4 files changed, 60 insertions, 2 deletions

diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 873d67f0ea9..30b0bd06df0 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -578,6 +578,7 @@ CREATE VIEW pg_stat_database AS
             pg_stat_get_db_conflict_all(D.oid) AS conflicts,
             pg_stat_get_db_temp_files(D.oid) AS temp_files,
             pg_stat_get_db_temp_bytes(D.oid) AS temp_bytes,
+            pg_stat_get_db_deadlocks(D.oid) AS deadlocks,
             pg_stat_get_db_stat_reset_time(D.oid) AS stats_reset
     FROM pg_database D;
 
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 3b7aa07014d..84d790a3faf 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -286,6 +286,7 @@ static void pgstat_recv_bgwriter(PgStat_MsgBgWriter *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
+static void pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len);
 static void pgstat_recv_tempfile(PgStat_MsgTempFile *msg, int len);
 
 
@@ -1340,6 +1341,24 @@ pgstat_report_recovery_conflict(int reason)
 	pgstat_send(&msg, sizeof(msg));
 }
 
+/* --------
+ * pgstat_report_deadlock() -
+ *
+ *	Tell the collector about a deadlock detected.
+ * --------
+ */
+void
+pgstat_report_deadlock(void)
+{
+	PgStat_MsgDeadlock msg;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_counts)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_DEADLOCK);
+	msg.m_databaseid = MyDatabaseId;
+	pgstat_send(&msg, sizeof(msg));
+}
 
 /* --------
  * pgstat_report_tempfile() -
@@ -1361,7 +1380,6 @@ pgstat_report_tempfile(size_t filesize)
 	pgstat_send(&msg, sizeof(msg));
 }
 
-;
 
 /* ----------
  * pgstat_ping() -
@@ -3242,6 +3260,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_recoveryconflict((PgStat_MsgRecoveryConflict *) &msg, len);
 					break;
 
+				case PGSTAT_MTYPE_DEADLOCK:
+					pgstat_recv_deadlock((PgStat_MsgDeadlock *) &msg, len);
+					break;
+
 				case PGSTAT_MTYPE_TEMPFILE:
 					pgstat_recv_tempfile((PgStat_MsgTempFile *) &msg, len);
 					break;
@@ -3329,6 +3351,7 @@ pgstat_get_db_entry(Oid databaseid, bool create)
 		result->n_conflict_startup_deadlock = 0;
 		result->n_temp_files = 0;
 		result->n_temp_bytes = 0;
+		result->n_deadlocks = 0;
 
 		result->stat_reset_timestamp = GetCurrentTimestamp();
 
@@ -4242,6 +4265,7 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 	dbentry->last_autovac_time = 0;
 	dbentry->n_temp_bytes = 0;
 	dbentry->n_temp_files = 0;
+	dbentry->n_deadlocks = 0;
 
 	dbentry->stat_reset_timestamp = GetCurrentTimestamp();
 
@@ -4468,6 +4492,22 @@ pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len)
 }
 
 /* ----------
+ * pgstat_recv_deadlock() -
+ *
+ *	Process as DEADLOCK message.
+ * ----------
+ */
+static void
+pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len)
+{
+	PgStat_StatDBEntry *dbentry;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	dbentry->n_deadlocks++;
+}
+
+/* ----------
  * pgstat_recv_tempfile() -
  *
  *	Process as PGSTAT_MTYPE_TEMPFILE message.
@@ -4482,7 +4522,6 @@ pgstat_recv_tempfile(PgStat_MsgTempFile *msg, int len)
 
 	dbentry->n_temp_bytes += msg->m_filesize;
 	dbentry->n_temp_files += 1;
-
 }
 
 /* ----------
diff --git a/src/backend/storage/lmgr/deadlock.c b/src/backend/storage/lmgr/deadlock.c
index 631db448baf..288186a6cee 100644
--- a/src/backend/storage/lmgr/deadlock.c
+++ b/src/backend/storage/lmgr/deadlock.c
@@ -938,6 +938,8 @@ DeadLockReport(void)
 					  pgstat_get_backend_current_activity(info->pid, false));
 	}
 
+	pgstat_report_deadlock();
+
 	ereport(ERROR,
 			(errcode(ERRCODE_T_R_DEADLOCK_DETECTED),
 			 errmsg("deadlock detected"),
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index c7b91a8c825..68b25274e38 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -78,6 +78,7 @@ extern Datum pg_stat_get_db_conflict_snapshot(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_db_conflict_bufferpin(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_db_conflict_startup_deadlock(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_db_conflict_all(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_db_deadlocks(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_db_stat_reset_time(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_db_temp_files(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_db_temp_bytes(PG_FUNCTION_ARGS);
@@ -1342,6 +1343,21 @@ pg_stat_get_db_conflict_all(PG_FUNCTION_ARGS)
 }
 
 Datum
+pg_stat_get_db_deadlocks(PG_FUNCTION_ARGS)
+{
+	Oid			dbid = PG_GETARG_OID(0);
+	int64		result;
+	PgStat_StatDBEntry *dbentry;
+
+	if ((dbentry = pgstat_fetch_stat_dbentry(dbid)) == NULL)
+		result = 0;
+	else
+		result = (int64) (dbentry->n_deadlocks);
+
+	PG_RETURN_INT64(result);
+}
+
+Datum
 pg_stat_get_bgwriter_timed_checkpoints(PG_FUNCTION_ARGS)
 {
 	PG_RETURN_INT64(pgstat_fetch_global()->timed_checkpoints);