PG_STAT_REPLICATION

PG_STAT_REPLICATION displays information about log synchronization status, such as the locations of the sender sending logs and the receiver receiving logs.

**Table 1** PG_STAT_REPLICATION columns
Name	Type	Description
pid	bigint	Process ID of the thread
usesysid	oid	User system ID
usename	name	Username
application_name	text	Program name
client_addr	inet	Client address
client_hostname	text	Client name
client_port	integer	Port of the client
backend_start	timestamp with time zone	Start time of the program
state	text	Log replication state: Catch-up state Consistent streaming state
sender_sent_location	text	Location where the sender sends logs
receiver_write_location	text	Location where the receiver writes logs
receiver_flush_location	text	Location where the receive end flushes logs
receiver_replay_location	text	Location where the receive end replays logs
sync_priority	integer	Priority of synchronous duplication (0 indicates asynchronization.)
sync_state	text	Synchronization state Asynchronous replication Synchronous replication Potential synchronization Qurom: switches between the synchronous and asynchronous states to ensure that there are more than a certain number of synchronous standby servers. Generally, the number of synchronous standby servers is (n+1)/2-1, where n indicates the total number of copies. Whether the standby server is synchronous depends on whether logs are received first. For details, see the description of the synchronous_standby_names parameter.