doc: Clarify when backend_xmin in pg_stat_replication can be NULL.
authorFujii Masao <fujii@postgresql.org>
Fri, 17 Oct 2025 05:03:42 +0000 (14:03 +0900)
committerFujii Masao <fujii@postgresql.org>
Fri, 17 Oct 2025 05:03:42 +0000 (14:03 +0900)
commite64aa1a39d4b8a9502be8ed8dfd67efd6f6acf28
tree84b784924823f12f873dbdb9f2f0b387e03dbe55
parentd1b80a31ed6dc185108af74f363bd6baad98104f
doc: Clarify when backend_xmin in pg_stat_replication can be NULL.

Improve the documentation of pg_stat_replication to explain when
the backend_xmin column becomes NULL. This happens when
a replication slot is used (the xmin is then shown in pg_replication_slots)
or when hot_standby_feedback is disabled.

Author: Renzo Dani <arons7@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CA+XOKQAMXzskpdUmj2sg03_5fmiXc2Gs0r3TX1_rmcFcqh+=xQ@mail.gmail.com
doc/src/sgml/monitoring.sgml