PostgreSQL is an amazing RDBMS. It's simple to install it and start using it, however administering it requires attention and knowledge.
This book covers PostgreSQL 11 from a database administration point of view. The install structure, the logical and physical layout along with the MVCC and the query execution are explained in details. Backup and restore with pg_dump are covered as well in order to give the DBA a starting point for understanding and controlling PostgreSQL.