[PROPOSAL] Detecting plan changes with plan_id in pg_stat_activity

From 7cd8ce4552b8e73baa8b607e7bbd4f4f32b384fb Mon Sep 17 00:00:00 2001
From: "Imseih (AWS)" <simseih@88665a22795f.ant.amazon.com>
Date: Wed, 15 Jun 2022 12:27:09 -0500
Subject: [PATCH 1/1] Compute Plan Id in Core

---
 contrib/pg_stat_statements/Makefile           |   1 +
 .../pg_stat_statements--1.10--1.11.sql        | 142 +++++
 .../pg_stat_statements/pg_stat_statements.c   | 290 +++++++---
 .../pg_stat_statements.control                |   2 +-
 doc/src/sgml/config.sgml                      |   2 +-
 doc/src/sgml/monitoring.sgml                  |  16 +
 doc/src/sgml/pgstatstatements.sgml            | 454 +++++++++++++++
 src/backend/catalog/system_views.sql          |   1 +
 src/backend/commands/explain.c                |   2 +
 src/backend/executor/execMain.c               |   8 +-
 src/backend/executor/execParallel.c           |   1 +
 src/backend/nodes/copyfuncs.c                 |   1 +
 src/backend/nodes/outfuncs.c                  |   1 +
 src/backend/nodes/readfuncs.c                 |   1 +
 src/backend/optimizer/plan/planner.c          |   7 +
 src/backend/tcop/postgres.c                   |   1 +
 src/backend/utils/activity/backend_status.c   |  65 +++
 src/backend/utils/adt/pgstatfuncs.c           |   8 +-
 src/backend/utils/error/csvlog.c              |   3 +
 src/backend/utils/error/elog.c                |  11 +
 src/backend/utils/error/jsonlog.c             |   3 +
 src/backend/utils/misc/postgresql.conf.sample |   2 +-
 src/backend/utils/misc/queryjumble.c          | 533 +++++++++++++++++-
 src/include/catalog/pg_proc.dat               |   6 +-
 src/include/nodes/plannodes.h                 |   1 +
 src/include/utils/backend_status.h            |   7 +-
 src/include/utils/queryjumble.h               |   2 +
 src/test/regress/expected/explain.out         |   3 +-
 src/test/regress/expected/rules.out           |   9 +-
 29 files changed, 1493 insertions(+), 90 deletions(-)
 create mode 100644 contrib/pg_stat_statements/pg_stat_statements--1.10--1.11.sql

diff --git a/contrib/pg_stat_statements/Makefile b/contrib/pg_stat_statements/Makefile
index edc40c8..8d78797 100644
--- a/contrib/pg_stat_statements/Makefile
+++ b/contrib/pg_stat_statements/Makefile
@@ -7,6 +7,7 @@ OBJS = \
 
 EXTENSION = pg_stat_statements
 DATA = pg_stat_statements--1.4.sql \
+	pg_stat_statements--1.10--1.11.sql \
 	pg_stat_statements--1.9--1.10.sql pg_stat_statements--1.8--1.9.sql \
 	pg_stat_statements--1.7--1.8.sql pg_stat_statements--1.6--1.7.sql \
 	pg_stat_statements--1.5--1.6.sql pg_stat_statements--1.4--1.5.sql \
diff --git a/contrib/pg_stat_statements/pg_stat_statements--1.10--1.11.sql b/contrib/pg_stat_statements/pg_stat_statements--1.10--1.11.sql
new file mode 100644
index 0000000..bd51394
--- /dev/null
+++ b/contrib/pg_stat_statements/pg_stat_statements--1.10--1.11.sql
@@ -0,0 +1,142 @@
+/* contrib/pg_stat_statements/pg_stat_statements--1.10--1.11.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION pg_stat_statements UPDATE TO '1.11'" to load this file. \quit
+
+/* First we have to remove them from the extension */
+ALTER EXTENSION pg_stat_statements DROP VIEW pg_stat_statements;
+ALTER EXTENSION pg_stat_statements DROP FUNCTION pg_stat_statements(boolean);
+
+/* Then we can drop them */
+DROP VIEW pg_stat_statements;
+DROP FUNCTION pg_stat_statements(boolean);
+
+/* Now redefine */
+CREATE FUNCTION pg_stat_statements(IN showtext boolean,
+    OUT userid oid,
+    OUT dbid oid,
+    OUT toplevel bool,
+    OUT queryid bigint,
+    OUT planid bigint,
+    OUT query text,
+    OUT plans int8,
+    OUT total_plan_time float8,
+    OUT min_plan_time float8,
+    OUT max_plan_time float8,
+    OUT mean_plan_time float8,
+    OUT stddev_plan_time float8,
+    OUT calls int8,
+    OUT total_exec_time float8,
+    OUT min_exec_time float8,
+    OUT max_exec_time float8,
+    OUT mean_exec_time float8,
+    OUT stddev_exec_time float8,
+    OUT rows int8,
+    OUT shared_blks_hit int8,
+    OUT shared_blks_read int8,
+    OUT shared_blks_dirtied int8,
+    OUT shared_blks_written int8,
+    OUT local_blks_hit int8,
+    OUT local_blks_read int8,
+    OUT local_blks_dirtied int8,
+    OUT local_blks_written int8,
+    OUT temp_blks_read int8,
+    OUT temp_blks_written int8,
+    OUT blk_read_time float8,
+    OUT blk_write_time float8,
+    OUT temp_blk_read_time float8,
+    OUT temp_blk_write_time float8,
+    OUT wal_records int8,
+    OUT wal_fpi int8,
+    OUT wal_bytes numeric,
+    OUT jit_functions int8,
+    OUT jit_generation_time float8,
+    OUT jit_inlining_count int8,
+    OUT jit_inlining_time float8,
+    OUT jit_optimization_count int8,
+    OUT jit_optimization_time float8,
+    OUT jit_emission_count int8,
+    OUT jit_emission_time float8
+)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'pg_stat_statements_1_11'
+LANGUAGE C STRICT VOLATILE PARALLEL SAFE;
+
+CREATE VIEW pg_stat_statements AS
+select
+    userid,
+    dbid,
+    toplevel,
+    queryid,
+    query,
+    SUM(plans) plans,
+    SUM(total_plan_time) as total_plan_time,
+    SUM(min_plan_time) as min_plan_time,
+    SUM(max_plan_time) as max_plan_time,
+    SUM(mean_plan_time) as mean_plan_time,
+    SUM(stddev_plan_time) as stddev_plan_time,
+    SUM(calls) as calls,
+    SUM(total_exec_time) as total_exec_time,
+    SUM(min_exec_time) as min_exec_time,
+    SUM(max_exec_time) as max_exec_time,
+    SUM(mean_exec_time) as mean_exec_time,
+    SUM(stddev_exec_time) as stddev_exec_time,
+    SUM(rows) as rows,
+    SUM(shared_blks_hit) as shared_blks_hit,
+    SUM(shared_blks_read) as shared_blks_read,
+    SUM(shared_blks_dirtied) as shared_blks_dirtied,
+    SUM(shared_blks_written) as shared_blks_written,
+    SUM(local_blks_hit) as local_blks_hit,
+    SUM(local_blks_read) as local_blks_read,
+    SUM(local_blks_dirtied) as local_blks_dirtied,
+    SUM(local_blks_written) as local_blks_written,
+    SUM(temp_blks_read) as temp_blks_read,
+    SUM(temp_blks_written) as temp_blks_written,
+    SUM(blk_read_time) as blk_read_time,
+    SUM(blk_write_time) as blk_write_time,
+    SUM(temp_blk_read_time) as temp_blk_read_time,
+    SUM(temp_blk_write_time) as temp_blk_write_time,
+    SUM(wal_records) as wal_records,
+    SUM(wal_fpi) as wal_fpi,
+    SUM(wal_bytes) as wal_bytes,
+    SUM(jit_functions) as jit_functions,
+    SUM(jit_generation_time) as jit_generation_time,
+    SUM(jit_inlining_count) as jit_inlining_count,
+    SUM(jit_inlining_time) as jit_inlining_time,
+    SUM(jit_optimization_count) as jit_optimization_count,
+    SUM(jit_optimization_time) as jit_optimization_time,
+    SUM(jit_emission_count) as jit_emission_count,
+    SUM(jit_emission_time) as jit_emission_time
+from pg_stat_statements(true)
+group by
+	userid,
+    dbid,
+    toplevel,
+    queryid,
+    query;
+
+GRANT SELECT ON pg_stat_statements TO PUBLIC;
+
+CREATE VIEW pg_stat_statements_plan AS
+	select * from pg_stat_statements(true);
+
+GRANT SELECT ON pg_stat_statements_plan TO PUBLIC;
+
+/* First we have to remove them from the extension */
+ALTER EXTENSION pg_stat_statements DROP FUNCTION pg_stat_statements_reset(oid, oid, bigint);
+
+/* Then we can drop them */
+DROP FUNCTION pg_stat_statements_reset(oid, oid, bigint);
+
+/* Now redefine */
+CREATE FUNCTION pg_stat_statements_reset(IN userid Oid DEFAULT 0,
+    IN dbid Oid DEFAULT 0,
+    IN queryid bigint DEFAULT 0,
+	IN planid bigint DEFAULT 0
+)
+RETURNS void
+AS 'MODULE_PATHNAME', 'pg_stat_statements_reset_1_11'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+-- Don't want this to be available to non-superusers.
+REVOKE ALL ON FUNCTION pg_stat_statements_reset(Oid, Oid, bigint, bigint) FROM PUBLIC;
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index 768cedd..c982d41 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -118,7 +118,8 @@ typedef enum pgssVersion
 	PGSS_V1_3,
 	PGSS_V1_8,
 	PGSS_V1_9,
-	PGSS_V1_10
+	PGSS_V1_10,
+	PGSS_V1_11
 } pgssVersion;
 
 typedef enum pgssStoreKind
@@ -150,9 +151,20 @@ typedef struct pgssHashKey
 	Oid			userid;			/* user OID */
 	Oid			dbid;			/* database OID */
 	uint64		queryid;		/* query identifier */
+	uint64		planid;			/* plan identifier */
 	bool		toplevel;		/* query executed at top level */
 } pgssHashKey;
 
+/*
+ * Hashtable key that defines the indentity of a query
+ * in the external query file.
+ */
+typedef struct qtextHashKey
+{
+	uint64		queryid;		/* query identifier */
+} qtextHashKey;
+
+
 /*
  * The actual stats counters kept within pgssEntry.
  */
@@ -228,6 +240,23 @@ typedef struct pgssEntry
 	slock_t		mutex;			/* protects the counters only */
 } pgssEntry;
 
+/*
+ * Offsets per query text
+ *
+ * This is a hash that allows for mapping the offsets
+ * of a query in the external text file using a queryid.
+ * This is required so when we attempt to allocate an
+ * entry in pgss_hash with a planid, we can do a lookup
+ * of the query text offsets. See comments in pgss_store
+ * for more details.
+ */
+typedef struct qtextEntry
+{
+	qtextHashKey key;           /* hash key of entry - MUST BE FIRST */
+	Size        query_offset;   /* query text offset in external file */
+	int         query_len;      /* # of valid bytes in query string, or -1 */
+} qtextEntry;
+
 /*
  * Global shared state
  */
@@ -265,6 +294,7 @@ static ProcessUtility_hook_type prev_ProcessUtility = NULL;
 /* Links to shared memory state */
 static pgssSharedState *pgss = NULL;
 static HTAB *pgss_hash = NULL;
+static HTAB *qtext_hash = NULL;
 
 /*---- GUC variables ----*/
 
@@ -309,11 +339,13 @@ void		_PG_init(void);
 
 PG_FUNCTION_INFO_V1(pg_stat_statements_reset);
 PG_FUNCTION_INFO_V1(pg_stat_statements_reset_1_7);
+PG_FUNCTION_INFO_V1(pg_stat_statements_reset_1_11);
 PG_FUNCTION_INFO_V1(pg_stat_statements_1_2);
 PG_FUNCTION_INFO_V1(pg_stat_statements_1_3);
 PG_FUNCTION_INFO_V1(pg_stat_statements_1_8);
 PG_FUNCTION_INFO_V1(pg_stat_statements_1_9);
 PG_FUNCTION_INFO_V1(pg_stat_statements_1_10);
+PG_FUNCTION_INFO_V1(pg_stat_statements_1_11);
 PG_FUNCTION_INFO_V1(pg_stat_statements);
 PG_FUNCTION_INFO_V1(pg_stat_statements_info);
 
@@ -337,7 +369,7 @@ static void pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
 								ProcessUtilityContext context, ParamListInfo params,
 								QueryEnvironment *queryEnv,
 								DestReceiver *dest, QueryCompletion *qc);
-static void pgss_store(const char *query, uint64 queryId,
+static void pgss_store(const char *query, uint64 queryId, uint64 planId,
 					   int query_location, int query_len,
 					   pgssStoreKind kind,
 					   double total_time, uint64 rows,
@@ -359,7 +391,7 @@ static char *qtext_fetch(Size query_offset, int query_len,
 						 char *buffer, Size buffer_size);
 static bool need_gc_qtexts(void);
 static void gc_qtexts(void);
-static void entry_reset(Oid userid, Oid dbid, uint64 queryid);
+static void entry_reset(Oid userid, Oid dbid, uint64 queryid, uint64 planid);
 static char *generate_normalized_query(JumbleState *jstate, const char *query,
 									   int query_loc, int *query_len_p);
 static void fill_in_constant_lengths(JumbleState *jstate, const char *query,
@@ -516,6 +548,7 @@ pgss_shmem_startup(void)
 	/* reset in case this is a restart within the postmaster */
 	pgss = NULL;
 	pgss_hash = NULL;
+	qtext_hash = NULL;
 
 	/*
 	 * Create or attach to the shared memory state, including hash table
@@ -547,6 +580,17 @@ pgss_shmem_startup(void)
 							  &info,
 							  HASH_ELEM | HASH_BLOBS);
 
+	/*
+	 * It may be ok to set the size of the qtext_hash to
+	 * something much smaller than pgss_max.
+	 */
+	info.keysize = sizeof(qtextHashKey);
+	info.entrysize = sizeof(qtextEntry);
+	qtext_hash = ShmemInitHash("pg_stat_statements query text hash",
+							  pgss_max, pgss_max,
+							  &info,
+							  HASH_ELEM | HASH_BLOBS);
+
 	LWLockRelease(AddinShmemInitLock);
 
 	/*
@@ -735,7 +779,7 @@ pgss_shmem_shutdown(int code, Datum arg)
 		return;
 
 	/* Safety check ... shouldn't get here unless shmem is set up. */
-	if (!pgss || !pgss_hash)
+	if (!pgss || !pgss_hash || !qtext_hash)
 		return;
 
 	/* Don't dump if told not to. */
@@ -827,7 +871,7 @@ pgss_post_parse_analyze(ParseState *pstate, Query *query, JumbleState *jstate)
 		prev_post_parse_analyze_hook(pstate, query, jstate);
 
 	/* Safety check... */
-	if (!pgss || !pgss_hash || !pgss_enabled(exec_nested_level))
+	if (!pgss || !pgss_hash || !pgss_enabled(exec_nested_level) || !qtext_hash)
 		return;
 
 	/*
@@ -852,6 +896,7 @@ pgss_post_parse_analyze(ParseState *pstate, Query *query, JumbleState *jstate)
 	if (jstate && jstate->clocations_count > 0)
 		pgss_store(pstate->p_sourcetext,
 				   query->queryId,
+				   0,
 				   query->stmt_location,
 				   query->stmt_len,
 				   PGSS_INVALID,
@@ -937,6 +982,7 @@ pgss_planner(Query *parse,
 
 		pgss_store(query_string,
 				   parse->queryId,
+				   result->planId,
 				   parse->stmt_location,
 				   parse->stmt_len,
 				   PGSS_PLAN,
@@ -1044,6 +1090,7 @@ static void
 pgss_ExecutorEnd(QueryDesc *queryDesc)
 {
 	uint64		queryId = queryDesc->plannedstmt->queryId;
+	uint64		planId = queryDesc->plannedstmt->planId;
 
 	if (queryId != UINT64CONST(0) && queryDesc->totaltime &&
 		pgss_enabled(exec_nested_level))
@@ -1056,6 +1103,7 @@ pgss_ExecutorEnd(QueryDesc *queryDesc)
 
 		pgss_store(queryDesc->sourceText,
 				   queryId,
+				   planId,
 				   queryDesc->plannedstmt->stmt_location,
 				   queryDesc->plannedstmt->stmt_len,
 				   PGSS_EXEC,
@@ -1174,6 +1222,7 @@ pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
 
 		pgss_store(queryString,
 				   saved_queryId,
+				   0,
 				   pstmt->stmt_location,
 				   pstmt->stmt_len,
 				   PGSS_EXEC,
@@ -1202,14 +1251,34 @@ pgss_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
  *
  * If jstate is not NULL then we're trying to create an entry for which
  * we have no statistics as yet; we just want to record the normalized
- * query string.  total_time, rows, bufusage and walusage are ignored in this
- * case.
+ * query string in the external text file and qtext_hash.
  *
  * If kind is PGSS_PLAN or PGSS_EXEC, its value is used as the array position
  * for the arrays in the Counters field.
+ *
+ * How does qtext_hash and pgss_hash work together?
+ * When we need to allocate a new entry in pgss_hash, we need
+ * to have the offsets of the query text.
+ *
+ * If a query text was previously added to pgss_hash using a
+ * different planid, we can consult qtext_hash for the offsets.
+ *
+ * If the offsets are found in qtext_hash, use them in the new
+ * pgss_hash entry, else add the text to the external file and
+ * qtext_hash. After that the new pgss_hash entry can be allocated.
+ *
+ * If qtext_hash runs out of memory, we remove all the rows from
+ * the hash and retry. There is edge case where after qtext_hash
+ * cleanup, a new pgss_hash entry with a different plan_id for an
+ * existing query text will end up creating a similar SQL text in
+ * the external file. This should not be a common case and the file
+ * will be cleaned up by gc_qtext soon after.
+ *
+ * The above interaction occurs while holding an exclusive lock on
+ * pgss->lock.
  */
 static void
-pgss_store(const char *query, uint64 queryId,
+pgss_store(const char *query, uint64 queryId, uint64 planId,
 		   int query_location, int query_len,
 		   pgssStoreKind kind,
 		   double total_time, uint64 rows,
@@ -1219,14 +1288,16 @@ pgss_store(const char *query, uint64 queryId,
 		   JumbleState *jstate)
 {
 	pgssHashKey key;
+	qtextHashKey qkey;
 	pgssEntry  *entry;
+	qtextEntry *qentry;
 	char	   *norm_query = NULL;
 	int			encoding = GetDatabaseEncoding();
 
 	Assert(query != NULL);
 
 	/* Safety check... */
-	if (!pgss || !pgss_hash)
+	if (!pgss || !pgss_hash || !qtext_hash)
 		return;
 
 	/*
@@ -1251,10 +1322,12 @@ pgss_store(const char *query, uint64 queryId,
 	key.userid = GetUserId();
 	key.dbid = MyDatabaseId;
 	key.queryid = queryId;
+	key.planid = planId;
+	qkey.queryid = queryId;
 	key.toplevel = (exec_nested_level == 0);
 
 	/* Lookup the hash table entry with shared lock. */
-	LWLockAcquire(pgss->lock, LW_SHARED);
+			LWLockAcquire(pgss->lock, LW_SHARED);
 
 	entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_FIND, NULL);
 
@@ -1264,57 +1337,87 @@ pgss_store(const char *query, uint64 queryId,
 		Size		query_offset;
 		int			gc_count;
 		bool		stored;
-		bool		do_gc;
+		bool		do_gc = false;
 
-		/*
-		 * Create a new, normalized query string if caller asked.  We don't
-		 * need to hold the lock while doing this work.  (Note: in any case,
-		 * it's possible that someone else creates a duplicate hashtable entry
-		 * in the interval where we don't hold the lock below.  That case is
-		 * handled by entry_alloc.)
-		 */
-		if (jstate)
+		qentry = (qtextEntry *) hash_search(qtext_hash, &qkey, HASH_FIND, NULL);
+		if (!qentry)
 		{
+			/*
+			 * Create a new, normalized query string if caller asked.  We don't
+			 * need to hold the lock while doing this work.  (Note: in any case,
+			 * it's possible that someone else creates a duplicate hashtable entry
+			 * in the interval where we don't hold the lock below.  That case is
+			 * handled by entry_alloc.)
+			 */
+			if (jstate)
+			{
+				LWLockRelease(pgss->lock);
+				norm_query = generate_normalized_query(jstate, query,
+													   query_location,
+													   &query_len);
+				LWLockAcquire(pgss->lock, LW_SHARED);
+			}
+
+			/* Append new query text to file with only shared lock held */
+			stored = qtext_store(norm_query ? norm_query : query, query_len,
+								 &query_offset, &gc_count);
+
+			/*
+			 * Determine whether we need to garbage collect external query texts
+			 * while the shared lock is still held.  This micro-optimization
+			 * avoids taking the time to decide this while holding exclusive lock.
+			 */
+			do_gc = need_gc_qtexts();
+
+			/* Need exclusive lock to make a new hashtable entry - promote */
 			LWLockRelease(pgss->lock);
-			norm_query = generate_normalized_query(jstate, query,
-												   query_location,
-												   &query_len);
-			LWLockAcquire(pgss->lock, LW_SHARED);
-		}
+			LWLockAcquire(pgss->lock, LW_EXCLUSIVE);
 
-		/* Append new query text to file with only shared lock held */
-		stored = qtext_store(norm_query ? norm_query : query, query_len,
-							 &query_offset, &gc_count);
+			/*
+			 * A garbage collection may have occurred while we weren't holding the
+			 * lock.  In the unlikely event that this happens, the query text we
+			 * stored above will have been garbage collected, so write it again.
+			 * This should be infrequent enough that doing it while holding
+			 * exclusive lock isn't a performance problem.
+			 */
+			if (!stored || pgss->gc_count != gc_count)
+				stored = qtext_store(norm_query ? norm_query : query, query_len,
+									 &query_offset, NULL);
 
-		/*
-		 * Determine whether we need to garbage collect external query texts
-		 * while the shared lock is still held.  This micro-optimization
-		 * avoids taking the time to decide this while holding exclusive lock.
-		 */
-		do_gc = need_gc_qtexts();
+			/* If we failed to write to the text file, give up */
+			if (!stored)
+				goto done;
 
-		/* Need exclusive lock to make a new hashtable entry - promote */
-		LWLockRelease(pgss->lock);
-		LWLockAcquire(pgss->lock, LW_EXCLUSIVE);
+			qentry = hash_search(qtext_hash, &qkey, HASH_ENTER_NULL, NULL);
 
-		/*
-		 * A garbage collection may have occurred while we weren't holding the
-		 * lock.  In the unlikely event that this happens, the query text we
-		 * stored above will have been garbage collected, so write it again.
-		 * This should be infrequent enough that doing it while holding
-		 * exclusive lock isn't a performance problem.
-		 */
-		if (!stored || pgss->gc_count != gc_count)
-			stored = qtext_store(norm_query ? norm_query : query, query_len,
-								 &query_offset, NULL);
+			if (!qentry)
+			{
+				qtextEntry *qqentry;
+				HASH_SEQ_STATUS hashq_seq;
 
-		/* If we failed to write to the text file, give up */
-		if (!stored)
-			goto done;
+				/* Remove all entries. */
+				hash_seq_init(&hashq_seq, qtext_hash);
+				while ((qqentry = hash_seq_search(&hashq_seq)) != NULL)
+					hash_search(qtext_hash, &qqentry->key, HASH_REMOVE, NULL);
 
-		/* OK to create a new hashtable entry */
-		entry = entry_alloc(&key, query_offset, query_len, encoding,
-							jstate != NULL);
+				qentry = hash_search(qtext_hash, &qkey, HASH_ENTER, NULL);
+				if (!qentry)
+					goto done;
+			}
+
+
+			qentry->query_offset = query_offset;
+			qentry->query_len = query_len;
+		} else
+		{
+			query_offset = qentry->query_offset;
+			query_len = qentry->query_len;
+		}
+
+		if (kind != PGSS_INVALID)
+			/* OK to create a new hashtable entry */
+			entry = entry_alloc(&key, query_offset, query_len, encoding,
+								jstate != NULL);
 
 		/* If needed, perform garbage collection while exclusive lock held */
 		if (do_gc)
@@ -1418,17 +1521,27 @@ done:
  * Reset statement statistics corresponding to userid, dbid, and queryid.
  */
 Datum
-pg_stat_statements_reset_1_7(PG_FUNCTION_ARGS)
-{
-	Oid			userid;
-	Oid			dbid;
-	uint64		queryid;
+pg_stat_statements_reset_1_11(PG_FUNCTION_ARGS)
+ {
+	Oid                     userid;
+	Oid                     dbid;
+	uint64          queryid;
+	uint64          planid;
 
 	userid = PG_GETARG_OID(0);
 	dbid = PG_GETARG_OID(1);
 	queryid = (uint64) PG_GETARG_INT64(2);
+	planid = (uint64) PG_GETARG_INT64(3);
+
+	entry_reset(userid, dbid, queryid, planid);
+
+	PG_RETURN_VOID();
+}
 
-	entry_reset(userid, dbid, queryid);
+Datum
+pg_stat_statements_reset_1_7(PG_FUNCTION_ARGS)
+{
+	entry_reset(0, 0, 0, 0);
 
 	PG_RETURN_VOID();
 }
@@ -1439,7 +1552,7 @@ pg_stat_statements_reset_1_7(PG_FUNCTION_ARGS)
 Datum
 pg_stat_statements_reset(PG_FUNCTION_ARGS)
 {
-	entry_reset(0, 0, 0);
+	entry_reset(0, 0, 0, 0);
 
 	PG_RETURN_VOID();
 }
@@ -1452,7 +1565,8 @@ pg_stat_statements_reset(PG_FUNCTION_ARGS)
 #define PG_STAT_STATEMENTS_COLS_V1_8	32
 #define PG_STAT_STATEMENTS_COLS_V1_9	33
 #define PG_STAT_STATEMENTS_COLS_V1_10	43
-#define PG_STAT_STATEMENTS_COLS			43	/* maximum of above */
+#define PG_STAT_STATEMENTS_COLS_V1_11	44
+#define PG_STAT_STATEMENTS_COLS			44	/* maximum of above */
 
 /*
  * Retrieve statement statistics.
@@ -1464,6 +1578,16 @@ pg_stat_statements_reset(PG_FUNCTION_ARGS)
  * expected API version is identified by embedding it in the C name of the
  * function.  Unfortunately we weren't bright enough to do that for 1.1.
  */
+Datum
+pg_stat_statements_1_11(PG_FUNCTION_ARGS)
+{
+	bool        showtext = PG_GETARG_BOOL(0);
+
+	pg_stat_statements_internal(fcinfo, PGSS_V1_11, showtext);
+
+	return (Datum) 0;
+}
+
 Datum
 pg_stat_statements_1_10(PG_FUNCTION_ARGS)
 {
@@ -1550,7 +1674,7 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 	is_allowed_role = has_privs_of_role(userid, ROLE_PG_READ_ALL_STATS);
 
 	/* hash table must exist already */
-	if (!pgss || !pgss_hash)
+	if (!pgss || !pgss_hash || !qtext_hash)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
@@ -1594,6 +1718,10 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 			if (api_version != PGSS_V1_10)
 				elog(ERROR, "incorrect number of output arguments");
 			break;
+		case PG_STAT_STATEMENTS_COLS_V1_11:
+			if (api_version != PGSS_V1_11)
+				elog(ERROR, "incorrect number of output arguments");
+			break;
 		default:
 			elog(ERROR, "incorrect number of output arguments");
 	}
@@ -1672,6 +1800,7 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 		Counters	tmp;
 		double		stddev;
 		int64		queryid = entry->key.queryid;
+		int64       planid = entry->key.planid;
 
 		memset(values, 0, sizeof(values));
 		memset(nulls, 0, sizeof(nulls));
@@ -1686,6 +1815,9 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 			if (api_version >= PGSS_V1_2)
 				values[i++] = Int64GetDatumFast(queryid);
 
+			if (api_version >= PGSS_V1_11)
+				values[i++] = Int64GetDatumFast(planid);
+
 			if (showtext)
 			{
 				char	   *qstr = qtext_fetch(entry->query_offset,
@@ -1724,6 +1856,10 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 			if (api_version >= PGSS_V1_2)
 				nulls[i++] = true;
 
+			/* Don't show planid */
+			if (api_version >= PGSS_V1_11)
+				nulls[i++] = true;
+
 			/*
 			 * Don't show query text, but hint as to the reason for not doing
 			 * so if it was requested
@@ -1835,6 +1971,7 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo,
 					 api_version == PGSS_V1_8 ? PG_STAT_STATEMENTS_COLS_V1_8 :
 					 api_version == PGSS_V1_9 ? PG_STAT_STATEMENTS_COLS_V1_9 :
 					 api_version == PGSS_V1_10 ? PG_STAT_STATEMENTS_COLS_V1_10 :
+					 api_version == PGSS_V1_10 ? PG_STAT_STATEMENTS_COLS_V1_11 :
 					 -1 /* fail if you forget to update this assert */ ));
 
 		tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
@@ -1860,7 +1997,7 @@ pg_stat_statements_info(PG_FUNCTION_ARGS)
 	Datum		values[PG_STAT_STATEMENTS_INFO_COLS];
 	bool		nulls[PG_STAT_STATEMENTS_INFO_COLS];
 
-	if (!pgss || !pgss_hash)
+	if (!pgss || !pgss_hash || !qtext_hash)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
@@ -2497,7 +2634,7 @@ gc_fail:
  * Release entries corresponding to parameters passed.
  */
 static void
-entry_reset(Oid userid, Oid dbid, uint64 queryid)
+entry_reset(Oid userid, Oid dbid, uint64 queryid, uint64 planid)
 {
 	HASH_SEQ_STATUS hash_seq;
 	pgssEntry  *entry;
@@ -2505,8 +2642,9 @@ entry_reset(Oid userid, Oid dbid, uint64 queryid)
 	long		num_entries;
 	long		num_remove = 0;
 	pgssHashKey key;
+	qtextHashKey qkey;
 
-	if (!pgss || !pgss_hash)
+	if (!pgss || !pgss_hash || !qtext_hash)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("pg_stat_statements must be loaded via shared_preload_libraries")));
@@ -2514,16 +2652,20 @@ entry_reset(Oid userid, Oid dbid, uint64 queryid)
 	LWLockAcquire(pgss->lock, LW_EXCLUSIVE);
 	num_entries = hash_get_num_entries(pgss_hash);
 
-	if (userid != 0 && dbid != 0 && queryid != UINT64CONST(0))
+	if (userid != 0 && dbid != 0 && queryid != UINT64CONST(0) && planid != UINT64CONST(0))
 	{
 		/* If all the parameters are available, use the fast path. */
 		memset(&key, 0, sizeof(pgssHashKey));
+		memset(&qkey, 0, sizeof(qtextHashKey));
 		key.userid = userid;
 		key.dbid = dbid;
 		key.queryid = queryid;
+		key.planid = planid;
+		qkey.queryid = queryid;
 
 		/* Remove the key if it exists, starting with the top-level entry  */
 		key.toplevel = false;
+
 		entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_REMOVE, NULL);
 		if (entry)				/* found */
 			num_remove++;
@@ -2535,8 +2677,10 @@ entry_reset(Oid userid, Oid dbid, uint64 queryid)
 		entry = (pgssEntry *) hash_search(pgss_hash, &key, HASH_REMOVE, NULL);
 		if (entry)				/* found */
 			num_remove++;
+
+		hash_search(qtext_hash, &qkey, HASH_REMOVE, NULL);
 	}
-	else if (userid != 0 || dbid != 0 || queryid != UINT64CONST(0))
+	else if (userid != 0 || dbid != 0 || queryid != UINT64CONST(0) || planid != UINT64CONST(0))
 	{
 		/* Remove entries corresponding to valid parameters. */
 		hash_seq_init(&hash_seq, pgss_hash);
@@ -2544,10 +2688,16 @@ entry_reset(Oid userid, Oid dbid, uint64 queryid)
 		{
 			if ((!userid || entry->key.userid == userid) &&
 				(!dbid || entry->key.dbid == dbid) &&
-				(!queryid || entry->key.queryid == queryid))
+				(!queryid || entry->key.queryid == queryid) &&
+				(!planid || entry->key.planid == planid))
 			{
 				hash_search(pgss_hash, &entry->key, HASH_REMOVE, NULL);
 				num_remove++;
+				if (queryid)
+				{
+					qkey.queryid = queryid;
+					hash_search(qtext_hash, &qkey, HASH_REMOVE, NULL);
+				}
 			}
 		}
 	}
@@ -2560,6 +2710,12 @@ entry_reset(Oid userid, Oid dbid, uint64 queryid)
 			hash_search(pgss_hash, &entry->key, HASH_REMOVE, NULL);
 			num_remove++;
 		}
+
+		hash_seq_init(&hash_seq, qtext_hash);
+		while ((entry = hash_seq_search(&hash_seq)) != NULL)
+		{
+			hash_search(qtext_hash, &entry->key, HASH_REMOVE, NULL);
+		}
 	}
 
 	/* All entries are removed? */
diff --git a/contrib/pg_stat_statements/pg_stat_statements.control b/contrib/pg_stat_statements/pg_stat_statements.control
index 0747e48..8a76106 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.control
+++ b/contrib/pg_stat_statements/pg_stat_statements.control
@@ -1,5 +1,5 @@
 # pg_stat_statements extension
 comment = 'track planning and execution statistics of all SQL statements executed'
-default_version = '1.10'
+default_version = '1.11'
 module_pathname = '$libdir/pg_stat_statements'
 relocatable = true
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 5b7ce65..b1fdeea 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -8088,7 +8088,7 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </term>
       <listitem>
        <para>
-        Enables in-core computation of a query identifier.
+        Enables in-core computation of a query identifiers.
         Query identifiers can be displayed in the <link
         linkend="monitoring-pg-stat-activity-view"><structname>pg_stat_activity</structname></link>
         view, using <command>EXPLAIN</command>, or emitted in the log if
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 4549c25..651dadc 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -947,6 +947,22 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
      </para></entry>
     </row>
 
+    <row>
+     <entry role="catalog_table_entry"><para role="column_definition">
+      <structfield>plan_id</structfield> <type>bigint</type>
+     </para>
+     <para>
+      Identifier of this backend's most recent query plan. If
+      <structfield>state</structfield> is <literal>active</literal> this
+      field shows the identifier of the currently executing query plan. In
+      all other states, it shows the identifier of last query plan that was
+      executed.  Query plan identifiers are not computed by default so this
+      field will be null unless <xref linkend="guc-compute-query-id"/>
+      parameter is enabled or a third-party module that computes query
+      identifiers is configured.
+     </para></entry>
+    </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>query</structfield> <type>text</type>
diff --git a/doc/src/sgml/pgstatstatements.sgml b/doc/src/sgml/pgstatstatements.sgml
index ecf6cd6..0ca0e4b 100644
--- a/doc/src/sgml/pgstatstatements.sgml
+++ b/doc/src/sgml/pgstatstatements.sgml
@@ -602,6 +602,460 @@
   </para>
  </sect2>
 
+ <sect2>
+  <title>The <structname>pg_stat_statements_plan</structname> View</title>
+
+  <para>
+   This is view is similar to <structname>pg_stat_statements_plan</structname>
+   with an additional plan ID for each distinct row.
+  </para>
+
+  <table id="pgstatstatements-columns">
+   <title><structname>pg_stat_statements</structname> Columns</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>userid</structfield> <type>oid</type>
+       (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of user who executed the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>dbid</structfield> <type>oid</type>
+       (references <link linkend="catalog-pg-database"><structname>pg_database</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of database in which the statement was executed
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>toplevel</structfield> <type>bool</type>
+      </para>
+      <para>
+       True if the query was executed as a top-level statement
+       (always true if <varname>pg_stat_statements.track</varname> is set to
+       <literal>top</literal>)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>queryid</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Hash code to identify identical normalized queries.
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>planid</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Hash code to identify the query plan.
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>query</structfield> <type>text</type>
+      </para>
+      <para>
+       Text of a representative statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>plans</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times the statement was planned
+       (if <varname>pg_stat_statements.track_planning</varname> is enabled,
+       otherwise zero)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_plan_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent planning the statement, in milliseconds
+       (if <varname>pg_stat_statements.track_planning</varname> is enabled,
+       otherwise zero)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>min_plan_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Minimum time spent planning the statement, in milliseconds
+       (if <varname>pg_stat_statements.track_planning</varname> is enabled,
+       otherwise zero)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>max_plan_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Maximum time spent planning the statement, in milliseconds
+       (if <varname>pg_stat_statements.track_planning</varname> is enabled,
+       otherwise zero)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>mean_plan_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Mean time spent planning the statement, in milliseconds
+       (if <varname>pg_stat_statements.track_planning</varname> is enabled,
+       otherwise zero)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>stddev_plan_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Population standard deviation of time spent planning the statement,
+       in milliseconds
+       (if <varname>pg_stat_statements.track_planning</varname> is enabled,
+       otherwise zero)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>calls</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times the statement was executed
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_exec_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent executing the statement, in milliseconds
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>min_exec_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Minimum time spent executing the statement, in milliseconds
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>max_exec_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Maximum time spent executing the statement, in milliseconds
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>mean_exec_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Mean time spent executing the statement, in milliseconds
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>stddev_exec_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Population standard deviation of time spent executing the statement, in milliseconds
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>rows</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of rows retrieved or affected by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>shared_blks_hit</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of shared block cache hits by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>shared_blks_read</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of shared blocks read by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>shared_blks_dirtied</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of shared blocks dirtied by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>shared_blks_written</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of shared blocks written by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>local_blks_hit</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of local block cache hits by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>local_blks_read</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of local blocks read by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>local_blks_dirtied</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of local blocks dirtied by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>local_blks_written</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of local blocks written by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>temp_blks_read</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of temp blocks read by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>temp_blks_written</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of temp blocks written by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>blk_read_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time the statement spent reading data file blocks, in milliseconds
+       (if <xref linkend="guc-track-io-timing"/> is enabled, otherwise zero)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>blk_write_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time the statement spent writing data file blocks, in milliseconds
+       (if <xref linkend="guc-track-io-timing"/> is enabled, otherwise zero)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>temp_blk_read_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time the statement spent reading temporary file blocks, in
+       milliseconds (if <xref linkend="guc-track-io-timing"/> is enabled,
+       otherwise zero)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>temp_blk_write_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time the statement spent writing temporary file blocks, in
+       milliseconds (if <xref linkend="guc-track-io-timing"/> is enabled,
+       otherwise zero)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>wal_records</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of WAL records generated by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>wal_fpi</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of WAL full page images generated by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>wal_bytes</structfield> <type>numeric</type>
+      </para>
+      <para>
+       Total amount of WAL generated by the statement in bytes
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>jit_functions</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total number of functions JIT-compiled by the statement
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>jit_generation_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent by the statement on generating JIT code, in milliseconds
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>jit_inlining_count</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times functions have been inlined
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>jit_inlining_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent by the statement on inlining functions, in milliseconds
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>jit_optimization_count</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times the statement has been optimized
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>jit_optimization_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent by the statement on optimizing, in milliseconds
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>jit_emission_count</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times code has been emitted
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>jit_emission_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent by the statement on emitting code, in milliseconds
+      </para></entry>
+     </row>
+    </tbody>
+   </tgroup>
+  </table>
+
+  <para>
+   For security reasons, only superusers and roles with privileges of the
+   <literal>pg_read_all_stats</literal> role are allowed to see the SQL text and
+   <structfield>queryid</structfield> of queries executed by other users.
+   Other users can see the statistics, however, if the view has been installed
+   in their database.
+  </para>
+ </sect2>
+
  <sect2>
   <title>The <structname>pg_stat_statements_info</structname> View</title>
 
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index fedaed5..86ff49e 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -863,6 +863,7 @@ CREATE VIEW pg_stat_activity AS
             S.backend_xid,
             s.backend_xmin,
             S.query_id,
+            S.plan_id,
             S.query,
             S.backend_type
     FROM pg_stat_get_activity(NULL) AS S
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 5d1f708..6d575c6 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -618,6 +618,8 @@ ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
 		 */
 		ExplainPropertyInteger("Query Identifier", NULL, (int64)
 							   plannedstmt->queryId, es);
+		ExplainPropertyInteger("Plan Identifier", NULL, (int64)
+							   plannedstmt->planId, es);
 	}
 
 	/* Show buffer usage in planning */
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index ef2fd46..4d132dd 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -132,11 +132,13 @@ ExecutorStart(QueryDesc *queryDesc, int eflags)
 {
 	/*
 	 * In some cases (e.g. an EXECUTE statement) a query execution will skip
-	 * parse analysis, which means that the query_id won't be reported.  Note
-	 * that it's harmless to report the query_id multiple time, as the call
-	 * will be ignored if the top level query_id has already been reported.
+	 * parse analysis and planning, which means that the query_id and plan_id
+	 * won't be reported.  Note that it's harmless to report the query_id and
+	 * plan_id multiple times, as the call will be ignored if the top level
+	 * query_id and plan_id has already been reported.
 	 */
 	pgstat_report_query_id(queryDesc->plannedstmt->queryId, false);
+	pgstat_report_plan_id(queryDesc->plannedstmt->planId, queryDesc->plannedstmt->queryId, false);
 
 	if (ExecutorStart_hook)
 		(*ExecutorStart_hook) (queryDesc, eflags);
diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c
index f1fd7f7..e23d5c0 100644
--- a/src/backend/executor/execParallel.c
+++ b/src/backend/executor/execParallel.c
@@ -176,6 +176,7 @@ ExecSerializePlan(Plan *plan, EState *estate)
 	pstmt = makeNode(PlannedStmt);
 	pstmt->commandType = CMD_SELECT;
 	pstmt->queryId = pgstat_get_my_query_id();
+	pstmt->planId = pgstat_get_my_plan_id();
 	pstmt->hasReturning = false;
 	pstmt->hasModifyingCTE = false;
 	pstmt->canSetTag = true;
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 51d630f..88a89a4 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -108,6 +108,7 @@ _copyPlannedStmt(const PlannedStmt *from)
 	COPY_NODE_FIELD(utilityStmt);
 	COPY_LOCATION_FIELD(stmt_location);
 	COPY_SCALAR_FIELD(stmt_len);
+	COPY_SCALAR_FIELD(planId);
 
 	return newnode;
 }
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index ce12915..6cdae95 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -313,6 +313,7 @@ _outPlannedStmt(StringInfo str, const PlannedStmt *node)
 
 	WRITE_ENUM_FIELD(commandType, CmdType);
 	WRITE_UINT64_FIELD(queryId);
+	WRITE_UINT64_FIELD(planId);
 	WRITE_BOOL_FIELD(hasReturning);
 	WRITE_BOOL_FIELD(hasModifyingCTE);
 	WRITE_BOOL_FIELD(canSetTag);
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 6a05b69..0c24e6f 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -1809,6 +1809,7 @@ _readPlannedStmt(void)
 
 	READ_ENUM_FIELD(commandType, CmdType);
 	READ_UINT64_FIELD(queryId);
+	READ_UINT64_FIELD(planId);
 	READ_BOOL_FIELD(hasReturning);
 	READ_BOOL_FIELD(hasModifyingCTE);
 	READ_BOOL_FIELD(canSetTag);
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index a0f2390..599fc4c 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -60,6 +60,7 @@
 #include "partitioning/partdesc.h"
 #include "rewrite/rewriteManip.h"
 #include "storage/dsm_impl.h"
+#include "utils/backend_status.h"
 #include "utils/lsyscache.h"
 #include "utils/rel.h"
 #include "utils/selfuncs.h"
@@ -560,6 +561,12 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
 	if (glob->partition_directory != NULL)
 		DestroyPartitionDirectory(glob->partition_directory);
 
+	/* If enabled, Compute the query and plan id */
+	if (IsQueryIdEnabled())
+		JumblePlan(result);
+
+	pgstat_report_plan_id(result->planId, result->queryId, false);
+
 	return result;
 }
 
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 8b6b5bb..fcf2838 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -1085,6 +1085,7 @@ exec_simple_query(const char *query_string)
 		DestReceiver *receiver;
 		int16		format;
 
+		pgstat_report_plan_id(0, 0, true);
 		pgstat_report_query_id(0, true);
 
 		/*
diff --git a/src/backend/utils/activity/backend_status.c b/src/backend/utils/activity/backend_status.c
index c7ed1e6..43d3bc1 100644
--- a/src/backend/utils/activity/backend_status.c
+++ b/src/backend/utils/activity/backend_status.c
@@ -399,6 +399,7 @@ pgstat_bestart(void)
 	lbeentry.st_progress_command = PROGRESS_COMMAND_INVALID;
 	lbeentry.st_progress_command_target = InvalidOid;
 	lbeentry.st_query_id = UINT64CONST(0);
+	lbeentry.st_plan_id = UINT64CONST(0);
 
 	/*
 	 * we don't zero st_progress_param here to save cycles; nobody should
@@ -549,6 +550,7 @@ pgstat_report_activity(BackendState state, const char *cmd_str)
 			/* st_xact_start_timestamp and wait_event_info are also disabled */
 			beentry->st_xact_start_timestamp = 0;
 			beentry->st_query_id = UINT64CONST(0);
+			beentry->st_plan_id = UINT64CONST(0);
 			proc->wait_event_info = 0;
 			PGSTAT_END_WRITE_ACTIVITY(beentry);
 		}
@@ -609,7 +611,10 @@ pgstat_report_activity(BackendState state, const char *cmd_str)
 	 * identifier.
 	 */
 	if (state == STATE_RUNNING)
+	{
+		beentry->st_plan_id = UINT64CONST(0);
 		beentry->st_query_id = UINT64CONST(0);
+	}
 
 	if (cmd_str != NULL)
 	{
@@ -625,6 +630,10 @@ pgstat_report_activity(BackendState state, const char *cmd_str)
  * pgstat_report_query_id() -
  *
  * Called to update top-level query identifier.
+ *
+ * Return if the query_id is updated. This is
+ * used to signal if the plan_id should be
+ * reported in pgstat_report_plan_id()
  * --------
  */
 void
@@ -660,6 +669,48 @@ pgstat_report_query_id(uint64 query_id, bool force)
 	PGSTAT_END_WRITE_ACTIVITY(beentry);
 }
 
+/* --------
+ * pgstat_report_plan_id() -
+ *
+ * Called to update the top-level plan identifier.
+ * --------
+ */
+void
+pgstat_report_plan_id(uint64 plan_id, uint64 query_id, bool force)
+{
+	volatile PgBackendStatus *beentry = MyBEEntry;
+
+	/*
+	 * if track_activities is disabled, st_query_id should already have been
+	 * reset
+	 */
+	if (!beentry || !pgstat_track_activities)
+		return;
+
+	/*
+	 * We only report the top-level plan identifiers.  The stored plan_id is
+	 * reset when a backend calls pgstat_report_activity(STATE_RUNNING), or
+	 * with an explicit call to this function using the force flag.  If the
+	 * saved plan identifier is not zero or the query identifier is 0,
+	 * it means that it's not a top-level command, so ignore the one provided
+	 * unless it's an explicit call to reset the identifier.
+	 *
+	 * NOTE: A query id being 0 by the time we set the plan_id indicates
+	 * that the we have already set the top-level query_id in the backend.
+	 */
+	if ((beentry->st_plan_id != 0 || query_id == 0) && !force)
+		return;
+
+	/*
+	 * Update my status entry, following the protocol of bumping
+	 * st_changecount before and after.  We use a volatile pointer here to
+	 * ensure the compiler doesn't try to get cute.
+	 */
+	PGSTAT_BEGIN_WRITE_ACTIVITY(beentry);
+	beentry->st_plan_id = plan_id;
+	PGSTAT_END_WRITE_ACTIVITY(beentry);
+}
+
 
 /* ----------
  * pgstat_report_appname() -
@@ -1045,6 +1096,20 @@ pgstat_get_my_query_id(void)
 	return MyBEEntry->st_query_id;
 }
 
+/* ----------
+ * pgstat_get_my_plan_id() -
+ *
+ * Return current backend's plan identifier.
+ */
+uint64
+pgstat_get_my_plan_id(void)
+{
+	if (!MyBEEntry)
+		return 0;
+
+	return MyBEEntry->st_plan_id;
+}
+
 
 /* ----------
  * pgstat_fetch_stat_beentry() -
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index 893690d..6fa5974 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -539,7 +539,7 @@ pg_stat_get_progress_info(PG_FUNCTION_ARGS)
 Datum
 pg_stat_get_activity(PG_FUNCTION_ARGS)
 {
-#define PG_STAT_GET_ACTIVITY_COLS	30
+#define PG_STAT_GET_ACTIVITY_COLS	31
 	int			num_backends = pgstat_fetch_stat_numbackends();
 	int			curr_backend;
 	int			pid = PG_ARGISNULL(0) ? -1 : PG_GETARG_INT32(0);
@@ -862,6 +862,11 @@ pg_stat_get_activity(PG_FUNCTION_ARGS)
 				nulls[29] = true;
 			else
 				values[29] = UInt64GetDatum(beentry->st_query_id);
+
+			if (beentry->st_plan_id == 0)
+				nulls[30] = true;
+			else
+				values[30] = UInt64GetDatum(beentry->st_plan_id);
 		}
 		else
 		{
@@ -890,6 +895,7 @@ pg_stat_get_activity(PG_FUNCTION_ARGS)
 			nulls[27] = true;
 			nulls[28] = true;
 			nulls[29] = true;
+			nulls[30] = true;
 		}
 
 		tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
diff --git a/src/backend/utils/error/csvlog.c b/src/backend/utils/error/csvlog.c
index 5c49bc4..f730bc5 100644
--- a/src/backend/utils/error/csvlog.c
+++ b/src/backend/utils/error/csvlog.c
@@ -252,6 +252,9 @@ write_csvlog(ErrorData *edata)
 	/* query id */
 	appendStringInfo(&buf, "%lld", (long long) pgstat_get_my_query_id());
 
+	/* plan id */
+	appendStringInfo(&buf, "%lld", (long long) pgstat_get_my_plan_id());
+
 	appendStringInfoChar(&buf, '\n');
 
 	/* If in the syslogger process, try to write messages direct to file */
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 55ee542..819affb 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -2777,11 +2777,22 @@ log_line_prefix(StringInfo buf, ErrorData *edata)
 				break;
 			case 'Q':
 				if (padding != 0)
+				{
 					appendStringInfo(buf, "%*lld", padding,
 									 (long long) pgstat_get_my_query_id());
+					appendStringInfo(buf, "%*s", padding, "/");
+
+					appendStringInfo(buf, "%*lld", padding,
+									 (long long) pgstat_get_my_plan_id());
+				}
 				else
+				{
 					appendStringInfo(buf, "%lld",
 									 (long long) pgstat_get_my_query_id());
+					appendStringInfo(buf, "%s", "/");
+					appendStringInfo(buf, "%lld",
+									 (long long) pgstat_get_my_plan_id());
+				}
 				break;
 			default:
 				/* format error - ignore it */
diff --git a/src/backend/utils/error/jsonlog.c b/src/backend/utils/error/jsonlog.c
index 27ad768..8514393 100644
--- a/src/backend/utils/error/jsonlog.c
+++ b/src/backend/utils/error/jsonlog.c
@@ -288,6 +288,9 @@ write_jsonlog(ErrorData *edata)
 	/* query id */
 	appendJSONKeyValueFmt(&buf, "query_id", false, "%lld",
 						  (long long) pgstat_get_my_query_id());
+	/* plan id */
+	appendJSONKeyValueFmt(&buf, "plan_id", false, "%lld",
+						 (long long) pgstat_get_my_plan_id());
 
 	/* Finish string */
 	appendStringInfoChar(&buf, '}');
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 48ad80c..88a6916 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -569,7 +569,7 @@
 					#   %t = timestamp without milliseconds
 					#   %m = timestamp with milliseconds
 					#   %n = timestamp with milliseconds (as a Unix epoch)
-					#   %Q = query ID (0 if none or not computed)
+					#   %Q = query ID and plan ID separated by "/" (0 if none or not computed)
 					#   %i = command tag
 					#   %e = SQL state
 					#   %c = session ID
diff --git a/src/backend/utils/misc/queryjumble.c b/src/backend/utils/misc/queryjumble.c
index eeaa0b3..b0d0fe9 100644
--- a/src/backend/utils/misc/queryjumble.c
+++ b/src/backend/utils/misc/queryjumble.c
@@ -15,11 +15,20 @@
  * information is ignored as irrelevant or not essential to the query, such
  * as the collations of Vars and, most notably, the values of constants.
  *
- * This jumble is acquired at the end of parse analysis of each query, and
- * a 64-bit hash of it is stored into the query's Query.queryId field.
- * The server then copies this value around, making it available in plan
- * tree(s) generated from the query.  The executor can then use this value
- * to blame query costs on the proper queryId.
+ * Additionaly, The plan tree of a planned statement is fingerprinted
+ * to differentiate plans for the same query.
+ *
+ * For Utility statements, a jumble of the query is acquired at the end
+ * of parse analysis. For planned statements, a jumble of the query is
+ * acquired before planning and a jumble of the plan is acquired after
+ * planning.
+ *
+ * The query jumble is stored as a 64-bit hash in the query's Query.queryid
+ * field and a plan jumble is similarly hashed and stored in the
+ * PlannedStmt.planid field.
+ *
+ * The executor can then use the queryid and planid values to properly
+ * blame the cost of a query.
  *
  * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
@@ -34,6 +43,7 @@
 
 #include "common/hashfn.h"
 #include "miscadmin.h"
+#include "nodes/plannodes.h"
 #include "parser/scansup.h"
 #include "utils/queryjumble.h"
 
@@ -54,6 +64,10 @@ static void JumbleRowMarks(JumbleState *jstate, List *rowMarks);
 static void JumbleExpr(JumbleState *jstate, Node *node);
 static void RecordConstLocation(JumbleState *jstate, int location);
 
+static void JumblePlanInternal(JumbleState *jstate, PlannedStmt *plan);
+static void JumblePlanHeader(JumbleState *jstate, Plan *plan);
+static void JumbleScanHeader(JumbleState *jstate, Scan *scan);
+
 /*
  * Given a possibly multi-statement source string, confine our attention to the
  * relevant part of the string.
@@ -285,7 +299,8 @@ JumbleRangeTable(JumbleState *jstate, List *rtable)
 				APP_JUMB(rte->inh);
 				break;
 			case RTE_SUBQUERY:
-				JumbleQueryInternal(jstate, rte->subquery);
+				if (rte->subquery)
+					JumbleQueryInternal(jstate, rte->subquery);
 				break;
 			case RTE_JOIN:
 				APP_JUMB(rte->jointype);
@@ -342,8 +357,11 @@ JumbleRowMarks(JumbleState *jstate, List *rowMarks)
 }
 
 /*
- * Jumble an expression tree
+ * Jumble an expression or plan tree
  *
+ * This function handles both query and plan nodes.
+ *
+ * Notes for query nodes:
  * In general this function should handle all the same node types that
  * expression_tree_walker() does, and therefore it's coded to be as parallel
  * to that function as possible.  However, since we are only invoked on
@@ -354,6 +372,12 @@ JumbleRowMarks(JumbleState *jstate, List *rowMarks)
  * point of that function is to support tree walkers that don't care about
  * most tree node types, but here we care about all types.  We should complain
  * about any unrecognized node type.
+ *
+ * Notes for plan nodes:
+ * The plan nodes that are defined in plannodes.h are handled
+ * here.
+ * We include nodes that are not required for jumbling to avoid
+ * encountering the "unrecognized node" case.
  */
 static void
 JumbleExpr(JumbleState *jstate, Node *node)
@@ -374,6 +398,7 @@ JumbleExpr(JumbleState *jstate, Node *node)
 
 	switch (nodeTag(node))
 	{
+		/* Query nodes */
 		case T_Var:
 			{
 				Var		   *var = (Var *) node;
@@ -387,6 +412,9 @@ JumbleExpr(JumbleState *jstate, Node *node)
 			{
 				Const	   *c = (Const *) node;
 
+				if (jstate->clocations == NULL)
+					break;
+
 				/* We jumble only the constant's type, not its value */
 				APP_JUMB(c->consttype);
 				/* Also, record its parse location for query normalization */
@@ -895,6 +923,421 @@ JumbleExpr(JumbleState *jstate, Node *node)
 				JumbleExpr(jstate, (Node *) tsc->repeatable);
 			}
 			break;
+		/* Plan nodes */
+		case T_SubPlan:
+			{
+				SubPlan *sp = (SubPlan *) node;
+				JumbleExpr(jstate, sp->testexpr);
+				foreach(temp, sp->setParam)
+				{
+					Node *param = (Node *) lfirst(temp);
+					JumbleExpr(jstate, param);
+				}
+				foreach(temp, sp->args)
+				{
+					Node *arg = (Node *) lfirst(temp);
+					JumbleExpr(jstate, arg);
+				}
+			}
+			break;
+		case T_AlternativeSubPlan:
+			{
+				AlternativeSubPlan *alt = (AlternativeSubPlan *) node;
+				foreach(temp, alt->subplans)
+				{
+					Node *subplan = (Node*) lfirst(temp);
+					/* Guard against infinite-recursion */
+					if (subplan != (Node*) alt)
+						JumbleExpr(jstate, subplan);
+				}
+			}
+			break;
+		case T_Result:
+			{
+				Result *res = (Result*) node;
+
+				JumblePlanHeader(jstate, &res->plan);
+				JumbleExpr(jstate, res->resconstantqual);
+			}
+			break;
+		case T_ProjectSet:
+			{
+				ProjectSet *ps = (ProjectSet *) node;
+
+				JumblePlanHeader(jstate, &ps->plan);
+			}
+			break;
+		case T_ModifyTable:
+			{
+				ModifyTable *mt = (ModifyTable *) node;
+
+				JumblePlanHeader(jstate, &mt->plan);
+				JumbleExpr(jstate, (Node *) mt->resultRelations);
+				JumbleExpr(jstate, (Node *) mt->returningLists);
+				JumbleExpr(jstate, (Node *) mt->rowMarks);
+			}
+			break;
+		case T_Append:
+			{
+				Append *a = (Append *) node;
+
+				JumblePlanHeader(jstate, &a->plan);
+				JumbleExpr(jstate, (Node *) a->appendplans);
+			}
+			break;
+		case T_MergeAppend:
+			{
+				MergeAppend *ma = (MergeAppend *) node;
+
+				JumblePlanHeader(jstate, &ma->plan);
+				JumbleExpr(jstate, (Node *) ma->mergeplans);
+			}
+			break;
+		case T_RecursiveUnion:
+			{
+				RecursiveUnion *ru = (RecursiveUnion *) node;
+
+				JumblePlanHeader(jstate, &ru->plan);
+			}
+			break;
+		case T_BitmapAnd:
+			{
+				BitmapAnd *ba = (BitmapAnd *) node;
+
+				JumblePlanHeader(jstate, &ba->plan);
+			}
+			break;
+		case T_BitmapOr:
+			{
+				BitmapOr *bo = (BitmapOr *) node;
+
+				JumblePlanHeader(jstate, &bo->plan);
+			}
+			break;
+		case T_NestLoop:
+			{
+				NestLoop *nl = (NestLoop *) node;
+
+				APP_JUMB(nl->join.jointype);
+				JumblePlanHeader(jstate, &nl->join.plan);
+				JumbleExpr(jstate, (Node *) nl->nestParams);
+			}
+			break;
+		case T_MergeJoin:
+			{
+				MergeJoin *mj = (MergeJoin *) node;
+
+				APP_JUMB(mj->join.jointype);
+				JumblePlanHeader(jstate, &mj->join.plan);
+				JumbleExpr(jstate, (Node *) mj->mergeclauses);
+			}
+			break;
+		case T_HashJoin:
+			{
+				HashJoin *hj = (HashJoin *) node;
+
+				APP_JUMB(hj->join.jointype);
+				JumblePlanHeader(jstate, &hj->join.plan);
+				JumbleExpr(jstate, (Node *) hj->hashclauses);
+			}
+			break;
+		case T_SeqScan:
+			{
+				SeqScan *sqs = (SeqScan *) node;
+
+				JumbleScanHeader(jstate, &sqs->scan);
+				JumblePlanHeader(jstate, &sqs->scan.plan);
+				APP_JUMB(sqs->scan.scanrelid);
+			}
+			break;
+		case T_SampleScan:
+			{
+				SampleScan *ss = (SampleScan *) node;
+
+				JumbleScanHeader(jstate, &ss->scan);
+			}
+			break;
+		case T_Gather:
+			{
+				Gather *g = (Gather *) node;
+
+				JumblePlanHeader(jstate, &g->plan);
+			}
+			break;
+		case T_GatherMerge:
+			{
+				GatherMerge *gm = (GatherMerge *) node;
+
+				JumblePlanHeader(jstate, &gm->plan);
+			}
+			break;
+		case T_IndexScan:
+			{
+				IndexScan *is = (IndexScan *) node;
+
+				JumbleScanHeader(jstate, &is->scan);
+				JumbleExpr(jstate, (Node *) is->indexqualorig);
+
+				JumbleExpr(jstate, (Node *) is->indexorderby);
+				JumbleExpr(jstate, (Node *) is->indexorderbyorig);
+
+				JumbleExpr(jstate, (Node *) is->indexqual);
+				APP_JUMB(is->indexid);
+				APP_JUMB(is->indexorderdir);
+			}
+			break;
+		case T_IndexOnlyScan:
+			{
+				IndexOnlyScan *ios = (IndexOnlyScan*) node;
+
+				JumbleExpr(jstate, (Node *) ios->indexorderby);
+				JumbleExpr(jstate, (Node *) ios->indexqual);
+				JumbleExpr(jstate, (Node *) ios->indextlist);
+
+				APP_JUMB(ios->indexid);
+				APP_JUMB(ios->indexorderdir);
+
+				JumbleScanHeader(jstate, &ios->scan);
+			}
+			break;
+		case T_BitmapIndexScan:
+			{
+				BitmapIndexScan *bis = (BitmapIndexScan *) node;
+
+				JumbleScanHeader(jstate, &bis->scan);
+				APP_JUMB(bis->indexid);
+				JumbleExpr(jstate, (Node *) bis->indexqual);
+				JumbleExpr(jstate, (Node *) bis->indexqualorig);
+			}
+			break;
+		case T_BitmapHeapScan:
+			{
+				BitmapHeapScan *bhs = (BitmapHeapScan *) node;
+
+				JumbleScanHeader(jstate, &bhs->scan);
+			}
+			break;
+		case T_TidScan:
+			{
+				TidScan *tsc = (TidScan *) node;
+
+				JumbleScanHeader(jstate, &tsc->scan);
+				JumbleExpr(jstate, (Node *) tsc->tidquals);
+			}
+			break;
+		case T_TidRangeScan:
+			{
+				TidRangeScan *trs = (TidRangeScan *) node;
+
+				JumbleScanHeader(jstate, &trs->scan);
+			}
+			break;
+		case T_SubqueryScan:
+			{
+				SubqueryScan *sqs = (SubqueryScan *) node;
+
+				JumbleScanHeader(jstate, &sqs->scan);
+				JumbleExpr(jstate, (Node *) sqs->subplan);
+			}
+			break;
+		case T_FunctionScan:
+			{
+				FunctionScan *fs = (FunctionScan *) node;
+
+				JumbleScanHeader(jstate, &fs->scan);
+			}
+			break;
+		case T_TableFuncScan:
+			{
+				TableFuncScan *tfs = (TableFuncScan *) node;
+
+				JumbleScanHeader(jstate, &tfs->scan);
+			}
+			break;
+		case T_ValuesScan:
+			{
+				ValuesScan *vs = (ValuesScan *) node;
+
+				JumbleScanHeader(jstate, &vs->scan);
+				JumbleExpr(jstate, (Node *) vs->values_lists);
+			}
+			break;
+		case T_CteScan:
+			{
+				CteScan *cs = (CteScan *) node;
+
+				JumbleScanHeader(jstate, &cs->scan);
+			}
+			break;
+		case T_NamedTuplestoreScan:
+			{
+				NamedTuplestoreScan *nts = (NamedTuplestoreScan *) node;
+
+				JumbleScanHeader(jstate, &nts->scan);
+			}
+			break;
+		case T_WorkTableScan:
+			{
+				WorkTableScan *ws = (WorkTableScan *) node;
+
+				JumbleScanHeader(jstate, &ws->scan);
+			}
+			break;
+		case T_ForeignScan:
+			{
+				ForeignScan *fs = (ForeignScan *) node;
+
+				JumbleScanHeader(jstate, &fs->scan);
+			}
+			break;
+		case T_CustomScan:
+			{
+				CustomScan *cs = (CustomScan *) node;
+
+				JumbleScanHeader(jstate, &cs->scan);
+			}
+			break;
+		case T_Material:
+			{
+				Material *m = (Material *) node;
+
+				JumblePlanHeader(jstate, &m->plan);
+			}
+			break;
+		case T_Memoize:
+			{
+				Memoize *m = (Memoize *) node;
+
+				JumblePlanHeader(jstate, &m->plan);
+			}
+			break;
+		case T_Sort:
+			{
+				Sort *so = (Sort *) node;
+				int i;
+
+				for (i = 0; i < so->numCols; i++)
+				{
+					AttrNumber	at = so->sortColIdx[i];
+					Oid			op = so->sortOperators[i];
+					bool		nf = so->nullsFirst[i];
+
+					APP_JUMB(at);
+					APP_JUMB(op);
+					APP_JUMB(nf);
+				}
+				JumblePlanHeader(jstate, &so->plan);
+			}
+			break;
+		case T_IncrementalSort:
+			{
+				IncrementalSort *is = (IncrementalSort *) node;
+				int i;
+
+				for (i = 0; i < is->sort.numCols; i++)
+				{
+					AttrNumber	at = is->sort.sortColIdx[i];
+					Oid			op = is->sort.sortOperators[i];
+					bool		nf = is->sort.nullsFirst[i];
+
+					APP_JUMB(at);
+					APP_JUMB(op);
+					APP_JUMB(nf);
+				}
+				JumblePlanHeader(jstate, &is->sort.plan);
+			}
+			break;
+		case T_Group:
+			{
+				Group *gr = (Group *) node;
+
+				JumblePlanHeader(jstate, &gr->plan);
+			}
+			break;
+		case T_Agg:
+			{
+				Agg *ag = (Agg *) node;
+
+				JumblePlanHeader(jstate, &ag->plan);
+			}
+			break;
+		case T_WindowAgg:
+			{
+				WindowAgg *wa = (WindowAgg *) node;
+
+				JumblePlanHeader(jstate, &wa->plan);
+			}
+			break;
+		case T_Unique:
+			{
+				Unique *un = (Unique *) node;
+
+				JumblePlanHeader(jstate, &un->plan);
+			}
+			break;
+		case T_SetOp:
+			{
+				SetOp *so = (SetOp *) node;
+
+				JumblePlanHeader(jstate, &so->plan);
+			}
+			break;
+		case T_LockRows:
+			{
+				LockRows *lr = (LockRows *) node;
+
+				JumblePlanHeader(jstate, &lr->plan);
+			}
+			break;
+		case T_Limit:
+			{
+				Limit *lim = (Limit *) node;
+
+				JumblePlanHeader(jstate, &lim->plan);
+			}
+			break;
+		case T_Hash:
+			{
+				Hash *hash = (Hash *) node;
+
+				JumblePlanHeader(jstate, &hash->plan);
+			}
+			break;
+		case T_NestLoopParam:
+			{
+				NestLoopParam *nlp = (NestLoopParam *) node;
+
+				JumbleExpr(jstate, (Node *) nlp->paramval);
+			}
+			break;
+		case T_PlanRowMark:
+			{
+				PlanRowMark *prm = (PlanRowMark*) node;
+				APP_JUMB(prm->markType);
+			}
+			break;
+		case T_PlanInvalItem:
+			{
+				PlanInvalItem *pii = (PlanInvalItem*) node;
+
+				APP_JUMB(pii->cacheId);
+				APP_JUMB(pii->hashValue);
+			}
+			break;
+		case T_GroupingSetData:
+			break;
+		case T_PlaceHolderVar:
+			break;
+		case T_RollupData:
+			break;
+		case T_SpecialJoinInfo:
+			break;
+		case T_RestrictInfo:
+			break;
+		case T_CustomPath:
+			break;
+		case T_IndexPath:
+			break;
 		default:
 			/* Only a warning, since we can stumble along anyway */
 			elog(WARNING, "unrecognized node type: %d",
@@ -928,3 +1371,79 @@ RecordConstLocation(JumbleState *jstate, int location)
 		jstate->clocations_count++;
 	}
 }
+
+JumbleState *
+JumblePlan(PlannedStmt *plan)
+{
+	JumbleState *jstate = NULL;
+	uint64 planid;
+
+	Assert(IsPlanIdEnabled());
+
+	jstate = (JumbleState *) palloc(sizeof(JumbleState));
+
+	/*
+	 * Set up workspace for plan jumbling.
+	 *
+	 * We don't need to setup constant
+	 * locations for plans.
+	 */
+	jstate->jumble = (unsigned char *) palloc(JUMBLE_SIZE);
+	jstate->jumble_len = 0;
+	jstate->clocations_buf_size = 0;
+	jstate->clocations = NULL;
+	jstate->clocations_count = 0;
+	jstate->highest_extern_param_id = 0;
+
+	/* Compute query ID and mark the Query node with it */
+	JumblePlanInternal(jstate, plan);
+	planid = DatumGetUInt64(hash_any_extended(jstate->jumble,
+											  jstate->jumble_len,
+											  0));
+
+	plan->planId = planid;
+
+	return jstate;
+};
+
+static void
+JumblePlanInternal(JumbleState *jstate, PlannedStmt *plan)
+{
+	Assert(IsA(plan, PlannedStmt));
+	Assert(plan->utilityStmt == NULL);
+
+	APP_JUMB(plan->commandType);
+	/* resultRelation is usually predictable from commandType */
+	JumbleExpr(jstate, (Node *) plan->planTree);
+	JumbleRangeTable(jstate, plan->rtable);
+	JumbleExpr(jstate, (Node *) plan->resultRelations);
+	JumbleExpr(jstate, (Node *) plan->utilityStmt);
+	JumbleExpr(jstate, (Node *) plan->subplans);
+	JumbleExpr(jstate, (Node *) plan->rewindPlanIDs);
+	JumbleExpr(jstate, (Node *) plan->rowMarks);
+};
+
+/*
+ * JumblePlanHeader: Jumble a Plan header.
+ *
+ * Ignore estimated execution costs, etc. We are only interested in fields that
+ * are essential to the plan.
+ */
+static void
+JumblePlanHeader(JumbleState *jstate, Plan *plan)
+{
+	JumbleExpr(jstate, (Node *) plan->qual);
+	JumbleExpr(jstate, (Node *) plan->targetlist);
+	JumbleExpr(jstate, (Node *) plan->lefttree);
+	JumbleExpr(jstate, (Node *) plan->righttree);
+}
+
+/*
+ * JumbleScan: Jumble the contents of a scan header.
+ */
+static void
+JumbleScanHeader(JumbleState *jstate, Scan *scan)
+{
+	JumblePlanHeader(jstate, &scan->plan);
+	APP_JUMB(scan->scanrelid);
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 87aa571..6a4913f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5340,9 +5340,9 @@
   proname => 'pg_stat_get_activity', prorows => '100', proisstrict => 'f',
   proretset => 't', provolatile => 's', proparallel => 'r',
   prorettype => 'record', proargtypes => 'int4',
-  proallargtypes => '{int4,oid,int4,oid,text,text,text,text,text,timestamptz,timestamptz,timestamptz,timestamptz,inet,text,int4,xid,xid,text,bool,text,text,int4,text,numeric,text,bool,text,bool,int4,int8}',
-  proargmodes => '{i,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
-  proargnames => '{pid,datid,pid,usesysid,application_name,state,query,wait_event_type,wait_event,xact_start,query_start,backend_start,state_change,client_addr,client_hostname,client_port,backend_xid,backend_xmin,backend_type,ssl,sslversion,sslcipher,sslbits,ssl_client_dn,ssl_client_serial,ssl_issuer_dn,gss_auth,gss_princ,gss_enc,leader_pid,query_id}',
+  proallargtypes => '{int4,oid,int4,oid,text,text,text,text,text,timestamptz,timestamptz,timestamptz,timestamptz,inet,text,int4,xid,xid,text,bool,text,text,int4,text,numeric,text,bool,text,bool,int4,int8,int8}',
+  proargmodes => '{i,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
+  proargnames => '{pid,datid,pid,usesysid,application_name,state,query,wait_event_type,wait_event,xact_start,query_start,backend_start,state_change,client_addr,client_hostname,client_port,backend_xid,backend_xmin,backend_type,ssl,sslversion,sslcipher,sslbits,ssl_client_dn,ssl_client_serial,ssl_issuer_dn,gss_auth,gss_princ,gss_enc,leader_pid,query_id,plan_id}',
   prosrc => 'pg_stat_get_activity' },
 { oid => '3318',
   descr => 'statistics: information about progress of backends running maintenance command',
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index 0ea9a22..6dd94ed 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -89,6 +89,7 @@ typedef struct PlannedStmt
 	/* statement location in source string (copied from Query) */
 	int			stmt_location;	/* start location, or -1 if unknown */
 	int			stmt_len;		/* length in bytes; 0 means "rest of string" */
+	int64		planId;			/* plan identifier (can be set by plugins) */
 } PlannedStmt;
 
 /* macro for fetching the Plan associated with a SubPlan node */
diff --git a/src/include/utils/backend_status.h b/src/include/utils/backend_status.h
index 7403bca..2a178a6 100644
--- a/src/include/utils/backend_status.h
+++ b/src/include/utils/backend_status.h
@@ -166,8 +166,11 @@ typedef struct PgBackendStatus
 	Oid			st_progress_command_target;
 	int64		st_progress_param[PGSTAT_NUM_PROGRESS_PARAM];
 
-	/* query identifier, optionally computed using post_parse_analyze_hook */
+	/* query identifier & plan identifier, both are optionally computed
+	 * using post_parse_analyze_hook.
+	 */
 	uint64		st_query_id;
+	uint64		st_plan_id;
 } PgBackendStatus;
 
 
@@ -298,6 +301,7 @@ extern void pgstat_clear_backend_activity_snapshot(void);
 /* Activity reporting functions */
 extern void pgstat_report_activity(BackendState state, const char *cmd_str);
 extern void pgstat_report_query_id(uint64 query_id, bool force);
+extern void pgstat_report_plan_id(uint64 plan_id, uint64 query_id, bool force);
 extern void pgstat_report_tempfile(size_t filesize);
 extern void pgstat_report_appname(const char *appname);
 extern void pgstat_report_xact_timestamp(TimestampTz tstamp);
@@ -305,6 +309,7 @@ extern const char *pgstat_get_backend_current_activity(int pid, bool checkUser);
 extern const char *pgstat_get_crashed_backend_activity(int pid, char *buffer,
 													   int buflen);
 extern uint64 pgstat_get_my_query_id(void);
+extern uint64 pgstat_get_my_plan_id(void);
 
 
 /* ----------
diff --git a/src/include/utils/queryjumble.h b/src/include/utils/queryjumble.h
index 3c2d9be..dffd794 100644
--- a/src/include/utils/queryjumble.h
+++ b/src/include/utils/queryjumble.h
@@ -15,6 +15,7 @@
 #define QUERYJUBLE_H
 
 #include "nodes/parsenodes.h"
+#include "nodes/plannodes.h"
 
 #define JUMBLE_SIZE				1024	/* query serialization buffer size */
 
@@ -67,6 +68,7 @@ extern PGDLLIMPORT int compute_query_id;
 
 extern const char *CleanQuerytext(const char *query, int *location, int *len);
 extern JumbleState *JumbleQuery(Query *query, const char *querytext);
+extern JumbleState *JumblePlan(PlannedStmt *plan);
 extern void EnableQueryId(void);
 
 extern PGDLLIMPORT bool query_id_enabled;
diff --git a/src/test/regress/expected/explain.out b/src/test/regress/expected/explain.out
index 48620ed..df7c43b 100644
--- a/src/test/regress/expected/explain.out
+++ b/src/test/regress/expected/explain.out
@@ -515,5 +515,6 @@ select explain_filter('explain (verbose) select * from int8_tbl i8');
  Seq Scan on public.int8_tbl i8  (cost=N.N..N.N rows=N width=N)
    Output: q1, q2
  Query Identifier: N
-(3 rows)
+ Plan Identifier: N
+(4 rows)
 
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index fc3cde3..85025ed 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1756,9 +1756,10 @@ pg_stat_activity| SELECT s.datid,
     s.backend_xid,
     s.backend_xmin,
     s.query_id,
+    s.plan_id,
     s.query,
     s.backend_type
-   FROM ((pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid, query_id)
+   FROM ((pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid, query_id, plan_id)
      LEFT JOIN pg_database d ON ((s.datid = d.oid)))
      LEFT JOIN pg_authid u ON ((s.usesysid = u.oid)));
 pg_stat_all_indexes| SELECT c.oid AS relid,
@@ -1870,7 +1871,7 @@ pg_stat_gssapi| SELECT s.pid,
     s.gss_auth AS gss_authenticated,
     s.gss_princ AS principal,
     s.gss_enc AS encrypted
-   FROM pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid, query_id)
+   FROM pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid, query_id, plan_id)
   WHERE (s.client_port IS NOT NULL);
 pg_stat_progress_analyze| SELECT s.pid,
     s.datid,
@@ -2051,7 +2052,7 @@ pg_stat_replication| SELECT s.pid,
     w.sync_priority,
     w.sync_state,
     w.reply_time
-   FROM ((pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid, query_id)
+   FROM ((pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid, query_id, plan_id)
      JOIN pg_stat_get_wal_senders() w(pid, state, sent_lsn, write_lsn, flush_lsn, replay_lsn, write_lag, flush_lag, replay_lag, sync_priority, sync_state, reply_time) ON ((s.pid = w.pid)))
      LEFT JOIN pg_authid u ON ((s.usesysid = u.oid)));
 pg_stat_replication_slots| SELECT s.slot_name,
@@ -2085,7 +2086,7 @@ pg_stat_ssl| SELECT s.pid,
     s.ssl_client_dn AS client_dn,
     s.ssl_client_serial AS client_serial,
     s.ssl_issuer_dn AS issuer_dn
-   FROM pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid, query_id)
+   FROM pg_stat_get_activity(NULL::integer) s(datid, pid, usesysid, application_name, state, query, wait_event_type, wait_event, xact_start, query_start, backend_start, state_change, client_addr, client_hostname, client_port, backend_xid, backend_xmin, backend_type, ssl, sslversion, sslcipher, sslbits, ssl_client_dn, ssl_client_serial, ssl_issuer_dn, gss_auth, gss_princ, gss_enc, leader_pid, query_id, plan_id)
   WHERE (s.client_port IS NOT NULL);
 pg_stat_subscription| SELECT su.oid AS subid,
     su.subname,
-- 
2.32.1 (Apple Git-133)