Upgrading Citrix Xenapp questions, can I please get some help?

[robertkwild]

upgrading citrix xenapp

hi all,

just a few questions about upgrading our citrix xenapp servers to 6.5

i need to create a database, can i install the database on one of the xen app farm servers or the secure gateway/web interface server

also do all the citrix servers need to be joined to the domain ie xen app farm servers and the secure gateway/web interface server, bear in mind the secure gateway/web interface server will be on the DMZ as i dont want it on the staff internal network

cheers,

rob