Netezza is an appliance... a combination of hardware and software.  Netezza does do proof of concepts for potential customers where a complete Netezza system is shipped to the customer's data center, data is loaded into the system, and the customer runs their own queries to see the actual proof of Netezza performance and manageability.

the default db name is system

provided the user is default user which is NZ and the password is also the same (NZ).

I dont think you will have the trail versions for Netezza, as Shawn rightly said if you are keen in pursuing the Netezza Appliance  Netezza does POC by having the servers onsite or of remote connectivity wehre you can get connectivity and check these out.

Thanks

Harish

The Aginity Workbench is not Netezza, it is a SQL query tool that can be used to connect to a Netezza system.  Netezza does not have a trial version of Netezza that is publicly available.  There is a software only version, but it is only available to partners and customers, and it also runs quite a bit slower than the real thing, although it does have the same features.