postgres is not an option if you often muck around with the directory storing the databases.
While the other DBMS usually store databases that relate to the name used in their creation (i.e.: if you do a 'CREATE DATABASE testdatabase;' in MySQL, MariaDB or even Mircrosoft SQL Server, the datadir will contain a file named 'testdatabase' or something along those lines), postgres uses a confusing numbering system (i.e.: performing a 'CREATE DATABASE testdatabase;' in postgres will result in a file named '00' or something else in the datadir). You can't just go into the datadir and start guessing whether file 00 or file 21 is the 'testdatabase' database that you are interested in.