PostgreSQL

PostgreSQL is a on open source SQL database under a BSD licence. It is available on all platforms. You may create a database by the name of 'cosmo', owned by a user called 'cosmo' with password 'cosmo' by typing the following as the admin user in a psql shell

create user cosmo with password 'cosmo';
create database cosmo with owner cosmo encoding='utf8'; 

MySQL

MySQL is an open source SQL database under a GPL licence. It is available on all platforms. You may create a database by the name of 'cosmo', owned by a user called 'cosmo' with password 'cosmo' by typing the following as the admin user in a mysql shell

Login to mysql and create a database and user using the commands below:

$ mysql -u root -p
Enter password: [password not shown] 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is xx
Server version: 5.0.51a-xxxxxx

mysql> grant all privileges on cosmo.* to 'cosmo' identified by 'cosmo';
Query OK, 0 rows affected (0.00 sec)

mysql> create database cosmo character set utf8;
Query OK, 1 row affected (0.00 sec)

mysql> quit
$

Derby

By default, Cosmo uses an embedded Derby database, which is configured in cosmo.properties. The location of the db is the JDBC connection URL, and will be automatically created for you.