If this is the Dockerfile [1] and he's not mounting a volume in, then he's running the Postgres data dir on a btrfs snapshot vs. probably ext4 w/o Docker [1]:

If this is the Dockerfile [1] and he's not mounting a volume in, then he's running the Postgres data dir on a btrfs snapshot vs. probably ext4 w/o Docker [1]: https://bitbucket.org/davidkerr/docker/src/c23b2040321b65d38665ede901b1be4edb1318c3/postgresql/9.3/ubuntu/Dockerfile?at=master https://bitbucket.org/davidkerr/docker/src/c23b2040321b65d38...