Postgresql - how to do backup/restore on a database level?
Except pg_dump which a logical backup tool, all other tools are physical backup tools and copy all database files from the cluster and transaction logs (WAL). AFAIK currently there is no way to make a physical backup of a single database. 

If you need to restore one single database from a physical backup you need to restore the whole cluster-wide backup to a temporary instance and use pg_dump/pg_restore to restore the single database from the temporary cluster into the original cluster.