How to measure replication lag in logical replication setup.

[rammohan ganapavarapu <rammohanganap@xxxxxxxxx>]

HI,

How to measure replication lag time in case of logical replication?

this query is returning empty

SELECT now() - pg_last_xact_replay_timestamp() AS time_lag;

 time_lag

----------

(1 row)

this is my slot details

SELECT * FROM pg_replication_slots;

 slot_name | plugin | slot_type | datoid | database | active | xmin | catalog_xmin | restart_lsn

-----------+--------+-----------+--------+----------+--------+------+--------------+-------------

 slot_1    |        | physical  |        |          | t      | 1983 |              | 0/50805C8

In my case slot_type is physical,  does it look ok or for logical replication the slot_type should be logical?

Thanks,

Ram