WAITLSN — wait for the target LSN to be replayed
WAITLSN provides a simple interprocess communication mechanism to wait for the target log sequence number (LSN) on standby in Postgres Pro databases with master-standby asynchronous replication. When run with the
LSN option, the
WAITLSN command waits for the specified LSN to be replayed. By default, wait time is unlimited. Waiting can be interrupted using
Ctrl+C, or by shutting down the
postgres server. You can also limit the wait time specifying the
wait_time option, in milliseconds.
Specify the target log sequence number to wait for.
Limit the time to wait for the LSN to be replayed. The specified
wait_timemust be an integer and is measured in milliseconds.
WAITLSN from psql, limiting wait time to 10000 milliseconds:
WAITLSN '0/3F07A6B1', 10000; NOTICE: LSN is not reached. Try to make bigger delay. WAITLSN
Wait until the specified LSN is replayed:
WAITLSN '0/3F07A611'; WAITLSN ------------- t (1 row)
Limit LSN wait time to 500000 milliseconds, and then cancel the command:
WAITLSN '0/3F0FF791', 500000; ^CCancel request sent NOTICE: LSN is not reached. Try to make bigger delay. ERROR: canceling statement due to user request
There is no
WAITLSN statement in the SQL standard.