diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index c602ee44277..3513e127b78 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -5716,6 +5716,7 @@ SELECT pg_stat_get_backend_pid(s.backendid) AS pid,
When creating an index on a partitioned table, this column is set to
the total number of partitions on which the index is to be created.
+ This field is 0 during a REINDEX.
@@ -5726,6 +5727,7 @@ SELECT pg_stat_get_backend_pid(s.backendid) AS pid,
When creating an index on a partitioned table, this column is set to
the number of partitions on which the index has been completed.
+ This field is 0 during a REINDEX.