The host file in Unix is usually located in the /etc directory.

A Unix host is simply a term used in a Unix operating system, which is most often used by servers or computers used for business or science. Usually the host file consists of a list of IP addresses and hostnames associated with them, each corresponding to a user on a networked computer.

Unix can host different database systems, so it depends on which database you are referring to. A dba will do the same types of things in Unix as you would in any other operating system.

Host names can be resolved by either using the /etc/hosts file or by using DNS.

Ifconfig