The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/18/routine-vacuuming.html
Description:
Hi All,
Doc ref:
https://www.postgresql.org/docs/current/routine-vacuuming.html#ROUTINE-VACUUMING
There are five points under this section;
"In this condition any transactions already in progress can continue, but
only read-only transactions can be started. Operations that modify database
records or truncate relations will fail. The VACUUM command can still be run
normally. Note that, contrary to what was sometimes recommended in earlier
releases, it is not necessary or desirable to stop the postmaster or enter
single user-mode in order to restore normal operation. Instead, follow these
steps:..."
In the third point it says "Use pg_stat_replication to find slots where
age(xmin) or age(catalog_xmin) is large. In many cases, such slots were
created for replication to servers that no longer exist, or that have been
down for a long time."
However, those columns, ie: xmin and catalog_xmin exists in
pg_replication_slots metadata view. :
https://www.postgresql.org/docs/18/view-pg-replication-slots.html
Not in the pg_stat_replication.
Please check if my observation is correct or not.
Thanks.
