndOutput(es); + + /* Remove last line break */ + if (es->str->len > 0 && es->str->data[es->str->len - 1] == '\n') + es->str->data[--es->str->len] = '\0'; + + /* Fix JSON to output an object */ + if (logFormat == EXPLAIN_FORMAT_JSON) + { + es->str->data[0] = '{'; + es->str->data[es->str->len - 1] = '}'; + } +} + /* * report_triggers - * report execution stats for a single relation's triggers @@ -1815,7 +1846,10 @@ ExplainNode(PlanState *planstate, List *ancestors, /* * We have to forcibly clean up the instrumentation state because we - * haven't done ExecutorEnd yet. This is pretty grotty ... + * haven't done ExecutorEnd yet. This is pretty grotty ... This cleanup + * should not be done when the query has already been executed and explain + * has been requested by signal, as the target query may use + * instrumentation and clean itself up. * * Note: contrib/auto_explain could cause instrumentation to be set up * even though we didn't ask for it here. Be careful not to print any @@ -1823,7 +1857,7 @@ ExplainNode(PlanState *planstate, List *ancestors, * InstrEndLoop call anyway, if possible, to reduce the number of cases * auto_explain has to contend with. */ - if (planstate->instrument) + if (planstate->instrument && !es->signaled) InstrEndLoop(planstate->instrument); if (es->analyze && diff --git a/src/backend/commands/meson.build b/src/backend/commands/meson.build index dd4cde41d32..4a64b8e9d09 100644 --- a/src/backend/commands/meson.build +++ b/src/backend/commands/meson.build @@ -20,6 +20,7 @@ backend_sources += files( 'define.c', 'discard.c', 'dropcmds.c', + 'dynamic_explain.c', 'event_trigger.c', 'explain.c', 'explain_dr.c', diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c index ff12e2e1364..b6f72d78ae6 100644 --- a/src/backend/executor/execMain.c +++ b/src/backend/executor/execMain.c @@ -43,6 +43,7 @@ #include "access/xact.h" #include "catalog/namespace.h" #include "catalog/partition.h" +#include "commands/dynamic_explain.h" #include "commands/matview.h" #include "commands/trigger.h" #include "executor/executor.h" @@ -312,6 +313,7 @@ standard_ExecutorRun(QueryDesc *queryDesc, DestReceiver *dest; bool sendTuples; MemoryContext oldcontext; + QueryDesc *oldQueryDesc; /* sanity checks */ Assert(queryDesc != NULL); @@ -324,6 +326,13 @@ standard_ExecutorRun(QueryDesc *queryDesc, /* caller must ensure the query's snapshot is active */ Assert(GetActiveSnapshot() == estate->es_snapshot); + /* + * Save current QueryDesc here to enable retrieval of the currently + * running queryDesc for nested queries. + */ + oldQueryDesc = GetCurrentQueryDesc(); + SetCurrentQueryDesc(queryDesc); + /* * Switch into per-query memory context */ @@ -386,6 +395,14 @@ standard_ExecutorRun(QueryDesc *queryDesc, InstrStopNode(queryDesc->totaltime, estate->es_processed); MemoryContextSwitchTo(oldcontext); + SetCurrentQueryDesc(oldQueryDesc); + + /* + * Ensure LogQueryPlanPending is initialized in case there was no time for + * logging the plan. Othewise plan will be logged at the next query + * execution on the same session. + */ + LogQueryPlanPending = false; } /* ---------------------------------------------------------------- diff --git a/src/backend/executor/execProcnode.c b/src/backend/executor/execProcnode.c index f5f9cfbeead..bf1e26b7af1 100644 --- a/src/backend/executor/execProcnode.c +++ b/src/backend/executor/execProcnode.c @@ -72,6 +72,7 @@ */ #include "postgres.h" +#include "commands/dynamic_explain.h" #include "executor/executor.h" #include "executor/nodeAgg.h" #include "executor/nodeAppend.h" @@ -431,9 +432,10 @@ ExecSetExecProcNode(PlanState *node, ExecProcNodeMtd function) { /* * Add a wrapper around the ExecProcNode callback that checks stack depth - * during the first execution and maybe adds an instrumentation wrapper. - * When the callback is changed after execution has already begun that - * means we'll superfluously execute ExecProcNodeFirst, but that seems ok. + * and query logging request during the execution and maybe adds an + * instrumentation wrapper. When the callback is changed after execution + * has already begun that means we'll superfluously execute + * ExecProcNodeFirst, but that seems ok. */ node->ExecProcNodeReal = function; node->ExecProcNode = ExecProcNodeFirst; @@ -441,27 +443,43 @@ ExecSetExecProcNode(PlanState *node, ExecProcNodeMtd function) /* - * ExecProcNode wrapper that performs some one-time checks, before calling + * ExecProcNode wrapper that performs some extra checks, before calling * the relevant node method (possibly via an instrumentation wrapper). + * + * Normally, this is just invoked once for the first call to any given node, + * and thereafter we arrange to call ExecProcNodeInstr or the relevant node + * method directly. However, it's legal to reset node->ExecProcNode back to + * this function at any time, and we do that whenever the query plan might + * need to be printed, so that we only incur the cost of checking for that + * case when required. */ static TupleTableSlot * ExecProcNodeFirst(PlanState *node) { /* - * Perform stack depth check during the first execution of the node. We - * only do so the first time round because it turns out to not be cheap on - * some common architectures (eg. x86). This relies on the assumption - * that ExecProcNode calls for a given plan node will always be made at - * roughly the same stack depth. + * Perform a stack depth check. We don't want to do this all the time + * because it turns out to not be cheap on some common architectures (eg. + * x86). This relies on the assumption that ExecProcNode calls for a + * given plan node will always be made at roughly the same stack depth. */ check_stack_depth(); + /* + * If we have been asked to print the query plan, do that now. We dare not + * try to do this directly from CHECK_FOR_INTERRUPTS() because we don't + * really know what the executor state is at that point, but we assume + * that when entering a node the state will be sufficiently consistent + * that trying to print the plan makes sense. + */ + if (LogQueryPlanPending) + LogQueryPlan(); + /* * If instrumentation is required, change the wrapper to one that just * does instrumentation. Otherwise we can dispense with all wrappers and * have ExecProcNode() directly call the relevant function from now on. */ - if (node->instrument) + else if (node->instrument) node->ExecProcNode = ExecProcNodeInstr; else node->ExecProcNode = node->ExecProcNodeReal; @@ -546,6 +564,91 @@ MultiExecProcNode(PlanState *node) return result; } +/* + * Wrap array of PlanState ExecProcNode with ExecProcNodeFirst. + */ +static void +ExecSetExecProcNodeArray(PlanState **planstates, int nplans) +{ + int i; + + for (i = 0; i < nplans; i++) + ExecSetExecProcNodeRecurse(planstates[i]); +} + +/* + * Wrap CustomScanState children's ExecProcNode with ExecProcNodeFirst. + */ +static void +CSSChildExecSetExecProcNodeArray(CustomScanState *css) +{ + ListCell *cell; + + foreach(cell, css->custom_ps) + ExecSetExecProcNodeRecurse((PlanState *) lfirst(cell)); +} + +/* + * Recursively wrap all the underlying ExecProcNode with ExecProcNodeFirst. + * + * Recursion is usually necessary because the next ExecProcNode() call may be + * invoked not only through the current node, but also via lefttree, righttree, + * subPlan, or other special child plans. + */ +void +ExecSetExecProcNodeRecurse(PlanState *ps) +{ + ExecSetExecProcNode(ps, ps->ExecProcNodeReal); + + if (ps->lefttree != NULL) + ExecSetExecProcNodeRecurse(ps->lefttree); + if (ps->righttree != NULL) + ExecSetExecProcNodeRecurse(ps->righttree); + if (ps->subPlan != NULL) + { + ListCell *l; + + foreach(l, ps->subPlan) + { + SubPlanState *sstate = (SubPlanState *) lfirst(l); + + ExecSetExecProcNodeRecurse(sstate->planstate); + } + } + + /* special child plans */ + switch (nodeTag(ps->plan)) + { + case T_Append: + ExecSetExecProcNodeArray(((AppendState *) ps)->appendplans, + ((AppendState *) ps)->as_nplans); + break; + case T_MergeAppend: + ExecSetExecProcNodeArray(((MergeAppendState *) ps)->mergeplans, + ((MergeAppendState *) ps)->ms_nplans); + break; + case T_BitmapAnd: + ExecSetExecProcNodeArray(((BitmapAndState *) ps)->bitmapplans, + ((BitmapAndState *) ps)->nplans); + break; + case T_BitmapOr: + ExecSetExecProcNodeArray(((BitmapOrState *) ps)->bitmapplans, + ((BitmapOrState *) ps)->nplans); + break; + case T_SubqueryScan: + ExecSetExecProcNodeRecurse(((SubqueryScanState *) ps)->subplan); + break; + case T_CteScan: + ExecSetExecProcNodeRecurse(((CteScanState *) ps)->cteplanstate); + break; + case T_CustomScan: + CSSChildExecSetExecProcNodeArray((CustomScanState *) ps); + break; + default: + break; + } +} + /* ---------------------------------------------------------------- * ExecEndNode diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c index 087821311cc..07fcac7f0bc 100644 --- a/src/backend/storage/ipc/procsignal.c +++ b/src/backend/storage/ipc/procsignal.c @@ -19,6 +19,7 @@ #include "access/parallel.h" #include "commands/async.h" +#include "commands/dynamic_explain.h" #include "miscadmin.h" #include "pgstat.h" #include "port/pg_bitutils.h" @@ -691,6 +692,9 @@ procsignal_sigusr1_handler(SIGNAL_ARGS) if (CheckProcSignal(PROCSIG_LOG_MEMORY_CONTEXT)) HandleLogMemoryContextInterrupt(); + if (CheckProcSignal(PROCSIG_LOG_QUERY_PLAN)) + HandleLogQueryPlanInterrupt(); + if (CheckProcSignal(PROCSIG_PARALLEL_APPLY_MESSAGE)) HandleParallelApplyMessageInterrupt(); diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c index d356830f756..c5a5cd47c8f 100644 --- a/src/backend/tcop/postgres.c +++ b/src/backend/tcop/postgres.c @@ -37,6 +37,7 @@ #include "catalog/pg_type.h" #include "commands/async.h" #include "commands/event_trigger.h" +#include "commands/dynamic_explain.h" #include "commands/prepare.h" #include "common/pg_prng.h" #include "jit/jit.h" @@ -3538,6 +3539,9 @@ ProcessInterrupts(void) if (LogMemoryContextPending) ProcessLogMemoryContextInterrupt(); + if (LogQueryPlanPending) + ProcessLogQueryPlanInterrupt(); + if (ParallelApplyMessagePending) ProcessParallelApplyMessages(); } diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c index d31cb45a058..927ccda0307 100644 --- a/src/backend/utils/init/globals.c +++ b/src/backend/utils/init/globals.c @@ -40,6 +40,8 @@ volatile sig_atomic_t IdleSessionTimeoutPending = false; volatile sig_atomic_t ProcSignalBarrierPending = false; volatile sig_atomic_t LogMemoryContextPending = false; volatile sig_atomic_t IdleStatsUpdateTimeoutPending = false; +volatile sig_atomic_t LogQueryPlanPending = false; + volatile uint32 InterruptHoldoffCount = 0; volatile uint32 QueryCancelHoldoffCount = 0; volatile uint32 CritSectionCount = 0; diff --git a/src/include/access/xact.h b/src/include/access/xact.h index 4528e51829e..3c6e3b7f2ce 100644 --- a/src/include/access/xact.h +++ b/src/include/access/xact.h @@ -432,6 +432,7 @@ typedef struct xl_xact_parsed_abort TimestampTz origin_timestamp; } xl_xact_parsed_abort; +typedef struct QueryDesc QueryDesc; /* ---------------- * extern definitions @@ -458,6 +459,8 @@ extern TimestampTz GetCurrentStatementStartTimestamp(void); extern TimestampTz GetCurrentTransactionStopTimestamp(void); extern void SetCurrentStatementStartTimestamp(void); extern int GetCurrentTransactionNestLevel(void); +QueryDesc *GetCurrentQueryDesc(void); +void SetCurrentQueryDesc(QueryDesc *queryDesc); extern bool TransactionIdIsCurrentTransactionId(TransactionId xid); extern void CommandCounterIncrement(void); extern void ForceSyncCommit(void); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 03e82d28c87..6b5ab18bebd 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -8609,6 +8609,12 @@ prorettype => 'bool', proargtypes => 'int4', prosrc => 'pg_log_backend_memory_contexts' }, +# logging plan of the running query on the specified backend +{ oid => '8000', descr => 'log plan of the running query on the specified backend', + proname => 'pg_log_query_plan', + provolatile => 'v', prorettype => 'bool', + proargtypes => 'int4', prosrc => 'pg_log_query_plan' }, + # non-persistent series generator { oid => '1066', descr => 'non-persistent series generator', proname => 'generate_series', prorows => '1000', diff --git a/src/include/commands/dynamic_explain.h b/src/include/commands/dynamic_explain.h new file mode 100644 index 00000000000..83c158731a1 --- /dev/null +++ b/src/include/commands/dynamic_explain.h @@ -0,0 +1,27 @@ +/*------------------------------------------------------------------------- + * + * dynamic_explain.h + * prototypes for dynamic_explain.c + * + * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group + * Portions Copyright (c) 1994-5, Regents of the University of California + * + * src/include/commands/dynamic_explain.h + * + *------------------------------------------------------------------------- + */ +#ifndef DYNAMIC_EXPLAIN_H +#define DYNAMIC_EXPLAIN_H + +#include "executor/executor.h" +#include "commands/explain_state.h" + +extern void HandleLogQueryPlanInterrupt(void); +extern void ResetLogQueryPlanState(void); +extern void ResetProcessLogQueryPlanInterruptActive(void); +extern void ProcessLogQueryPlanInterrupt(void); +extern TupleTableSlot *ExecProcNodeWithExplain(PlanState *ps); +extern void LogQueryPlan(void); +extern Datum pg_log_query_plan(PG_FUNCTION_ARGS); + +#endif /* DYNAMIC_EXPLAIN_H */ diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h index 6e51d50efc7..0dc160fa7b4 100644 --- a/src/include/commands/explain.h +++ b/src/include/commands/explain.h @@ -70,8 +70,10 @@ extern void ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, const BufferUsage *bufusage, const MemoryContextCounters *mem_counters); -extern void ExplainPrintPlan(ExplainState *es, QueryDesc *queryDesc); -extern void ExplainPrintTriggers(ExplainState *es, +extern void ExplainPrintPlan(struct ExplainState *es, QueryDesc *queryDesc); +extern void ExplainPrintTriggers(struct ExplainState *es, QueryDesc *queryDesc); +extern void ExplainPrintPlan(struct ExplainState *es, QueryDesc *queryDesc); +extern void ExplainPrintTriggers(struct ExplainState *es, QueryDesc *queryDesc); extern void ExplainPrintJITSummary(ExplainState *es, @@ -80,5 +82,8 @@ extern void ExplainPrintJITSummary(ExplainState *es, extern void ExplainQueryText(ExplainState *es, QueryDesc *queryDesc); extern void ExplainQueryParameters(ExplainState *es, ParamListInfo params, int maxlen); +extern void ExplainStringAssemble(struct ExplainState *es, QueryDesc *queryDesc, + int logFormat, bool logTriggers, + int logParameterMaxLength); #endif /* EXPLAIN_H */ diff --git a/src/include/commands/explain_state.h b/src/include/commands/explain_state.h index ba073b86918..bf40fdabff5 100644 --- a/src/include/commands/explain_state.h +++ b/src/include/commands/explain_state.h @@ -71,6 +71,7 @@ typedef struct ExplainState * entry */ /* state related to the current plan node */ ExplainWorkersState *workers_state; /* needed if parallel plan */ + bool signaled; /* whether explain is called by signal */ /* extensions */ void **extension_state; int extension_state_allocated; diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h index 3248e78cd28..c66df11e71a 100644 --- a/src/include/executor/executor.h +++ b/src/include/executor/executor.h @@ -295,6 +295,7 @@ extern void EvalPlanQualEnd(EPQState *epqstate); extern PlanState *ExecInitNode(Plan *node, EState *estate, int eflags); extern void ExecSetExecProcNode(PlanState *node, ExecProcNodeMtd function); extern Node *MultiExecProcNode(PlanState *node); +extern void ExecSetExecProcNodeRecurse(PlanState *ps); extern void ExecEndNode(PlanState *node); extern void ExecShutdownNode(PlanState *node); extern void ExecSetTupleBound(int64 tuples_needed, PlanState *child_node); diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h index 1bef98471c3..22b945e918c 100644 --- a/src/include/miscadmin.h +++ b/src/include/miscadmin.h @@ -96,6 +96,7 @@ extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending; extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending; extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending; extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending; +extern PGDLLIMPORT volatile sig_atomic_t LogQueryPlanPending; extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending; extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost; diff --git a/src/include/storage/procsignal.h b/src/include/storage/procsignal.h index afeeb1ca019..ea26242c868 100644 --- a/src/include/storage/procsignal.h +++ b/src/include/storage/procsignal.h @@ -35,6 +35,8 @@ typedef enum PROCSIG_WALSND_INIT_STOPPING, /* ask walsenders to prepare for shutdown */ PROCSIG_BARRIER, /* global barrier interrupt */ PROCSIG_LOG_MEMORY_CONTEXT, /* ask backend to log the memory contexts */ + PROCSIG_LOG_QUERY_PLAN, /* ask backend to log plan of the current + * query */ PROCSIG_PARALLEL_APPLY_MESSAGE, /* Message from parallel apply workers */ /* Recovery conflict reasons */ diff --git a/src/test/regress/expected/misc_functions.out b/src/test/regress/expected/misc_functions.out index c3b2b9d8603..c2cc2609e94 100644 --- a/src/test/regress/expected/misc_functions.out +++ b/src/test/regress/expected/misc_functions.out @@ -366,6 +366,49 @@ REVOKE EXECUTE ON FUNCTION pg_log_backend_memory_contexts(integer) FROM regress_log_memory; DROP ROLE regress_log_memory; -- +-- pg_log_query_plan() +-- +-- Plans are logged and they are not returned to the function. +-- Furthermore, their contents can vary depending on the optimizer. However, +-- we can at least verify that the code doesn't fail, and that the +-- permissions are set properly. +WITH t AS MATERIALIZED (SELECT pg_log_query_plan(pg_backend_pid())) + SELECT * FROM t; + pg_log_query_plan +------------------- + t +(1 row) + +CREATE ROLE regress_log_plan; +SELECT has_function_privilege('regress_log_plan', + 'pg_log_query_plan(integer)', 'EXECUTE'); -- no + has_function_privilege +------------------------ + f +(1 row) + +GRANT EXECUTE ON FUNCTION pg_log_query_plan(integer) + TO regress_log_plan; +SELECT has_function_privilege('regress_log_plan', + 'pg_log_query_plan(integer)', 'EXECUTE'); -- yes + has_function_privilege +------------------------ + t +(1 row) + +SET ROLE regress_log_plan; +WITH t AS MATERIALIZED (SELECT pg_log_query_plan(pg_backend_pid())) + SELECT * FROM t; + pg_log_query_plan +------------------- + t +(1 row) + +RESET ROLE; +REVOKE EXECUTE ON FUNCTION pg_log_query_plan(integer) + FROM regress_log_plan; +DROP ROLE regress_log_plan; +-- -- Test some built-in SRFs -- -- The outputs of these are variable, so we can't just print their results diff --git a/src/test/regress/sql/misc_functions.sql b/src/test/regress/sql/misc_functions.sql index 23792c4132a..88be4b6ef2a 100644 --- a/src/test/regress/sql/misc_functions.sql +++ b/src/test/regress/sql/misc_functions.sql @@ -143,6 +143,38 @@ REVOKE EXECUTE ON FUNCTION pg_log_backend_memory_contexts(integer) DROP ROLE regress_log_memory; +-- +-- pg_log_query_plan() +-- +-- Plans are logged and they are not returned to the function. +-- Furthermore, their contents can vary depending on the optimizer. However, +-- we can at least verify that the code doesn't fail, and that the +-- permissions are set properly. + +WITH t AS MATERIALIZED (SELECT pg_log_query_plan(pg_backend_pid())) + SELECT * FROM t; + +CREATE ROLE regress_log_plan; + +SELECT has_function_privilege('regress_log_plan', + 'pg_log_query_plan(integer)', 'EXECUTE'); -- no + +GRANT EXECUTE ON FUNCTION pg_log_query_plan(integer) + TO regress_log_plan; + +SELECT has_function_privilege('regress_log_plan', + 'pg_log_query_plan(integer)', 'EXECUTE'); -- yes + +SET ROLE regress_log_plan; +WITH t AS MATERIALIZED (SELECT pg_log_query_plan(pg_backend_pid())) + SELECT * FROM t; +RESET ROLE; + +REVOKE EXECUTE ON FUNCTION pg_log_query_plan(integer) + FROM regress_log_plan; + +DROP ROLE regress_log_plan; + -- -- Test some built-in SRFs -- -- 2.48.1