May 2018
Intermediate to advanced
576 pages
30h 25m
English
Transaction log (WAL) files will be written on the master. Setting wal_level to archive ensures that we collect all of the changed data, and that WAL is never optimized away. WAL is sent from the master to the archive using archive_command, and from there, the standby reads WAL files using restore_command. Then, it replays the changes.
The archive_command is executed when a file becomes full, or an archive_timeout number of seconds have passed since any user inserted change data into the transaction log. If the server does not write any new transaction log data for an extended period, then files will switch every checkpoint_timeout seconds. This is normal, and not a problem.
The preceding configuration assumes that the archive ...