PostgreSQL 12 High Availability Cookbook - Third Edition

Recovering WAL files

Every good command has an analog, right? We can send WAL files, so we must also be able to receive them. Imagine we have a replica system or a backup we've recently pulled from a tape archive. Now we want to use our safe and secure WAL files previously stored in the cloud. Like all good PostgreSQL restores, we need to start with a properly prepared recovery.conf file.

To use WAL-E to restore remotely stored transaction logs to a recovered database, start with something like this:

restore_command = 'envdir ~postgres/env wal-e wal-fetch "%f" "%p"' 

Of course, this would cause our PostgreSQL server to constantly spam the cloud service with file requests. This is fine so long as there are files to retrieve, but if we've reached ...