On 2023-10-25 12:40, Ashutosh Bapat wrote:
On Wed, Oct 18, 2023 at 10:04 PM James Coleman <jtc...@gmail.com>
wrote:
While that decision as regards auto_explain has long since been made
(and there would be work to undo it), I don't believe that we should
repeat that choice here. I'm -10 on moving this into auto_explain.
Right.
However perhaps there is still an opportunity for moving some of the
auto_explain code into core so as to enable deduplicating the code.
Right. That's what I also think.
Thanks for your comments.
Attached patch adds a new function which assembles es->str for logging
according to specified contents and format.
This is called from both auto_explain and pg_log_query_plan().
On 2023-10-11 16:22, Ashutosh Bapat wrote:
I am also wondering whether it's better to report the WARNING as
status column in the output.
Attached patch left as it was since the inconsistency with
pg_terminate_backend() and pg_log_backend_memory_contexts() as you
pointed out.
--
Regards,
--
Atsushi Torikoshi
NTT DATA Group Corporation
From 336ba3943f631dcbc0d1226ebd0a7675cf78c1f8 Mon Sep 17 00:00:00 2001
From: Atsushi Torikoshi <torikos...@oss.nttdata.com>
Date: Thu, 26 Oct 2023 15:42:36 +0900
Subject: [PATCH v32] Add function to log the plan of the query
Currently, we have to wait for the query execution to finish
to check its plan. This is not so convenient when
investigating long-running queries on production environments
where we cannot use debuggers.
To improve this situation, this patch adds
pg_log_query_plan() function that requests to log the
plan of the specified backend process.
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.
On receipt of the request, at the next CHECK_FOR_INTERRUPTS(),
the target backend logs its plan at LOG_SERVER_ONLY level, so
that these plans will appear in the server log but not be sent
to the client.
Reviewed-by: Bharath Rupireddy, Fujii Masao, Dilip Kumar,
Masahiro Ikeda, Ekaterina Sokolova, Justin Pryzby, Kyotaro
Horiguchi, Robert Treat, Alena Rybakina, Ashutosh Bapat
Co-authored-by: James Coleman <jamecole...@paypal.com>
---
contrib/auto_explain/auto_explain.c | 23 +-
doc/src/sgml/func.sgml | 49 +++++
src/backend/access/transam/xact.c | 13 ++
src/backend/catalog/system_functions.sql | 2 +
src/backend/commands/explain.c | 209 ++++++++++++++++++-
src/backend/executor/execMain.c | 14 ++
src/backend/storage/ipc/procsignal.c | 4 +
src/backend/storage/lmgr/lock.c | 9 +-
src/backend/tcop/postgres.c | 4 +
src/backend/utils/error/elog.c | 2 +
src/backend/utils/init/globals.c | 2 +
src/include/catalog/pg_proc.dat | 6 +
src/include/commands/explain.h | 8 +
src/include/miscadmin.h | 1 +
src/include/storage/lock.h | 2 -
src/include/storage/procsignal.h | 1 +
src/include/tcop/pquery.h | 2 +-
src/include/utils/elog.h | 1 +
src/test/regress/expected/misc_functions.out | 54 ++++-
src/test/regress/sql/misc_functions.sql | 41 +++-
20 files changed, 399 insertions(+), 48 deletions(-)
diff --git a/contrib/auto_explain/auto_explain.c b/contrib/auto_explain/auto_explain.c
index c3ac27ae99..20a73df8c4 100644
--- a/contrib/auto_explain/auto_explain.c
+++ b/contrib/auto_explain/auto_explain.c
@@ -399,26 +399,9 @@ 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] = '}';
- }
+ ExplainAssembleLogOutput(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.sgml b/doc/src/sgml/func.sgml
index 7c3e940afe..8d77fe1a5b 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -26406,6 +26406,25 @@ SELECT collation for ('foo' COLLATE "de_DE");
</para></entry>
</row>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_log_query_plan</primary>
+ </indexterm>
+ <function>pg_log_query_plan</function> ( <parameter>pid</parameter> <type>integer</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Requests to log the plan of the query currently running on the
+ backend with specified process ID.
+ It will be logged at <literal>LOG</literal> message level and
+ will appear in the server log based on the log
+ configuration set (See <xref linkend="runtime-config-logging"/>
+ for more information), but will not be sent to the client
+ regardless of <xref linkend="guc-client-min-messages"/>.
+ </para></entry>
+ </row>
+
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
@@ -26626,6 +26645,36 @@ LOG: Grand total: 1651920 bytes in 201 blocks; 622360 free (88 chunks); 1029560
because it may generate a large number of log messages.
</para>
+ <para>
+ <function>pg_log_query_plan</function> can be used
+ to log the plan of a backend process. For example:
+<programlisting>
+postgres=# SELECT pg_log_query_plan(201116);
+ pg_log_query_plan
+---------------------------
+ t
+(1 row)
+</programlisting>
+The format of the query plan is the same as when <literal>VERBOSE</literal>,
+<literal>COSTS</literal>, <literal>SETTINGS</literal> and
+<literal>FORMAT TEXT</literal> are used in the <command>EXPLAIN</command>
+command. For example:
+<screen>
+LOG: query plan running on backend with PID 201116 is:
+ Query Text: SELECT * FROM pgbench_accounts;
+ Seq Scan on public.pgbench_accounts (cost=0.00..52787.00 rows=2000000 width=97)
+ Output: aid, bid, abalance, filler
+ Settings: work_mem = '1MB'
+</screen>
+ Note that when statements are executed inside a function, only the
+ plan of the most deeply nested query is logged.
+ </para>
+
+ <para>
+ When a subtransaction is aborted, <function>pg_log_query_plan</function>
+ cannot log the query plan after the abort.
+ </para>
+
</sect2>
<sect2 id="functions-admin-backup">
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 37c5e34cce..a2b0266dd3 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -61,6 +61,7 @@
#include "storage/procarray.h"
#include "storage/sinvaladt.h"
#include "storage/smgr.h"
+#include "tcop/pquery.h"
#include "utils/builtins.h"
#include "utils/catcache.h"
#include "utils/combocid.h"
@@ -2750,6 +2751,12 @@ AbortTransaction(void)
*/
sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
+ /*
+ * When ActiveQueryDesc is referenced after abort, some of its elements
+ * are freed. To avoid accessing them, reset ActiveQueryDesc here.
+ */
+ ActiveQueryDesc = NULL;
+
/*
* check the current transaction state
*/
@@ -5109,6 +5116,12 @@ AbortSubTransaction(void)
*/
sigprocmask(SIG_SETMASK, &UnBlockSig, NULL);
+ /*
+ * When ActiveQueryDesc is referenced after abort, some of its elements
+ * are freed. To avoid accessing them, reset ActiveQueryDesc here.
+ */
+ ActiveQueryDesc = NULL;
+
/*
* check the current transaction state
*/
diff --git a/src/backend/catalog/system_functions.sql b/src/backend/catalog/system_functions.sql
index 35d738d576..e42db525dc 100644
--- a/src/backend/catalog/system_functions.sql
+++ b/src/backend/catalog/system_functions.sql
@@ -742,6 +742,8 @@ 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/explain.c b/src/backend/commands/explain.c
index f1d71bc54e..db2fcbd5cf 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -21,6 +21,7 @@
#include "executor/nodeHash.h"
#include "foreign/fdwapi.h"
#include "jit/jit.h"
+#include "miscadmin.h"
#include "nodes/extensible.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
@@ -28,7 +29,10 @@
#include "parser/parsetree.h"
#include "rewrite/rewriteHandler.h"
#include "storage/bufmgr.h"
+#include "storage/procarray.h"
+#include "tcop/pquery.h"
#include "tcop/tcopprot.h"
+#include "utils/backend_status.h"
#include "utils/builtins.h"
#include "utils/guc_tables.h"
#include "utils/json.h"
@@ -737,6 +741,37 @@ ExplainPrintSettings(ExplainState *es)
}
}
+/*
+ * ExplainAssembleLogOutput -
+ * Assemble es->str for logging according to specified contents and format
+ */
+
+void
+ExplainAssembleLogOutput(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] = '}';
+ }
+}
+
/*
* ExplainPrintPlan -
* convert a QueryDesc's plan tree to text and append it to es->str
@@ -1647,6 +1682,9 @@ 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 ...
+ * This cleanup should not be done when the query has already been
+ * executed and explain has been called 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
@@ -1654,7 +1692,7 @@ 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 &&
@@ -5082,3 +5120,172 @@ escape_yaml(StringInfo buf, const char *str)
{
escape_json(buf, str);
}
+
+/*
+ * HandleLogQueryPlanInterrupt
+ * 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 */
+}
+
+bool ProcessLogQueryPlanInterruptActive = false;
+/*
+ * ProcessLogQueryPlanInterrupt
+ * Perform logging the plan of the currently running query on this
+ * backend process.
+ *
+ * Any backend that participates in ProcSignal signaling must arrange to call
+ * this function if we see LogQueryPlanPending set.
+ * It is called from CHECK_FOR_INTERRUPTS(), which is enough because the target
+ * process for logging plan is a backend.
+ */
+void
+ProcessLogQueryPlanInterrupt(void)
+{
+ ExplainState *es;
+ HASH_SEQ_STATUS status;
+ LOCALLOCK *locallock;
+ MemoryContext cxt;
+ MemoryContext old_cxt;
+ LogQueryPlanPending = false;
+
+ /* Cannot re-enter. */
+ if (ProcessLogQueryPlanInterruptActive)
+ return;
+
+ ProcessLogQueryPlanInterruptActive = true;
+
+ if (ActiveQueryDesc == NULL)
+ {
+ ereport(LOG_SERVER_ONLY,
+ errmsg("backend with PID %d is not running a query or a subtransaction is aborted",
+ MyProcPid),
+ errhidestmt(true),
+ errhidecontext(true));
+
+ ProcessLogQueryPlanInterruptActive = false;
+ return;
+ }
+
+ /*
+ * Ensure no page lock is held on this process.
+ *
+ * If page lock is held at the time of the interrupt, we can't acquire any
+ * other heavyweight lock, which might be necessary for explaining the plan
+ * when retrieving column names.
+ *
+ * This may be overkill, but since page locks are held for a short duration
+ * we check all the LocalLock entries and when finding even one, give up
+ * logging the plan.
+ */
+ hash_seq_init(&status, GetLockMethodLocalHash());
+ while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
+ {
+ if (LOCALLOCK_LOCKTAG(*locallock) == LOCKTAG_PAGE)
+ {
+ ereport(LOG_SERVER_ONLY,
+ errmsg("ignored request for logging query plan due to page lock confilcts"),
+ errdetail("You can try again in a moment."));
+ hash_seq_term(&status);
+
+ ProcessLogQueryPlanInterruptActive = false;
+ return;
+ }
+ }
+
+ /*
+ * Ensure no locks already held on the lockable object.
+ *
+ * Otherwise EXPLAIN can be also hold on it.
+ */
+ if (MyProc->heldLocks)
+ {
+ ereport(LOG_SERVER_ONLY,
+ errmsg("ignored request for logging query plan due to lock confilcts"),
+ errdetail("You can try again in a moment."));
+ return;
+ }
+
+ 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;
+
+ ExplainAssembleLogOutput(es, ActiveQueryDesc, EXPLAIN_FORMAT_TEXT, 0, -1);
+
+ ereport(LOG_SERVER_ONLY,
+ errmsg("query plan running on backend with PID %d is:\n%s",
+ MyProcPid, es->str->data),
+ errhidestmt(true),
+ errhidecontext(true));
+
+ MemoryContextSwitchTo(old_cxt);
+ MemoryContextDelete(cxt);
+
+ ProcessLogQueryPlanInterruptActive = false;
+}
+
+/*
+ * pg_log_query_plan
+ * 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_backend_id(proc->backendId);
+ 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->backendId) < 0)
+ {
+ /* Again, just a warning to allow loops */
+ 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/executor/execMain.c b/src/backend/executor/execMain.c
index 4c5a7bbf62..4772cb97e7 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -78,6 +78,9 @@ ExecutorEnd_hook_type ExecutorEnd_hook = NULL;
/* Hook for plugin to get control in ExecCheckPermissions() */
ExecutorCheckPerms_hook_type ExecutorCheckPerms_hook = NULL;
+/* Currently executing query's QueryDesc */
+QueryDesc *ActiveQueryDesc = NULL;
+
/* decls for local routines only used within this module */
static void InitPlan(QueryDesc *queryDesc, int eflags);
static void CheckValidRowMarkRel(Relation rel, RowMarkType markType);
@@ -303,10 +306,21 @@ ExecutorRun(QueryDesc *queryDesc,
ScanDirection direction, uint64 count,
bool execute_once)
{
+ /*
+ * Update ActiveQueryDesc here to enable retrieval of the currently
+ * running queryDesc for nested queries.
+ */
+ QueryDesc *save_ActiveQueryDesc;
+
+ save_ActiveQueryDesc = ActiveQueryDesc;
+ ActiveQueryDesc = queryDesc;
+
if (ExecutorRun_hook)
(*ExecutorRun_hook) (queryDesc, direction, count, execute_once);
else
standard_ExecutorRun(queryDesc, direction, count, execute_once);
+
+ ActiveQueryDesc = save_ActiveQueryDesc;
}
void
diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c
index b7427906de..ddaf829917 100644
--- a/src/backend/storage/ipc/procsignal.c
+++ b/src/backend/storage/ipc/procsignal.c
@@ -20,6 +20,7 @@
#include "access/parallel.h"
#include "port/pg_bitutils.h"
#include "commands/async.h"
+#include "commands/explain.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "replication/logicalworker.h"
@@ -658,6 +659,9 @@ 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/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index ec6240fbae..c6eb340d7a 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -602,17 +602,18 @@ LockHeldByMe(const LOCKTAG *locktag, LOCKMODE lockmode)
return (locallock && locallock->nLocks > 0);
}
-#ifdef USE_ASSERT_CHECKING
/*
- * GetLockMethodLocalHash -- return the hash of local locks, for modules that
- * evaluate assertions based on all locks held.
+ * GetLockMethodLocalHash -- return the hash of local locks, mainly for
+ * modules that evaluate assertions based on all locks held.
+ *
+ * NOTE: When there are many entries in LockMethodLocalHash, calling this
+ * function and looking into all of them can lead to performance problems.
*/
HTAB *
GetLockMethodLocalHash(void)
{
return LockMethodLocalHash;
}
-#endif
/*
* LockHasWaiters -- look up 'locktag' and check if releasing this
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 6a070b5d8c..320c0148b4 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/explain.h"
#include "commands/prepare.h"
#include "common/pg_prng.h"
#include "jit/jit.h"
@@ -3457,6 +3458,9 @@ ProcessInterrupts(void)
if (LogMemoryContextPending)
ProcessLogMemoryContextInterrupt();
+ if (LogQueryPlanPending)
+ ProcessLogQueryPlanInterrupt();
+
if (ParallelApplyMessagePending)
HandleParallelApplyMessages();
}
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index eeb238331e..63b99dafa5 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -513,6 +513,8 @@ errfinish(const char *filename, int lineno, const char *funcname)
econtext = econtext->previous)
econtext->callback(econtext->arg);
+ if (elevel >= ERROR)
+ ProcessLogQueryPlanInterruptActive = false;
/*
* If ERROR (not more nor less) we pass it off to the current handler.
* Printing it and popping the stack is the responsibility of the handler.
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 60bc1217fb..fee49243a6 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -37,6 +37,8 @@ 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/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 06435e8b92..7002a71792 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -8250,6 +8250,12 @@
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/explain.h b/src/include/commands/explain.h
index 3d3e632a0c..99358222ae 100644
--- a/src/include/commands/explain.h
+++ b/src/include/commands/explain.h
@@ -17,6 +17,7 @@
#include "lib/stringinfo.h"
#include "parser/parse_node.h"
+extern PGDLLIMPORT bool ProcessLogQueryPlanInterruptActive;
typedef enum ExplainFormat
{
EXPLAIN_FORMAT_TEXT,
@@ -60,6 +61,7 @@ typedef struct ExplainState
bool hide_workers; /* set if we find an invisible Gather */
/* state related to the current plan node */
ExplainWorkersState *workers_state; /* needed if parallel plan */
+ bool signaled; /* whether explain is called by signal */
} ExplainState;
/* Hook for plugins to get control in ExplainOneQuery() */
@@ -94,6 +96,10 @@ extern void ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into,
const instr_time *planduration,
const BufferUsage *bufusage);
+extern void ExplainAssembleLogOutput(ExplainState *es, QueryDesc *queryDesc,
+ int logFormat, bool logTriggers,
+ int logParameterMaxLength);
+
extern void ExplainPrintPlan(ExplainState *es, QueryDesc *queryDesc);
extern void ExplainPrintTriggers(ExplainState *es, QueryDesc *queryDesc);
@@ -126,4 +132,6 @@ extern void ExplainOpenGroup(const char *objtype, const char *labelname,
extern void ExplainCloseGroup(const char *objtype, const char *labelname,
bool labeled, ExplainState *es);
+extern void HandleLogQueryPlanInterrupt(void);
+extern void ProcessLogQueryPlanInterrupt(void);
#endif /* EXPLAIN_H */
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 7232b03e37..9258640ac4 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -95,6 +95,7 @@ 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/lock.h b/src/include/storage/lock.h
index 8575bea25c..63f0454378 100644
--- a/src/include/storage/lock.h
+++ b/src/include/storage/lock.h
@@ -569,9 +569,7 @@ extern void LockReleaseSession(LOCKMETHODID lockmethodid);
extern void LockReleaseCurrentOwner(LOCALLOCK **locallocks, int nlocks);
extern void LockReassignCurrentOwner(LOCALLOCK **locallocks, int nlocks);
extern bool LockHeldByMe(const LOCKTAG *locktag, LOCKMODE lockmode);
-#ifdef USE_ASSERT_CHECKING
extern HTAB *GetLockMethodLocalHash(void);
-#endif
extern bool LockHasWaiters(const LOCKTAG *locktag,
LOCKMODE lockmode, bool sessionLock);
extern VirtualTransactionId *GetLockConflicts(const LOCKTAG *locktag,
diff --git a/src/include/storage/procsignal.h b/src/include/storage/procsignal.h
index 3a3a7eca77..b5d2a1be28 100644
--- a/src/include/storage/procsignal.h
+++ b/src/include/storage/procsignal.h
@@ -35,6 +35,7 @@ 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/include/tcop/pquery.h b/src/include/tcop/pquery.h
index a5e65b98aa..a6ae947a0f 100644
--- a/src/include/tcop/pquery.h
+++ b/src/include/tcop/pquery.h
@@ -21,7 +21,7 @@ struct PlannedStmt; /* avoid including plannodes.h here */
extern PGDLLIMPORT Portal ActivePortal;
-
+extern PGDLLIMPORT QueryDesc *ActiveQueryDesc;
extern PortalStrategy ChoosePortalStrategy(List *stmts);
diff --git a/src/include/utils/elog.h b/src/include/utils/elog.h
index 0292e88b4f..1e35f57a3e 100644
--- a/src/include/utils/elog.h
+++ b/src/include/utils/elog.h
@@ -167,6 +167,7 @@ struct Node;
extern bool message_level_is_interesting(int elevel);
+extern PGDLLIMPORT bool ProcessLogQueryPlanInterruptActive;
extern bool errstart(int elevel, const char *domain);
extern pg_attribute_cold bool errstart_cold(int elevel, const char *domain);
extern void errfinish(const char *filename, int lineno, const char *funcname);
diff --git a/src/test/regress/expected/misc_functions.out b/src/test/regress/expected/misc_functions.out
index c669948370..0b98f8a972 100644
--- a/src/test/regress/expected/misc_functions.out
+++ b/src/test/regress/expected/misc_functions.out
@@ -276,14 +276,15 @@ SELECT test_canonicalize_path('./abc/./def/.././ghi/../../../jkl/mno');
../jkl/mno
(1 row)
+-- Test logging functions
--
--- pg_log_backend_memory_contexts()
---
--- Memory contexts are logged and they are not returned to the function.
+-- The outputs of these functions are logged and they are not returned to
+-- the function.
-- Furthermore, their contents can vary depending on the timing. However,
-- we can at least verify that the code doesn't fail, and that the
-- permissions are set properly.
--
+-- pg_log_backend_memory_contexts()
SELECT pg_log_backend_memory_contexts(pg_backend_pid());
pg_log_backend_memory_contexts
--------------------------------
@@ -297,8 +298,8 @@ SELECT pg_log_backend_memory_contexts(pid) FROM pg_stat_activity
t
(1 row)
-CREATE ROLE regress_log_memory;
-SELECT has_function_privilege('regress_log_memory',
+CREATE ROLE regress_log_function;
+SELECT has_function_privilege('regress_log_function',
'pg_log_backend_memory_contexts(integer)', 'EXECUTE'); -- no
has_function_privilege
------------------------
@@ -306,15 +307,15 @@ SELECT has_function_privilege('regress_log_memory',
(1 row)
GRANT EXECUTE ON FUNCTION pg_log_backend_memory_contexts(integer)
- TO regress_log_memory;
-SELECT has_function_privilege('regress_log_memory',
+ TO regress_log_function;
+SELECT has_function_privilege('regress_log_function',
'pg_log_backend_memory_contexts(integer)', 'EXECUTE'); -- yes
has_function_privilege
------------------------
t
(1 row)
-SET ROLE regress_log_memory;
+SET ROLE regress_log_function;
SELECT pg_log_backend_memory_contexts(pg_backend_pid());
pg_log_backend_memory_contexts
--------------------------------
@@ -323,8 +324,41 @@ SELECT pg_log_backend_memory_contexts(pg_backend_pid());
RESET ROLE;
REVOKE EXECUTE ON FUNCTION pg_log_backend_memory_contexts(integer)
- FROM regress_log_memory;
-DROP ROLE regress_log_memory;
+ FROM regress_log_function;
+-- pg_log_query_plan()
+SELECT pg_log_query_plan(pg_backend_pid());
+ pg_log_query_plan
+-------------------
+ t
+(1 row)
+
+SELECT has_function_privilege('regress_log_function',
+ '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_function;
+SELECT has_function_privilege('regress_log_function',
+ 'pg_log_query_plan(integer)', 'EXECUTE'); -- yes
+ has_function_privilege
+------------------------
+ t
+(1 row)
+
+SET ROLE regress_log_function;
+SELECT pg_log_query_plan(pg_backend_pid());
+ pg_log_query_plan
+-------------------
+ t
+(1 row)
+
+RESET ROLE;
+REVOKE EXECUTE ON FUNCTION pg_log_query_plan(integer)
+ FROM regress_log_function;
+DROP ROLE regress_log_function;
--
-- Test some built-in SRFs
--
diff --git a/src/test/regress/sql/misc_functions.sql b/src/test/regress/sql/misc_functions.sql
index b57f01f3e9..84327408d8 100644
--- a/src/test/regress/sql/misc_functions.sql
+++ b/src/test/regress/sql/misc_functions.sql
@@ -68,39 +68,60 @@ SELECT test_canonicalize_path('./abc/./def/.');
SELECT test_canonicalize_path('./abc/././def/.');
SELECT test_canonicalize_path('./abc/./def/.././ghi/../../../jkl/mno');
+-- Test logging functions
--
--- pg_log_backend_memory_contexts()
---
--- Memory contexts are logged and they are not returned to the function.
+-- The outputs of these functions are logged and they are not returned to
+-- the function.
-- Furthermore, their contents can vary depending on the timing. However,
-- we can at least verify that the code doesn't fail, and that the
-- permissions are set properly.
--
+-- pg_log_backend_memory_contexts()
+
SELECT pg_log_backend_memory_contexts(pg_backend_pid());
SELECT pg_log_backend_memory_contexts(pid) FROM pg_stat_activity
WHERE backend_type = 'checkpointer';
-CREATE ROLE regress_log_memory;
+CREATE ROLE regress_log_function;
-SELECT has_function_privilege('regress_log_memory',
+SELECT has_function_privilege('regress_log_function',
'pg_log_backend_memory_contexts(integer)', 'EXECUTE'); -- no
GRANT EXECUTE ON FUNCTION pg_log_backend_memory_contexts(integer)
- TO regress_log_memory;
+ TO regress_log_function;
-SELECT has_function_privilege('regress_log_memory',
+SELECT has_function_privilege('regress_log_function',
'pg_log_backend_memory_contexts(integer)', 'EXECUTE'); -- yes
-SET ROLE regress_log_memory;
+SET ROLE regress_log_function;
SELECT pg_log_backend_memory_contexts(pg_backend_pid());
RESET ROLE;
REVOKE EXECUTE ON FUNCTION pg_log_backend_memory_contexts(integer)
- FROM regress_log_memory;
+ FROM regress_log_function;
+
+-- pg_log_query_plan()
+SELECT pg_log_query_plan(pg_backend_pid());
+
+SELECT has_function_privilege('regress_log_function',
+ 'pg_log_query_plan(integer)', 'EXECUTE'); -- no
+
+GRANT EXECUTE ON FUNCTION pg_log_query_plan(integer)
+ TO regress_log_function;
+
+SELECT has_function_privilege('regress_log_function',
+ 'pg_log_query_plan(integer)', 'EXECUTE'); -- yes
+
+SET ROLE regress_log_function;
+SELECT pg_log_query_plan(pg_backend_pid());
+RESET ROLE;
+
+REVOKE EXECUTE ON FUNCTION pg_log_query_plan(integer)
+ FROM regress_log_function;
-DROP ROLE regress_log_memory;
+DROP ROLE regress_log_function;
--
-- Test some built-in SRFs
base-commit: f0efa5aec19358e2282d4968a03db1db56f0ac3f
--
2.39.2
