Mastering PostgreSQL 12 - Third Edition

Replaying the transaction log

Let's sum up the process so far. We have adjusted the postgresql.conf file (wal_level, max_wal_senders, archive_mode, and archive_command) and we have allowed for the pg_basebackup command in the pg_hba.conf file. Then, the database was restarted and a base backup was successfully produced.

Keep in mind that base backups can only happen while the database is fully operational—only a brief restart to change the max_wal_sender and wal_level variables is needed. 

Now that the system is working properly, we might face a crash that we will want to recover from. Therefore, we can perform PITR to restore as much data as possible. The first thing we've got to do is take the base backup and put it in the desired location. ...