I'm a complete newbie with PostgreSQL - please forgive my gaffs - and have inherited a service using a master-slave cluster at the backend.
Currently on the slave, the disk is filling up with WAL files in the archive directory.
On a slave (replica) I presume the archived WAL files been applied to the local instance of the database since there are files in pg_xlog with current filestamps.
Q1: Is this correct?
Q2: What is the criteria by which the system decides that a WAL file is eligible to be moved from pg_xlog to the archive?
The backup/restore model is predicated around filesystem snapshots - so a restore operation would rely on crash recovery. I infer from this that I should only need the artchived WAL files since the last file-system snapshot to be available (although keeping at least 2 generations would be a better idea).
Q3: Is this correct?