Add views and functions to monitor hot standby query conflicts

Add the view pg_stat_database_conflicts and a column to pg_stat_database,
and the underlying functions to provide the information.

1 files changed, 101 insertions, 0 deletions

diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index d357b5c8b5d..a95ba8b3eb3 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -71,6 +71,12 @@ extern Datum pg_stat_get_db_tuples_fetched(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_db_tuples_inserted(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_db_tuples_updated(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_db_tuples_deleted(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_db_conflict_tablespace(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_db_conflict_lock(PG_FUNCTION_ARGS);
+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_bgwriter_timed_checkpoints(PG_FUNCTION_ARGS);
 extern Datum pg_stat_get_bgwriter_requested_checkpoints(PG_FUNCTION_ARGS);
@@ -1130,6 +1136,101 @@ pg_stat_get_db_tuples_deleted(PG_FUNCTION_ARGS)
 }
 
 Datum
+pg_stat_get_db_conflict_tablespace(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_conflict_tablespace);
+
+	PG_RETURN_INT64(result);
+}
+
+Datum
+pg_stat_get_db_conflict_lock(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_conflict_lock);
+
+	PG_RETURN_INT64(result);
+}
+
+Datum
+pg_stat_get_db_conflict_snapshot(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_conflict_snapshot);
+
+	PG_RETURN_INT64(result);
+}
+
+Datum
+pg_stat_get_db_conflict_bufferpin(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_conflict_bufferpin);
+
+	PG_RETURN_INT64(result);
+}
+
+Datum
+pg_stat_get_db_conflict_startup_deadlock(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_conflict_startup_deadlock);
+
+	PG_RETURN_INT64(result);
+}
+
+Datum
+pg_stat_get_db_conflict_all(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_conflict_tablespace +
+			dbentry->n_conflict_lock +
+			dbentry->n_conflict_snapshot +
+			dbentry->n_conflict_bufferpin +
+			dbentry->n_conflict_startup_deadlock);
+
+	PG_RETURN_INT64(result);
+}
+
+Datum
 pg_stat_get_bgwriter_timed_checkpoints(PG_FUNCTION_ARGS)
 {
 	PG_RETURN_INT64(pgstat_fetch_global()->timed_checkpoints);