Unable to run the first query and third query. I believe it's a version issue, as we are running 9.2.4.
Looks like backend_xmin was added in 9.4; shoot
Replication slots was added in 9.4, too; no slots to worry about.
Since you don’t have access to backend_xmin; you have check the master and all the replicas as you have feedback enabled.
I would look at all non “idle” sessions — i.e. “idle in tran” could be holding on to an old xmin.
select pid
, usename
, client_addr
, client_port
, state
, age(now(), state_change) as state_time
, age(now(), xact_start) as xact_time
from pg_stat_activity
where state != 'idle'
order by xact_time desc
;
