Fenced and unfenced mode

UDXs operate in fenced mode, which is a safety feature that provides a separate process environment for user-defined objects.

Fencing allows developers to create and run their UDXs in a protected address space on the host and snippet processing units (SPUs); it minimizes the effect of an incorrectly designed UDX by helping to protect against Netezza Performance Server software or system crashes. The SPUPad feature is not supported by fenced UDXs.

Fenced mode is the default for the system. Any new UDXs that you create are fenced unless you specifically register them as not fenced. (Your database user account must have the Unfence administrative privilege to create or alter UDXs to be unfenced.)

Important: Fencing negatively affects the performance of a UDX. After you test and debug your fenced UDXs, you can alter them to run unfenced to improve the performance of those UDXs and to take advantage of SPUPads if applicable.