α=> CREATE DATABASE backup_overview;

CREATE DATABASE

α=> \c backup_overview

You are now connected to database "backup_overview" as user "student".

α=> CREATE TABLE t(n integer);

CREATE TABLE

α=> INSERT INTO t VALUES (1), (2), (3);

INSERT 0 3

postgres$ pg_dump -f /var/lib/postgresql/backup_overview.dump -d backup_overview --create

α=> \c postgres

You are now connected to database "postgres" as user "student".

α=> DROP DATABASE backup_overview;

DROP DATABASE

postgres$ psql -f /var/lib/postgresql/backup_overview.dump

SET
SET
SET
SET
SET
 set_config 
------------
 
(1 row)

SET
SET
SET
CREATE DATABASE
ALTER DATABASE
You are now connected to database "backup_overview" as user "postgres".
SET
SET
SET
SET
SET
 set_config 
------------
 
(1 row)

SET
SET
SET
SET
SET
CREATE TABLE
ALTER TABLE
COPY 3

α=> \c backup_overview

You are now connected to database "backup_overview" as user "student".

α=> SELECT * FROM t;

 n 
---
 1
 2
 3
(3 rows)

postgres$ rm -rf /var/lib/postgresql/11/beta/*

postgres$ pg_basebackup --pgdata=/var/lib/postgresql/11/beta

student$ psql -p 5432 -d backup_overview

α=> DELETE FROM t;

DELETE 3

postgres$ echo 'port = 5433' >> /var/lib/postgresql/11/beta/postgresql.auto.conf

student$ sudo pg_ctlcluster 11 beta start

student$ psql -p 5433 -d backup_overview

β=> SELECT * FROM t;

 n 
---
 1
 2
 3
(3 rows)