基于复制select * from pg_stat_replication；  postgres=# select * from pg_stat_replication;  -[ RECORD 1 ]----+------------------------------ pid              | 55694  usesysid         | 24746  usename          | repl  application_name | walreceiver  client_addr      | 192.168.18.82  client_hostname  |   client_port      | 31550  backend_start    | 2021-01-20 09:54:57.039779+08  backend_xmin     |   state            | streaming  sent_lsn         | 6/D2A17120  write_lsn        | 6/D2A17120  flush_lsn        | 6/D2A17120  replay_lsn       | 6/D2A170B8  write_lag        | 00:00:00.000119  flush_lag        | 00:00:00.000239  replay_lag       | 00:00:50.653858  sync_priority    | 0  sync_state       | async  reply_time       | 2021-01-20 14:11:31.704194+08  1.2.3.4.5.6.7.8.9.10.11.12.13.14.15.16.17.18.19.20.21.22.23.